Cometic head gasket for 120?

[cruzmisl]

Anyone have a part number for a .030" Cometic head gasket for a 120? Just want to bump the compression a bit and want to be sure I order the right one. Any suggestions for a good vendor?
Thanks,
Joe

[No Cents]

If it's a 120R with a standard 4.060 bore...the .030 Cometic head gasket part# is:
C9070-030
Listed $44.99 a set.
Cometic is right below you in Ohio...and will sell direct.
Their phone number is:
(800)752-9850

.030 milled off them MVA heads and a .030 Cometic gasket will wake that 120R up!!!

Just my 2 cents...from No Cents

[aubeagle]

Cents, With .030 being milled and the .030 head gasket what kind of increase in compression could be had. I must be reading to much since it get the brain rolling in warp speed.

S.

[cruzmisl]

thats perfect. Thanks brother.

[No Cents]

It puts the static compression right at 11.0:1 with a .030 cut on the heads and a .030 head gasket. Gives the 120R a lot better bottom end pull...the stock 266 cams love the added compression.
It produces pretty much the same results as running the domed piston that GMR offers for the 120R.

No Cents

[JohnCA58]

When I call Cometic for my 120, I ask for a .027 Head Gasket at 4.090 and a week later it is on my porch.

[Tribal]

While you have the heads off, check piston height. You can fine tune deck height with a thinner or thicker base gasket. From memory Cometic base gaskets are $20.00. If front to rear cylinder height is not the same, get one thickness for the rear cylinder, and a different thickness for the front.

[cruzmisl]

Is there a tutorial on how to check the deck height? I'd like to be certain I'm doing it properly.

[Tribal]

At one of the site sponsors, Big Boyz. Here's the link.

http://www.bigboyzcycles.com/showthread.php?t=92

[splitting_lanes]

I find that the solder method is the easier way to check squish, as you can do it before disassembly - here's one example:

http://hammerperf.com/ttcheckingsquish.shtml

I prefer to just leave the motor assembled and use a long peice of solder with a 90 degree bend in it inserted through the spark plug hole and held against the cylinder wall directly above the piston pin.

I check it on each side of the piston, and shoot for .030-.035 squish -- and if it's higher, get a thinner base gasket to correct.

If your squish is set nice and tight you'll notice a snappier midrange and less pinging (my compression is much higher than stock, running the same cam, but getting less pinging than before -- and I attribute it to having the squish set correctly)

[nw_guy4_fun]

Use this bridge and a dial travel indicator

[Knighty-Knight]

Originally Posted by nw_guy4_fun

Use this bridge and a dial travel indicator

This device measures squish clearance?

[nw_guy4_fun]

Add a travel indicator and then read the actual TDC piston depth, then an intelligent head gasket decision can be made. I know typical on the 120r but you never know for sure until it is measured and straight edges and a feeler gauge is a recipe for problems in the hands of most.

[mike jesse]

Randy's vid. will walk you through the measurements.
Watch the vid. at the top of the page.

http://kingofcubes.com/?page_id=148