Reusing head bolts.

T

Terranova

Senior Member
I have a 49-53 engine that I want to open up to check what condition my condition is in. Do I need to replace the head bolts or can I reuse what I have, assuming (naively) that they all come out ok. If I replace them, should I do bolts or studs?



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For anything but a high performance build, I agree with "jetmek" about avoiding studs. This is in addition to financial considerations. As to the existing bolts, clean 'em up and check them out for obvious problems, and re-use them. I'm sure I have some bolts that have been used 5 or 6 times in my engines and I have never had a problem.

Take a little care in removing them. Hit 'em with some penetrant and let 'em sit a day or two. Hit 'em again, and use some finesse on any that give you trouble, and they should all come out fine.
 
To check for stretching hold two bolts together so the threads are intertwined with each other. If they fit together without any light showing through they are ok. If they do not fit snugly together, and sort of rock when trying to fit them together then one may be stretched.

I always reuse old hardware unless obviously stretched or otherwise damaged.

You have to ask yourself, What would a typical repair garage have done in the 1950s? They would just reuse what they had.

Having to not reuse head bolts is a modern phenomenon that came about with stretch bolts.

Mart.
 
Someone would have to be over torqueing a flathead head bolt to get much stretch on it. But you never know what it has seen in the past.
 
One thing I have learned since I got my Flathead,,,,,,,Ford had excellent quality bolts !
The steel is great quality,,,,the threads are tight,,,,,and the threads in the holes are tight as well .
You have to have respect for something when the quality was that strict,,,,,,all that long ago.

Tommy
 
If you are just checking it out and putting new gaskets on. Have at it. Do the standard torque sequence. It'll be fine.


Bolts on 8ba's



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If the bolts aren't too badly corroded, I would reuse them. Mine were in varying degrees of corrosion, and not all were the same manufacturer. Not sure where you can get 48 Grade 8 bolts for $70, as my searches have shown more like $2.50 - $3.00 each. ARP studs are like $500, but you can find much less expensive ones.
 
Look for apparent water damage that rust may have caused in the area just under the head of the bolt. I cleaned up a set on a wire wheel about 16 years ago and some showed corrosion damage in that area. I ended up getting new ones, just cuz... They were only about $40 a set back then Chap
 
We had to temporarily make them unavailable for a bit but they are now back in stock. I’ll have to fix that little glitch.....
 
Ziggster said:
If the bolts aren't too badly corroded, I would reuse them. Mine were in varying degrees of corrosion, and not all were the same manufacturer. Not sure where you can get 48 Grade 8 bolts for $70, as my searches have shown more like $2.50 - $3.00 each. ARP studs are like $500, but you can find much less expensive ones.
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Need to go to Allen's Fastners. Best prices on ARP bolts and studs. Volume discounts.

http://www.allensfasteners.com/
 
I have a copy of Ford Motor Company's overhaul/repair manual for their V8 engine. They give tolerances and wear limits and all that stuff, but never a mention that one might need to purchase new head bolts or studs???? From my experience (which is limited) the ford fastenings are of extremely high quality. Some of my favorites are carb mounting studs on manifolds. Tall nuts, and with old crippled fingers I can always start them with a quarter turn, or less, then spin them down with a total scar tissue fingertip to contact for about a half turn on a half inch wrench.They aren't yield to stretch or stretch to yield , they are just really nice fastenings.
 
GB i think when they stretch they are done stretching. Doesn't mean they are bad.


Don't throw the baby out with the bath water as they say. Don't overthink it, as you are saying.


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Tinker said:
GB i think when they stretch they are done stretching. Doesn't mean they are bad.


Don't throw the baby out with the bath water as they say. Don't overthink it, as you are saying.


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I agree with this logic for everything but head bolts or studs. Check them out and make sure they are good. If there is any doubt what so ever, toss them.

Breaking one off in the block can be a real b*itch to get out. I don't want to gamble for I've lost too many times.
 
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check the bolts against each other tail to shoulder if there are any that have stretched they wont be a snug fit [old school cummins mechs will know what i mean they supplied a gauge in the gasket kit] again check for corrosion or obvious physical damage otherwise all good
 
Good stuff. thank you. Think on a regular flathead I wouldn't be to concerned. But if all checks out good, slap some new gaskets on and some new bolts.
 
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Henry's bolts & fasteners were top notch. Never had a problem with any of them, and always reuse them as 1st choice, unless there is some obvious problem as mentioned. On the 8BA's head bolts I found an interesting variation, Some have 3 strikes on the head, some none, some 6 strikes, and some Ford script & #1041. If you drop ones these from a few inches on the a group of them you can gear the quality of the bolt by the ring sound. I sold fasteners for Lawson products, so I know the business. had a long talk with Roy about it Hershey 1 year.
 
I don't think a high quality bolt is necessary. A grade #5 would be more than adequate for this project, unless your going to exceed the yield strength of the bolt. At 45 ft/lbs, these would work just fine.. I don't use them, because they don't have 11/16 heads and my chrome plastic covers don't fit
 
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