coolant leak sealant thoughts... engine builder input needed.

[undy]

I've been plagued from day one with a porous water/glycol coolant jacket in my Tunnel Wedge intake. One weld repair has proved unsuccessful and It's currently holding it's own running a coolant additive "block sealer". I plan on doing another tear-down to repair it (again) during the hard winter months. I'll do an elevated 100 psi pressure test prior to repairs also.

Here's my thoughts and resultant questions.. I was thinking of having the entire internal water passage aluminum ceramic coated (like sidepipes). There's only one passage in the front so it shouldn't be too expensive or extensive. My rational is that HPC coating is water-proof, very durable, expansion resistant and long lasting.

Has anyone had experience using HPC coating in this fashion? Any thoughts or discussion would be greatly appreciated.

BTW... I've had several extensive conversations with BarryR on the subject. He seems to think it should work but has no knowledge/experience of it actually being done.

Dave

[Bobcat]

Undy .... some years ago , a friend of mine sealed a pair of aluminum heads on a GT 40 replica that had coolant leaks so bad , water came out the exhaust ports . His name is Harold Elliott and owns H. M. Elliott & Co in Mooresville , NC . .... phone is 704-663-8226 . I`ve had him do work for me for years .... as have almost all of the NASCAR teams out there . He also used to build engines for the Penske team and Junior Johnson . If I remember correctly , he came up with a way to pull a vacuum on the heads that drew the sealant into the pores etc . while it cured . Great guy who has always come up with a solution for my problems .

Bob

[philminotti]

Hi Dave-

Don't mean to go off topic, as I have nothing intelligent to add about your problem...

I was wondering if you used any sealant on your head gaskets on the Pond block? Coolant leakage is a problem I'm becoming intimately familiar with...

phil

BTW, we talked a while back about intake gaskets and sealing for the KCR stage 2 heads... KCR has some new custom Cometic intake gaskets for the stage 2 heads. Also, the builder at KCR I spoke with no longer recommends using 3M weatherstrip adhesive on the head side of the gasket. Silicone (or whatever) both sides. Just FYI.

[vector1]

i've read chevrolet from the factory puts some kind of sealant into the coolant system to help with any leak problem, maybe look into this.

[ERA Chas]

undy,

By any chance is your intake a Dove? Mine is. Very early first batch in the '90's.

Looked like the surface of the moon when I got it. P'test revealed no water leaks however some port runners were paper thin in spots. My solution as follows:

Bead blasting to get a clean surface and 100psi air clean-out. Then used JB Weld like a 'spot putty' to fill divots and smaller pock marks. File and sand to suit.

Once cleaned up, sent it for ceramic coating silver with instructions to try to keep the oven below 400 deg and just let it gloss for a longer period. Worked perfectly-did not lift the JB. I don't think the ceramic is dense enough to fill your crack or fissure, but like Barry, have no practical experience doing that. I do know that JB, (if you can 'vee-out' your opening and have access to apply it) will withstand at least 25 psi as your system is only 16 to 18 psi.

I have no experience with the internal sealing systems the other guys recommend but JB has been a part of my intake since 1991.

BTW, have JB in small areas of block where 250 deg temps and oil drenching are prevalent. No problem either.

[Ronbo]

Epoxie coat the passage, for those exhaust coatings to work they have to be heated to 400deg or so to setup. Not so sure that's a good idea on a already troublesome manifold.

You could also use Glyptal (electric motor winding paint), this is an old school practice for block coating. I think Eastwoods and Whitneys have it.

[undy]

Originally Posted by Bobcat

Undy .... some years ago , a friend of mine sealed a pair of aluminum heads on a GT 40 replica that had coolant leaks so bad , water came out the exhaust ports . His name is Harold Elliott and owns H. M. Elliott & Co in Mooresville , NC . .... phone is 704-663-8226 . I`ve had him do work for me for years .... as have almost all of the NASCAR teams out there . He also used to build engines for the Penske team and Junior Johnson . If I remember correctly , he came up with a way to pull a vacuum on the heads that drew the sealant into the pores etc . while it cured . Great guy who has always come up with a solution for my problems . Bob

Thanks Bob, I just might give him a call. I need to see first if I can better pin-point the leak better. I plan on doing the next pressure test myself.

Originally Posted by philminotti

Hi Dave-
I was wondering if you used any sealant on your head gaskets on the Pond block? Coolant leakage is a problem I'm becoming intimately familiar with...

phil

BTW, we talked a while back about intake gaskets and sealing for the KCR stage 2 heads... KCR has some new custom Cometic intake gaskets for the stage 2 heads. Also, the builder at KCR I spoke with no longer recommends using 3M weatherstrip adhesive on the head side of the gasket. Silicone (or whatever) both sides. Just FYI.

No, I put the Felpros on dry. I'm pretty sure my problem's not the head gaskets as the heads were on long before the Tunnel Wedge was. The leaks only came with the Tunnel Wedge install. Everything was tighter than Dick's hat-band prior to that.

Insteresting on the Cometics. I'll have to call Shelly for a set. I've had intakes on and off the Pond motor 4 times and every time I pulled the intake the gaskets were seated perfectly with no signs of any leakage or potential for leaks either. I wonder why they changed methodology??

Originally Posted by vector1

i've read chevrolet from the factory puts some kind of sealant into the coolant system to help with any leak problem, maybe look into this.

The sealant I have is already doing the job.. I just consider it a band-aide and want to pursue a permanent fix.

Originally Posted by ERA Chas

undy,

By any chance is your intake a Dove? Mine is. Very early first batch in the '90's.

Looked like the surface of the moon when I got it. P'test revealed no water leaks however some port runners were paper thin in spots. My solution as follows:

Bead blasting to get a clean surface and 100psi air clean-out. Then used JB Weld like a 'spot putty' to fill divots and smaller pock marks. File and sand to suit.

Once cleaned up, sent it for ceramic coating silver with instructions to try to keep the oven below 400 deg and just let it gloss for a longer period. Worked perfectly-did not lift the JB. I don't think the ceramic is dense enough to fill your crack or fissure, but like Barry, have no practical experience doing that. I do know that JB, (if you can 'vee-out' your opening and have access to apply it) will withstand at least 25 psi as your system is only 16 to 18 psi.

I have no experience with the internal sealing systems the other guys recommend but JB has been a part of my intake since 1991.

BTW, have JB in small areas of block where 250 deg temps and oil drenching are prevalent. No problem either.

Yep, Dove ... nobody else makes the Tunnel Wedge any more.

My leak's very small. Over a period of 2 months of driving it didn't taint the oil enough to see a coloration difference in the oil, just the froth in the valve covers. That being said, the porosity is very minimal and I thing the ceramic/aluminum should fill any minute pores quite adequately. The leak is so small nobody can pick it up by a visual inspection of the intake, even on a work bench with good lighting.

Once I put 100 psi on the thing I'm hoping to find the leak. I plan on pressure testing it while it's submerged in a wheel barrow full of water

I've still some more research to do when it comes to figuring out what I'm going to use. I've even heard of coating the inside of the water passages with melted bowling balls..

Originally Posted by Ronbo

Epoxie coat the passage, for those exhaust coatings to work they have to be heated to 400deg or so to setup. Not so sure that's a good idea on a already troublesome manifold.

You could also use Glyptal (electric motor winding paint), this is an old school practice for block coating. I think Eastwoods and Whitneys have it.

BarryR has had terrible luck with Glyptal as a coolant passage coating. It seem the hot water/glycol mix breaks down the Glyptal over a period of time and it starts to disolve, delaminate and break off.

Dave

[ERA Chas]

"I've still some more research to do when it comes to figuring out what I'm going to use. I've even heard of coating the inside of the water passages with melted bowling balls.."


Well find out at what temp they melt Dave. Your coolant passage will see 230+...:>((