Head gaskets or shim for RX1?

[LANEO]

Looking for best set up to get down to around 9.5 to 1. Doest anyone have experience with using 3 head gaskets or .009 shim? Whats the best way to go?

 

[rxrider]

You could use 3 stock yamaha head gaskets to get about 9.5:1 that way. (MCXpress delivers 3 with their 240 HP rearmount so you could stack gaskets, no problems). A set of 10:1 JE og Wiseco low compression pistons would be nice tho together with on or two xtra gaskets, should get you close. Anyone having the xact numbers using 1 or two xtra gaskets?

 

[Jonny Rocket]

Here is something Superdave posted some time ago. You can find a lot of stuff if you do a search.

J.

www.powderlites.com
RX1 Compression ratio
Stock pistons

Ratio 10 to 1 pistons
Stock gasket .030 11.8 .030 10.
.060 10.50 .060 9.05
.090 9.41 .090 8.28
.100 9.11 .100 8.00
.110 8.83
.120 8.38

Stock RS Vector Compression ratio
stock .020 11.3
.040 10.55
.060 9.89
.080 9.33
.100 8.83
.110 8.6
.120 8.38
Shims are made in .080 and can build .090, .100
.120 Total in head on Vector cam sprockets slotted with lobe centers set apart more and 4 degree retard timing key running on 14 lbs boost seems very responsive and runs with RX1 at about 2 lbs boost less.
Stock exhaust on Vector is about 4 lbs more boost compared to Turbo muffler.

Boost ratio Boost Ratio 5000ft
8 11.8 17.22
8 10.5 15.21
8 9.41 13.53
8 8.00 11.35 sealevel 12.35
14 8.38 15.36
20 8.00 17.88

 

[Jonny Rocket]

OK that didn't turn out antything like it was suppose to. here is the link to the thread. you will have to download the file under the picture of the Head gasket on the thread.

J.

http://www.ty4stroke.com/viewtopic.php? ... ad+gaskets

 

[rxrider]

Thanks to SuperDave for posting the exact numbers, and Johnny Rocket for posting the link.