Maximum RPM sorck 5.0 block can take?

[tjm73]

Anyone know the maximum rpm a stock 5.0 block can handle with a main girdle and 3.25 stroke crank in a N/A application? Could it live a resonably long life (say 40,000-50,000 miles) with frequent short blasts to say 6500 to maybe 7000 rpm?

We all know that 5.0 blocks tend to split if hp and rpm gets too high.

Block would be align honed, main grirdled, main studs, head studs. Internals would be precision ballenced.

If the 5.0 block can't take the rpm's, what year block could?

 

[90mustangGT]

I doubt RPM's would split the block. The vibrations and harmonics might though, so balance would have alot to do with this.

 

[MustangPunk302]

My 347 has 351 main studs (1/2"), a gridle, and screw in freeze plugs. Turns to 7,600 with no problems... yet... Though I'm not gonna be surprised when the mains decide they want the crank to take a hike. This is a nitrous fed stroker too.. I just hope I can salvage the internals if the **** does hit the fan.. Sorry I can't give you a exact hp/rpm limit...

 

[tjm73]

My 347 has 351 main studs (1/2"), a gridle, and screw in freeze plugs. Turns to 7,600 with no problems......Sorry I can't give you a exact hp/rpm limit...

No, don't appoligize....this is good info. I have a '90 5.0 block form my GT Mustang and I want to put a naturaly aspirated (no power adders) 331 together for a light weight street rod and I want to be able to spin it to about 7000 rpm max from time to time. I'll never be able to load the engine like a drag car. Ballence is the key IMO. That's why I want to make sure it's precision ballenced.

 

[04sleeper]

I had a stock block 306 built with a stock crank and reconditioned rods and TRW Forged pistons. It had a solid cam and I used to shift it from 6800-7000 RPM all the time. It made around 350 RWHP and had a 160 shot of nitrous on it and it never had a problem. I guess it depends on the builder. I had a good one. Heads By Rick in Hollywood FL.