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Summary of 1990 (L98) Reconditioning/Modifications (#8550)
New SW Headers
New Magnaflow Exhaust
New TPiS Air pump delete kit with New Billet Aluminum Pullley.
New 180 deg thermostat
New Chrome Water Pump
New Chrome Alternator
New Plug wires
New C4 Beam Plates
New Wilwood 6 Piston, 13" Drilled Rotors
New Differential oil drain plug (drilled and tapped)
New Differential oil drain plug
New Billet Aluminum oil cap
Existing Aluminum Radiator
New Oil Pan and Gasket including New Milodon 18309 Oil Pump Pickup
Fluids Mobile 1 75W-90 Differential oil (limited slip)
Fluids Mobile 1 10W-30 synthetic Engine oil
Fluids Castrol TWS 10W-60 Transmission oil
Eliminated Water Pump Frisbee and added Aluminum Water Pump Pulley
Eliminated Air Induction system
Eliminated CATS
Eliminated EGR
Doc Don's Bose Refurbished Starter
Modified Oil Cooler Use NAPA 8020 and 9808 hoses cut to length L98 Oil Cooler Housing Modifications for Headers
Modified Marc Haibeck Chips
87 octane calibration (ARFPCL)
29 deg at WOT.
Enabled manual transmission.
Both fans to go on at 195 and both off at 190 degs.
Added +5% at WOT fuel to support +20 hp from headers.
Disabled deceleration fuel cut off.
Disabled EGR.
Idle speed is OE at 600 rpm.
91 octane calibration (ARFPCL1)
29 deg + 4 deg = 33 deg at WOT.
Enabled manual transmission.
Both fans to go on at 195 and both off at 190 degs.
Added +5% at WOT fuel to support +20 hp from headers.
Disabled deceleration fuel cut off.
Knock retard reduced by 50%.
Disabled EGR.
Idle speed is OE at 600 rpm.
I had to modify my oil cooler with two additional slots so I could rotate the Oil Cooler and associated Hoses a bit more towards the block away from SW Headers
I rotated the oil cooler such that the two long bolts (of the spin on oil filter adapter) fit in the
new slots of the oil cooler. I then tightened the big hex nut on the oil cooler
I used new NAPA 8020 and 9808 hoses cut to length replacing the old oil cooler hoses shown which work perfectly.
I know this has come up before but am not sure if there is another water pump out there that would work for my 90'. The back of stock water pump has a plate and bolts which interfere with the JEGS cast aluminum timing cover (I would say 1/8 inch interference when water pump backing plate bolts are removed).
Is there any water pump with just a bit more clearance on the back side with the same distance to the center of the water pump pully from face of engine
The JEGS Spectre 4935 cast alumimum timing chain cover is extremely nice and sturdy....not tinny
Aluminum Finned Oil Pan including New Milodon 18307 Oil Pump Pickup
Aluminum Finned Oil Pan and Gasket including New Milodon 18307 Oil Pump Pickup
1. The Oil Pan Modification began by draining the Coolant such that the Oil Cooler line could be separated under the Oil Pan. The two Front Angled Struts under the front of the Oil Pan were removed (two 18mm and two 14mm bolts each).
2. The Bell Housing Shield had to be removed to remove the Oil Pan. This required that the Starter be removed. The Starter was reconditioned by separating components, cleaning and repacking the gears and bearings with grease, and reconditioning the Starter Solenoid (wire brushing the contacts and cleaning the cylinder.
The Thickness of the new one piece blue gasket and the thickness of the New Aluminum Oil Pan Bosses is 1/8 inch
thicker than Original Oil Pan flange, flange stiffener (separate bar on each side) and gasket. This required that New
longer Oil Pan bolts be used as shown on left in photo.
3. The Existing Oil Pick Up shown at top in photo will be replaced by the Milodon Oil Pump Pickup to fit inside the
Aluminum Finned Oil Pan shown at bottom in photo.
Milodon 18307 Oil Pump Pickup. The Milodon 18307 shown below is the correct Oil Pump Pickup to be used in this application which intake will end up in front of the Oil Pump.
All the Internal Alternator Parts between the Front Cover and Rear Cover (including Bearings, Voltage Regulator, Capacitor, Brushes, and Rectifier), are available on Ebay. In this case the Rectifier was toasted by maybe a screw driver stuck in the wrong place from the rear frying a Diode. The Chrome Alternator now charges perfectly.
1. Standard Motor Products RX131 Alternator Brush Assembly 2. NEW HEAVY DUTY VOLTAGE REGULATOR FOR DELCO 13120469, D677, D685, D698, VR472 3. Standard D-72 Alternator Rectifier - Diode(N) or Rectifier Assembly
A very nice Billet Aluminum Pulley is also available on Ebay. This Alternator Pulley is the correct size replacing the Stock Alternator Pulley.
The Serpentine Belts does not have to be changed in most installations. MCH-208 Pulley installedSeeAll Aluminum Alternator Pulley
Alternator Major Parts
Bench Testing Alternator Components A. You can check the resistance of the Stator with Ohm Meter (checking each of three Stator wires to Stator Housing). Should NOT be an open circuit. B. You can check each Diode with the Diode checker on Ohm Meter. Should be Infinity one direction and low reading other direction. C. You can check the continuity and shorting of the Circuit from the Capacitor to Top Brush. Should be Infinity Reading on Ohm Meter. D. You can check Bottom Brush to ground.....should be zero Ohms on Ohm Meter. E. With Alternator assembled you can check Battery Post to Case with Diode checker on Ohm Meter. Should be infinity one direction and low reading other direction.
Rotor and Front Cover Separated from Rear Cover holding the Stator, Rectifier, Regulator, Capacitor, Brushes
Rear Cover with Stator Removed..................................Rear Cover with Rectifier Be careful when removing Rear Cover
as Brushes can get caught on Rotor Bearings
A Stainless Steel Air Intake with K & N Air Filter was added.
The Stainless Steel Air Box has been offered for those that want to add Bling and Higher Intake Air Flow for the LT5 or L98
1. SS Air Box Installation and Air Filter Selection
George Braml fabricates the SS Air Box.
Just an installation tip....If you use that Orange FRAM Air Filter you will find it about 1/4 inch too high. The bottom end of the SS Air Box Square Filter Retainer lip will not engage the Built In (L) of the Air Box at the bottom end as shown in the first photo (the Orange Fram Air Filter has a gap at the bottom end). You will also notice the two Retaining screws for the Square SS Air Box Filter Retainer have tilted towards the engine indicating the top Square Retainer has moved upward out of the SS Air Box (L) at the bottom end.
If you look closely at the SS Air Box Square Filter Retainer you will see a cut out about 1/4 inch deep and the width of the Square Filter Retainer on the bottom end. The height of the Air Filter cannot be higher than that cut out (The Orange Fram Filter is about 1/4 inch higher than that cut out).
The K&N 33-2035 High Flow Air Filter is the correct Air Filter matching the SS Air Box Cut Out.
George Braml did a perfect fabrication job on the L98 SS Air Box as he did on the LT5 SS Air Box (Both SS Air Boxes are IDENTICAL)
2. Facts and Photos
The L98 and LT5 SS Air Box and Air Filters are Identical.
A. The Air Filter opening is 9.5 in x 16.25 in or 154 square inches (both OEM and SS).
B. The Air path inside the Air Filter housing to the oval outlet is 1 in x 17.25 in or 17.25 square inches (both OEM and SS).
C. The OEM metal cover Louvers are 3/8 in x 4 in or 1.5 square inches and there are 24 Louvers or 36 square inches for Air Flow into the Air Filter area (OEM only).
D. Space between top of OEM metal Louvered cover and closed hood exceeds 1 inch all around (more space with SS Air box since metal louvered cover is not used.
C. Using SS Air Box with FRAM decreases the space between top of Air Filter and closed hood by 1/4 inch or 12.5 square inches around the perimeter of the Air Filter.
D. Using the SS Air Box with K&N High Flow Air Filter eliminates the need for the OEM metal Air Box cover (36 inches of air flow area) making available the total air flow area of 154 square inches to the K&N 33-2035 High Flow Air Filter.
E. The K&N 33-2035 High Flow Air Filter is Washable and Reusable.K&N 33-2035 High Flow Air Filter
SS Air Box installed with FRAM Air Filter with bottom of Filter Square Retainer not engaged
3. Technical Discussion
The air is drawn from top side of Air Filter in the OEM set up through the louvers in the metal cover. There is a gap of at least an inch between that Air Filter metal cover and closed hood (OEM or SS Air Box).
With the SS Air Filter housing, there is NO metal cover and air is drawn from air gap between the filter and closed hood not restricted by the 36 square inch Louver area of the OEM Metal cover. With a K&N High Flow Air Filter that gap is 1/4 inch larger (than when using a FRAM Air Filter).
The OEM filter housing metal cover will accomodate both FRAM and K&N 33-2035 Air Filters. The difference between the SS Air Box and OEM Air Box is that the SS Air box rides a bit higher requiring the 1/4 inch Cut Out for the small front crossover (see photos of the bottom of both the OEM and SS Air Box.
Because of the Cut Out the SS Air Filter housing with correct K&N 33-2035 High Flow Air Filter will sit at the same height as an OEM Air Box. However if you use a higher FRAM Air Filter that exceedes the Cut Out height in the SS Square Retainer, the overall height of the top of the filter has changed and will interfere with the front small corss over.This will in turn cause interference bwtween the FRAM Air Filter and small cross over preventing the Top Square Retainer of the SS Air Box from engaging at the bottom end.
The L98 and LT5 are IDENTICAL in regard to these issues as the OEM Air Filter housings are IDENTICAL and the radiator shrouds appear to be IDENTICAL in regard to top side of that shroud.
5. Powder Coating or Painting SS Air Box I did not Powder Coat or Paint the SS Air Box as it looks very very nice as a SS Machined look and the welding is absolutly perfect......so why cover up with Powder Coating or Paint
C4 beam plates and Installation (ZF S6 40 Transmission)
C4 beam plates and Installation (ZF S6 40 Transmission)
1. Advantages of C4 Beam Plates. a. The C4 Beam Plates also tie together each pair of bolts (Transmisison pair and Differential pair) with a SS Plate vice aluminum. b. Each C4 Beam Plate also offers a larger contact area of the tensile bolt loads onto the C-Frame. This eliminates the wear on the "C" Frame from a smaller original washer and resulting release of bolt tension. c. The C4 Beam Plate also acts like one big washer wherein the tensile load from each individual bolt is now shared a bit between bolts (minimum effect). d. The C4 Beam Plates correct the condition caused by the bolt holes in the Aluminum C-Frame getting bigger or elongated with wear or the thickness of the Aluminum C-Frame from top to bottom between the original bolt two washers becoming worn so that thickness is less releasing bolt tension. The C4 Beam Plates are definitely worth it if only for the Bolt Load Distribution (Two BIG SS washers on each end) on the C Frame and Ease of Installation. Take Note of the additional Stiffeners on each C4 Beam Plate (The BIG H). There is a BIG Difference between a Clamping Load distibution by two washers and the Clamping Load on ONE BIG PLATE on the Transmission Yoke as well as the Differential Housing.
2. Captured Free Floating Nut Design.
The C4 Beam Plates by Bill Boudreau have Free Floating Captured Nuts on the Top Plate as previously mentioned (which is a bit more complex in manufacture than a welded nut on a plate) This Captured Nut allows the Nut to Float a bit making it even easier to catch with the bolts as you insert them from the bottom.
This Captured Free Floating Nut Concept also allows self equalization of the distance between bolts (as if you are inserting them singularly THE TOP BOLT HOLES ONLY) especially after having one bolt started. The Nuts float and are prevented from turning by the design of the Capture. This Free Floating Capture of the Nuts in the Bill Boudreau Design is more important from an engineering concept (even if only floating on the TOP END) and overlooked by many in this discussion
3. Installation of C4 Beam Plates. a. ALIGN DRIVELINE COMPONENTS: Take the following measurements directly above and to the right of the Propeller shaft front yolk universal joint between the C-Frame and the inside of the underbody. b. To ensure proper alignment of the driveline, a clearance of 45 mm +/- 6mm (1.77 in +/- 0.236 in) must be maintained between the top of the support to the underbody. I set the clearance to 1.5 in to account for unloading deflection when I remove the hydraulic jack supporting the transmission. c. A clearance of 28 mm+/-6 mm (1.1 in +/- 0.236 in) from the (passenger side of vehicle) right side of the support to the side wall. d.Do not use any of the 4 original C-Frame bolt washers on the front (Transmission) or rear (Differential) bolts. e. Tighten support bolts at Carrier (Differential) to 80 Nm (59 lb-ft). f. Tighten support bolts at Transmission to 50 Nm (37 lb-ft). g.Do not go over the Bolt Torque on the Carrier and Transmission or you risk changing the Dimensions of the Carrier and Transmission Connections.
C4 Beam Plate Installed On Differential......................C4 Beam Plate Installed On Transmission ........................................ ........................................ ..Note C4 Beam Plate Bevel Location
4. Why Take Measurements?
It is kind of a corny measurement since you are measuring between the C-Frame and the side wall/Underbody which is heavily coated and made of light steel and the accuracy of the measurement needs only to be within 1/4 inch + or -. I think you are just making sure you did not put an angle in that front driveline U-joint by moving the transmission appreciably during the installation of the new C4 Beam Plates.
A Quick Measurement in regard to Transmission Yoke height can be checked from inside the car by measuring the height of the Shifter. A height of 6.25 inches from the counsel to the top of the shifter (at the center of the shifter in neutral) will be very close to the correct transmission height.
a. The 1.77 in spacer should fit between the top of the driveline support to the underbody. The 1.1 in spacer should fit between the right side (passenger side) of the driveline support to the side wall. b. You might check that alignment spacing before you start the project to see where your alignment is now. Then just keep that alignment with the installation of the new C4 Beam Plates.
Secondary to Transmission/Driveline Alignment is ground clearance of Transmission Drain Plug. The Transmission Drain Plug clearance to ground is approximately 4 to 4.5 inches on my ZR-1s which is NOT the lowest point on the ZR-1 Drive Train/Chassis. The Ground Clearance depends on many things including Tire Pressure, Tires, Wheels, and Suspension.
5. Caution on Jacking the Engine. Always remove the C4 Beam plate bolts on the transmission yoke when jacking/lifting the engine to minimize potential of twisting transmission yoke or C-Frame.
Installed an aftermarket Differential Case Drain Plug for easy fluid change.
The kit is available from Corvette Central
The kit provides a template that puts the hole just left of the center bolt in the valley of the differential.
Original Photos provided by Scrrem with Red notes added.
The tap size is 1/8-27 pipe and it installs easily with drill (11/32) and tap supplied in the kit.
I drilled the bottom flange just under the ring gear and let the old fluid drain (which drained in about 10 minutes). I then tapped the drilled hole for the 1/8 inch allen pipe plug. When you tap the hole, try the pipe plug several times as you tap so you end up with the pipe plug out maybe 1/16 inch when tight .
I inserted the 1/8 inch allen pipe plug and pumped in a bit over 3 pints of Mobile 1 75W-90 into the fill port on the North side of the differential (Z facing West)
The Differential case can be COMPLETELY drained and flushed with new oil using this method as compared to trying to suck out the old oil.
1. The Wilwood 140-8337 Brake Kit was installed on a 1990 Standard Corvette (12" Rotors replaced with Wilwood 13" Rotors).
2. The Wilwood 140-8337 Brake Kit was also installed on a 1990 ZR1 Corvette (13" Rotors replaced with Wilwood 13" Rotors).
The stock Wheels (Salad Shooters) on the 1990 Corvette had plenty of clearance between the wheel and Wilwood Caliper. The Wilwood Caliper is a bit wider than the stock 1990 Corvette Brake Caliper.
1991 Sawblades were installed on the 1990 ZR1 in which case I used 1/8" Spacers between the Rotor and the wheel to increase wheel spoke clearance (I used Shims to center the Caliper on the Rotor which resulted in moving the Caliper closer to the Sawblade Wheel Spokes).
The Hats are first torqued 100 in-lbs each of 12 bolts to the Rotors (Twelve 1/4x20 bolts with 8mm 12 Point heads).
The Rotor is installed on the Wheel Bearing Hub. Two threaded bolts holding the Wilwood Adapter to the Wheel Bearing Hub Housing are torqued to 150 ft-lbs.
The Caliper is installed on the Wilwood Adapter (30 ft-lbs) with correct shims to center the Rotor within the Caliper. The Caliper also has to be adjusted on the radius of the Rotor such that the Brake Pads are completely on the surface of the Rotor.
The new Wilwood Caliper Adapters were installed using the original 21mm Hex Head bolts during both installation (1990 Standard and 1990 ZR1 Corvette).
The Brake Kit came with many shims to assure centering of the Rotor with the Calipers. No shims were required in the Standard 1990 Corvette installation. 2 shims top and bottom of the Caliper adapter on one side and three shims top and bottom on other side of 1990 ZR1 installation were required (I used Shims to center the Caliper on the Rotor which resulted in moving the Caliper closer to the Sawblade Wheel Spokes).
Shims are used to center the Rotor within the Calipers (The larger shims)?
Using the larger shims actually moves the caliper closer to the Wheel Spokes.
Shims are also used to align the Brake Pads on the Wear Surface of the Rotors (The small shims)?
The need for shims varies from wheel to wheel. Wilwood provides 12 large shims (.015") and 16 small shims (.025") with each 140-8337 Brake Kit.
The stock Brake Lines were replaced with a Wilwood 220-8338 Flexline Front Brake Line Kit in both Standard 1990 and 1990 ZR1 installation.
2. 1990 Standard Corvette Compared to 1990 ZR-1 Corvette with 1991 Sawblade wheels
The Wilwood Brake Kit 140-8337 will fit the Standard Corvette and the ZR-1.
All the measurements are identical.
Standard Corvette.....
ZR-1 Corvette.....
The ZR-1 wheel spokes (Sawblade wheels) are within about 1/16" of the Wilwood Caliper. Spacers adding an additional 1/8" gap between the Sawblade Spokes and the Wilwood Caliper were installed between the Hat and the Wheel. The 1/8" Spacers leave enough wheel bolt thread for complete engagement of the wheel Lug Nut.
Salad Shooters on the front of a ZR1 do not require spacers for a C5-Z06 Front Brake Upgrade......
3.Wheel Alignment
Adjust Caster, Camber and then toe....... in that order.
Caster is most difficult and I adusted that to level out "pull" between right and left front wheel but mostly by eyeball.
The Caster is always Positive.
Camber I found the use of a level adjusting camber by adjusting two sets of spacers on the upper control arm.
The level was used very accurately on reasonable level concrete with level in the vertical position against the upper and lower tire side wall.
(Making sure the level is near the front or rear of the tire to eliminate side wall deflection at the bottom of the tire from wheel load)
I set the camber at zero or level bubble centered for both the right and left front wheels. The Camber for Rear wheels is actually Negative which I do not change as long as it is equal for left and right rear wheels and rear wheel tire wear is normal each side.
Toe was a bit more complicated by setting up a taught fishing line on both sides of the wheel base at the center height of the wheel.
The fishing line was set within 1/16" of both sidewalls of the rear tire with a 1/16" gap between line and side wall of tire.
I then adjusted steering on one side of front tires so that front sidewall of front tire was also 1/16' gap between line and tire sidewall. (You can take measurements between wheel rim and line also to confirm).
I then repeated this on other side of vehicle (without adjusting steering) paying specific attention to gap between front side wall of that front tire and line. This is your initial Toe.
I then loosen lock nut on Tie Rod on that side and adjust toe. I then repeated the process several times It is better to adjust Wheel Toe with the front Wheels on small plastic sheets or fine sand to eliminate turning drag between two front wheels. I shoot for 1/8" total Toe-In. (A 22 mm Open End Wrench was used to loosen the 22 mm Tie Rod locking nut and a Crescent Wrench was used on the flats of the Tie Rod to adjust for Toe).
On the ZR-1 the rear tire sidwwalls are further out than the front tire sidewalls. Just measure from the line to the rim of the wheel (from front of tire and from rear of tire).
All have C4 Beam Plates, Billet Aluminum Pulleys (Alternator, Water Pump, Power Steering, Belt Tensioner), Carter Bling, Oil Cooler SS Braided Hoses, TB Coolant Blocked, New 180 deg Thermostat, New Radiator Hoses, Radiator Debree Screen, Haibeck Chips (91 Octain), New Aluminum Radiator, New Charcoal Canister, Starter Relay, Battery Disconnect, Full Power Key Reconditioned, INFL REST Sensor Re-installed, New Linkage for Secondary Port Throttles, New Secondary Vacuum System, New BKRSEIX Spark Plugs, 10W40 Amsoil Engine Oil, 10W60 Castrol Transmission Oil, 75W90 Mobile 1 Differential Oil and Differential Case Drain, New Serpentine Belt, New Hood Support.
1. 1990 #2067 UL LOSE
1990 Z 1G1YZ23J7L5802067
SD 76,300 miles Nov 2012
AYBKG4GS1a Haibeck 91 Octane
New 124 Amp R111799A Alternator
Re-conditioned Starter
Improved Fuel Pressure Regulator
Full Power Key Reconditioned
New Coils
Air Induction Eliminated
SS Air Intake
New Water Pump
SW Headers/Exhaust
New Nitto Tires
Wilwood C5 Z06 Brakes
Oil Catch Can
2. 1990 #3032 ULNOTWN (Last 1990 Sold)
1990 Z 1G1YZ23J4L5803032
SD 57,750 miles June 2014
AYBKG4 Haibeck 91 Octane
New 124 Amp R111799A Alternator
Re-conditioned Starter
Improved Fuel Pressure Regulator
New Fuel Filter
Full Power Key Reconditioned
Fluidyne Radiator
New Heater Core
New Nitto Tires NT555 F, Dunlop 8000 R
RC Injectors
Air Pump Delete
New Windshield
3. 1990 #0072 UWLNTWN
1990 Z 1G1YZ23J1L5800072
CA 38,000 miles March 2014
AYBKG5 Haibeck 91 Octane
New 124 Amp R111799A Alternator
Re-conditioned Starter
Improved Fuel Pressure Regulator (1st edition) Mar 2018
Yellow Plug inside Drivers Re-installed
Replaced CDM
Ron Davis Radiator
New Fuel Filter Sep 2016
RC Injectors
New NT555 Front Dunlop 8000 Rear
New Wheels Saw Blades
New Windshield/Weather stripping (David Johnson) Apr 2016
Oil Catch Can
New Oil Pan Gasket Sep 2016
Air Duct SS Support Hoops
Air Pump Deleted
New Gauge Oil Pressure Sensor
Braided SS Oil Cooler Lines
4. 1991 #1427 BAD Z
1991 Z 1G1YZ23J4M5801427
CA 50,000 miles Mar 2009
BFXBG2CS2 Haibeck 91 Octane
Full Power Key Reconditioned
New 200 Amp Alternator
Air Induction Eliminated
SS Air Intake
Replaced CDM
Ron Davis Radiator
RC Injectors
1990 Heads 27K miles with modified Injector Housings.
SW Headers, Air Injection Eliminated
New Nitto Tires NT555
Modified Camshafts
Ported Plenum/Inj Housing
Secondaries Eliminated
Wilwood C5 Z06 Brakes
Oil Catch Can
New Oil Pan Gasket
New Blue Label Transmission
5. 1995 #0186
1995 Z 1G1YZ22J5S5800186
CA 87,600 miles Apr 2016
BMCBG4 Haibeck 91 Octane
Dunn Heads Left and Right
Full Power Key Reconditioned
Injectors Fuse Issue Red Wire Looms
New 200 amp Alternator
Fluidyne Radiator
New Fuel Filter July 2016
Improved Fuel Pressure Regulator Mar 2018
Wilwood C5 Z06 Brakes
Oil Catch Can
Rebuilt ZFdoc Black Label Trans with short shifter Aug 2015
New U-Joints Main Drive Shaft
New U-Joints Half Shafts
New Rear Wheel Bearings
1990 1G1YY2382L5108550
CA 56,000 miles July 2009
EGR1990 L98 UWONTWN
ARFPCL Haibeck Low Octane installed
SW Exhaust
Eliminated Water Pump Frisbee
Eliminated Air Induction system
Eliminated CATS
Chrome Alternator
Chrome Water Pump
Billet Aluminum Oil Pan with New Oil Pickup
SW Headers with Air Injection Eliminated
Ron Davis Radiator
Oil Filter Adapter Modified to fit with SW Headers
1991 Bebuilt
91' heads 28K miles Corvettenutz
with painted cam covers CA installed in rebuilt 91’
91' LT5 36K miles CA Jan 2015
Extras
91' Heads 36K miles CA Jan 2015
91' transmission 36K miles CA Jan 2015
95’ Tramsmission 88K miles CA (ZFdoc)
95’ Crate Engine
91’ Injector Housings PCV Restricted
91’ Heads Plained Bad Z CA
Rebuilt 91’ Bad Z Trans installed in 95’ Aug 2015
91zrocket 90’ Heads with 27K miles in BAD Z PCV restricted
91zrocket 90' Transmission 27K miles SD
AUAH 8555. Stock first half SD spare
91’ AXFK Stock Last Half
90’ AYBK Stock
91’ BFXBG2JE Fans On 165 deg Haibeck
91’ BFXBG2CS3 Low Octain
Originally Posted by 91zrocket
Complete zf s6-40(black label)trans from my '90 with 27k on the clock. would sell whole tranny setup from flywheel to shifter or will seperate if needed.no issues with trans,shifts great....i due believe flywheel was starting to make noise though
Asking $2,000.00 complete (flywheel,pressure plate,clutch disc,bellhousing,trans,shifter assembly) or will seperate
614-937-5112 scott
New Rear Wheel Bearings (SKF BR930024)
Just completed installing SKFBR930024 rear wheel bearings as recommended by Phil (Jagdpanzer)
Also installed Spicer U-Joints (Dana Spicer 5-3615X U-Joints w/Coated Caps for Alum Half shafts) in the Half shafts as well as new Brake Pads
SKFBR930024 rear wheel bearings and some smaller tools used to install the U-Joints, Half Shafts, and Bearings. The three (Torx T55). bolts that hold each Rear Wheel Bearings in the Bearing Housing are shown. The Torx T55 is shown on the 3/8 inch socket and the smaller 1/4 inch socket and extensions were used to remove the Half Shaft U-Joint straps. The needle nose vice grips were used to remove the Spicer U-joint spring clips from within the Half shaft. The larger ball bean hammer was used to remove the Spicer U-joints and caps from the Half Shaft using a couple sockets (one 22mm and one 35mm).
The original Rear Wheel Bearings in this 95' with 95K miles were not really loose in any way but there was some lubricant that had leaked our of the bearing indicating time for a change. If there is black oily dust collected around the bottom of the bearing or around the U-Joints....time for a changeout of Bearings or U-Joints.
After removing the 36mm Axle Nut (using a pipe extension on a 3/4 inch socket wrench)…..The BIG Trick was the disconnection of the lower Sway Arm just below the Rear Bearing Housing and then pulling the bottom of the housing out about an inch or so using a come-a-long attached to my truck
The Half shaft was then easily disconnected and removed out the bottom where the Sway Arm was disconnected and lowered on the Bearing End. The Axle spline floats within the bearing once the Axle Nut is removed allowing free play for removing the Half Shaft if you pull a bit on the bottom of the Bearing Housing. That "Trick" worked perfectly
Once the Half Shaft was removed, the Spline was slipped out of the bearing from the inside of the Bearing Housing before using the Torx T55 to remove the three Bearing bolts from the inside of the Bearing Housing. The Rear Wheel Bearing was then removed from the front.<br />The two large bolts are one from each Sway Bar beneath the Bearing Housing.
The two spline Teflon coated washers shown were coated with Brake pad grease (had it on hand) and the splines were coated with anti-sieze before re-installation into the New Rear Wheel Bearings.
Also drilled out the Cotter Pin hole in the axle shaft to 3/16 for a tight fitting 3/16 cotter pin.
The Dana Spicer 5-3615X U-Joints were installed using a couple sockets (22mm and 35 mm) to remove the old U-joints and install the Spicer.
The smaller socket was used on top of the yoke on the top U-Joint Cap (tapped firmly) such that the top cap is forced into the yoke. The larger socket was used on the bottom of the yoke with the U-Joint bottom cap forced into the larger 35 mm socket.
Dana Spicer 5-3615X U-Joints with spring clips are shown. The Half Shafts are marked (left and right......inside and outside).
Cooler Termostats, Thermostat Modifications and Engine RPM
Cooler Termostats, Thermostat Modifications and Engine RPM
Here is what I have found regarding LT5 Stant Thermostats.
1. You want to run the engine at coolant Temperatures of 180 deg as the design requirement...……...Running cooler Thermostats only helps at coolant temperatures below 180 deg F. Simply because once the 180 deg Thermostat and 160 deg Thermostat are fully open at 180 deg, Coolant flow is the same through each Thermostat.
2. Drilling Holes in Thermostats offers minimal additional Coolant Flow...….A 1/8 inch diameter hole in the flange will offer additional flow area of .0123 square inches. Which one such hole will increase the total flow area by .016 or 1.6% (three 1/8 inch diameter holes would increase the flow area by 4.7%). This thinking does not address the change in coefficient of Discharge of such small holes. The Stants tested would be fully open with a flow area of approximately .785 square inches at 185 deg F.
3. The Stant Thermostat Opens a bit less with age......…...Marc suggests a 15% deterioration in Full opening area of the Thermostat over time as the Thermostat ages.
4. Lastly, The LT5 Water Pump Flow is proportional to Engine RPM. ......The LT5 Water Pump Flow rate is insufficient at RPMs less than 2,000 RPM for adequate Coolant flow at the higher Ambient Temperatures. Larger Aluminum Radiators DO compensate for inadequate Coolant Flow at low RPMs. Fans Turning on at 205 deg F do help considerably. And KEEP The Radiator, Oil Cooler, AC Condenser CLEAN.
Now compared to the normal aging of the thermostat of 15% over several years of use one would be much better off installing a NEW Stant Thermostat gaining 15% flow area as compared to drilling three 1/8 inch holes in an older Stant Thermostat only gaining 4.7% flow area.
This Powder Coated Steel Belt Tensioner Pulley is the Best that I have installed so far.
This Tensioner Pulley would last a Very Long Time as it is Powder Coated, Steel, and Exact size as Original.
This Powder Coated Steel Belt Tensioner Pulley is on Ebay......Belt Tensioner Pulley
I installed the Powder Coated Steel Pulley with the Boss on the inside
The Tensioner Pulley Boss is shown in the above image.
I did check several "polymer" original Belt Tensioner Pulleys and they all show wear similar to the wear of the Belt Riding Surface of the aluminum Belt Tensioner Pulleys. I would suggest that either the Aluminum or Polymer Pulleys will last 100,000 miles given the wear I see on the riding surface of moderate mileage Polymer or Aluminum Tensioner Pulleys .
The aluminum Pulley on the left has a riding surface wear of about .003" in over 5,000 miles. The Polymer original pulley on the right has more similar wear on the belt riding surface but more miles. The thickness of the belt riding surface of the aluminum Pulley is .106". Assuming a tolerable wear of the belt riding surface of 1/16" the life would be about 100,000 miles for the aluminum Pulley with 1/16" thickness of the riding surface left which should be adequate for structural capability. The same life estimate goes for the original Polymer pulley. The various types of Belt Tensioner Pulleys should be checked for wear periodically as Belts vary in age, texture, flexibility and tension. The Pulley Bearings should also be checked for smoothness of rotation and "play".
Also, this all depends on the Belt slippage with respect to the Belt Tensioner Pulley Riding Surface under rapid rotational acceleration of the engine (Revving) especially in neutral (Going from 800 rpm to 7,000 rpm in a second or two for example). The Belt Tensioner Pulley is probably spinning at twice that rpm given it is half the diameter of the Harmonic Balancer and just cannot angular accelerate that fast from 1,600 rpm (Idle) to 14,000 rpm in under two seconds. The Belt may actually slacken a bit between the Harmonic Balancer and Alternator during hard revving.
The three Belt Tensioner Pulley failures known appear to be the result of a failure of the Belt Tensioner Pulley Bearing.
The Steel Powder Coated Tensioner Pulleys should show NO wear on the belt riding surface of the Pulley over time simply because they are Powder Coated on Steel.. The greater weight of the Steel Tensioner Pulleys will result in greater Belt slippage on the riding surface of the pulley during rapid changes in engine rpm (revs in neutral) due to greater resistance to angular acceleration.
You will notice only the Water pump Pulley and Belt Tensioner Pulley rides on the back smooth side of the belt. The Water Pump Pulley has almost a complete Belt Wrap while the Belt Tensioner Pulley has almost no wrap at all. This leads to the assumption that there is potential for much greater slippage during high REVS in Neutral of the Belt Tesnioner Pulley.You may also notice the gap between the two insides of the Belt (opposite the Belt Tensioner) on this Crate Engine which indicates considerable Belt Tension. This is unlike some where the gap is less than an inch indicating a rather loose Belt which would slip more during High Revs.
All of this discussion is probably moot given the Belt Tensioner, Belt, and Belt Tensioner Pulley should probably be reconditioned between 50,000 and 100,000 miles to avoid having to carry spare Belts and Pulleys
I install several Powder Coated Steel Belt Tensioner Pulleys and will be interesting how the Powder Coating stands up with use.
I also checked several original "Polymer" Belt Tensioner Pulley Bearings (Average 50,000-70,000 miles) and found a couple that were a bit rough when turning indicating a bearing needing replacement. Most Pulleys do allow for replacement of the bearing only.
The outside filter gasket (part of the filter) that fits into the cover is.....
17-3/8" by 10-5/8" outside dimensions and inside dimensions of the cover.....
The Air Filter fits up into the Cover.......not down into the Air Filter Housing.
This is for a 1990 ZR1 or 1995 ZR1....I assume for all ZR1s 1990 to 1995.
The Air Filter total height can be up to 1-1/2".
I show the Air Filter Housing, two ZR1 filters and the filter cover in the photo.
The 1990 Air Filter Housing has the hose connection on the Drivers side for the Air Injection Pump.
1. General Installation
There are three cap screws.....the Center Cap Screw is shorter than the other two on outside. The Center Cap Screw is inserted into the filter housing after the the filter is installed in the cover (Tighten the center Cap Screw before the complete filter housing is placed in front of the radiator). The Center Cap Screw screws into the filter housing only.
Make sure the five tabs are inserted into the filter cover. The five tabs are part of the filter housing (not the air filter).
The other two cap screws are inserted into the filter housing after the filter housing is placed in front of the radiator. Those two Cap Screws screw all the way into the radiator housing and are tightened after the complete filter housing is installed.
2. Connecting the Air Filter Housing to the Plenum
Lastly the Corrugated Flexible Air Connection between Filter Housing and engine Plenum air intake (Leave the Corrugated Flexible Air Connection connected to the Plenum Air Intake. The Filter Housing end of the Air Connection is slipped onto the Filter Housing before the Filter Housing is screwed into place with the two outside Filter Housing Cap Screws. The Air Corrugated Connection is tightened with a Band Clamp (Screw Band Clamp....use 7mm 1/4" socket with extension or flat head screw driver).
3. Details for Installing the K&N Air Filter
Installing a K&N 33-2035 is a bit complicated for the simple reason K&N provides foam spacers that can be compressed to different thickness which should cover the alignment issues of the "Plastic" Air Box........but an Air Box that is not flat at the Air filter Cover interface within 1/4" presents a problem when the interface is warped significantly more than 1/4". A NEW AIR BOX IS THEN REQUIRED unless the gaps between the box and Air Filter Cover can be filled with Silicon Seal or some other filler.
Use the provided K&N lubrication on the filter gasket (flat part) with the filter inserted into the Top Cover facing into the Top Cover. I then remove the filter from the Top Cover and set in place on the K&N foam gasket of the Filter Housing (which Foam Gasket is glued in place with Gorilla glue) if the foam gasket does not stick in place.
The "Trick" is to lubricate the Filter Gasket rubber facing the cap screws (towards rear of car). The Filter Top Cover is then positioned by inserting the five Tabs into the Top Cover (while keeping the Filter positioned on the Filter Housing). Then while keeping the five Tabs inserted, press down on the rear of the cover as it "slides" (the reason for the lubrication at that location) down in place on the filter as you tighten the middle front Cap Screw (THIS IS THE MOST DIFFICULT PART).
Documentation of the Installation of the K&N 33-2035 Air Filter.........It is a bit complicated to install a K&N 33-2305 Air Filter. These instructions come with the K&N 33-2035 Air Filter.....
Plenum $499
Plenum throttle cable clips with screws $75
Complete set of OEM plenum bolts $35
Rubber double vacuum line connector to plenum Sold
Injector housings $399
Injector Housing bolt set. $35
Throttle body $450
Throttle cover $49
Throttle body bolt set $35
Air horn Sold
Coolant pipes to IH $199
Fuel rail with pressure regulator $399
Fuel rail bolts 4 $10
Fuel lines from rail the chassis. $199
Pressure regulator vacuum line $15
16 fuel injector clips $35
Map Sensor with plenum bracket $85
Map Sensor with the ECM bracket $85
2 secondary actuators tested good $75 ea.
Secondary vacuum reservoir $55
Secondary vacuum solenoid $65
Complete secondary system vacuum hoses Tested to hold vacuum. Includes the check valves and other under plenum vacuum hoses as well. $99
DIS Module $1200
1 secondary injector control module $299
Stock 1990 Memcal Chip AUAH coded. $189
4 Coils Original with coil tray. $149
Coil tray mounting bolts 4 $10
2 sets of original AC hoses. Rubber hoses in good flexible condition. One set is slightly dented but functional, priced accordingly. $199 undented $99 dented.
AC compressor mounting bolts 3 $15
Alternator mounting bolts 4 with brackets $35
Original coolant hoses with the metal distribution pipe. $199
IAC Motor $25
Intake air temp sensor $25
Both under plenum water temp sensors $35
2 sport seat air pumps, tested working (came with the lot) $35 ea.
Drive shaft with the yoke attached $299
ZF S6 Transmission Black Label $2299
Cam cover vent lines both sides. $39
Complete engine wiring harness. Sold
Dual Mass Flywheel very tight $349
Clutch disk $99
Pressure plate $249
Throwout Bearing Green INA $139
Dip Stick and Tube $135
2 New Knock modules (90’ only) $75 ea
ZR1 with 6800 miles.............
Coolant Outlet covers (Right and Left, Pair) - $300
Spark Plug wire Set (Corvette Lt5) - $200
Intake Plenum - $400
Throttle Body - $400
Intake Air Horn - $65
Fuel Injector Housing (Pair) - $800
Fuel Rails (Pair) - $225
Fuel Rail Crossover Tubes - $115
Fuel regulator - Sold
Coil Tray with 4 Coils - $110
Ignition Control Module - $800
Alternator - $100
Clutch Master Cylinder - $75
Clutch Slave Cylinder - $75
Clutch Master to Slave line - $40
Secondary linkage, diagrams, shielding and hardware - $175
Exhaust shielding (5 pieces) and bolts - $125
PCV valves and crossover - $75
Engine shielding (7 pieces) - $135
Positive battery cable - $40
Negative battery cable - $35
Bellhousing, fork, pivot and Dust Shield - $325
Starter - $135
Power Steering Pump - $125
Power Steering Pump Bracket - $85
Power Steering reservoir and hose - $40
Front Leaf Spring - $85
Rear Leaf Spring - $85
Front Leaf Spring Mounting Hardware - $45
Rear Leaf Spring Mounting Hardware - $45
Front Sway Bar and Mounting Hardware - $100
Rear Sway Bar and Mounting Hardware - $100
Front Selective Ride Shocks (pair) - $200
Front Electrical Actuator (pair) - $250
Rear Selective Ride Shocks (pair) - $200
Rear Electrical Actuator (pair) - $250
Front Shock Mounting bolts - $15
Rear Shock Mounting Hardware - $35
Intake Air Horn Bolts - $20
Water Pump Bolts - $35
Fuel Injector Housing bolts - $40
Exhaust Manifold bolts with spacers - $40
Throttle Body shield and bolts - $40
Coil Tray Bolts - $15
Ignition Control Module Bolts - $20
Alternator Bracket and bolts - $40
Flywheel Bolts - $30
Coolant outlet cover bolts - $25
Transmission to bellhousing bolts - $20
Bellhousing to Engine bolts (Includes dust shield bolts) - $30
Water Pump to A/C bracket and bolts - $30
Intake Plenum Bolts - $30
Just some Clarifications on severity of issues found on several ZR-1s......all fixes found in signature.
Do ask what Fluids have been used and Do Change ALL fluids on a ZR-1 when purchased...….seePost 3 - LT5/ZR-1 Fluids
Do Run a Compression Check on ALL Cylinders once ZR-1 is received.
Used ZR-1 Evaluation Checklist (Ccmano and Dynomite in RED).
Injectors Have they been replaced
Vacuum leaks There will be minor vacuum leaks which do not effect performance unless you replace the vacuum lines and connectors ($100 Ebay)
Secondaries operable Can be viewed by grounding Hot wire (pin C17) on ECM
Ingnition coils and wires replaced A Note of reference if the engine stumbles
Timing chain noise (normal to a small degree on 90's) Only before full oil pressure within 10 seconds
Starter Most often the Starter Solenoid Points need reconditioning
Oil leaks especially the pan and oil cooler lines Check the Oil Pressure Regulating Valve Cover Plate
Fuel pumps Keep in mind Jim's Fuel Pump Switching connector
Is it throwing any engine, abs or body codes (multiple possibilities here) Mostly INFL REST which is easy fix
Are any DIC lights on. (Multiple possibilities here as well)
Is the adjustable shocks system working Replaced shocks on two Zs
Windshield delamination I had Safelite replace a 1990 windshield which I furnished with new gaskets
A/C functionality (compressor is unique to the Z, cooling capacity lower) Replaced Dryer, Fittings and added R12 on one ZR-1, R134 on 95'
Power switch functionality and keys (are there 2) Power switch fix (disassemble and bend points into position)
Transmission syncro's, (first gear is always noisy) shifter alignment can mimick synco problems. Had one Trans Rebuilt by ZFdoc
Clutch functionality (they all let in high, was it ever changed) Have replaced clutch plates and use Needle Pilot Bushings
EGR system on later models
Engine mounts No Fixes on 5 Zs
C4 Issues
Head lights operable Simple fix changing tip up Gears
Radiator blocked or simply clogged, electric fans operable Usually leaves and sometimes oil contamination from Oil Cooler Leaks but that is rare (install debris screen)
Wheel bearings Replaced Rear Wheel Bearings (good at 90K miles) and drive shaft/half shaft U-Joints on high mileage 95'
Suspension bushings No Fixes on 5 Zs
Condition of all door, top and hatch seals Window frame seals sometimes ragged
Glass roof cracking No Fixes on 5 Zs
Instrument cluster functionality especially the tach (tends to read high with age) also note the lighting of the cluster No Fixes on 5 Zs
DIC button functionality No Fixes on 5 Zs
Steering wheel excessive movement No Fixes on 5 Zs
Radio functionality (especially speaker amps) and antenna Usually CD may not function send to Doc Dons (Amps inexpensive Nissan Max 975s or 075s)
Sport seat functionality (transmission, switches, pumps and bladders)
Door window switches No Fixes on 5 Zs
Door window lifter and internal rattles No Fixes on 5 Zs
Fuel tank bladder collapse (results in small capacity) No Fixes on 5 Zs
Differential noise (whine) No Fixes on 5 Zs
Additionally...…..
1. Have replaced tires, Coils, Plug Wires, Plug on some Zs and have Replaced ALL Vacuum lines and Connectors on ALL Zs ($100 Ebay).
2. Have upgraded Air Intake, Brake Rotors and Brake Calipers, Headers and Exhaust, Injectors on some Zs.
3. Have Added Oil Catch Cans on some Zs, Modified Fuel Pressure Regulators on ALL Zs.
4. Have done a Top End Restoration on ALL Zs including Starter, Valley Drain, including New Thermostats and New Aluminum Radiators on ALL Zs.
5. Have Eliminated Secondary System on one Z.
6. Have installed MarcH Chips on all Zs.
Here’s a list Ccmano (Hans Meyer) and Dynomite (Cliff) put together some time back.
Injectors, Have they been replaced
Vacuum leaks, indicated by high idle. There will be minor vacuum leaks which do not effect performance unless you replace the vacuum lines and connectors.
Secondaries operable, can you feel full power mode. Can be viewed by grounding Hot wire (pin C17) on ECM
Ingnition coils and wires replaced, A Note of reference if the engine stumbles
Timing chain noise on cold start (normal to a some degree on 90's) Only before full oil pressure within 10 seconds
Starter, is there history of starting issues. Most often the Starter Solenoid Points need reconditioning
Oil leaks especially the pan and oil cooler lines, Check the Oil Pressure Regulating Valve Cover Plate
Fuel pumps, have they been replaced.
Is it throwing any engine, abs or body codes, SES light on (multiple possibilities here)
Are any other DIC lights on. (Multiple possibilities here as well)
Is the adjustable shocks system working Replaced shocks on two Zs
Windshield delamination, foggy around outside of windshield. I had Safelite replace a 1990 windshield which I furnished with new gaskets
A/C functionality (compressor is unique to the Z, cooling capacity lower) Replaced Dryer, Fittings and added R12 on one ZR-1, R134 on 95'
Power switch functionality and keys (are there 2) Power switch fix (disassemble and bend points into position)
Transmission syncro's, (first gear is always noisy) shifter alignment can mimick synco problems. Had one Trans Rebuilt by ZFdoc
Clutch functionality (they all let in high, was it ever changed) Have replaced clutch plates and use Needle Pilot Bushings, leaking Master or slave.
EGR system on later models, rough idle, hesitation.
Engine mounts, hard to diagnose without visual inspection.
C4 Issues
Head lights operable Simple fix changing tip up Gears
Radiator blocked or simply clogged, runs hot, electric fans operable. Usually leaves and sometimes oil contamination from Oil Cooler Leaks but that is rare (install debris screen)
Wheel bearings, Replaced Rear Wheel Bearings (good at 90K miles) and drive shaft/half shaft U-Joints on high mileage 95'
Suspension bushings,
Condition of all door, top and hatch seals Window frame seals sometimes ragged
Glass roof cracking or crazing.
Instrument cluster functionality especially the tach (tends to read high with age) also note the lighting of the cluster.
DIC button functionality.
Steering wheel excessive movement (tilting) when entering car.
Radio functionality (especially speaker amps) and antenna Usually CD may not function send to Doc Dons (Amps inexpensive Nissan Max 975s or 075s)
Sport seat functionality (transmission, switches, pumps and bladders)
Door window switches
Door window lifter and internal rattles
Fuel tank bladder collapse (results in smaller capacity)
Differential noise.
06-26-2016, 04:09 PM
90’ (#8550) Corvette (L98) Modifications
