LS1 Swap
#1
LS1 Swap
After the original 5sp transmission shelled (rear countershaft bearing) in my '88 ExraCab, I swapped in a TBI 4.3 with a 700R4, although I really wanted a V8. So with that engine worn out, I decided on something radical. The engine is an earlier model LS1 out of a Corvette that will adapt to my existing 700R4, which has had all the internal weak links addressed. I'm running the Painless EMC for control.
The first step was to address the problem of access
My solution was to modify the front clip into a tilting, removable unit. Seemed easy enough...
The engine
Now before everyone goes off on me about the axles and T-case, I say SPARE ME! I'm not new at this. Please leave the space for constructive comments. Thanks.
The first step was to address the problem of access
My solution was to modify the front clip into a tilting, removable unit. Seemed easy enough...
The engine
Now before everyone goes off on me about the axles and T-case, I say SPARE ME! I'm not new at this. Please leave the space for constructive comments. Thanks.
Last edited by 88ECToy; 04-08-2015 at 08:26 PM.
#2
Registered User
Umm... Could we convince you to post more pics of the modifications for the tilting front clip?? A lot of us doing other exotic swaps would probably love to consider the idea.
Oh, and I can't wait to see the LS1 nestled comfortably into yer truck. (sub'd)
Oh, and I can't wait to see the LS1 nestled comfortably into yer truck. (sub'd)
Last edited by technojunkie; 11-12-2012 at 10:15 AM.
#3
#4
I'll do the best I can as the box with the best pictures is having serious issues (anyone know how to reload XP without losing saved photos?) and I don't have much on this one.
The bumper is a Reunel that was custom built for this truck. These things are massive from the factory, way overdone for this application. I trimmed what I thought I could get away with without sacrificing strength. The supplied mount brackets were built with the same vigor as the bumper itself.
I welded the brackets to the frame then cut away enough to allow the bumper to pivot about the lower mount bolt
With the bumper remounted, up stops and down stops were located and welded
...then tested
The bumper is a Reunel that was custom built for this truck. These things are massive from the factory, way overdone for this application. I trimmed what I thought I could get away with without sacrificing strength. The supplied mount brackets were built with the same vigor as the bumper itself.
I welded the brackets to the frame then cut away enough to allow the bumper to pivot about the lower mount bolt
With the bumper remounted, up stops and down stops were located and welded
...then tested
#5
The engine bay was gutted of everything not absolutely required. Anything that could be mounted somewhere else was removed. This is what made things difficult because now there is a ton of wasted space over and in front of the wheel wells as well as along the fire wall. This was also the time to map out the cut lines. No second chances here!
Before any cut was made and while the body was still bolted to the frame mounts, the bracing had to made and installed to prevent excessive distortion. I used angle and small tube in order to keep the weight down. The brace is bolted to the bumper, and welded to the tin everywhere I could (photos taken after the fact for the above mentioned reason). I haven't decided on how to secure the hood, whether to make it removable or welded down. There really is no reason to remove it from the clip once everything is done.
With the wheel wells sliced and the fwd frame mounts chopped off, the clip tilts very nicely and with the hood on, is balanced surprisingly well.
What's also nice is that the only indication of the mod is the short horizontal cut in the outside sheet metal behind the wheel cutout. I'll post details on that later.
Before any cut was made and while the body was still bolted to the frame mounts, the bracing had to made and installed to prevent excessive distortion. I used angle and small tube in order to keep the weight down. The brace is bolted to the bumper, and welded to the tin everywhere I could (photos taken after the fact for the above mentioned reason). I haven't decided on how to secure the hood, whether to make it removable or welded down. There really is no reason to remove it from the clip once everything is done.
With the wheel wells sliced and the fwd frame mounts chopped off, the clip tilts very nicely and with the hood on, is balanced surprisingly well.
What's also nice is that the only indication of the mod is the short horizontal cut in the outside sheet metal behind the wheel cutout. I'll post details on that later.
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#8
At first, it looked like I would be able to reuse the same mounts used on the 4.3 which also meant no changes to the cross member. Should have known.
Although the Corvette water pump/wheel combination is the shortest of the LSx group, it didn't take long to see the need to move the engine rearward as far as possible. So much for the easy mount up. Front mounts were fabricated from scratch, so was the crossmember (which needed done anyway). The radiator was situated as far forward as possible as well.
Back to the drawing board to figure out how to mount the radiator now located. Large trucks I've worked on have it bolted down near the base with support rods running from the top back to the firewall over the top of the engine. There wasn't room here for that, plus I didn't like the idea. I took a bunch of sheet aluminum, bent some up and made these laminated stays that bolted to 'T' patterned frame welded tabs.
It'll all be fine as long as this is enough radiator.
Another factor in dictating block position was the clearance between the P/S wheel and the pressure/return fittings on the steering box. Since neither could be feasibly relocated, I had to compromise.
Although the Corvette water pump/wheel combination is the shortest of the LSx group, it didn't take long to see the need to move the engine rearward as far as possible. So much for the easy mount up. Front mounts were fabricated from scratch, so was the crossmember (which needed done anyway). The radiator was situated as far forward as possible as well.
Back to the drawing board to figure out how to mount the radiator now located. Large trucks I've worked on have it bolted down near the base with support rods running from the top back to the firewall over the top of the engine. There wasn't room here for that, plus I didn't like the idea. I took a bunch of sheet aluminum, bent some up and made these laminated stays that bolted to 'T' patterned frame welded tabs.
It'll all be fine as long as this is enough radiator.
Another factor in dictating block position was the clearance between the P/S wheel and the pressure/return fittings on the steering box. Since neither could be feasibly relocated, I had to compromise.
Last edited by 88ECToy; 11-13-2012 at 07:00 AM.
#10
Registered User
my friends swap the rx7s (fc/fd) with ls1's and we also swapped a c30 rollback with an lq4. do you plan on using the drive by wire setup? they all used a throttle cable instead.
#12
Here's where the fun begins- making everything work.
Note in a previous pic how the thermostat housing nipple pointed fwd and outward, which wasn't going to work. The only space was straight down, so I made a clocking ring out 1/4 in. aluminum. I just happened to have the right hole saw to cut a groove for the O-ring. I then cut off the nipple and welded on a 120* tube. Combined with the 180, the hose now mates nicely to the radiator nip.
Note in a previous pic how the thermostat housing nipple pointed fwd and outward, which wasn't going to work. The only space was straight down, so I made a clocking ring out 1/4 in. aluminum. I just happened to have the right hole saw to cut a groove for the O-ring. I then cut off the nipple and welded on a 120* tube. Combined with the 180, the hose now mates nicely to the radiator nip.
Last edited by 88ECToy; 11-14-2012 at 01:05 PM.
#13
P/S Plumbing
The steering hydraulics took a lot of bending and flaring of the SS tubing for the 37* AN fittings used to tie it all together. I decided to cut and weld a 90* fitting to the steering box port that was closest to the pump wheel thinking I could gain some clearance. Now, I've always been careful not to consider or call myself a welder knowing full well the talent and skills possessed by REAL welders, but I can usually get the job done. Welding this fitting gave me fits, couldn't get good penetration on the housing until, by whatever magic world changing force that suddenly occurs out of nowhere, I realized the housing is cast. Duh! A little consultation with someone who actually knows and some preheating, it should be done. We'll see once the pressure os on.
The steering hydraulics took a lot of bending and flaring of the SS tubing for the 37* AN fittings used to tie it all together. I decided to cut and weld a 90* fitting to the steering box port that was closest to the pump wheel thinking I could gain some clearance. Now, I've always been careful not to consider or call myself a welder knowing full well the talent and skills possessed by REAL welders, but I can usually get the job done. Welding this fitting gave me fits, couldn't get good penetration on the housing until, by whatever magic world changing force that suddenly occurs out of nowhere, I realized the housing is cast. Duh! A little consultation with someone who actually knows and some preheating, it should be done. We'll see once the pressure os on.
#16
With the batteries no longer up front, the most logical new location was within the frame rails behind the cab. I also liked the idea of centralizing more mass for CG considerations. I tried to concoct some sort fancy slide-out tray for access, but am not smart enough to figure that out. So, I'll have to rely on a removable panel in the floor of the bed.
The fwd battery is the ship's, the rear one is dedicated to the winch.
That was also a good place to mount the trans fluid cooler, up and out of harm's way.
The fwd battery is the ship's, the rear one is dedicated to the winch.
That was also a good place to mount the trans fluid cooler, up and out of harm's way.
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stereoguy (11-11-2018)
#17
Once the chassis harness was made up, it had to be secured hugging the firewall so that the inner fender wouldn't hit when the hood was opened. In retrospect, I wish I'd made more room here. Live and learn.
Before final installation, the engine was dressed up, harness wrapped, routed and secured. There were a couple issues uncovered here that were easily resolved on the bench. Are we learning as we live?
I wanted to be able to disconnect the engine harness in order to be able to facilitate future engine removal and the answer was a pair of Weatherpack bulkhead connectors. Again, for clearance (uh!), they had to be recessed so that the harness could be secured tight against the firewall which really didn't turn out too bad.
Power from the front through the firewall and in from the battery to the cabin. Is this when we call in the professionals?
Before final installation, the engine was dressed up, harness wrapped, routed and secured. There were a couple issues uncovered here that were easily resolved on the bench. Are we learning as we live?
I wanted to be able to disconnect the engine harness in order to be able to facilitate future engine removal and the answer was a pair of Weatherpack bulkhead connectors. Again, for clearance (uh!), they had to be recessed so that the harness could be secured tight against the firewall which really didn't turn out too bad.
Power from the front through the firewall and in from the battery to the cabin. Is this when we call in the professionals?
#18
With all the known issues resolved, final installation can commence.
It was at about this time I was considering a removable tunnel, or at least a few access panels. Life would have been a lot easier when it came to fuel line clearances.
After several partial removes, I finally got everything situated. Engine in and bolted down.
It was at about this time I was considering a removable tunnel, or at least a few access panels. Life would have been a lot easier when it came to fuel line clearances.
After several partial removes, I finally got everything situated. Engine in and bolted down.