Tech Info - LT5 Added Systems
Note the Gun Metal Oil Cap
on passenger side.
Ebay Aluminum billet oil cap (fits 90' & 91' LT5 & L98)
May require dressing up the threads just a bit with a file but the threads of the cap are the same
Items 1 - 6 are Added to ALL engines.
1. 91' ZR1 (LT5) Debree Screen.
Use 1/8 inch steel pop rivets with washers backside of air deflector and on front of screen
(approximately 5/16 inch mesh). Drill 1/8 inch holes in the rubberized air deflector.
Use cable ties on top side of screen.
2. Differential case drain installation
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
on another topic 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 pumped in a pint of Mobile 1 75W-90 and let that drain cleaning out a lot of old oil and any tap debris. 1/8 inch Aluminum Allen Head NPT pipe plugs
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.
3. PCV Connectors.
In addition to the Oil Catch Can, new PCV dual connectors have been added replacing the old connectors.
Jerry's Dual PCV Valve Connector
Jerry's Dual PCV Valve Connector Hose
Jerry's Dual PCV Valve Connector Grommet
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 connectors or leaking Highly Recommended
Right up near Top Of List with Blocking TB Coolant at each Injector Housing
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. Starter Relay Tricks Starter Relay, Wiring Harness, and Plugs Tricks
See Item #2 Electrical Ground Connections and Installing Starter Relay
60 / 80 AMP RELAY SPDT SINGLE POLE DOUBLE THROW NEW 654
Installed under ECM and in slot between brake booster and fire wall (perfect place for location of Relay).
Wiring modified a bit to assure Pin #87a is not hot at any time
Pin #30: Purple wire to starter (use 3/8 inch connector on relay).
Pin #87: Red wire battery positive 12v use 3/8 inch connector on relay (connected to battery positive multiple connection post).
Pin #86: Battery ground (1/4 inch connector on relay connected to ground where battery 12 gauge wire grounded).
Pin #85: Purple wire from ECM use 1/4 inch connector on relay (Red wire on early 1990 ZR-1
Pin #87a: Not hot at any time
and not used.
Insert a short 1/2 inch long section of plastic hose
over the center connector on the Relay which is NOT
used in this application.
5. SS Braided Oil Cooler Lines
See SS Braided Oil Cooler Hoses and Fittings
6. Billet Aluminum Ultra Light Belt Tensioner Pulley
This Belt Tensioner Pulley will fit the ZR-1 (LT5) as well as a standard C4 with L98 engine.
Ebay Billet Aluminum Belt Tensioner Pulley
Belt Tensioner with High Speed Idler Pulley...............Diameter of Billet Aluminum Pulley is
Use Red Loctite on Pulley Bolt......................................3/16 inch larger than stock pulley
Hand File Small Bevel around diameter of outer ...........Pulley is placed on Belt Tensioner with pulley
Collar to clear bearing Snap Ring.................................bearing Snap Ring facing Collar (Forward)
Close up of minor modification of Belt Tensioner Flange
The amount of pressure on the belt depends on belt length and compression of the Belt Tensioner itself. You want enough slack to get the Belt over the Alternator Pulley when Belt Tensioner is fully compressed using a long 1/2 inch Socket wrench. You can start the compression process of the Belt Tensioner by using a heavy Broom Handle compressing the Belt Tensioner so you can engage the socket in the Belt Tensioner socket 1/2 inch socket hole provided. This Billet Aluminum Belt Tensioner Pulley will give you just a bit more belt tension given the pulley is a bit (1/8 inch more or less) larger in diameter than a stock pulley.
As an aside......
After removing the Serpentine Belt, remove the Belt Tensioner Bolt and Washer. Get hand under passenger side coolant manifold in front of alternator pulley and grab hold of Belt Tensioner Pulley. Lift Belt Tensioner up and sideways through slot under coolant manifold/Radiator Inlet Pipe (Passenger Side) while lifting coolant Radiator Inlet Pipe (Do NOT disconnect any coolant hoses). Use Red Loctite on Belt Tensioner Pulley Bolt
Items A, B, and C are Added to Some Engines.
A. Oil Catch Can has been added.
See Details for Oil Catch Can Installation
was one of the first I think Oil Catch Can Photo
The PCV hose
connected under front of plenum (Vacuum source) is connected using SS braided hose to an Oil Catch Can
external to the engine which Oil Catch Can
is connected using SS braided hose to the dual PVC valves
hard line located at the rear of the plenum. The Oil Catch Can
is located on the drivers side inside wheel well (using a small channel ground and drilled to conform to the inside fender well as a spacer).
The Oil Catch Can used here is the Elite Engineering Oil Catch Can
(I use wing nuts for quick Catch Can Maintenance
B. SS Air Box.
See Stainless Steel Air Box and Air Filter (L98 and LT5) For installation details including the proper K&N Air Filter.
C. Reground Camshafts and ....................2. Oil Pressure Sensor Modification.
Billet Aluminum Camshaft Retainers............
The oil pressure sensor has been modified
LT5 Camshaft Specifications........................
by adding a brass T fitting which can also
be used to attach a mechanical oil pressure gauge.
Last UPDATE of post 3 Feb, 2015