Re-using heads bolts-Good or bad idea?

T

Tim Ayers

Well-known member
While packing up for my move, I found two complete sets of 8BA heads bolts that I saved. Both bolt sets are in great condition and the threads look good.

Is there any reason why I should re-use them? With all this talk of replacements being the incorrect thread, I'm leaning toward re-using them.

Good idea of Yankee thriftiness or penny wise, dollar foolish?
 
Tim, Most of the time the old ford parts are made alot better than what we can get now. At least they were made in the USA. Run the theads over a wire wheel they are good as new. Chuck S.
 
You also want to make sure they are not necked down in the center showing
signs of being stretched. G.M.
 
I agree with Walt if threads are still good then you can conclude the bolts haven't been over taut . The bolts get longer when over tightened .

Back in the day I erected tower cranes and the bolts were a important topic.
 
I bought a new set of aluminum heads to replace an old corroded set and decided that a set of studs would be cool. Bought a set from Summit with new nuts and correct washers. What a nightmare that turned out to be. I had leaks from the stud threads no matter what I did! I used a new Permatex teflon product, silicon product, the old tried and true Permatex (hardening and non-hardening) and all efforts failed. Of course, each removal meant new head gaskets and hours of labor.

I finally pulled the original '51 head bolts out of the bolt bucket and re-used them with silicon adhesive. No more leaks! Turned out after a close inspection and several discussions with Summit Technical, that they were Chinese studs and the threads were not true with the center line of the studs. Summit fianally admitted that they had been having problems with these studs and refunded my money.

I am happy that they took them back, but you can still buy these from them! Of course too, Summit made no offer to compensate me for my expense of an extra 3 sets of head gaskets and all of that labor.

By all means, use the old Ford bolts unless they show a lot of pitting! At the torque values specified, there is no way that a Ford head bolt will ever stretch unless they have gotten so hot that they have been annealed and that is very unlikely. The only head bolt that you should not re-use is some that torque to a given value and then are torqued an extra certain number of degrees. That extra torgue os to purposely induce stretch to assure proper clamping of the gasket and these bolts should not be re-used, although I have seen them successfully re-used when replacements were not readily available.
 
Call me a cheapskate, but when I had a problem with my engine soon after the initial startup I pulled the heads and when refitting them reused the almost new gaskets. Actually I did this twice (gulp). The engine has been together for a couple of years now and seems to be fine.

I also reuse the original Ford head bolts - for a start they have the correct sized head. These were off French motors so were relatively new.

Mart.
 
I consider all critical engine fasteners, like head and main bolts/studs, to be replaced during a rebuild, but especially if engine history is unknown. Add the facts many do not/did not use (or own) a torque wrench, based on many comments here and other forums, and the relatively high cost of rebuilding vintage engines, along with original parts harder to find as time goes on.
I would pay a little extra and stay with high quality fasteners like those from ARP. Now you have bolts/studs that can be safely reused if torqued properly. JMO :)
 
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Considering the fact that you only torque to 45.ft lbs I don't feel you can hurt them. But it pays to check them as Walt says.
 
G.M. said:
You also want to make sure they are not necked down in the center showing
signs of being stretched. G.M.
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Really surprised to see you make such a statement. What are you using to determine this, a micrometer? Really? Never saw one like that. Then I never considered a microscopic evaluation a sensible thing to do.
 
Ant catastrophic stories about re-using old bolts? Engines have been rebuilt for years using original bolts. I know there are some new high tech ones with stretch built into them that makes them a one use bolt but I have never read in any of the old manuals to replace bolts with new ones.
 
Agree completely with re-using stock bolts. Much better thread fit than replacements unless you get special studs / bolts made to order. Generally, you can see if a bolt is necked and you can most assuredly feel it by passing the bolt between your thumb and forefinger. Examine carefully and you'll be surprised what you can see. In case of doubt, use a pitch gauge or a thread micrometer.
 
I did find one that looked stretched once and discarded it. A good visual check should be adequate to sort out any dodgy ones.

But I can only speak for myself - I am prepared to trust my own judgement and face the consequences if it goes wrong. (And I am a cheapskate). Obviously I cannot recommend anyone else to do this, they must be their own judge.

Mart.
 
V8 Bob said:
I consider all critical engine fasteners, like head and main bolts/studs, to be replaced during a rebuild, but especially if engine history is unknown. Add the facts many do not/did not use (or own) a torque wrench, based on many comments here and other forums, and the relatively high cost of rebuilding vintage engines, along with original parts harder to find as time goes on.
I would pay a little extra and stay with high quality fasteners like those from ARP. Now you have bolts/studs that can be safely reused if torqued properly. JMO :)
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THAT IS DEAD ON.
I would trust the old stuff if I was tearing down an engine that had never been worked on since new from the factory but that isn't going to happen at this point in time. For the same reasons I don't trust the threads in the block on my race engines and steel plug all the head stud holes.
 
Pete said:
THAT IS DEAD ON.
I would trust the old stuff if I was tearing down an engine that had never been worked on since new from the factory but that isn't going to happen at this point in time. For the same reasons I don't trust the threads in the block on my race engines and steel plug all the head stud holes.
Click to expand...

I'm concerned about some of threads and was hoping to avoid plugging them. Not that I wouldn't if need be, just rather not have to at this point.
 
Tim Ayers said:
I'm concerned about some of threads and was hoping to avoid plugging them. Not that I wouldn't if need be, just rather not have to at this point.
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Well, if there is any doubt, it is better to do them rather than have it pull out on assembly. Mucho time lost then.
 
I have seen studs that stretched in the center where there are no threads. Don't know if they were aftermarket studs or not. G.M.
 
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