I am using a 78 Windsor motor with a single T4 for my 75 Volvo, and am going to run the car full time on E85 using Megasquirt. I am starting to realize that even a small turbo can produce a serious amount of power and I am wondering what all this stock stuff is good for. The motor is 60 over, 9.6:1 compression with stock iron heads from a later motor (not GT40). I have it torn down to a short block, and it all looks like a very recent rebuild so I am using the rotating assembly as-is. Cam will be swapped to a turbo grind, and I'll be using mpfi. This motor will never go over 6000k rpm. It's a tractor motor for a tractor car.

So can I just let 'er rip on the T4 and let it boost as much as it can? Theoretically, it will run out of lungs before it splits the block in half. Will the pistons survive that kind of treatment? Is there enough detonation resistance baked in with e85 to let the boost ramp up in midrange before it falls off towards redline?

Thanks!

Aaron

 

500 hp is about the limit of the stock 302 block. Some have used the limits without hand grenading the block while some people broke them at less than 500hp. If your dissapointed & want a stock Ford engine you should look into a 351W you should be good to about 650hp

 

I have heard the 500hp cap on the block, is the stock rotating assembly up to that level too? I guess my disbelief comes from working with imports. With honda engines you get formulas for boost. At 8psi you get rods, at 12psi you need head studs, etc, etc. It seems like the v8 handles the cylinder pressure better as long as it doesn't spin too fast. I'm just surprised 78 truck rods and pistons with do 500hp, alky or not.

My turbo is so small I am not worried too much about overpowering the block just yet. This is going in a 2800lb car, so it should be pretty lively even at 400rwhp. I just don't know if I need to restrict the boost at all, or if I can just let it boost unrestricted (still with wastegates to relieve exhaust pressure, but with the 'max psi' set so high it's irrelevant)

 

Umm, what turbo now? T4 is hardly exact.

And whatever it is, set the gate to around 8psi and work it up from there, slowly.

 

I haven't bought the turbo yet. It's the easiest part to acquire, so I am trying to nail down the specs first. I know I can't just weld it all up and hit go, but knowing what pressure ratios I am shooting for will help me pick the specs for the turbo. Budget favors an HX40 or Powerstroke if it will fit the bill.

The gasoline builds seem to stick to around 11-12psi, maybe a hair more with a good tune. The limiting factor seems to be knock and I am anticipating more overhead in that department with alcohol. If I can let the boost rise to 16-17psi those diesel turbos look more attractive. If I can't run so much boost, I would rather skew small on the turbo size to favor spool.

 

Factory iron heads don't have a thick deck surface & have a problem with lift which leads to blowing head gaskets.aluminum heads cure the problem. The block is still the problem when pushed past the limit they crack down the middle

 

https://www.theturboforums.com/threads/358359-1980-Notch-351-S480-8-11-13-9-73-140/page7

post #131 stock block and factory gt40 heads.

Then jump to the end and see how fast with stock bottom end. Has to be tuned right.

 

^... Stock windsors will last an extremely long time with a good tune especially on E85 like above. It doesn't detonate like regular fuel which is reason a lot of people are taking stock parts far these days. If you keep it below 6K, I would say 700HP would not be an issue for a long time. We took a stock 351W out of a van with crappy heads and hit it will a 200 shot for a couple years... Motor still is together even after blowing an intake off it after the ignition box freeze. Goes low 10s like clock work and he drives it everywhere.

 

With E85 and the engine tuned correctly will get you very decent power. The E85 will also run your engine much cooler.

Start with a safe timing tune and add boost 1-2 psi at a time. Keep an eye on your A/F and read your plugs. I run E85 with no intercooler and the car stays under 190 on the temps.