What water addititive for leaky Cometics ?

Hello,

This is one of many threads on preping the Cometics.

https://board.moparts.org/ubbthreads/show...e=9#Post5016854

Do a search and you will find the required deck finish also.

Damon

prestone make a sealer that looks like baby spew but it seals real well. can't think of the name of it but it gets my thumbs up

since nobody has asked yet, have you backed off one bolt/stud at a time and retorqued them yet. often times that solves the problem. what was the torque # you used initially and what kind of block?

My W5s leaked on start up . used barrs leak , sealed good, seems when you drain system you will need the barrs leak again,

Yes, i've retorqued the studs and i'm at 90lbs with them. This is on a stock 340 block, with super smooth finishes on both the heads and block, we also drilled the rivets and sprayed coppercoat between the layers and used silicone around the water jackets. I was really hoping not to add anything, but i guess i have to. Funny thing though, they only leak when the car is running, not when the engine is cold. Thanks for the help guys, Jesse

On my 340 I followed the smooth surface,loosen & retourqe,& rivet clearance. I had a leak on start up. I used some Unnamed Autozone sealer. 3 years ago street & race, high engine temps in traffic, no water loss. I agree the Moroso sealer is the best. I have had it seal 6" long crack in the side of my 440 block for over 3 seasons of racing. no drips, no water loss.
Doug

just wondering if you tried anything yet??, im in the same boat, very small leak on the outside of the block

not yet, picked up a can of bars leak today, just not had time to put it in, Jesse

Some of the later versions have the slotted steam hole towards the top between middle cylinder instead of a round hole, this slot protrudes outside the enbossment on the cometic causing a leak. i've got two sets like this one i have had welded up,i had a pic but cant find a good one now.

That's interesting, i did not pay attention to that, my heads are a later casting so i bet they are slotted, thanks for bringing that to my attention, Jesse

What did you find?

I put bars leak in and it sealed it up. I made four passes and everything seems to be fine. I'm just hoping i don't spring a leak when i put it on the jug! The car ran a best of 6.38 @ 107 on the first outing, so i'm pretty happy. We're going to a test and tune tommorrow to do some more tuning. I'm sure there is a little more in it that i'm going to try and find before we go to the nitrous, Jesse

I use barrs seal with w5s , seals fast , if you let the engine sit or drain it , it may leak on start up , just add more , I wondered about the slotted water port , I think thats where mine leaks ,