My new SBC head bolts (Victor Reinz) have a sealer already applied to the threads. The pre-applied sealer is dry and quite hard.

Of all the sealants I can recall, ALL are pliable to some extent. Sounds to me as though the sealer is possibly too old- there should be some pliability to the material, else it'll either flake off or just not do the job in the first place.

But with that said, I would thread a nut onto one of the head bolts to see just how the sealer behaved. There's a distinct possibility that this is how that particular sealant is supposed to appear.

But if the dried and hardened condition of the sealer is found to be abnormal, I'd plan on wire wheeling it off (soft steel or brass wire wheel) and then using a traditional sealant of your choice.

 

I've used that style head bolt with pre-applied sealant many times on stock apps and it works great. It's what GM has been using for years. The sealant looks white and chalky when you get it but activates when it's sheared by the threads during installation.

 

My new SBC head bolts (Victor Reinz) have a sealer already applied to the threads. The pre-applied sealer is dry and quite hard. Should I use 'as is' or should I wire brush all the pre-applied sealer off and put fresh liquid sealer on in its place? Seems 'wrong' installing head bolts with a dry sealer substance on the threads after taking all the trouble to clean the threads in the bolt holes of exactly that kind of stuff in the first place.

I always apply Teflon plumbers paste style sealer into open ended bolt holes using a long wooden stick that will reach to the end of the bolt hole. The point I'm trying to achieve is to keep the bolt pushing an amount of sealer into the threads ahead of it, rather than have sealer that trails behind the leading edge of the bolt's threads which eventually results in threads running ahead of the sealer, leaving the bottom threads exposed to the corrosive action of coolant, even though the overall bolt may be sufficiently sealed in higher portions of the thread to prevent coolant leakage past it. I use this method whether the bolts have factory sealer on them or not. Just part of my overkill campaign I guess.

Be cautious if using this technique not to use it in blind fastener holes as one could get enough sealer pushed into the space between the end of the fastener and the closed bottom of its hole to cause a hydraulic lock which could crack or blow the bottom out of the bolt hole damaging if not ruining the casting.

Bogie

 

Great info, thanks guys :thumbup:

 

I always apply Teflon plumbers paste style sealer into open ended bolt holes using a long wooden stick that will reach to the end of the bolt hole. The point I'm trying to achieve is to keep the bolt pushing an amount of sealer into the threads ahead of it, rather than have sealer that trails behind the leading edge of the bolt's threads which eventually results in threads running ahead of the sealer, leaving the bottom threads exposed to the corrosive action of coolant, even though the overall bolt may be sufficiently sealed in higher portions of the thread to prevent coolant leakage past it. I use this method whether the bolts have factory sealer on them or not. Just part of my overkill campaign I guess.

Be cautious if using this technique not to use it in blind fastener holes as one could get enough sealer pushed into the space between the end of the fastener and the closed bottom of its hole to cause a hydraulic lock which could crack or blow the bottom out of the bolt hole damaging if not ruining the casting.

Bogie

Hey Bogie, I have a question. If you use to much sealant can't it come loose in the water jacket and possible plug an area and make a cylinder overheat? I've heard of this happening.

 

Hey Bogie, I have a question. If you use to much sealant can't it come loose in the water jacket and possible plug an area and make a cylinder overheat? I've heard of this happening.

These type sealants don't cure as does silicon rubber. When blobs are exposed to flowing cooalnt they just erode away.

Bogie