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Has anyone had any luck with building a .060 302? What issues have you had?

I recenly broke my 302. the block need to go out to .060 and im thinking about doing a 3.4 stroke and making it a 352.

Would it be a better idea to change blocks?

Keep in mind this will be a 500+ hp motor.
 

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I got a 30 over 302. If you plan on spending the money anyway useing that block be best to have it checked for the weak side of the cylinders and bore it on the strongest sides. Place a stud girdle on bottom end.

If you gona spend the money build a 351
 

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Have run a bunch of them at .060. Only one had a problem but it was turbocharged (24 psi) and was into detonation pretty hard before I could get out of it. Blew the cylinder wall out.
 

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I have a .060 over 302 in my F150. Flat tops, ported(by me) E7 heads, 268 hydraulic .480 lift cam. It runs great and on the low edge of normal temp all the time. The shop checked the block before boring to make sure it had enough material left.

I would not run a stroker with a .060 over stock 302 block.
 

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Mustang? You think as bottom end girdle serves no purpose?not cheap insurance when stroking a 302 to 347,
I know when we built my stroker the shop felt it was cheap insurance,
Just wondering what the general concencus is on Btoom end girdles with arp studs, to me its gotta help keep it together,no?
 

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There are several threads regarding girdles for stock SBF blocks if you want to get more background. While they are a good thing on some engines, they do not provide the stability desired on this block design. It has to do with the dynamics of the main caps and how they go out-of-round, pulling from the registers and both studs to one side. In the process, the stud on the side of the firing cylinder is pulled in towards the crank center-line, cracking the block from the edge of the stud hole in the main web and up through the cam bore. This results in the famous split 302 blocks. A girdle does not help to remove these forces, and some say actually makes it worse by allowing the second stud to pull harder on the first.

While I have not modeled all of the stresses, I followed some of the basic theory and it makes complete sense. This is why cross-bolts were added to hipo FE blocks - to prevent the caps from pulling away from the registers, and one of the reasons that keying the main caps can help. Also, the way the heads and intake are installed can reduce the lateral stresses and improve main web integrity. My belief is that fully and properly blueprinting the block to remove or reduce stress risers is more beneficial than any bolt-on fix. Blueprinting is very labor intensive and becoming a lost art - at least outside of serious racing circles.

David
 

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I just run ARP studs in mine and they have held up fine but I'm only making in the low 400 horsepower somewhere. I'm sure there is a breaking point somewhere with horsepower versus the stock block. I will also say that I run a 1972 302 block and not a later 5.0 block. I have heard/read that these are not as strong as the earlier blocks. Don't know if that is true or not.

The new coyote engine has cross bolted mains too and those things are tough.
 

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I;ve heard this early stronger than later too,
i used a 70;s 302 block as a 347 base, with roller cam,
builder led me to believe stud girdle ARP engine kit wouldn;t hurt, but was saying as PSIG alluded to the forces & how they affect the factory sm.block Ford. But, i did kinda glaze over when he got very technical!
Anyway, its done & made wonderful power from 2700 thru 6600rpm
but, i;ve mentioned here before, an annoying top end clatter that we couldn;t chase down, decided to pull her apart for a looksee.
On the good side, my youngest son, got hired by the builder because he is so busy, building Cascar mills,just pulling motors to pieces to start. My son handling her now to see whats up. Kinda cool calling my son to talk motors
 

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Has anyone had any luck with building a .060 302? What issues have you had?

I recenly broke my 302. the block need to go out to .060 and im thinking about doing a 3.4 stroke and making it a 352.

Would it be a better idea to change blocks?

Keep in mind this will be a 500+ hp motor.
I currently run a .060 over 289 block with a 289 crank. I'm also currently having another 289 block machined and taken .060 over if all checks out for a 302 I'm piecing together.

I would certainly sonic check to see if the cylinder walls are thick enough to go .060 over. I also have been told the early blocks will often be OK .060 over where the later thin wall casting 5.0L blocks will hardley ever have cylinder walls thick enough to go that big.

You're talking 500+ hp with a 347 stroker. I would certainly save up for a SHP block at that power level and while at it go 4.125 bore for a 363. The SHP block's bores will distort less and keep ring seal better which will be good for some power. The block is money well spent and going large bore is practically free.
 

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I use ARP studs and no girdle. I don't have money to throw away. Might be worth the dough if it makes you sleep better.
 

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... The SHP block's bores will distort less and keep ring seal better which will be good for some power. ...
This is the biggest reason to not go .060 on a stock block. Unless a block is picked with zero or slightly negative core shift, the higher pressures of making 500hp distort the thinner cylinder walls and ring sealing is compromised.

Ford Racing rates the stock 302/5.0 block at 400hp and (IIRC) 6500 rpm. They do not differentiate between the two. We all know you can get 500 out of a stock block NA when properly built, and 600 with 'soft' power like boost. RPM is what kills them at that power level, so if you're making that, keep the R's down for longevity, balance well, and tune fuel and spark like you have OCD. The way you know if you're pushing too far is 'cap fretting' or brinneling of the cap/block junction ("cap walk"), indicating the caps are distorting away from the registers and will eventually let go.

If it is street, there is less stress, as any dyno 500 will be 400+ with a decent filter, WP, mufflers, etc., and can live a long life. If going to the 500 range on the track NA, I'd consider going to a stock 351 block for a minimum 100+ extra capability and more power for the same money, or aftermarket for a 302-based engine.

David
 
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