l35 engine swap???

[lil red s-10]

engine in my sy is slowly being built and i mean slowly...

have a good opportunity to puck up a cpi injection engine out of a early 90s astro for next to nothing

i know the mains are different from the stock engine (wont be as strong) and these had l35 heads according to the casting number (14099064) but was thinking about picking it up while i slowly build the stock engine just to get the truck back on the road so it isnt taking up my 3 car garage any longer than need be. obviously would do a turbo tweak chip and fuel system.

any reason that this engine wouldn't work?

 

[atomicmecha]

Re: l35 engine swap???

You'll need to change 3 things. First, the pistons. You'll need to get different pistons to lower the compression so it wont pop under boost. Next you'll need the intake from another truck. That CPI intake wont work with the turbo without making some custom piping. And definitely wont work with the stock intercooler. The only other thing is that you'll need to tap the block and oil pan for the coolant and oil feed and returns for the turbo.

 

[lil red s-10]

Re: l35 engine swap???

didnt think about compression ratios... well this would be pointless the stock engine was removed because of cracked pistons........

any way possible to tune it for lower boost like 8 psi max?

 

[Static]

Re: l35 engine swap???

Should be able to be done with the higher CR, others have. It will all be in how well you tune the TT chip. Swap in the intake and pan from the old motor. You can run the vac line of the wastegate to the turbo to get base boost of 8psi.

 

[dgoodhue]

Re: l35 engine swap???

I have a stock 03 Vortec short block in my Syclone. So here is my :2cents:

They changed a few things between 92-95 L35 Balance Shaft motors. You can search for the Holy Grail of 4.3 information for the changes to the balance shaft blocks. 95 BS motors seem messy to me and unclear if the stock syty oil pan will work the different timing covers.

You should be able to use your SyTy oil pan for oil return (unless their is some timing cover change issues). You probably need to swap the oil pick up since its a astrovan. The block should be already tapped for the oil lines and the coolant return. The knock sensor may not be the right thread size, but it could be just a bolt on affair as well.

I am not sure if the Turbotweak chip has the flexibility to adjust for the L35 motor. The TT chip might be able to compensate, but I have no experience with it. I use code $59 to tune and initially found my engine ran pretty lean at higher rpm with base files. You need to be looking at your ecm through scan tool with datalogging. If you just bolt it in and expect the TT chip just be plugged in without adjusting the settings it will likely quickly become another blown motor that is a waste of time and money.

The L35 cam is pretty aggressive for a stock cam. Most of the hp gains from the LB4 to L35 is from the cam. I think the compression ratio is advertised as 9.0:1. 11 psi is approximately similar cylinder pressures that the stock motor is seeing with stock boost. I run alky now but initially was able to run 13psi on pump gas and I didn't fully dial my tune in. I do have Vortec heads, so they are suppose to be less detonation prone. My motor has 7000 miles since the swap and I have been regularly running 14-15psi and I have had my engine run 17psi for a short periods. My Syclone will run mid 11's on lower boost. IMO The balance shaft motors are not as fragile as some have claimed over the years. As long the ecm is tuned for the motor it should be fine short term.

 

[lil red s-10]

Re: l35 engine swap???

Thanks after I posted my first reply I did some decent amount of digging and I believe this is what I am going to do I might call TT and shoot them this idea and see what he says about getting a chip for it

 

[lil red s-10]

Re: l35 engine swap???

Could I move the knock sensor to a different location for ease of access? That are kinda a pain to get to just thinking out loud here

 

[dgoodhue]

Re: l35 engine swap???

Could I move the knock sensor to a different location for ease of access? That are kinda a pain to get to just thinking out loud here

I move mine to the front of the intake but it does desensitize it a little. When was having knock problems it seem to delay the knock retard by about 1/2 sec on the datalogs.

 

[Static]

Re: l35 engine swap???

I moved mine to the front of the intake. Mine actually quit working and started throwing a code. I recommend using a GM sensor. You will need to drill and tap the existing bolt hole. Left my existing sensor in place plugged in but disconnected it from the ecm, and ran a new wire from a junk harness I had. Didn't feel like cutting my harness.

 

[dgoodhue]

Re: l35 engine swap???

My knock sensor is in the same place. I have an adapter that a friend made, so the adapter screws into the intake and the knock sensor screws into the adapter. I made a harness so I didn't have to cut my factory harness as well.