is this true about BLOCK STRENGTH

[deadly97snake]

i have a 91 gt 5.0. it has 100k miles on it. i was looking to replace the block and build a motor because i was thinking the block was old and couldnt handle any mods.

well, i was just talking to an engine builder, and he said that miles dont weaken a block. rpm's do. he said, not matter what mod you do, if you dont over rev the rpm's the block should last. haveing 100k miles on it shouldnt mean a thing

anyone else agree,disagree?

oh by the way, i was planning on doing e trick flow top end kit with a blower in the future

 

[cbr repsol]

I wouldnt worrie about it. Your block will be fine.

 

[deadly97snake]

wow. thanks for reassuring me. this saves me a lot of money for now. i figured ill have some fun and when it blows up if it does, i'll worry about it then lol

 

[cbr repsol]

I have a 351w Im putting together right now. it from 1969 and Ive abused the crap out of it and its fine. Its going to swallow a 3.85 stroker crank this week when I assemble it to be a 393 cubic inch torque monster.

If you are going to rev it alot and beat on her install a main girdle for added insurance on your rebuild. You can get them from probe industries or d.s.s.
It helps keep the main caps in place at high r.p.m.

the 5.0 is a true legend its been around forever almost. If you build a stroker go with the 331 rather than the 347. The 331 is more reliable I feel and will do you better on the street. The wrist pin on the 347 goes into the oil ring . the skirts are really short, putting alot of side load on the pistion with that stroke crank.

 

[ford_racer]

Add a 500 shot of nitrous to your block and spray at 1500 and see if your engine builder was correct.

 

[97WHITEVENOM]

i have a 91 gt 5.0. it has 100k miles on it. i was looking to replace the block and build a motor because i was thinking the block was old and couldnt handle any mods.

well, i was just talking to an engine builder, and he said that miles dont weaken a block. rpm's do. he said, not matter what mod you do, if you dont over rev the rpm's the block should last. haveing 100k miles on it shouldnt mean a thing

anyone else agree,disagree?

oh by the way, i was planning on doing e trick flow top end kit with a blower in the future

I answered you on listangs

 

[Got Boost?]

Generally speaking, a block itself will not gain all that much wear from miles. Bearings do. Your engine builder is definitely right about RPM's killing blocks. Generally, a 550rwhp blown HCI motor shifting at 6,000, would last longer than a 450rwhp NA 347 spinning to 7,500. RPM and the tune dictate how "reliable" a certain combination will be - more so than the power that combo makes itself, to a certain extent.

 

[cbr repsol]

Most poeple will never need a aftermarket block on a street car . I think a 302 will be just fine at 500rwhp. anymore than that I would get a dart block or the new boss. But then I wouldnt be such a small motor I would stroke it to a 427 or 460 with a centrifical blower, power here we come.

 

[deadly97snake]

what about the internals. pistons,rods,crank? do you think i can still rely on them with 100k miles on them?

 

[cbr repsol]

The trick flow heads are good but I like air flow reserch heads alot better. be prepared to spent about 2k on some cnc ported ones.

 

[cbr repsol]

what about the internals. pistons,rods,crank? do you think i can still rely on them with 100k miles on them?

Pistions are garbage, rods are ok with arp bolts, crank will be fine just get it machined. for a naturally asperated combo 400 to 450 hp.


For the blower you are planing on its a big no no. you will need forged pistion,forged crank and some quality forged rods H beam I prefer. You also have to have a lower compression ratio for the blower,like 8.5 to 1 or 9 to 1 .
I like probe industries you can get a quality short block kit for 1500 to 2 k if u put it together yourself. If u go with a stroker keep in mind you will have to clearance the block otherwise the rod bolts will smack the bottom of the cylinders. IF u have other questions I can point u the right way let me know Ive been working on pushrod ford motors for a long time.

 

[Venomous98Cobra]

Overheating kills blocks...not mileage.

 

[BuckChoklit]

A block with miles on it is called "seasoned" and is more desirable to some engine builders than brand new blocks.

 

[97WHITEVENOM]

OP actually means shortblock

 

[canibus]

i'd say take his word for it.

 

[youngone]

A lot of things play a role in destroying a block
Tune
RPM
internal weight
who built the motor
motor mounts? or front/midplate?
is the block in good shape to begin with?


A 91 comes from the factory with forged internals that will take a beating and last longer than the block. I wouldnt worry about it, do the top end and S/C and have fun.

 

[mustangless]

Don't spend money to build the stock block.

The Turbo Forums.com

The block usually gives before anything else.

 

[LSUstang05]

A block with miles on it is called "seasoned" and is more desirable to some engine builders than brand new blocks.

This man speaks the truth. Don't need a new block, just put new internals in it, lower the compression for the blower, and be on your merry way :beer:

 

[50 Proof]

lol who here builds a supercharged stroker just to not rev the piss out of it? I've always read that anything over 500hp puts you on borrowed time. Don't get too greedy with the power and the revs. But then again what's the point if you can't rev it? For what it'll cost to build a supercharged stroker, is a new boss 302 block really going to set you back that much?

 

[fiveohhhstang]

Eh, I don't trust anyone's opinon about that kind of stuff except my dad's.

100k is nothing, btw, it should be fine.