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Tech Info - LT5 New Rebuild Issues (Lifters, Camshafts, and Valves)
Tech Info - LT5 New Rebuild Issues (Lifters, Camshafts, and Valves)
Zero Compression as a result of Valve Stem Clearance, Hydraulic Lifter aberrations, and camshaft regrinds during engine rebuilds is discussed in several posts.
The first thing to check is for locked hydraulic lifters. It may be as simple as the lifters are hydraulically locked extended (uncompressed) when they were installed which they usually will bleed down over time. If that is the case, recheck the compression at a later date to see if the lifters did in fact bleed down (that may not happen rapidly if there is already oil pumped around the lifter). Rotate the crankshaft/camshafts such that as many valves are open as possible and leave the engine sit in that condition to bleed down those associated lifters. The lifters will not extend (uncompress) past the base circle once bled down (valves will then completely close).
Associated issues are discussed in the posts cited above. There are also variations in lifter geometry (lifter unplunged height) also discussed. You can also reset the lifters by removing them and thrapping them smartly on a hard surface unseating the plunger.
You may be able to turn the engine over (hot wire starter) getting oil pressure to help reset the lifters (camshafts and camcovers installed) If the engine sits for several days, some of those lifters bleed down and are then pumped up during initial start up (but less likely a quick bleed down if you have had oil pressure around the lifter and the lifter has not failed in any way).
If the issue is lifters, you may have to remove camshafts....but not the heads....if the issue is valve stem lengths, you would have to remove the heads.
The posts cited above may help if the low compression issue is valve stem clearance, lifters, or camshafts geometry including reground valves and reground camshafts.
Lifters when first installed may be locked unplunged or fully extended. One theory is that when you remove the camshaft, some of those lifters suck in oil essentially pumping themselves fully extended. When you reinstall the camshafts you now have valves staying open unless you can remove the oil from the lifter before you install the camshafts. This is in addition to the valve stem height issue from a new valve job exceeding the lifter limits which no amount of lifter oil relief will solve. This is also in addition to the scheme where you do NOT mix lifter locations when reinstalling used lifters to protect yourself from lifter wear aberrations and lifter locked position aberrations.
Once you crank the engine or run the engine for a few minutes lifters will bleed down. But for those lifters which extended and locked themselves fully extended during camshaft removal it is an issue because now those valves will open farther than they should when you crank the engine for a few minutes.
BUT still another issue involves the existence of several variants of the same HT 2236 Sealed Power Lifter.
Lifter on left is STOCK (91' LT5), Lifter second right (identical to stock) is new made in Mexico, Lifter third right is new made in China, Lifter fourth right is new made in Mexico. I wonder for those who bought new lifters.....how many installed several different variants of the same lifter in a single head without knowing it.Prolly would work fine but just kind of messy mechanic work.
BUT...... all the lifters cited above (except the left lifter which is stock) come in Sealed Power HT 2236 boxes (some made in China and some made in Mexico).
Then there is the Melling JB 2236 which is identical to the stock lifter (left lifter) of the above lifters.
I measured the LC (Lifter Compression) or difference between maximum and minimum height of the stock lifter and found .120 inches.
Also measured LH (Lifter height) or maximum height of stock lifter (uncompressed from plunger to top of lifter) and found .800 inches.
There is a variance in Lifter Height and Lifter Compression among lifters.....
The Mellings JB2236 are identical to stock original Lifters as you can get.
I received 16 JB2236 Lifters today from Clark Discount (Type in JB2236 in the Search By Key Word). Perfect...exactly what I was looking for
Lifters and Valve Stem dimensions (reground valves)
Lifters and Valve Stem dimensions (reground valves)
Lifters can be compressed .120 fully loadedanything above that the lifter is totally plunged and will hang valves open. Cams take up .075 from base circle.
The Base circle is .075 above the main journals so when you bolt down the camshaft it will push the lifter down .075 plus the factory has the lifter set above the journal another .015 so a stock motor takes up .090 of the .120 leaving .030 for compression of the lifter to account for valve stem clearance apperations (valve regrind for example).
If you do one valve job you should be ok. If you do a second or third valve job or even a poor valve job the valve will sink into the seat which will bring the valve farther into the lifter bore. This will result in having to grind the valve stems to compensate for the valve seat changes.
If the valve seat is ground and the valve stem comes higher into the lifter bore (more than .035) the valves will hang open and will result in very low compression #'s.
All of the above is an easy fix by just grinding the valve stems. Be careful when grinding valve stems to make sure you don't take off too much not leaving enough valve stem above the retainer (at least .020-.025). If inadequate valve stem above the retainer, the lifter can knock the keepers out which will cause even bigger iisues.
Example Lifter and Valve Stem Clearance Measurements (Valves reground) All dimensions are in inches. (Actual numbers for stock lifter in Dark Green). LC.....(Lifter Compression) difference between maximum and minimum height of lifter typical .120. LIP.....(Lifter initial compression) camshaft in neutral position .090 Stock setting. LRP.....(Lifter remaining compression) compression of lifter to account for changes in valve stem position .030 Stock setting. LH......(Lifter height) from plunger to top of lifter (not compressed). (.800 measured stock lifter). VC......(Valve clearance) distance between valve stem and journal (valve closed). (.750 measured after valve recondition). Preset.....Height of uncompressed lifter above journal typical .015. (measured .047 avg after valve reconditioned. Recommended .005). PL......Preload is half the difference between journal diameter and camshaft base circle diameter typical .075. (.080 stock cam shaft).
An example after a valve regrind Preset=.047 is different than stock .015. Which Preset (.047 avg) is too much.
A Mellings JB 2236 lifter is very close in gemetry to the stock lifter (left lifter) in the photos in the post above . The Mellings JB 2236 Lifter Height LH is .794
The Valve Stem Clearance Measurement Tool consists of a 14 inch aluminum round stock 1.140 diameter (all in inches) with a dial gage inserted at the center (with a countersunk set screw). This valve stem clearance measurement tool allows the measurement of valve stem clearance (shortest distance to journal surface) on the axis of the valve stem. The dial gage is set to zero on the journal surface. The aluminum round stock is lightly lubricated during the measurements.
Rotating the aluminum round stock valve stem clearance measurement tool in the journal slightly moving the tip of the dial gauge back and forth across the tip of the valve stem will give you a minimum valve stem clearance. The valve clearance to journal varies from the sides of the valve stem tip by .002 with minimum clearance at the center of the valve stem tip.
The valve stem clearance is the shortest distance from the end of the valve stem to the bottom surface of the camshaft bearing journal
Once you set a zero at the journal, all 32 valve clearances can be measured in about 5 minutes. I have checked all valves several times and get within .001 each time checked so the measurements are very repeatable. The .001 variance depends on exactly where the dial gage plunger is set on top of the valve stem.
Valve Stem Clearance Measurements (Stock Llfters)
Zero at the journal.
Checking valve stem clearance.
The stock lifter height unplunged is .800. The maximum lifter plunge is .120. Camshaft base circle Preload is .080.
The example valve stem clearance as measured below to the journal is .739. The dial gage shows .261 which to get to 1.0 which is the zero setting above we would go .739.
The lifter will Preset above the journal .800-.739 or .061 in this case. Adding Preset and camshaft Preload we get .136 which exceeds the maximum lifter plunge of .120. The valve will stay open. Lifter Preset is the height of the top of the lifter (unplunged) above the journal surface.
You may think you have extra clearance with the camshafts in the neutral position (using the stock retainers) being able to plung the lifter a tad. However, do not be mislead, when you install the camcovers, you loose that excess clearance the stock retainers provide and can end up with a valve in the open position.
Camshaft and Lifter Measurements (Stock and Regrind) all in inches
Camshaft and Lifter Measurements (Stock and Regrind) all in inches
Stock Camshafts
Journal diameter is 1.140.
Base circle is 1.300.
The Preload would be (1.300 - 1.140)/2 = .160/2 = .080 (read in reverse since extended)
Regrind Camshafts
Journal diameter is 1.140.
Base circle Intake cams is 1.150.
Base circle Exhaust cams is 1.220.
The Preload Intake cams would be (1.150 - 1.140)/2 = .010/2 = .005
The Preload Exhaust cams would be (1.220 - 1.140)/2 = .080/2 = .040
A Summary of 1995 Reconditioning/Modifications (#0186).
Everything removed/restored/replaced on Top End (Plenum, Secondary Vacuum system, HVAC Vacuum, Plugs, Coils, Starter, Crank Case Vent Cover, Alternator, AC Compressor (not disconnected).
1. Rebuilt Starter
2. New 200 amp Alternator (Just Because)
3. New Secondary Vacuum System and Linkage (Complete)
4. All Injectors Ohmed (12.4 Ohms) and Cleaned with New "O" Rings
5. New Plugs and New LT5 Plug Wires (Raised to Plenum)
6. TB Coolant Blocked at Injector Housing (Re-installed TB Coolant Hoses for looks only)
7. Billet Aluminum (Oil Cap, Power Steering Pulley, Water Pump Pulley)
8. Lees MAP Sensor Cover with 1995 #186
9. New Crankcase Vent Cover Gasket with red Loctite on all bolts and two New Vent Cover Hoses from Jerry
10. Four New PCV Hoses from Jerry not requiring any clamps of any kind
11. New Charcoal Canister
12. Engine completely Degreased and Cleaned (Pressure Washed) with Compression at 215-220 on ALL eight Cylinders
13. Differential Drain Plug Installed
14. All New Fluids (Differential, Trans, Engine) and New Oil Filter
15. New TB Coolant Hoses albeit there is NO TB Coolant
16. New "O" Rings (Injectors, Fuel Rail, Cam Cover PCV)
17. New MAP Hose and New Fuel Pressure Regulator Hose
18. SS Allen Bolts (Plenum, MAP, Air Horn, Injector Housing Coolant Manifolds)
19. New Tires (Came with ZR-1)
20. And.....New Garmin Mapping (In case I get Lost being distracted while driving the "New" ZR-1)
21. And almost forgot.....Wireless XM Radio....Just Tune Bose to same frequency (using IPhone APP to find frequency)
22. Complete set of Metric tools behind Passenger Seat
23. Gorilla Lug Nut Wrench and Dynomite Tow Bar beside Passenger Seat
24. K40 Radar installed (Came with ZR-1)
25. LoJack Installed (Came with ZR-1)
26. Carter Bling (Billet Aluminum Covers for Oil Filter, Brake Fluid, Coolant Over Flow, Power Steering, Wiper Fluid, Throttle Cable)
27. New Radiator Hoses
28. New Fluidyne Aluminum Radiator
29. New 180 deg Thermostat
30. Radiator (oil cooler and Air Condenser) was Clean of Trash (may install Radiator Screen)
31. Under Side of Engine and Differential was degreased and pressure washed (No Oil Leaks)
32. C4 Beam Plates Installed (ZF doc)
33. New Hood Support
34. Recharged the R134a AC System
35. Greased zerks on Front A-Arms (Top and Bottom) and Inspected/Restored Brake Calipers/Pads
36. Reinstalled Canadian daytime running lamps Module mounted on ASR Box
37. Radiator Debree Screen installed
38. Inspect Chain Guide Wear
39. Braided SS Oil Cooler Lines
40. Installation of Wilwood Rotors, Hats, and C5-Z06 Calipers.
41. Rebuilt Black Label Transmission Installed with New Pilot Bearing.
42. New Drive Shaft U-Joints.
43. ZFdoc C4 Beam Plates Installed.
44. New Serpentine Belt (K060802).
45. Elite Oil Catch Can.
46. New MSD 8224 Coils Installed.
47. New Rear Wheel Bearings (SKF BR930024).
48. New Rear Brake Pads.
49. New Half Shaft Spicer U-Joints.
50. New Modified Fuel Pressure Regulator (Apr 2019).
All 95' cars have the Dunn heads on the left side: #10225121
This 95' has the Dunn head on the right side also: #10225122
(use a mirror to read photo below).
From the Registry Web Site.......
A Total 448 each year 93's, 94's, and 95's.
1994-95 production model of the ZR-1 they started installing the new Dunn heads except they ran out of the left side Birmal heads first so some '94 ZR-1s have the new Dunn heads only on the left side. Eventually GM started installing Dunn heads on both sides but only later built '95 ZR-1s got Dunn heads on both sides:
All '95 cars have the Dunn heads on the left side: #10225121 Most of the '95's still have the Birmal heads on the right side: #10174390
In '95 is when they started installing some of the Dunn heads on the right side: #10225122
These are the 95' ZR-1's that definitely have a (SET) of Dunn heads (#10225121 and #10225122) on them from the factory (See #186).
#118, #161, #186, #188, #211, #220, #227, #229, #235, #236, #249, #258, #275, #293, #310, #357, #368, #389, #390, #392, #393, #394, #398, #416, #418, #420, #425, #428, #435, #442, #444
1. Plenum, Alternator, AC Compressor, Fuel Rails, Injectors, Secondary Vacuum System, Coils, Starter Removed.
This includes the Cruize, Charcoal Canister, HVAC Vacuum System which is also removed.
2. It all Started with great compression of 215-220 on all 8 cylinders without TB plates open but did have a vacuum leak. All injectors checked out at 12.4 Ohms.
3. Inspection of Chain Guide Wear.
The passenger side Chain Guide Wear can be inspected through the Oil Fill Cap. The Top Chain Guide attached to the Valve Cover can be seen making sure it is not broken and the Tab is intact. The Camshaft Chain can also be seen resting on the Lower Chain Guide and the Wear on that Chain Guide observed.
The Lower Chain Guide on Passenger Side associated with the Chain Tensioner on that side can be seen and with a flashlight and the general condition verified (no broken tip or sides). With a Bore Scope, the Chain Guide Wear can be observed noting the depth of the wear on each side of the links as noted. Also the center portion of the Chain Guide on which the rollers roll can also be seen. In general, Chain guide wears relatively fast until the rollers come in contact with the Chain Guide. At this point in the Chain Guide Wear, the Wear is extremely slow. One looks for less than a 1/16 inch depth of the links at which time the rollers are in contact with the Chain Guide.
Clean Up of Valley, Installation of Battery Disconnect Switch and Coils
1. Clean Up of Valley and Removal Of Crankcase Cover (gasket replaced)
Valley was cleaned by Degreasing followed by Pressure Washing. The Valley Drain being considerably larger on the 95' was able to drain considerable Pressure Washed Debree.
Valley with New Crankcase Cover Gasket installed
New Crankcase Ventilation Hoses Installed (Left and Right)
In addition, the Secondary Actuator System was reconditioned with NEW Secondary Linkage (with just a bit of white grease on each Secondary Lever Ball).
2. Battery Disconnect Switch and Installation of Coils
Installation of Rebuilt Starter, New Alternator, and SS Braided Oil Cooler Lines
Installation of Rebuilt Starter, New Alternator, and Braided SS Oil Cooler Lines
1. Rebuilt Starter
2. New 200 Amp Alternator
3. Braided SS Oil Cooler Lines
1. Place SS Braided hose in vice and cut SS Braided hose to length using Angle Grinder with Cut Off wheel. Angle grinder is preferred since minimal SS wires are left free of the cut.
2. Make sure no SS Braided wires enter the hose end and make sure all loose SS Braided wires are ground flush with end. Keep the hose in the vice with about 2 inches on the free end out of the vice. (Clean the inside of the hose end Cut Off before going further with Cotton Cue Tip .
3. Take the AN reusable hose fitting and unscrew the male part from the female part. The other end of the male part will have an NPT pipe thread or "O" ring seal thread size (AN) as desired.
4. Take the AN reusable hose fitting female part and screw onto the SS Braided hose (counterclockwise) by hand pushing onto the hose as you rotate the female hose fitting counterclockwise.
5. Screw the AN female reusable hose fitting onto the hose such that the hose is at a depth into the female fitting as defined by the lines on the female fitting surface.
6. Lubricate the inside diameter of the SS Braided hose with oil through the end of the female fitting.
7. Insert the male reusable hose fitting into the lubricated hose through the end of the female fitting.
8. Push the male fitting into the hose as you rotate the male fitting clockwise using a cresent wrench (Box Wrench preferred). Once the threads are caught, continue rotating the male fitting into the hose untill approximately 1/16 inch space is left between the hexigon of the male fitting and female fitting.
9. Install the second hydraulic reusable hose fitting on the other end of the hose as per steps 2 through 8 above.
10. Last...but not least....take an air hose (Air Compressor) and blow the hose clear to make sure you have a clean assembly (if the SS Braided hose is not too long look through the hose end to end for any debree). You now have a SS Braided hydraulic hose with fittings good for maybe 2,000 psi hydraulic pressure more or less.
Parts Required for SS Braided Oil Cooler Lines with Re-Usable Fittings.
The SS Oil Cooler Lines are very easy to make up in SS Braided hose using Aeroquip reusable fittings and SS Braided hose available from Summit Racing.
The first seven items can be found at Summit Racing.
Jeffvette Design of Oil Cooler Adapter
I have never had one of these hydraulic lines with Aeroquip Reusable Fittings leak and they are much much tougher than original crimped fittings and easily replaced or adjusted if you want to at some point make them longer or shorter (the fittings are reusable and swivel). And......you will find a much better routing of the lines if you make them yourself by looking at the routing of the existing Hydraulic Lines. The Aeroquip Reusable Fittings come in all sizes and angles to fit any situation. You can make your own oil cooler lines as shown here and Power Steering Lines or any other hydraulic line you might need on the ZR-1.
Once you experiment with making your own hydraulic lines with some using SS Braided hose you will never look back at buying ready made hydraulic lines again. All you need is a vice, hand grinder (or even a hack saw will work), and a couple box wrenches of appropriate size. Oh...and an air compressor to blow clean the lines after assembly.
The KEY Element is the offset of the Rotor to match the offset of the Caliper Bracket. This Wilwood Rotor with Z06 Caliper Modification described herein is IDENTICAL on BOTH the 90' ZR-1, 91' ZR-1, and 95' ZR-1.
1. Rotors. Wilwood SRP Drilled Performance rotors 12.8 inch diameter and 1.25 inch width with 12x7.06 Rotor Bolt Circle (160-7744-BK RH and 160-7745-LH).
2. Hats.
Two Wilwood Big Brake short offset (offset 1/4 inch) Hats (Aluminum Alloy) with 5x4.75 Wheel Stud Circle and 12x7.06 Rotor Bolt Circle (#170-7746) will fit the Wilwood SRP Drilled Performance Rotors.
Also need the Bolt Kit (230-8008) 12 pack for bolting the Hats to each Rotor.
3. Brake Pads.
Four (4) 15Q-8012K PolymatrixQ pads for a C5-Z06 (Wilwood is souce).
5. Bracket Bolt Kits. #14121 (Caliper Guide Pin) and Brake Hardware Kit (Spacers and Seals) #H5634Q at O'Reilly Auto Parts.
6. Adapters.
(Corvette C4 to C5-Z06 conversion brackets, late spindle) C4 to C5-Z06 Conversion Adapters (Ebay) (Note the countersunk surface for Bracket Boss)
I used two aluminum washers under the Banjo Bolt Head and one aluminum washer between the brake line adapter and Banjo Bolt Port on the Calipers. The two washers keep the brake fluid port in the Banjo bolt centered on the brake line adapter. NO LEAKS
Installation of New Secondary Port Vacuum System Lines
Installation of New Secondary Port Vacuum System lines
Just a Heads Up....Ebay has New Secondary Port Throttle Vacuum System (Complete) for the 93'-95', New Map Vacuum Hose, and New Fuel Regulator Vacuum Hose. I highly recommend These hoses along with the New PCV System four Hose/Connectors which totally eliminates the need for Nylon Ties, and Screw Type Hose Clamps. Oh Ya......These NEW Lines/Connectors also TOTALLY Eliminate all Vacuum System Leakage. New Secondary Vacuum System
1. New Map Vacuum Hose, and New Fuel Regulator Vacuum Hose.
2. New Secondary Port Control Solenoid Valve Filter (95') made from a Sponge.
The Secondary Port Control Solenoid Valve for the 95' (Bottom which has the silver Vent Tube requiring a Filter) is different than the Secondary Port Control Solenoid Valve for the 90'-91' (Top)
3. New Secondary Port Throttle Vacuum System for 1995. Installed New Secondary Port Throttle Vacuum System for 93'-95'. Secondary Port Throttle Vacuum System.
This is an absolute Must Do if you Really are serious about reconditioning the
Secondary Port Vacuum System (the original Rubber Connectors are Hard and Deteriorated).
4. New Secondary Port Throttle Vacuum System for 1990-1995.
This complete NEW vacuum system designed for the 93'-95' can be installed on a 1990-1995 ZR-1. For 1990-1992 this can be accomplished by substituting the longer Manifold Differential Pressure vacuum line on the original 1990-1992 ZR-1 Vacuum System for the shorter curled MDP Vacuum line in the New 93'-95' Secondary Port Throttle Vacuum System.
The New vacuum system connectors are New soft rubber and easy to disconnect connectors which are very tight (just twist the plastic tube back and forth and they will let loose). The Original hard rubber connectors are impossible to disconnect without cutting the connector lengthwise (with razor blade) to remove the plastic tube.
3. Modifications (re-arrangement of connectors) of the New Secondary Vacuum System to fit 1990-1992.
A. The Tee (T) was moved and a 1 inch long 1/8" Fuel Line PCV/EEC (SAE 30R7 obtained at O'Reillys) was used as a splice where the T was located. The T was installed for the Drivers Side Secondary Canister which is identical to the Stock
B. The Stock 1990 Manifold Differential Pressure (MDP) Vacuum Line was used and added to the New Secondary Vacuum System. I replaced the stock L fitting on the 1990 MDP was replaced with the New L fitting removed when T was re-installed for the Drivers Side Secondary Canister which is identical to the Stock 1990 Secondary Vacuum System configuration.
C. In this case I also used the Stock line with New L fitting from the check valve to the Vacuum Pump line as that Stock line was just a bit longer
Went for a test drive with the 1990 and ALL is perfect
4. New Secondary Vacuum System Availability.
These New Secondary Vacuum Systems for 93'-95 which can easily be modified for 1990-1992s are offered on Ebay for $100 but one can buy them with an offer for less
Installation of Reconditioned Injectors with New "O" Rings
Installation of Reconditioned Injectors with New "O" Rings
1. Injectors Cleaned and Ohmed (12.4 Ohms)
New Injector "O" Rings Installed (Top and Bottom "O" Rings are Identical)
2. Installation of Reconditioned Injectors with New "O" Rings (Always use just a bit of white grease on the "O" rings for ease of insertion into the Injector Housing and Fuel Rail) Injectors with White Ring are Primary and Injectors with Blue Ring are Secondary
3. Installation of Retainer on Reconditioned Injectors with New "O" Rings Make Sure the Injectors are Inserted completely all the way into the Fuel Rail Before Installing the Retainer Clip.
New PCV Connections, Installation/Relocation of Plug Wires and New Spark Plugs
PCV System upgrade and Installation/Relocation of Plug Wires and New Spark Plugs
1. New PCV Hoses installed (No Nylon Ties or Wire Clamps required)
In addition to the Oil Catch Can, new PCV dual connectors have been added replacing the old connectors.
I installed Jerry's New Dual PCV Connectors on ALL engines getting rid of all the Clap Trap Nylon Ties and Hose Clamps to keep the Old (hardened Rubber) Dual PCV connectors from slipping off the PCV valves/lines or leakingHighly Recommended Right up near Top Of List with Blocking TB Coolant at each Injector Housing.
2. Installation/Relocation of Plug Wires with New Billet Aluminum Plug Wire Separators
3. Location of Plug Wire Separator Moved to Upper Plenum Bolt from Injector Housing Bolt
Along with the PCV Upgrades is the raised Plug Wires from Injector Housing Bolt to Plenum Bolt on ALL engines. This allows the Dual PCV Connector to be attached in front of and at the same location as the Plug Wires and above the Cam Covers A Very Clean Installation lifting the Plug Wires OFF the Cam Covers.
4. New Spark Plugs
For my 95' NGK Iridium BKR5EIX Eagle
Gapped .043"
I use anti-sieze on stainless steel bolts, spark plugs, and header bolts (Permatex Anti-Sieze 133A).
I use just a bit of white grease on the Spark Plug porcelain top to make installation of the Spark Plug Rubber boot easy.
I also use a bit of white grease near the top of the rubber boot where it engages the top of the Cam Cover.
Those swivel Spark Plug Sockets have a nice rubber insert. My only issue was that the spark plug held on to the insert separating the short wobble extension from the end of the swivel socket when done inserting the spark plug. A little white grease on the rubber insert cured that issue
The most difficult part to TB Coolant Blocking is the removal of the two Injector Housing Coolant Pipes. Those 4 bolts in each pipe may be impossible to remove without heat. Just take a torch and heat each manifold along the whole length of the bolt a bit before removing the 6mm x 50mm torx T-30 bolts (I replace with SS Allen Head bolts).
First.....Tape the Injector Housing Ports so no filings get into the Intake Ports at any time during the drilling/threading Process.
After using a 21/64 or 11/32 drill to enlarge the TB Coolant Port use a 1/8 NPT Tap for the Pipe Plug.
The threading proceeded in stages each time trying the New Red Plug such that the last stage resulted in the Plug Tight and almost flush with the surface of the Injector Housing to Plenum Mating Surface. A file was used to dress up the plug surface flush with the Injector Housing to Plenum Mating Surface. Red Loctite was used on the Red 1/8 inch NPT Pipe Plug.
After the 1/8 inch NPT Pipe Plug was installed a shop vacuum was used to suck out any and all aluminum shavings caught within the injector housing coolant manifold port.
Once the Plenum was installed the rubber hose on the Passenger Side connecting the Coolant Tank with the TB Coolant was blocked (using an internal brass connector that was soldered closed) using one screw clamp on the Coolant Tank Side. All other TB Coolant rubber hoses were installed NEW but without any screw clamps since no coolant pressure will exist within those hoses with TB Coolant blocked from both directions.
Marc Haibeck has found that the throttle body has no problem with ice when the ambient temperature is at 20 degrees and the humidity is 90%. I have calculated that the coolant flow Dynamics assure ALL air is washed from the Top End of the engine at higher engine rpms (only need the air washed out once) even with TB Coolant Blocked .
2. Fluidyne Radiator.
I was FedXed the Fluidyne Radiator in a matter of hours after purchase from Hib. I am saving the Original Fluidyne Colorful Box as a Souvenir (picture later today). A extremely well made ALL Aluminum Radiator.
The Stock Radiator with Plastic End Caps...................................All Aluminum Fluidyne Radiator
3. Removal of the Cowling.
A. Remove Corrugated Air Duct.
B. Remove Air Filter Housing Assembly.
C. To Remove the Cowling first remove all bolts/screws/nuts including the three 7mm on each side lower front of Cowling.
Details
a. There are three 7mm screws on each side lower front of Cowling.
b. There are two 10 mm nuts on Passenger Side Lower Flange of Cowling on frame rail.
c. There is one 10 mm nut on Drivers Side Lower Flange of Cowling on frame rail.
d. There is one 13 mm nut on Passenger Side Lower Flange of Cowling on Frame Rail.
e. There is one 13 mm nut on Drivers Side Lower Flange of Cowling on Frame Rail.
f. There is two 10 mm bolts horizontal on Drivers side just below Coolant Inlet.
g. There are five 10 mm bolts holding the top of the Fan Housing to the Cowling.
Additional Details
a. I also remove the three screws on the bottom of the Fan Housing.
b. Remove the Oil Cooler Hose Adapter by removing the center nut from the Oil Cooler.
c. Unplug Air Sensor Passenger side front lower end of Cowling.
d. Remove sensors on Drivers Side of Cowling.
Now the Hard to Explain Part......
Lift the Cowling up on the drivers side so that is clear of the hood Pivot. With the Drivers Side lifted up high, go to the Passenger Side and lift up by bending the lower tabs of the Cowling so they squeeze by the AC lines. The Cowling should then be free.
4. Modification of Fan Housing and Cowling.
The Thicker Fluidyne Radiator fit under the Cowling without any modifications of the Fan Housing even though it was a thicker Radiator.
The 95' Cowling was cut in several places for removal by someone else so I replaced the 95' Cowling with a 91' Cowling.
The 91' Cowling only has one sensor attached (brass screw holes) and the 95' has three sensors requiring two holes each. I drilled the holes in the 91' Cowling to match the 95' Cowling.
Thickness of Stock compared to Fluidyne Radiator........................Modification of 91' Cowling to fit 95'
Lift the Cowling up on the drivers side so that is clear of the hood Pivot. With the Drivers Side lifted up high, go to the Passenger Side and lift up by bending the lower tabs of the Cowling so they squeeze by the AC lines. The Cowling should then be free.
6. Replacing the Thermostat.
I always replace the Stock Thermostats with a 180 deg F New Thermostat but there are TRICKS. Now the TRICK....Disconnect the Thermostat Housing two bolts to the frame and the single bolt holding the Thermostat Housing pipe pointing to the Drivers side. The Thermostat Housing can then be moved so you can disconnect/Connect that New lower radiator hose after installation of a New 180 deg F Thermostat. You can split the Thermostat housing (I had a frozen bolt on the last one which is another story).
Use a flat scraper blade to hold the New Thermostat in place tight (as it wants to spring outward as the main spring of the Thermostat is compressed when installed) as you install the two Thermostat Housing halves (yes....I use a bit of Permatex on the faces of the Thermostat Housing and on the rubber seal of the Thermostat)
You do NOT want to pinch that Thermostat rubber seal on the flat surfaces of the two Thermostat Halves (the rubber seal resides in a groove of the Thermostat Housing Half containing the Thermostat).
After the New Thermostat is installed in the Thermostat Housing you can then install that short lower Radiator Hose using Permatex on the inside of each end of the Hose. Before you tighten the Hose Clamps, align the two bolt holes of the Thermostat Housing Bracket with the threaded holes in the Frame Rail. Install those two bolts aligning the Thermostat Housing squarely with the New Radiator Lower Connection. Lastly, tighten the two lower Radiator Hose Clamps.
7. Filling with Coolant.
I fill with Coolant/Distilled Water. Then the BIG Secret......
A. I use a vice grips and close off the coolant to the Plastic Overflow under Passenger Headlight.
B. I fill Black Coolant Reservoir in front of passenger side window and when the bubbling stops.....Blow into/pressurize that Reservoir holding pressure for about 10 seconds. More bubbles will come from the top of the radiator hose. I refill with Distilled Water and Blow into/pressurize the Coolant System again. I repeat this maybe three times until no bubbles come back from the top of the Radiator. I then replace the Coolant Reservoir Cap and remove Vice Grips.....and fire up the LT5 keeping a hand on the Injector Housing Coolant Manifolds to assure they get warm within a minute. (That Happens with this method of Coolant Filling 100% of the time).
With this procedure you are pressurizing both sides of the radiator but with each pressurizing cycle more coolant is being pushed into the coolant system and more air is bubbling out from the top of the radiator.
8. The Test ride and Flushing out of remaining air in the Coolant System.
First........A Theory about Thermostats before the Test Ride to flush out any additional air in the Coolant System.
I use 180deg Thermostats in ALL LT5s. A theory I have is that the 165 deg Thermostat will open sooner but once fully open at say 170deg will flow the same as a fully open 180deg Thermostat at say 185deg. No Difference in Cooling after both Thermostats are fully open. The Exception is that on cool days the 165deg Thermostat will keep the engine cooler than at 180deg Thermostat....say 170deg. That is actually too cool and some block air flow through the radiator on those cool days to achieve what a normal 180deg Thermostat would accomplish.
Marc Haibeck says The thermostat for all LT5's has a temperature rating of 180 degs F. The 180 deg thermostat begins to open at 180 and is fully open at 195 degrees. A thermostat with over 50k miles generally opens 5 degrees later and opens about 80%. I installed a NEW 180 deg Thermostat in this 95'.
9. Last......a Theory regarding The Dual Function Thermostat on the LT5.
My thinking is that the whole purpose of the Dual Opening Thermostat Housing (Thermostat can open at the Temperature side or on the other end at the Pressure side) is to keep Radiator Pressure to acceptable limits. In other words the Thermostat functions when the engine is cool and when the engine is at high rpm.
When the engine is at high RPM, the Bypass on the thermostat will be open completely do to the water pump developed coolant pressure on the bottom of the Thermostat. This Higher pressure being developed at the bypass end of the thermostat because the Thermostat is closed on the Temperature end or because the high water pump RPM is developing too much pressure on the radiator on the Bypass end of the thermostat.
In other words the Thermostat can open on either end (one end temperature controlled and the other end differential pressure controlled). And even it the Temperature End of the Thermostat is fully open, HIGH water pump RPMs may develop greater pressure than the radiator can stand on the Bypass End and the Thermostat would then open on both ends to allow more coolant to recirculate rather than ALL of the coolant flow being forced through the Radiator. 7,000 Engine RPM does that to you
Reconditioning and Installation of Plenum with SS Allen Head Bolts
Reconditioning and Installation of Plenum with SS Allen Head Bolts Including New MAP Vacuum Hose, New Fuel Regulator Vacuum Hose, and New TB Coolant Hoses (Non Functional)
Also included here are New PCV Hoses and Fittings (Injector Housing Fittings, PCV Valve Hose, and PCV Top Fitting) It is highly recommended that these four Hose/Fittings be replaced with New Jerry's Hose/Fittings which do NOT require Nylon Ties or Screw Hose Clamps of any kind to keep from leaking.
The Same Replacement applies to the MAP Vacuum Hose and Fuel Regulator Vacuum Hose to eliminate the need for Nylon Ties or Screw Hose Clamps.
New Rear Wheel Bearings and New Half Shaft U-Joints
New Rear Wheel Bearings and Half Shaft U-Joints in a 1995 ZR-1
The New Rear Wheel Bearings selected are SKF BR930024.
Two new SKFBR930024 rear wheel bearings as recommended by Phil (Jagdpanzer) were installed in a 95' ZR-1
Also installed Spicer U-Joints (Dana Spicer 5-3615X U-Joints w/Coated Caps) 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 are shown. The three (Torx T55). bolts that hold each Rear Wheel Bearing in the Bearing Housing are also shown. The Torx T55 driver is shown on the 3/8 inch socket and the smaller 1/4 inch 8mm socket and extensions were used to remove the Half Shaft U-Joint straps. The needle nose vice grips was 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 of 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 out 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....that is an indication for a possible changeout of Bearings or U-Joints.
After removing the 36mm Axle Nut (using a two foot long pipe extension on a 3/4 inch socket wrench) allowing the spline shaft to slide freely within the bearing spline…..The BIG Trick was the disconnection of the lower Strut Rod 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 by removing the U-Joint Cap Straps (8mm bolts) and removed out the bottom where the Strut Rod was disconnected and rotated downward. The Axle spline floats within the Wheel 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. A Torx T55 driver and 3/8 inch socket wrench was used to remove the three Bearing bolts from the inside of the Bearing Housing. The Rear Wheel Bearing was then removed from the front. The two large bolts shown are one from each Strut Rod 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.
The Cotter Pin hole of the threaded end of the spline shaft was drilled out to 3/16 inch for a tight fitting 3/16 inch diameter cotter pin.
The Dana Spicer 5-3615X U-Joints were installed using a couple sockets (35mm and 22 mm) to remove the old U-joints and install the New Spicer U-Joints.
The smaller socket was used on top of the yoke of the Half Shaft 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. After the lower U-Joint Cap is tapped free, flip the Half Shaft 180 deg and using the same set up tap the second cap free.
Dana Spicer 5-3615X U-Joints with spring clips are shown. The Half Shafts are marked (left and right......inside and outside).
Note:
The Strut Rod is what keeps the Wheel Bearing tight against the Half Shaft once the Axle Nut is removed. The Axle Spline does not move with respect to the Wheel Bearing Spline once that Axle Nut is tight.
With the Axle Nut in place, the Half Shaft is held tight between the Wheel Bearing and Differential. The Wheel Bearing can move in and out just a bit depending on the compressibility of the rubber grommets in the Strut Rod as the bearing moves up and down with respect to the chassis (the distance between the Wheel Bearing and Differential changes just a bit as the angle of the Half Shaft changes just a bit).
With the Axle Nut remove, the Wheel Bearing is still held firmly by the Strut Rod. Once the Strut Rod is removed there is limited free play between the Axle Spline and Wheel Bearing Spline (in and out). That free play can be increased by applying a lateral force outward on the bottom of the Wheel Bearing where the Strut Rod was located using Come-A-Long attached to my Truck. If you pull outward on the bottom of the Wheel Bearing Housing just a bit that free play allows the easy removal of the U-Joints from being trapped by the U-Joint sockets once the Strap Bolts are removed. That Free Play is what is needed to overcome all the Difficulty removing the Half Shafts from being trapped between the Differential and Wheel Bearing even when the Axle Spline Nut is removed. Gaining that Free Play requires a relatively small force using a Come-A-Long to Help with the Lateral outward movement of the lower part of the Wheel Bearing Housing of an inch or so.
10-24-2015, 05:11 AM
Tech Info - LT5 New Rebuild Issues (Lifters, Camshafts, and Valves)
