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Discussion Starter #1
I have an 86 gt with a 93 cobra block in it. the motor was rebiult about 8 months ago and i just turned 13,000 miles and the crankshaft broke in half right behind cylinder 2. idling down a hill in a neighborhood. I came to find out the timing was advanced 12 degrees when it should have been retarded 9 degrees. I know detonation was my problem and i was hitting a feul cut. The block is 30 over with stock rods and 10 or 10.5 to 1 flat top pistons with 2 valve relifs. It has a double roller timing setup with an e303 cam. Stock cobra upper and lower intake and gt 40 heads. Im looking at going with a scat low compression 347 strokerker or just putting it back together with a new stock crank. the main thing im curious on is how much horsepower will a stock uncut crank hold? Will a stock crank hold up on 10 pounds of boost with a safe tune?
 
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I would not be to concerned about the crank & rods.....

The block will crack first......
 

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Go with forged rods and pistons, if you do nothing else.

And have the block checked. It might have problems, too.
 

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i have 87 with 93 cobra engine running gt40 heads e303 cam bbk headers with vortech v1 at 10pds and have had no problems.:bigthumbsup
 

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The stock bottom end has a bad rap it doesn't deserve. The block will break before the stock rods and pistons will.
 

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Discussion Starter #6
Yeah i know about the blocks and how cheesy they are. i think the preblem i had was the crank being cut 10/10 and by looking closely at it it had been cracked a long time you can see discoloration around the crack from where oil had been running up inside. or it got dropped which i wouldnt doubt either. the car barely ever sees boost and when it does it may be 4 pounds. SO i think im gone get a new crank and let it ride.
 

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That's a good idea, that crank isn't any good anymore.
 

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Discussion Starter #8
that crank is definitely not any good anymore its a real nice trophy though .
 

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??

The stock bottom end has a bad rap it doesn't deserve. The block will break before the stock rods and pistons will.
I don't know Eagle? From what the Thread starter said it seems the pistons aren't stock? If they are I'd be concerned running them with a 10lb Vortech, in 93 Ford switched from Forged to the Hypers!!
I knew a few guys back in the day that melted and put holes in their stock 93 pistons running High boost and squeeze!!
 

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I have an 86 gt with a 93 cobra block in it. the motor was rebiult about 8 months ago and i just turned 13,000 miles and the crankshaft broke in half right behind cylinder 2. idling down a hill in a neighborhood. I came to find out the timing was advanced 12 degrees when it should have been retarded 9 degrees. I know detonation was my problem and i was hitting a feul cut. The block is 30 over with stock rods and 10 or 10.5 to 1 flat top pistons with 2 valve relifs. It has a double roller timing setup with an e303 cam. Stock cobra upper and lower intake and gt 40 heads. Im looking at going with a scat low compression 347 strokerker or just putting it back together with a new stock crank. the main thing im curious on is how much horsepower will a stock uncut crank hold? Will a stock crank hold up on 10 pounds of boost with a safe tune?

why would you need to have your timing retarded so much?
 

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Discussion Starter #11
they aren't stock pistons they are forged 30 over flat tops with 2 valve relifs. The timing retarted so much.. its a 10-12 pulley 9 degrees is usually the number that does the trick on most cars ive seen with that setup. the main thing im trying to steer away from is pre detonation. the dyno shall determine where the timing needs to be to be most efficient. Anyone of you guys know where i can find a set of #42 or larger injectors for under $400? I have a good set of used #30 ford racing with 13,000 miles on them i could possibly trade and give some cash..:hihi:
 

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I put 8-10psi on my stock 91 GT no problems, but I have a retard control to 15 degrees. The internals will handle about 500HP. DB performance claims that they put 25psi and 786HP to a stock block with different head gaskets and a proper tune, they didn't blow the motor!!
 

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I put 8-10psi on my stock 91 GT no problems, but I have a retard control to 15 degrees. The internals will handle about 500HP. DB performance claims that they put 25psi and 786HP to a stock block with different head gaskets and a proper tune, they didn't blow the motor!!
That's because you have a 91 with better Forged pistons!
And Thread starter Ford Racing 42lb injectors can be had for about $200, you just gotta look in some of the Forum classifieds!
 

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Discussion Starter #14
25psi .. i'd be scared to put that on a fully studded and fully forged 347 stroker regaurdless of the tune. I dont see how the block didnt come apart.

Thanks i will look into the classifieds and see what i can come up with.
 

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:bigthumbsupI am running 11 Psi on my 93 Cobra . Havent had any problems block or internals related......just blew head gaskets....that caused me all sorts of other problems....and my motor is stock...aside from injectors and mass air.....good luck
 
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