re-using bolts on rebiuld
Post Fiend
Joined: Feb 2001
Posts: 6,624
Likes: 8
From: Missouri
re-using bolts on rebiuld
This is not the wrong forum for this but you may want to post this in the 400M forum. Some engines have different rules when it comes to this. For example on a 390 reusing the head bolts can be done for a minimum budget build but they say never to do it on a 5.0L. If you can afford it I would replace all the bolts with ARP hardware. They are going to give the most uniform clamping pressures and least amount of stretch. It also heavily depends on what you want to do with the engine. I know right next to nothing on the 335 motors so I can't be of much help.
Logistics Pro
Joined: Jan 2002
Posts: 4,907
Likes: 39
From: suburban atlanta
re-using bolts on rebiuld
Unless you are going racing... I'd only replace bolts that are 'stretch to torque' or those that are recommended by the mfg to be replaced. Newer head bolts are tightened to a specified torque, and then turned 1/4 turn or so past that point. The torque is not measured on the last part, and the bolt is stretched a specified amount beyond its original length. They can be used but once...
I have done 352 & 390's without replacing head bolts. Just clean 'em up and make sure that the threads and bolt holes are clean. Lightly oil, and install. Did replace rod bolts on one engine, but that was 'cuz there was a FoMoCo recommendation to do so. ('59 T-bird 352) Older style bolts are more than likely way understressed as there was MUCH less concern about excess weight caused by using bolts a size too big. Today, there is more concern about weight, so smaller bolts are used, and they are much closer to their limitations than older designs. Materials used have also changed, improving strenght to weight ratio.
What the heck, if they look bad, they probably are. Don't cost too much, so feel free to replace whatever you want. But, you don't have to.
That's my opining for the day.
tom
I have done 352 & 390's without replacing head bolts. Just clean 'em up and make sure that the threads and bolt holes are clean. Lightly oil, and install. Did replace rod bolts on one engine, but that was 'cuz there was a FoMoCo recommendation to do so. ('59 T-bird 352) Older style bolts are more than likely way understressed as there was MUCH less concern about excess weight caused by using bolts a size too big. Today, there is more concern about weight, so smaller bolts are used, and they are much closer to their limitations than older designs. Materials used have also changed, improving strenght to weight ratio.
What the heck, if they look bad, they probably are. Don't cost too much, so feel free to replace whatever you want. But, you don't have to.
That's my opining for the day.
tom
Senior User
Joined: Apr 2002
Posts: 406
Likes: 1
From: cedar rapids usa
re-using bolts on rebiuld
I used ARP's Main and Head stud kit and their wavlock 8740 rod bolts when putting my 406 together. I am known for going a little overboard in the name of buying quaility over quantity, but when you spend 4800+ building an engine another 220 on bolts seems like cheap insurance.
