Can I use regular stock head bolts with the washers for the 1/2 in holes to put AFR185 heads on an old 302 or are longer bolts and such required.
Can I use regular stock head bolts with the washers for the 1/2 in holes to put AFR185 heads on an old 302 or are longer bolts and such required.
Only the modular engines use stretch to yield bolts. I have the factory 89 Mustang Service Manual and it gives torque values and not degrees of turn. Stock bolts may be reused, there is no mention needing to replace the bolts after they have been used. Stock bolts are tightened in 2 steps using the pattern given in the Service manual. 1st pass =55-65 ft/lb, 2nd pass =65-72 ft/lb. Use antiseize under the heads of all bolts and on the threads of the long bolts. The short bolts get the threads coated with Teflon pipe dope or ARP PTFE Sealers 100-9904.Don't use the stock head bolts RD. Unlike the old bolts from the 70s engines, these are torque to yield bolts.. meaning they stretch. They will fit with the washers, but will give you problems. 1st hand experience talking here. Go ahead and pop for ARP bolts or studs.
There is a lot of debate on when Ford actually started using TTY bolts in the 302 OHV. I have personally had half a dozen or more mid/late-80's and earyl-90's HO and non HO 5.0L's apart that were equipped with standard head bolts.....NOT torque to yield. This leads me to believe that the head bolts may have changed somewhere around the mid-90's with the SN95 cars? TTY bolts can generally be identified by its use of a narrow shank. Standard bolts are as beefy, or beefier throughout the shank section than the threaded section. In the case of the RE-use of a standard style bolt, I would not and have not hesitated to use them multiple times on stock rebuilds and have never....EVER had a single issue. However....for a set of high dollar aluminum heads, with added compression, that may see elevated cylinder pressure/temps due to the use of a power adder, the piece of mind associated with spending any extra $50-$100 on a set of ARP fasters can be worth their replacement cost alone.
That being said, I did managed to twist off an ARP bolt inside my current block at the recommended torque after a single reuse. Thankfully, I was able to remove it in one piece....the two halves being held together by a spaghetti strand size sliver of metal. The threads were chased with a tap prior to reassembly and the recommended thread lube was used....it was simply just a defective bolt. So be aware...it can happen to fancy aftermarket bolts, just like the stockers.
Now I am not doubting your experience and your knowledge, but my ford assembly manuel for my 89 gt says the head bolts are torque to yield and are not reuseable. Thats head bolts right?
And in your opinion are studs overkill for na setups?
You'll notice though....that engine was a 1995 production engine....which falls right into the theory that Ford went TTY at some point during the switch to the SN95 redesign.Here's a Ford Racing oem long block spec sheet. Go down to torque specs and look at head bolts. Torque to yield.
https://www.manualslib.com/manual/53134/Ford-M-6007-F50.html?page=2
@Gearbanger 101 @jrichker
Now, again.. I've read lots of conflicting info on whether this is fact or fiction.. but there is this and other Ford documents I've seen. I realize this is for a crate engine, but I've seen other Ford repair manual docs that say not to reuse those headbolts, they are indeed tty. I've also disassembled numerous engines to find headbolts with stretched threads... So it remains to be kind of like bigfoot. A few photos and 1st hand sightings with statements noone believes.
Funny thing is....Grandma's Lincoln, Grandpa's F150, Cousin Eds Econoline, or Joe Blow's fox body. It's all the same engine. Like I said. Aluminum heads or something with a little cylinder pressure behind them would most certainly get new fasteners, but for your average iron head stocker's/GT40/GT40P's, etc....if the stock bolts were in good shape and standard fashion, they'd be going right back in. Its really not a case of saving a few bucks for me. I wouldn't change the stock non torque to yield head bolts to new ones, for the same reason I wouldn't change valve cover bolts, or timing cover bolts if they were still in good shape. It just isn't necessary.considering all of us are not building stock engines for the most part, I think the debate is rather moot. Wouldn't catch me reusing stock head bolts regardless. Maybe if you are rebuilding Grandma's 88 Lincoln I'd take the chance, but probably not because of fear they stretched.
I think it is just good insurance to upgrade. 40 year old bolts with 100's of thousands of heat cycles and millions of combustion cycles....I think they have earned their retirement.
Joe
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