lowering compression with an extra gasket

[DAVE BRADY]

Hi,

An 0.080 (2mm) gasket from British Cycle Supply is about £45 plus postage so I either buy a sheet of 2mm copper and cut one out myself or use two gaskets.  The sheet would probably cost about the same as two gaskets or I use an annealed used one and a new one stuck together.
So stick them together with what?  Copper gasket spray seems the best idea so has anyone used such a product?

Dave.

[rhyatt]

Wellseal maybe?

[Gup holland]

Just go to your local plumber or roofer for a piece of copper sheet 2 mm. Made one myself one evening in the mancave. The head of the A65 was to many times skimmed off. Just copied the original gasket.
For me it was easy to obtain a piece of copper sheet, as a plumber.
I always annealed it before reuse,

Gr gup

[DAVE BRADY]

Hi Gup,

Which plumbing supplies companies have 2mm copper sheet?

Dave.

[Gup holland]

I understand your question, mostly you find thinner. We had some, left over from a work. I think, when you look for companies who work with sheet copper ,hopefully they got wat left overs .
You don't need much, maybe sheet metal companies who can sell by cm/inch?

Look for aliexpres, sold 200x200 mm  1,2,and 3 mm thick.

Gr gup

[Allan G]

Just go to your local plumber or roofer for a piece of copper sheet 2 mm. Made one myself one evening in the mancave. The head of the A65 was to many times skimmed off. Just copied the original gasket.
For me it was easy to obtain a piece of copper sheet, as a plumber.
I always annealed it before reuse,

Gr gup

Is this the one your tracing or the one you made?

[Gup holland]

The one on the picture you mean? This one made myself. 2mm thick.

[Allan G]

The one on the picture you mean? This one made myself. 2mm thick.

In the picture yes. You certainly have a talent there! it looks factory made!

[DAVE BRADY]

If I end up making one I hope it turns pout as good.  Although once it is on it will not be seen.

Dave

[Gup holland]

I made it about 25 years ago I think. Had lots of trouble with pinking when engine was hot. Mate of mine did compression test ( then had no tools for it). What the outcome was exactly I don't know anymore but remembered the number 13. He said looks like a diesel 
Took a sheet of 2 mm copper and copied the original one on the sheet precisely with a scribe. Then find back the center of every hole. The cilinder was drilled with a holecuttervoor steel. The smaller one start with a small dril and build it up.
When you see you moved out of center , drill max dia and correct it with a needle (small file), I had one hole i corrected this way.
When you've got a drill, a set off file small and big ones, caliper, scribe, steel drills and a bit of patience , you succeed.
Here in Holland you can order copper sheet online by the cm needed, possibly in the UK also. I found even on aliexpress.
At least I think it's cheaper as 45£ for one gasket,  and is fun to do.

Good luck, cheers, gup

[DAVE BRADY]

Hi,

Just a bit of an update.  I have sourced a piece of 2mm copper about A5 size for £15.80 that will give me a gasket and a company that will cut it out for £20.  So with a bit of postage it will be about £40 so a bit cheaper than two 1mm gaskets.

Dave.

[TTJOHN]

Hi,

After a search only the British Cycle Supply Company (Canada) offer a thicker gasket at 0.080.  Not cheap especially with postage added.

Dave.

If I can find an old gasket somewhere I'll check on how much it would cost to make a batch of ten or so at whatever thickness you want, it's just the initial cost of doing a cad drawing etc, lett me know the thickness you want and I'll do a check. The firm I use only do gaskets for me, once the cad is done, they are exclusive to me, so I could actually have some made thinner after yours have been done.
Regards John

[DAVE BRADY]

Hi John,

As above I have ordered a piece of 2mm copper and found a gasket man who will cut it out for £20 so not too expensive.  However, it may still be worth you making the enquiries.  I do not know what the demand would be but that could be influenced by the cost.

If there are others out there who need a lower compression for easier starting, this is the easiest and cheapest way to go.  Also, if a head has been skimmed one time too many then the risk of valves hitting pistons can be elevated by using a thick head gasket to get the clearance back.

Dave.

[Allan G]

I think it would be worth doing, power loss will be negligible, yet starting would be easier and the thicker gasket should help improve sealing.

[DAVE BRADY]

Hi,

Finally sorted the gasket.  Sent the piece off for cutting but got it back unfinished and no charge.  The extra thickness was a problem but at least the bores and bolt holes had been done.
I ordered some rotary files and while waiting for them I cut off as much surplus material as possible.  So I fitted a 12mm rotary file in my drill press and set it to max speed.  Rather rough probably because it was not rotating fast enough.  A smaller 6mm seemed ok.  Still not dead smooth but it managed to get it done.  A bit of titivating needed so I put the rotary file in the Dremel and what a difference.  The Dremel goes much faster and the file worked so much better at the higher speed.  I did not over smooth the outer edges as they are not critical and I was getting fed up.
I did check the gasket on the barrels to ensure a good fit by putting a few head bolts in place.  One edge did protrude in to the bore a bit so I dressed this back.  It may not have been a problem but I thought that perhaps it may serve as heat spot or a weak spot so a few more minutes and I am now happy.  I won't post an image as it just looks like a gasket.

Dave.