Max boost for stock 5.0

[wpurple]

What is the max boost that you can safely run and still get decent longevity out of the motor?

Was thinking of upgrading my BD-11 to the new gear driven one and going from 6psi to 9 or 10 psi....

comments?

 

[Cobraguy]

A lot of things come into play with boost. But in a general sense, 6 psi is all you want to go on a stock engine...especially with stock compression. That's if you want a safe, long lasting engine. I don't think 10 psi is advisable without a purpose built short block. It will live at 10 psi...just not a long time and you could easily run into detonation problems with stock compression.

 

[Expl0ring]

A lot of things come into play with boost. But in a general sense, 6 psi is all you want to go on a stock engine...especially with stock compression. That's if you want a safe, long lasting engine. I don't think 10 psi is advisable without a purpose built short block. It will live at 10 psi...just not a long time and you could easily run into detonation problems with stock compression.

Incorrect. In something such as an explorer, you can run 10psi with ease, i know many people that are running 10psi+ and around 550rwhp with a stock block 5.0 in their foxs (mustangs) as long as you have a good tune, and keep the revs down (easy in an explorer) it COULD last for years and years...

but then again, ive also seen stock blocks crack at 230rwhp... so its just luck of the draw i guess.

but i think with a good tune, 10psi is pretty safe on a stock block 5.0.

 

[Spdrcer34]

Some 5.0L that were installed into Mustangs/MkVII had Forged Pistons in stock form. The Explorers DID NOT have forged pistons. All things being equal, a motor with Forged Pistons CAN live longer under boost vs. the cast/hyper. pistons.

A good tune, good intercooler, good headgaskets, and high octane fuel.

Ryan

 

[Cobraguy]

Some 5.0L that were installed into Mustangs/MkVII had Forged Pistons in stock form. The Explorers DID NOT have forged pistons. All things being equal, a motor with Forged Pistons CAN live longer under boost vs. the cast/hyper. pistons.

A good tune, good intercooler, good headgaskets, and high octane fuel.

Ryan

You are correct. And that makes a huge difference. I guess Exploring and I will have to agree to disagree on this one. I know I wouldn't run my Explorer at 10 psi. Not on a stock engine. If there are Explorers getting away with that, then more power to them.

 

[Expl0ring]

Well, i know a few guys with 5.0 explorers with forged pistons, i believe from 87-92? mustangs came with forged pistons and beginning in 93 they started using hyper pistons, which yes you are correct, i was under the impression that SOME explorer motors (older ones) came factory with forged pistons/internals also.

Maybe im wrong?

 

[Silver X]

I'm running 15psi in my Mustang on a stock '93 shortblock. It has Edelbrock heads/intake and F303 cam too. It lasted for about a year at 15psi, but recently started losing coolant and dripping a bunch of oil when parked. I'm hoping it is just a head gasket. After the engine gets a rebuild, the boost will be dropped down to 9 or 10 psi to last a little longer.

I wish I could've swapped a turbo 5.0 into my Explorer when I replaced the 4.0, but the wife wasn't going for it.

 

[htrdlncn]

86-92 LSCs and I think 85-92 Mustangs all had the forged pistons,
you will lift the heads and can crack the block before you would ever
have to worry about pistons, all the other 5.0s came with the Hyperpathetics
which will live under low to moderate boost for a while but sooner or later they will go.
Some 93 Mustangs did end up with leftover 92 engines so its a crap shoot what is in it..

 

[99SportX]

If there are Explorers getting away with that, then more power to them.

lol, literally.

 

[jah81592]

What is the max boost that you can safely run and still get decent longevity out of the motor?

Was thinking of upgrading my BD-11 to the new gear driven one and going from 6psi to 9 or 10 psi....

comments?

8-10 psi on a bone stock engine. I have tuned a few which have seen 14# boost. I haven't heard of any engine failures (you know I would be the 1st if it were to happen). But my recommendation was 10# max.-j

 

[Cobraguy]

8-10 psi on a bone stock engine. I have tuned a few which have seen 14# boost. I haven't heard of any engine failures (you know I would be the 1st if it were to happen). But my recommendation was 10# max.-j

I would contact Jeff Smith and ask him what happens at 10 psi on hypereutectic pistons.

Ask most blower manufacturers what they recommend on this stock short block. I haven't seen a single one over 6 psi...positive displacement or centrifugal.

14 psi on a stock Explorer short block is insane. But if you have more money than sense, then it will be fun while it lasts!