Well weathers getting warmer so out in the garage tinkering again.I am just putting the head back on the 239 for the 49 Pontiac i'm working on.I checked the manual and it mentions coating the threads in lead sealant.Not sure what they mean by lead sealant.I have tf 15 lead thread sealant that we use on piping at the shop,but not sure if that's the same thing.Any suggestions out there?
the best tip is: use white loctite sealer on head bolt thread, but NOT on the bolt it self, on the block thread only. Clean them before carefully. You will experience a torque problem with the head bolts, they wl not torque to the spec for some, if you experience this don't over torque, you must replace them. I've done same thing on mine and other engine I've make. It's life, those bolt are not strong enough not.
this is the advice i was given from FITZ makes sense to me will be doing the same in the next few days
-- Edited by timbuk on Thursday 12th of March 2015 11:15:25 AM
.........excellent stuff.......have used on many engines, never a problem but as always when assembling
a head to the block be careful torquing bolts as the threads are now wet........use incremental of 30 - 60 - max spec ft lbs. in the manufacturer's prescribed sequence.
-- Edited by bjburnout on Saturday 28th of March 2015 02:20:08 PM
-- Edited by bjburnout on Saturday 28th of March 2015 02:21:35 PM
__________________
......big block, 4 speed, bench seat, it doesn't get much better
And if the bolt don't reach the spec of torque, don't leave it that way, replace the bolt. Where you can find new bolts? Anywhere! You have to make them yourself with the proper material. Once you get new bolts, they will torque perfectly. Look at the damage of the head gasket when too much sealer is applied on the bolt thread, on some engine it could cause to leak.
ok got the sealer now just need a spare hour to get the head back on.Can a guy use grade 8 bolts to replace the originals?I don't think this head has ever been off befrore so the originals still may be ok.But I do have to replace one as my motor had a block heater down through one bolt hole and it broke in two pieces when I tried to remove it.Got it out of the block but now have one hole without a bolt.
You can't use grade 8 bolt since it's not accurate (don't know if it's the correct word) against the original bolts, and, grade 8 bolts don't have the shoulder under the head that help to seal from coolant leak. I can send you a bolt for you to replace the one that broke, I've some spare. Those bolts can be reuse, you'll know only when it's the time to torque again it if they are OK for another run...
Fitz.
__________________
www.FitzbackGarage.com Look for Easy Steering in your vintage Poncho, Look for the EasyDrive Power Steering System in the web site
