Gasket Thickness Valve Clearance

HoneyBadgerRy · October 19th, 2015, 01:21 PM

I know I am unlikely to get an awnser out of this, but I figured it is worth a shot. Does anybody know the thickness and material of the base gasket and the head gasket? Also does anybody know the clearance between the valves and the pistons (ie how much can I shave off of the top of the jug before I have a probblem)? I have dirt cheap access to a engine tunning shop, so since the winter months are coming I am planning on getting three angle valve seats, higher compression, (run on 93 octane gas) play with cam and ignition timing, remove casting flaws from intake port, and polish exhaust port. I will keep this thread posted on how the molding is going, thanks in advance if you know the tolerances.

The gaskets are metal cruch gaskets and less than a thousandth of an inch thick.

HoneyBadgerRy · October 19th, 2015, 01:44 PM

Looking around it appears I have 0.020" to play with as far as valve clearance and 0.010" mill seems like enough for me anybody have any factual statistics?

Racer x · October 19th, 2015, 03:31 PM

The service limit on the head is .019 thousands. You can take .010 thousands of an inch off the block top. Don't cut the head. The valves are to close to the edge already. Ten thousands is enough to make a difference. And you can still run 13 to 1 JE pistons.

By cutting the block down you move the cam timing . So you need to be able to adjust that back to a better cam timing than you will end up with if you use stock sprockets with a difference distance between the crank and cam.

I have done all of this myself years ago. Makes about 34 hp and winds up nice on the right fuel.

HoneyBadgerRy · October 19th, 2015, 04:17 PM

How much did you mill and what octane did you end up using? Did you advance your ignition? How much do you need to alter the cam sprocket? Can you retard the can a whole tooth with the partial advance for better 10-12k performance?

Racer x · October 19th, 2015, 06:16 PM

I took .010 off the block. I have use different fuels. Under 110 octane seems to be the best. I have a BTR ignition module and use some different maps. Usually about 40+- deg of timing. Then 30-35 with nitrous.

I have not done much with cam timing. I made the tools and there is a thread someplace. But I just have not had a chance to test the engine. It's ready to go.

October 19th, 2015, 01:21 PM	#1
HoneyBadgerRy ninjette.org certified postwhore Name: Ryan Location: Beaufort SC Join Date: Aug 2015 Motorcycle(s): 05 Ninja 250, 04 KTM 625 SMC, 01 Xc250 Posts: A lot. Blog Entries: 3	Gasket Thickness Valve Clearance I know I am unlikely to get an awnser out of this, but I figured it is worth a shot. Does anybody know the thickness and material of the base gasket and the head gasket? Also does anybody know the clearance between the valves and the pistons (ie how much can I shave off of the top of the jug before I have a probblem)? I have dirt cheap access to a engine tunning shop, so since the winter months are coming I am planning on getting three angle valve seats, higher compression, (run on 93 octane gas) play with cam and ignition timing, remove casting flaws from intake port, and polish exhaust port. I will keep this thread posted on how the molding is going, thanks in advance if you know the tolerances. The gaskets are metal cruch gaskets and less than a thousandth of an inch thick. Last futzed with by HoneyBadgerRy; October 21st, 2015 at 04:36 PM.

October 19th, 2015, 03:31 PM	#3
Racer x ninjette.org certified postwhore Name: Eric Location: Iowa City Join Date: May 2009 Motorcycle(s): 2008 Kawmeracchi 350 2010 Project X Posts: A lot. Blog Entries: 54 MOTM - Sep '18, Feb '16	The service limit on the head is .019 thousands. You can take .010 thousands of an inch off the block top. Don't cut the head. The valves are to close to the edge already. Ten thousands is enough to make a difference. And you can still run 13 to 1 JE pistons. By cutting the block down you move the cam timing . So you need to be able to adjust that back to a better cam timing than you will end up with if you use stock sprockets with a difference distance between the crank and cam. I have done all of this myself years ago. Makes about 34 hp and winds up nice on the right fuel. __________________________________________________ Top speed 123.369mph. Ohio mile Worlds fastest 250 ninja
	1 out of 1 members found this post helpful.

October 19th, 2015, 04:17 PM	#4
HoneyBadgerRy ninjette.org certified postwhore Name: Ryan Location: Beaufort SC Join Date: Aug 2015 Motorcycle(s): 05 Ninja 250, 04 KTM 625 SMC, 01 Xc250 Posts: A lot. Blog Entries: 3	How much did you mill and what octane did you end up using? Did you advance your ignition? How much do you need to alter the cam sprocket? Can you retard the can a whole tooth with the partial advance for better 10-12k performance? Last futzed with by HoneyBadgerRy; October 19th, 2015 at 04:43 PM. Reason: Timing error

October 19th, 2015, 06:16 PM	#5
Racer x ninjette.org certified postwhore Name: Eric Location: Iowa City Join Date: May 2009 Motorcycle(s): 2008 Kawmeracchi 350 2010 Project X Posts: A lot. Blog Entries: 54 MOTM - Sep '18, Feb '16	I took .010 off the block. I have use different fuels. Under 110 octane seems to be the best. I have a BTR ignition module and use some different maps. Usually about 40+- deg of timing. Then 30-35 with nitrous. I have not done much with cam timing. I made the tools and there is a thread someplace. But I just have not had a chance to test the engine. It's ready to go. __________________________________________________ Top speed 123.369mph. Ohio mile Worlds fastest 250 ninja
	1 out of 1 members found this post helpful.

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October 19th, 2015, 01:44 PM	#2
HoneyBadgerRy ninjette.org certified postwhore Name: Ryan Location: Beaufort SC Join Date: Aug 2015 Motorcycle(s): 05 Ninja 250, 04 KTM 625 SMC, 01 Xc250 Posts: A lot. Blog Entries: 3	Looking around it appears I have 0.020" to play with as far as valve clearance and 0.010" mill seems like enough for me anybody have any factual statistics?