TR6 Bearing cap bolts

[charlie74]

Greetings all! Due to some sticker shock from the suppliers website regarding the price of mains and connecting rod bearing cap bolts got me wondering whats so special about them…? Nevermind the ARP stuff! Are they stretch bolts that are single use only? I know the shop manual says to replace “WITH NEW”…
regards,
c74

 

[Sarastro]

I would use new connecting-rod bolts, but I think you can reuse the main-bearing cap bolts. The latter are stronger and are subject to less stress.

The latest connecting-rod bolts for the TR4A are "stretch" bolts. They have a thinner section that allows more elongation as they are tightened; the elasticity of that section tends to help prevent them from loosening. I don't know, but suspect that the TR6 bolts are the same. I don't think they are strictly single-use, but by time you need to rebuild the engine, probably they should be replaced.

I have heard expert opinion that you can reuse crank bolts. I also am aware of one case where a reused crank bolt broke and destroyed a newly rebuilt engine. Those suckers are expensive, I know, but they're still cheap insurance.

 

[charlie74]

Thanks for the reply Steve! I have some in my shopping cart, cheers!
c74

 

[Sarastro]

I forgot to say, a little high-temperature Loctite is probably a good idea, too.

 

[Rut]

I’m always conflicted on main bolts, but rod, head and flywheel bolts get replaced with ARP on my rebuilds. Once upon a time I reused rod bolts on a hot MGB engine rebuild after the machine shop and I both measured them and pronounced them good…won’t do that again!
Rut

 

[charlie74]

Yikes, that’s nasty! Thanks for the pics…

 

[Sarastro]

Just one word: Wow!

Unfortunately, ARP does not make connecting-rod bolts for the TR3/4 engine. If they did, I would have bought them happily. I did get ARP head studs, though; that's the only thing they make for our engines.

 

[Rut]

Just one word: Wow!

Unfortunately, ARP does not make connecting-rod bolts for the TR3/4 engine. If they did, I would have bought them happily. I did get ARP head studs, though; that's the only thing they make for our engines.

Steve, I wonder if there’s a bolt that will cross reference like the Ford flywheel bolts for the MGB? I’ll do some research.
Rut

 

[TR-3rg]

Hi,
Try Ted Schumacher, www.tsimportedautomotive.com. He lists an ARP rod bolt for the TR-3 /4. I bought set for my TR 3 about 10 years ago and no issues. I think they were for a big block Ford. He sold them as packs of 8, instead of 16. I think I also bought Flywheel bolts from him.

Good luck, Roy G