Copper head Gasket

[smithdavidjames]

Hi all,

Looking to invest in a copper head gasket... engine is a 4G52 2.0ltr, Question is what thickness... forum search reveals 1.5mm to 2mm. Recommendations...

Thanks, David

[astronturbo77]

what modifcations have you got to warrant a copper headgasket?

[smithdavidjames]

Just looking for insane reliability... engine came out of a rally lancer so higher compression ratio (how high not sure) also on straight LPG, so a little drier in the combustion chamber. Want to have a go at supercharging in the future, so just getting some ground work done in advance.

David

[cheaterparts]

some time ago when I was running a 2 lt I had a copper head gasket made by Ridgecrest eng

http://www.ridgecrest.com.au/

I had a 0.020" or about 0.5 mm copper gasket made with the 84 mm bores and it worked a treat

[A112H]

I would say if you have a rally Lancer engine making high PSi I would look at selling/swapping that for a stocker if you wish to reduce compression.
You could be sitting on a rare engine there without knowing it.

[shuggy]

Haha yeah like when I bought my last coupe. Came with a mint 2L with brand new 2.6 head, arp all round, flat top pistons, baffled sump, knife edged, 11:1 compression. Cant wait to drop that in something!

[smithdavidjames]

Got a couple of quotes back and it's looking like the guys at Ridgecrest gonna get the business with a very affordable figure for a 1mm thick gasket, plus the recommendation from Cheater sold it!! Further investigation has relieved a standard head gasket is 0.8mm so 1mm should be perfect in the short term at least to get me back on the road and keep me there.

Thanks, David

[rx22nv]

Is your head and block O ringed? If they aren't O ringed then forget the copper gasket.

Make sure you lay the gasket on the block and check that all the galleries match. Same with the head. I had to die grind a few out to open them up.

Use a good sealant like 3 bond but get the correct grade for copper. Spread it very thin, when the head clamps down, it will go everywhere. This is to seal the water and oil galleries.

You also have to have the tuning spot on. You will now have a gasket that won't blow, so the next weakest link is the pistons.

[cheaterparts]

Is your head and block O ringed? If they aren't O ringed then forget the copper gasket.

Make sure you lay the gasket on the block and check that all the galleries match. Same with the head. I had to die grind a few out to open them up.

Use a good sealant like 3 bond but get the correct grade for copper. Spread it very thin, when the head clamps down, it will go everywhere. This is to seal the water and oil galleries.

I must say I didn't have an O ringed block when I did mine both the block and heads were flat ( I know as I had machined both my self )
the block had about 2 mm decked from it - cant remember how much the head had off it but would have been about 2 mm

I had to machine a tapered section around the pistons as they were proud of the block and the combution chambers were also machined to clear the pistons with the thin copper head gasket . The piston to head clearance was kept pretty tight around this squish area

anyway the motor ran over 11 : 1 comp and I just used copper coat as a sealer and put and little silicon around the oil gallery holes
I also only used the std head bolts and not studs

the head sealed fine - about the only other thing was I anealed the gasket each time before use

[rx22nv]

In theory, it doesn't make sense for it to work. There is no ring to compress and clamp down like a regular gasket. There is no O ring to bite in. Did you ever strip it down? Was there any evidence of combustion leaking out?

I used bolts for a long time in mine. The last rebuild I chucked in a set of studs, not because of any problems but because they were cheap enough.

Mine had a 3mm to start with, then I tried a 2mm and lastly a 1mm. I think I'd like to go the 20thou one if I ever have to rebuild it again. Ran over 30psi with each one, went no where until I went to a Paul Testa/Bezerkely cam. I have no idea what any of the specs are but it worked.

Anyway, back to head gaskets. You should probably work out your comp ratio especially if you plan to go forced induction later on.

[cheaterparts]

In theory, it doesn't make sense for it to work. There is no ring to compress and clamp down like a regular gasket. There is no O ring to bite in. Did you ever strip it down? Was there any evidence of combustion leaking out?

yes the joys of a race engine - burnt hole in piston ( my fault to lean and long straights ) checked for burn marks across any where - no problem and it must have bean pre igniting it brains out

ran a bearing at one stange ( faulty oil pump , every thing checked on strip down including head gasket ) no issues

I only ran the copper gasket in the 2 lt mainly because I couldn't get head gaskets with small enough bore holes the 2.6 gasket would have done for a road car but trying to get the most out of the 2 lt I didn't wont fuel/air mix anywhere but in the chamber
and didn't use one in my 2.6 race engines as head gaskets were easier to get with the right size holes

[rx22nv]

I definitely didn't think that would work, especially on something with high compression. There is no forgiveness, if something is wrong, the pistons and the rod bearings will take the hit.

Did you re torque after the initial assembly? I did roughly 1000kms and then retightened, it was fairly loose on the 2nd attempt.

[smithdavidjames]

Great info guys... my block doesn't have o rings, although I was told it did when I purchased it...the higher compression ratio's work well with my straight LPG set-up thanks to the higher octane levels and I actually find using a "Hiclone" to induce swirl in the intake manifold helps. The incident which sparked my interest in copper head gaskets happened last year when due to detonation I burnt a valve and blew the head gasket between 2 and 3. This was my fault as I had been experimenting with advancing the ignition timing and went a bit to far making the engine lean out at higher RPM when climbing Old Bathurst Road. Having conducted some additional research it seems that there is advice for and against so I can see where both cheater and rx22nv are coming from which has tempered my initial enthusiasm. Rx22nv your comment about there being no forgiveness has been playing on my mind and in addition my deadline has been brought forward and I really need my sigma back as my daily drive. So it's looking like it may be a standard head gasket for now with a copper ordered for future uses/experimentation if and when I get time to play or I blow another gasket...

As always thanks for the sage advise, David

[rx22nv]

Happy to share my experiences David. The gaskets are cheap enough and if they work without the need for the o rings, then that is a bonus.

Adding to that, I've also been happy using ACL hypereutectic pistons rather than full forged pistons. When something goes bad, it will melt the edge off, rather than shatter and wreck the bore. Plus I was only paying $300 per set from local guys.

Dan

[jigganought]

I used a copper head gasket from ridgecrest for my 2.6 GJ with mixed results. You must get block o-ringed spot on. I had slightly to much interferance fit on wire the wire the first time and the head didn't seat down right and after a couple thousand kays had oil leak.. Made new cutter and remachined block assembled went fine. Lasted until I put slightly to much ignition timing into tune on warmer day and it went. Both failures were my fault not the product though.... Now using MLS gaskets from Top End Performance in California and am very happy with them..