Ford 5.0 help

[David_Ingermann]

does anyone know how much boost/power is safe to run on a stock 5.0 and C-4? I've looked all over and found 100 different answers. I want to run 600hp or so from a 66mm BorgWarner turbo. what modifications would you guys recommend on a boosted car? I've already got new cylinder heads and a roller cam along with new intake and carb. motor should be running around 400 hp currently. I don't know how feasible it is but i'd also like to put in a valve in the duct work to enable and disable the turbo's boost, ideas? So, How much psi is too much and what should I do to reinforce the engine? Car would be street use only.

Opinions much appreciated!

[Boydster]

From what I've seen and read, 500hp is about the limit for the factory 5.0 block. If you want to go higher than that, an aftermarket block with siamese cylinders and 4 bolt mains is strongly suggested.

[edwardb]

You're right. You will get 100 different answers because there are no absolutes and there are so many different experiences. Guys split them open at relatively low numbers. Others beat on them at high numbers and get away with it. My engine builder says anything north of 400 hp is at risk. Obviously the risk is much lower there, but keep going up and the risk gets higher. Personally, I think 600 HP is really stretching your luck. But you'll have lots of people say they haven't had any trouble at that power. There are various girdles and such that are supposed to add strength and may help some. But when they go, they usually split open like an egg right through the lifter valleys. Not too much going to prevent that. Keep in mind the engine was originally designed for 225 hp. For what you're describing, I'd be looking at an aftermarket block like a Dart. But not cheap I realize.

[carbon fiber]

Skip trying to beef up the 302 block. The easiest/cheapest solution to me would be to find a 4bolt main 351w (the 2bolt main 351w is way stronger than the 302 also) and build the shortblock to use with the rest of your parts. (way cheaper than a Dart block) I'd also go with fuel injection over the carb with a turbo. You'll get better performance and gas mileage. Sell your intake/carb to help pay for the other parts. JMHO.

[Bob Cowan]

600hp in a street car will last a long time because you'll rarely ever see the top numbers. In a road race or drag race car, it won't last long at because you're making 500hp lap after lap, pass after pass.

If your plan is to make 600 safe HP, skip the stock block. Spend the money on a Dart block and be done with it. There are places to save money, and this isn't one of them.

I also agree that you should seriously consider EFI.

[rich grsc]

Easy answer, keep upping the boost till it blows, then back it off a couple #

[MPTech]

600hp with a stock block?
this will be your final upgrade:
https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcTBz0IUJSvfYThE2hpOowIb_YVM_Xj3T iYOzSqlXeqINZ8Q0he0

If I were shooting for that kind of hp, I'd strongly consider starting with a 4-bolt main 351W. Easier to get to that level and much stronger (more torque too!)

[cgundermann]

EFI and on a stock 5.0 (original 225 horse) - boosted to 450-500 horses for street driving. That's crazy power for a 2200+ pound car. Truly want to go big for bragging rights to push 600 horses - Dart or 351 block...

[CraigS]

To add a point of reference. A few years ago I was rebuilding my 351 and talked to Scat about cranks and their cast steel vs their forged. He said their cast steel plain jane, standard issue crank is good for 700 HP. I agree w/ others who recommend a 351. As standard equipment you get rod bolts, main cap bolts, and head bolts one size larger than a 302. Also you can easily go to 408 CID w/ a stock block. What's not to like.

[carbon fiber]

I agree w/ others who recommend a 351. As standard equipment you get rod bolts, main cap bolts, and head bolts one size larger than a 302.

Not to mention the taller deck height, that adds a lot of strength too.

[edwardb]

To add a point of reference. A few years ago I was rebuilding my 351 and talked to Scat about cranks and their cast steel vs their forged. He said their cast steel plain jane, standard issue crank is good for 700 HP. I agree w/ others who recommend a 351. As standard equipment you get rod bolts, main cap bolts, and head bolts one size larger than a 302. Also you can easily go to 408 CID w/ a stock block. What's not to like.


Not to mention the taller deck height, that adds a lot of strength too.

The taller deck height also makes plug and header access really tight. There are footbox mods to make it easier, or just live with it. There also also some limits on induction due to the reduced available space. Guy's have managed with thinner or dropped base air filters, but is a consideration. And then there's the whole 3 inch main discussion. Probably not a concern for street driving, but the performance guys reduce them. All to say every engine has pluses and minuses. And the OP did ask about a 5.0.

[skullandbones]

Hi David,

It would serve you well to read a book about turbo powered engines. I started with "Maximum Boost". I was told it is one of the best about the subject. If you have a stock 5.0 which I assumed from your post, then you are starting wrong. If the compression ratio of your engine is around 9.5 or 10 to 1 you can only run about 5 or 6 psi safely (not going to give you nearly 600hp). You should be starting out with about 8.5 to 1 which would mean short block modification. BTW: if I'm not mistaken all turbo systems run "waste gates" if you didn't have one, it would be very unsafe besides the mechanical damage that would most likely happen (boom!). Your best bet is to run a Dart block if it is 302 based with the correct pistons for compression ratio. If you run a 351W block you can probably get by but still need the right compression ratio. Match the turbo to your particular displacement. If you don't, it's probably going to mean some behavior like turbo lag that will mean undesirable performance. I would not want to drive a light, short wheel based car like the roadster with an unmanageable engine such as one with serious turbo lag. Many have stated to have the roadster pointed in the right direction before you hit the throttle. It's hard enough to keep it that way than if you start off in the wrong direction trying to correct it (waiting for the boost to hit). Look on U tube if you want to see turbo lag disasters.

Not wanting to ran on your parade but don't start your project with the stated goal based on a stock 5.0.

Good luck,

WEK.