C4 Engine Upgrade
Thread Starter
5th Gear
Joined: May 2011
Posts: 5
Likes: 0
From: Vancleave Mississippi
C4 Engine Upgrade
Folks:
Just a few lines regarding a C4 change from the L98 to LQ-9 with upgrades. I have a 1985 C4 that had an L-98 that blew a head gasket, I considered building a L-98 stroker but opted for a more modern Gen 3 engine and drive train package. The complete drivetrain was removed from a 1995 Sierra Denali with 75K on the clock. I have transplanted the LQ-9 which was completely refreshed with Comp Cam upgrade and associated valve springs. I am using C5 accessories and drive system. I am using a C6 intake with 98mm throttle body C6 injectors and fuel rail. I have retained and am using the fly by wire petal from the donor vehicle. I have installed a fresh late model 4L65E transmission that is controlled by the PCM. The old LED instrument cluster has been removed and replaced by an instrument panel and Autometer/Procomp gauges. The battery has been moved to behind the passenger seat and that space has been used to house the relay panel, PCM and TAC module. The cooling system has been upgraded with a Dewitt radiator. There was a lot of small issues to solve but most have been addressed. The PCM was reprogrammed by Speartech and is working great. I have included a couple of pictures of the engine for observation.
Regards:
Just a few lines regarding a C4 change from the L98 to LQ-9 with upgrades. I have a 1985 C4 that had an L-98 that blew a head gasket, I considered building a L-98 stroker but opted for a more modern Gen 3 engine and drive train package. The complete drivetrain was removed from a 1995 Sierra Denali with 75K on the clock. I have transplanted the LQ-9 which was completely refreshed with Comp Cam upgrade and associated valve springs. I am using C5 accessories and drive system. I am using a C6 intake with 98mm throttle body C6 injectors and fuel rail. I have retained and am using the fly by wire petal from the donor vehicle. I have installed a fresh late model 4L65E transmission that is controlled by the PCM. The old LED instrument cluster has been removed and replaced by an instrument panel and Autometer/Procomp gauges. The battery has been moved to behind the passenger seat and that space has been used to house the relay panel, PCM and TAC module. The cooling system has been upgraded with a Dewitt radiator. There was a lot of small issues to solve but most have been addressed. The PCM was reprogrammed by Speartech and is working great. I have included a couple of pictures of the engine for observation.
Regards:
Team Owner
Joined: Sep 2003
Posts: 25,383
Likes: 2,736
That's a very attractive and well thought out install I'd say. Looks great and generally "appearance can be interpreted as performs well also"
Quiz - wiper motor?
Quiz - wiper motor?
Last edited by WVZR-1; Feb 22, 2016 at 04:12 PM.
Thread Starter
5th Gear
Joined: May 2011
Posts: 5
Likes: 0
From: Vancleave Mississippi
WVZR-1:
Wiper motor was a challenge, I had to cut out all factory mounting points and rebuild mounting surface to use C6 birdcage mounts this allowed me to raise the motor and move it forward the required amount to clear the wiper motor. I tried to use all factory available parts where possible. Way more invested than I'll ever get back.
Regards:
Wiper motor was a challenge, I had to cut out all factory mounting points and rebuild mounting surface to use C6 birdcage mounts this allowed me to raise the motor and move it forward the required amount to clear the wiper motor. I tried to use all factory available parts where possible. Way more invested than I'll ever get back.
Regards:
Race Director
Joined: Sep 2001
Posts: 14,668
Likes: 749
From: NEwhere Ohio
great job. looks awesome!!
i did notice something...
did you get rid of the fuel line return? my 93 has a return on it.
i heard starting with later c5 corvettes, they went to returnless setups
i did notice something...
did you get rid of the fuel line return? my 93 has a return on it.
i heard starting with later c5 corvettes, they went to returnless setups
Last edited by dizwiz24; Feb 22, 2016 at 07:28 PM.
Racer
Joined: Apr 2010
Posts: 372
Likes: 23
From: Harper Woods MI
WVZR-1:
Wiper motor was a challenge, I had to cut out all factory mounting points and rebuild mounting surface to use C6 birdcage mounts this allowed me to raise the motor and move it forward the required amount to clear the wiper motor. I tried to use all factory available parts where possible. Way more invested than I'll ever get back.
Regards:
Wiper motor was a challenge, I had to cut out all factory mounting points and rebuild mounting surface to use C6 birdcage mounts this allowed me to raise the motor and move it forward the required amount to clear the wiper motor. I tried to use all factory available parts where possible. Way more invested than I'll ever get back.
Regards:
I love the clearance that you have on the passenger side.
I am in the process of planning my LS build right now. I'm looking to retain as much convenience comforts thou.
Nice build.
Thread Starter
5th Gear
Joined: May 2011
Posts: 5
Likes: 0
From: Vancleave Mississippi
dizwiz24:
The intake, injectors and throttlebody were takeoffs from a new C5/C6, they went to the returnless system by then. The intake is cathedral port so I believe it came off of an LS-6.
PEZTER22:
There was no clearance a the 6 & 8 plug positions, I have removed the heater box and associated parts with the intent of modifying the heater box to provide adequate clearance for maintenance. That and a custom breather/filter system is still on the drawing board.
The intake, injectors and throttlebody were takeoffs from a new C5/C6, they went to the returnless system by then. The intake is cathedral port so I believe it came off of an LS-6.
PEZTER22:
There was no clearance a the 6 & 8 plug positions, I have removed the heater box and associated parts with the intent of modifying the heater box to provide adequate clearance for maintenance. That and a custom breather/filter system is still on the drawing board.
Racer
Joined: Oct 2014
Posts: 323
Likes: 21
From: Apache Junction AZ
Hi Tinktoy,
That is an impressive fab/mod project. You just moved stuff out of the way or made your own spaces. It looks much more orderly in the engine bay. Great work!
I'll bet you have some serious coin in that machine!
Thanks for sharing,
WEK.
That is an impressive fab/mod project. You just moved stuff out of the way or made your own spaces. It looks much more orderly in the engine bay. Great work!
I'll bet you have some serious coin in that machine!
Thanks for sharing,
WEK.
Last edited by skullandbones; Feb 23, 2016 at 01:38 AM.
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Melting Slicks
Joined: Oct 2001
Posts: 2,315
Likes: 110
From: Brandon Fl
I'm using stock wiper motor in the stock location.
The return is in the fuel filter on C5's. I am going to convert mine to that set up one day.
I had the heater box in mine for a while after my swap. It all fits. It's tight but fits. I removed mine, I plan on using aftermarket air in the future.
Didn't mean to hijack just saw some questions I could answer.
I see you got rid of the heater box on the passenger side as well. Is there no heat or air conditioning? Was it too much of a hassle to have the heater box in the way?
I love the clearance that you have on the passenger side.
I am in the process of planning my LS build right now. I'm looking to retain as much convenience comforts thou.
Nice build.
I love the clearance that you have on the passenger side.
I am in the process of planning my LS build right now. I'm looking to retain as much convenience comforts thou.
Nice build.
Didn't mean to hijack just saw some questions I could answer.