Sq4 Block to crankcase spacer?

[john.bebb]

Hi Peoples,

Please, through innumerable skims o'er the years... piston crown periphery is become proud of the liners...

I believe that one of our European colleagues is able to supply a base gasket spacer.

Please would someone be so kind as to forward contact details for this gentleman? Thank you.

Cheers, John

[GuyWalton]

As no one has answered you query , dont know myself , What I would do is to make my own base gasket out of a thick gasket paper . The original is very thin but you can purchase various thickness gasket paper up to 1,5mm thick . You could put more than one on if you need it thicker .

[Gui.dorey]

John,
I don‘t know if anyone ever made a spacer, but the suggestion above would also be what I would try. I had a similar problem with my original head which had been skimmed so much by the PO, that I didn‘t have enough valve clearances. Even if I did, I would probably have too much compression, which is also not good. In the end it was hopeless and I had to find another head to replace the old one.

[Paul_Linden]

There is this place in the USA that makes custom copper gaskets, mostly for motorbikes. I’ve never used them but they have good reviews on other bike forums. You could send them a paper base gasket as a pattern.
https://coppergaskets.us/shop?olsPage=products

[JohnnyBeckett]

Their has been posts on this forum befour about crankcase spacer hope he will see you post and gets in touch with you

[nevhunter]

You usually have enough metal on the Piston crowns to machine a bit from there if that's your only problem. Spacer at the bottom may require longer studs and your cam follower blocks are up from the cam more.Thin gaskets are the best at cylinder BASE locations so you don't just load near where the studs are. Nev

[john.bebb]

Nev - thanks for your comments - I'll see what the protrusion is on initial dry-fit assembly....
& do some measurements & sums to ascertain any possibility of valve to piston crown clash
Cheers, John

[bob cottam]

Hi, What pistons are you using?- I had this issue too and I found that the IMD pistons have a crown height that is significantly higher than say, Hepolites. Somewhere on this forum I posted a photo to illustrate this with one of each type of piston linked side by side with the same gudgeon pin. I found there was plenty of meat on the IMD pistons to machine down to comparable levels with the Hepolite, and with a slightly thicker base gasket thrown in, I got to a situation where the edges of the piston crown (MK2) were level with the block top face.... which I assume is about right. It runs like a swiss clock …..Bob C

[john.bebb]

Hi Bob - I'm using IMD, the hi-comp style in a Mk1...
Here's a excerpt from a msg string I had with Andy Wright of IMD; -

Hi John,
Yes, this is the correct compression that you require.
We also have designed the piston in such a way that there is enough material on the top that you can lower the compression if desired.
As soon as I hear from our partners, I will give you a call and we can get the order moving forward.

Best Regards
Andrew
A Wright
http://imdpistons.com/

Running like a Swiss clock? - hope mine does similar when it's rebuilt (bottom end currently with Hamlins)...

Swiss clocks are fine until the time it says "CUCKOO"....

Cheers, John