Making a Copper head gasket

[vn1uz]

hey guys just a few questions on copper head gaskets
what is actual involved in making one ie are they just cut out of what ever thickness copper as i could probably get some made
i get them drawn up on auto cad maybe even scan them in or some thing dad is real wiz with it and then get them laser cut ?? is this how they work ??
i have done this with manifold flanges in the past and has worked well
from just mesuring up the gaskets?
or where in oz could i buy some ??

 

[Lextreme II]

If you have all the tools and equipment, then it pretty much it. However, there are few advances in copper gaskets in the past year or so. Company now can insert O-rings for the pistons and other openings. I have copper gaskets with .093" and it works great. I over heated my car 2-3 times and no problem with the gaskets. Installation would be a pain, but you only have to do it once. Perhaps might be cheaper to buy instead of making. However, if you plan to produce it, then its worth the trouble.

 

[mycarhasposessedme]

Ridgecrest here in oz make them for 1uz. http://www.ridgecrest.com.au/

 

[vn1uz]

thanks guys
I had a look at that site and they say the only come in sizes up to 2mm but the size lextreme has worked out for a ~8.7 is closer to 2.5 mm
i have emailed them and asked for prices so i will let you know also the make custom rods so i asked about them but i can see them being cheap at all.

What happens to the cam timming on these engines when you install the gaskets as the heads move apart more? can we get adjustable gears so we can adjust them back so they are the same ??

 

[mycarhasposessedme]

QCA (pete) from this forum has adjustable cam gears, give him a pm.
He is in Queensland.
2mm will give you 9.25:1 if you start with a 10:1 standard engine.
2.364mm or .093 will give you 8.96:1 which is what I beleive lextreme is using.
Cheers
Trev

 

[vn1uz]

thanks for that

 

[Lextreme II]

Timing belt is little tight. However, with increase in HG height, you will need to double up the head/lower intake gaskets. Thicker HG will move the heads further apart and double up the lower intake gaskets will comprensate for that change.

 

[BlownV8]

This australian mob supply gasket thicknesses of .5mm,.7mm,1mm,1.2mm,1.6mm & 2mm. Could someone do the maths as too what they would all change comp ratio too. Starting from both 10:1 and 10.4:1 THANX

 

[mycarhasposessedme]

I have done some calculations for the 10:1 engine, they are in the tech section.
Here is the link http://www.lextreme.com/cr.html
I have not personally stripped the 10.4:1 later engine to be able to CC everything and get the volumes to work out different combinations.
That said, it is possible to get the chamber volumes by using just the swept volume and existing cr but I personally find this method is not accurate enough.
Maybe someone else has done this.
Cheers
Trev

 

[Lextreme II]

Mycar,

Great link. I also forgot about that link. Thanks'

 

[Vssc400]

thank you for the link. Just ordered a set of .7mm for my 1UZ. Anyone take a guess at the final compression?

 

[mycarhasposessedme]

What CR are you trying to achieve?
And there is no need to guess with compression ratios, just simple math.

 

[Vssc400]

What CR are you trying to achieve?
And there is no need to guess with compression ratios, just simple math.

I was trying to reach 11.0:1

.7mm gasket was as close it got to it without over doing it.

 

[Vssc400]

I was looking at the CR page... I am not sure if you calculated the CR taking the deck height into account.... please verify

thank you

 

[mycarhasposessedme]

Yes deck height was accounted for when cc'ing the piston at TDC

 

[Gollumandsmeagol]

Who here has actually run a thick copper gasket at higher PSI with stock pistons?

The reason I ask is simple, quench. The stock heads have a smaller chamber opening than the piston's surface area (meaning it's not round, it tapers down to a smaller size). Quench is one of the many modern advancements in enging/head design and allows for less detonation. With a copper gasket you're going to end up increasing the air that doesn't actually make it into the head's chamber.

It's not this huge issue, i'm just curious if it's caused anyone problems. I'd imagine even if you lowered the compression to 8.5:1 via gasket you wouldn't be able to run even 80% of the same PSI as a motor with 8.5:1 compression via piston dish'ing, regarless of other limits.

 

[ed_ma61]

actually it IS a huge issue...

squish/quench whatever you want to call it provides turbulence to the cumbusion process which significantly iproves detonation resistance

decompressing a motor with a thicker gasket to drop CR will actually make the engine MORE likely to detonate. rather counter to the whole point isnt it = worst idea evah...

suggest reading here:
http://www.v-eight.com/tech_forum/viewtopic.php?t=39

secondly, copper needs to be annealed, so everyday copper sheeting thats laser/profile cut wont do. id suggest gettiong what you can from ridgecrest as previously mentioned.

finally, copper hg's SHOULDNT be used without o-ring fire rings. its a completely pointless exercise otherwise.

cheers
ed

 

[cribbj]

Who here has actually run a thick copper gasket at higher PSI with stock pistons?

To answer your question, DaveH, who is/was a member here, has been running decompressed 2JZ-GE motors for years with thicker head gaskets. He's the granddaddy of the Supra NA-T concept.

Last I knew, his 2JZ NA-T motor was putting out something north of 700 RWHP and doing 9 second 1/4's.

As Ed points out, to do it right means not altering the squish characteristics of the chamber, and this means going with lower compression pistons, however thicker head gaskets are certainly a cheaper alternative, in some cases.

 

[Lextreme II]

SCE makes copper head gaskets for the 1uzfe at any thickness. I used and didn't enjoy the retorquing process.

 

[turboteener]

Copper head gaskets are for drag motors and the history books. They do not tend to seal around the oil and water passages, plus the re-torqueing as stated above.

Call Cometic and get a head gasket custom made for pretty cheap. They should be able to do any bore size and thickness you need. I am not a big fan of thicker head gaskets as a band-aid for dished pistons. You lose quench and that is not good.

Our engines can handle boost with the stock compression you just have to tune it right.