Turbo 240 w/EFI

jdlaugh430

New member
Never satisfied with leaving well enough alone, I'm in the process of building a EFI turbo setup for my '65 Econoline pickup using the original 240ci engine. I've built and installed a MegaSquirt EFI system controlling a Chevy throttle body injection (TBI) setup. The turbo is hanging back by the transmission and hooks up to a custom exhaust using two rear EFI manifolds from a 90s F150 4.9. It's still a work in progress, but coming along nicely.

I'm still finishing up body work while slowly putting together the turbo setup, and still a few weeks away (at least) from getting it driveable. It's been an interesting challenge so far. I'm hopeful that 7-8 pounds of boost from the little Subaru WRX turbo will really wake up the 240 -- although it already ran fine on the old single barrel carb.

turbo_11.jpg


The turbo hangs back by the transmission and is supported by a fixed hanger attached to the transmission and a flexible hanger bolted to the bed floor. The tiny intercooler is horizontal to the air flow under the truck, and I'm not sure how much cooling it will provide, but probably better than nothing.

Right now the turbo is drawing air through a cone filter above the intercooler next to the bed floor. I'm still debating whether I should route a pipe to the front of the truck or just leave it there.

intake12.jpg


The intake pipe is routed between the headers. I plan to wrap the headers to help reduce heat in the engine compartment and also keep the intake air a little cooler.

intake10.jpg



I build a custom intake plenum to direct air into the TBI. It easily fits inside the engine compartment. My next step is to finish plumbing water and oil to the turbo and finally hook up the exhaust.
 
Very creative!
I looked at your posts on the Mega Squirt section. I like your approach to the whole project.
Keep us posted

What are you doing for oil return from the turbocharger to the oil pan?
By rights it should be gravity return using a large diameter line to the oil pan above the oil level in the pan.

You realize that once you get this tuned and running well, after a while you're going to start thinking about engine upgrades for more boost.
 
Oil to the turbo comes from a spin-on adapter sandwiched between the oil filter and block. I have a 1/2" drain pipe coming out of the bottom of the turbo to a scavenger pump that will push the oil back to a 1/2" fitting installed on the oil pan. Given the tight engine compartment, there was no way I could install the turbo in the normal manner with a drain back to the pan.

I see a few different paths to upgrade performance. I think the old 240 is stout enough to handle a fair amount of boost -- if I keep a careful eye on air/fuel ratio. Right now I'm aiming for 7-8 psi but the WRX turbo in stock form puts out 14 psi and can do a lot more. The WRX forums claim it can push their cars above 250 hp, but that's in a modern engine that flows a whole lot better than the 240.

Upgraded pistons and stronger valve springs would help the 240 handle more boost and higher rpms, but before I got that route I would be tempted to swap in a modern 300 ci engine, since it's a direct swap. One stumbling block is the amount of fuel I can flow through the TBI. With stock fuel pressure and injectors from a 350 ci Chevy, it's only good to a little over 200 hp. You can buy stronger springs for the FPR to boost fuel pressure to support more HP but I'm sure there's an upper limit for what's reasonable.

Of course, I could always build a custom multi-port fuel system and then the sky's the limit. But that's way down the road. 8)
 
You're the second person to suggest a fan. There's plenty of room and I already have to run power to the scavenger pump in the same general area so it would be fairly easy to do. Still, my initial thought is to fashion a scoop to direct air up thru the IC. My only concern would be how much road crap it would collect.
 
Megasquirt does provide the option to control a fan based on boost level, so definitely something to consider...
 
I mounted the heat exchanger for my water-to-air intercooler under the body of my Tahoe. I had 2 electric fans mounted underneath it that ran continuously. I didn't have any temp sensors mounted to see how well it was cooling the water (green antifreeze), but I had a general feeling that it just worked "ok". I have since moved the heat exchanger to my front bumper. One of the fans only lasted 1 year, but I daily drive mine, which includes snowy roads with salt on them, so that didn't help. I'm guessing in Oklahoma you'd be ok, but I just thought I'd share my experience. Neat project.
 
I have been watching your build for a while. Thanks for sharing. Do you plan on using the bed of you truck as a bed of a truck because it looks like a great place to put a turbo,inter cooler, and oil return lines.
 
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