Who has had heads leaking after installing .040 gaskets? I have a set of new Darts 205cc and wanted to use .040 head gaskets but have heard of them leaking. This is a daily driver and only have a old motorcycle to ride if they start leaking.

Thanks.

Bill

 

Cometics are VERRY sensitve to surface prep. If the heads or block wasnt absolutly clean you will run into problems.

 

It helps to use copper spray on thin gaskets. You can get it almost anywhere so it's hard not to do.

 

What kind of heads do you have? Casting #?

 

I just put on a set of heads using the .040's and didn't spray them. So far no leaks and it's been a couple of weeks since. And surface prep wasn't perfect. It was good but not spotless like some say.

 

making sure the heads are true would also help. take your heads to a machine shop to make sure there not warped. if they are, shave them just enough to make them flat again. that will also give your heads a new clean surface.

i installed some .040 cometics 1,000 miles ago and i have had no leaks. i know your asking who "HAS" had leaks, but i figured I'd just give some advice.



# 1,000

 

yeah copper spray allways works good had a problem on one of my smallblocks in my chevelle and i changed the gaskets and used the copper spray no leaks.

 

Copper spray on mine and it worked well. Over 5000 KMS.

 

Clean the block and head surfaces very well. As mentionned shave heads .002/.003 as clean up if necessary.

As far as spraying the Cometics, although Cometic says not to do it, for the past few years we use them on LS motors, many of us do spray copper sealant and they run better that way. From my personal experience.

 

yeah, this was me worrying about the same thing bout 6 months ago. no worries anymore. predator convinced me. doin good, only got about 500 miles on it though. and I also CLEANED both surfaces like brane new. just take your time and use brake parts cleaner to remove the old head gasket material along with a plastic gasket scraper and a gentle touch. my decks look like a new block with the cross hatch from the machining. and resurfaced the heads too.


its worth the extra effort and cost IMO.

 

I have a set of new Dart 205cc heads so heads should not be a problem.

Bill

 

I am glad I started this poll before I bought the head gaskets. I am going to go with the .040's and copper spray.

Is cometics the ones to get?

Thanks everyone.

Bill

 

I'm running .027" cometics without any leakage, no copper spray either.

 

I used cometics and copper spray. dont know if there are any other companies selling thin gaskets? heard of felpro, and mrgasket, but couldnt find either when it came down to it. anyone got part #s for either of those?

 

1 out of 19 people had leaks. 95% did not have any leaks. I am going with the Cometic .040 head gasket. Anyone one know which part number for Dart 205cc heads? They have a 4.060 and a 4.160 in the Cometic gaskets. Dart says use a 4.100.

Bill

 

Another Cometic .040" user here. Sprayed silver paint on 'em, slapped 'em on there, and no problems after 5-6k miles. Stockish compression, 230/236 on 112LSA cam (so, lower DCR), and 7k RPMs over and over again. Good to go!

 

no copper spray on mine and all we did was clean the block and heads real good. hasn't leaked yet.

 

Is there any reason people use copper specifically?

 

I think if you have a stock bore, you shouldn't use a 4.1 gasket.

 

The Dart chambers are wider, I used GM 6.0 MLS gaskets on mine.