rob rossitto

sorted through the final wiring, fuel, ECU, and misc issues from the conversion/OH and finally got the old gal's new 6.4L stroker fired up and it sounds like my license will be in jepardy/won't last long

but - those fine cometic head gaskets are leaking water "like fountians"

although I had considered water injection - water ejection was not a goal... and while turning my U-Boat into a portable car wash was an idea, I suppose it might look nice in brittney spear's pool as a last resort

of course, the shark's heads were supposedly torqued properly, and the heads and block were supposedly resurfaced fairly well... cometic has not responded yet - but the warrenty is nil, zip, nada - so I'm not surprised...

anybody BTDT with these things??? should "somebody" have used silly putty or whatever to seal the gaskets??? maybe it's just a sealing ritual that "goes away" after a few heat cycles??

good thing I used bolts and not studs, but I'm not real anxious to tear this thing apart again already....


as always - fire at will and thx!

Tony

When did you buy the gaskets?
There has been a designe change in them that may help you.
I still need to send mine back.

Gretch

Man!!! I HATE it when that happens...................You gotta go in and look, and you know you do.....no sense in putting it off..............

rob rossitto

hey tony - design change??? like a version that won't leak?? lol... they were made in jan 05... I heard GM uses a sealer in their new cars from the factory... might be an option, so your's leaked too??

hey gretch - why do you always have to be so damn right??? if the heat cycles or GM's magic sealer don't totally cure it (I'll be quite pleasently surprised if they do), then I don't see any other choice, and we'll have to see what really happened/is going on... arrrrrhh... would be easier to justify if it just threw a rod, bent a valve, etc... but for a darn water leak/so close yet so far.... on the other hand - it could be the tip of a rapidly melting iceberg....

guess the license might have a reprieve.... too bad - all those starving CHP folks hoping for a nice bonus will have to wait too...

jserio

Hey Rob, Saw your car the other day. Engine looks sweet. Why did you cover the engine to an S4 when you could have gottn the same power out of your S motor.

BC

Please do update us on the gaskets. Alot of people (including me) were planning on Cometic for engine builds. I think Murph has already installed a few - not sure of any issues.

Ketchmi

Hey Rob!

I have had the same thing happen during my Cometic head gasket useage. I have found a "cure" that seems to work. Moroso ceramic block sealant is a bit of a pain to use but has sealed up a couple of Cometic's fine quality leakers. The Cometics seem to seal the combustion chambers quite well but anti-freeze to the outside world is a different story. I have heard that silver paint on the gaskets before installation works good also. (a little late for that!)

As far as the Moroso sealant,

http://www.moroso.com/catalog/catego...?catcode=22005

You must drain and flush the entire cooling system completly before using. It cannot come into contact with anti-freeze or it will solidify on contact. I have used it on a supercharged 89' with Cometics that leaked from initial fill. It worked perfectly without any noticeable decrease in cooling ability.

Glad to hear your beast is turning under it's own power, now it's time to produce some!

Oh yeah, when I approached Cometic about this problem they said that they had never had it happen before and to send the head gaskets back to them for replacement. Yeah, right! Customer's engine, just rebuilt and installed. I'm supposed to pull it out on my dime and replace them?

Th Dude

6.4L STROKER? Cool.

D

Garth S

If you use the Moroso ceramic sealant ( neat tip, BTW!), is it worthwhile to run a compression test beforehand to confirm good cylinder sealing? - and that the only leaks are in the water to atmosphere side ...

Ketchmi

I have never seen a Cometic leak cylinder pressure or coolant into the combustion chamber, only coolant to the outside world. Amazing enough, I haven't seen them leak oil from the passages either! A couple of the ones I had leak seemed to be fine if the engine was up to operating temp but leaked quite bad when cool.

slate blue

Sorry to hear of your trouble Rob, mate I feel for you, I know how frustrating these things can get, hope you have it back on the road soon.

Lagavulin

Congratulations Rob!

I am sorry to hear this; where are they leaking from? Please provide more details.

In the meantime, there are several engines assembled here in Wisconsin using Cometic gaskets, and none of them leak.

One reason I can fathom them leaking is that there may be an uneven deck.

For example, using scotchbrite or something similar to remove gasket material from the block. If that was done, any MLS (..multi-layer steel) gasket will be unforgiving since it has no 'give' to fill in the 'valleys' caused by the sanding process.

As stated above, there are 5 engines here that I know of using Cometic gaskets with no leakage whatsoever, and all were assembled 'dry'.

SharkSkin

That sucks Rob... Just when you were so close!

rob rossitto

thx for responses!!!

if you are considering cometics, this might be worth noting - I spoke w/cometic today (very nice/informative guys), recap below:

1) there is a left (pn 1972) and right (pn 1973) gasket - but NO other indication as to Lt vs Rt
2) rivits hold the layers together
3) if the gaskets are installed backwards (and they'll look just fine - uncompressed), OR if for some reason (casting issues) the rivits dont' clear, it's flood city...
4) the rivits can be removed, just holding the layers together
5) no sealant should be used/is required
6) although heat cycling will help a bit, as it helps expand materials to full size - if the rivits are in the way, it'll just never properly seal...
7) there also were some embossing issues around the cylinder - but since resolved (ie, tony's reference) - didn't affect water issues, was related to chamber sealing...

8) this sucks... guess it's time to pull it apart...

thx joe - same power from an S motor?? I wish!!! the 32V stuff from 85/86 and 87/90 and 91/93 are quite different motors... think the oil caps fit all years, but that's about it... as a result, power, oil control, reliability, etc are all affected (and generally quite improved) as a result... IMO, all the performance gains are mostly from top end improvements (valves, ports, engine management, intake designs - and the GTS stroke change) that together contribute a significant performance improvement over the earlier 32V stuff - and once you change the heads it's all down hill from there.... or kinda like niagra falls in my case...

as my dear o'l grandfather used to say: you can learn from my mistakes - but just don't laugh!!

hope this helps...

rob rossitto

update: today it seems that the leaks have significantly disapated... either ran out of water (lol) or gaskets really just need to seat and maybe no rivits got in the way after all (I hope)... think we'll run it a bit more and see what happens - if it blows up, we'll have to take it apart anyway... ha!