raising compression/skimming the head

Want the specs for a valve adjustment? Can you provide tips for bleeding brakes? Please use this section.
Post Reply
adg
New Poster
Posts: 17
Joined: Thu Mar 13, 2003 7:48 pm

raising compression/skimming the head

Post by adg »

Anyone know how much I can skim the head and top of the block in order to get the last few HP ??<br><br>I dont want to take it too far so that Id need to run on AvGas, but there must be some reasonable amount like 20 thou' that can be safely removed ?<br><br>Im pretty certain that such a small amount wont really affect the piston/valve clearance.<br><br>ade <p></p><i></i>

exupturbo
Veteran Poster
Posts: 247
Joined: Sun Mar 10, 2002 12:27 pm
Location: Essex, England

I wouldn't

Post by exupturbo »

Buy the Wiesco 1040 kit if you would like a higher CR, on mine it gave close to 13:1. If you skim the head/block then there is a very real risk of valve to piston contact<!--EZCODE EMOTICON START :( --><img src=http://www.ezboard.com/images/emoticons/frown.gif ALT=":("><!--EZCODE EMOTICON END--> <br>I had a set of big end bearings fail and there were witness marks on the pistons from where the valves had touched, no damage done but it does prove that there is not much room for skimming.<br><br>Mark <p></p><i></i>

adg
New Poster
Posts: 17
Joined: Thu Mar 13, 2003 7:48 pm

raising compression/skimming the head

Post by adg »

I didnt realise the piston valve clearance was so tight!<br><br>thanks for the help.<br><br>ade <p></p><i></i>

yzf 1
Posts: 8
Joined: Thu Jun 05, 2003 6:01 pm

raising comp / skimming heads

Post by yzf 1 »

My '97 t/ace has had the top of the barrels planned enough to give us approx 14/15:1 comp ratio. It has a very mild port job, altered cam timing, aftermarket 4-1, flat slides & runs on methanol - hence the high comp-ratio. The bike runs well & for the last 3 yrs have had no trouble - hope this helps. <p></p><i></i>

adg
New Poster
Posts: 17
Joined: Thu Mar 13, 2003 7:48 pm

raising comp / skimming heads

Post by adg »

yzf 1: how much did you have removed? <p></p><i></i>

yzf 1
Posts: 8
Joined: Thu Jun 05, 2003 6:01 pm

head-skimming

Post by yzf 1 »

We ended up taking off around 0.5mm Keep in mind that this engine will not perform on pump gas or aviation fuel without some octane boost type products <p></p><i></i>

flyingcircus68
Veteran Poster
Posts: 258
Joined: Sun Apr 07, 2002 8:10 am

Re: head-skimming

Post by flyingcircus68 »

Methanol?<br><br>Do you race? I can't imagine you can go to far on the road without someone trailing behind you carrying gas cans full of methenol. The energy density is so much lower, so fuel is consumed quickly. Have you ever dynoed it? I would imagine that it runs furiously with output in the high 100s. <p></p><i></i>

yzf 1
Posts: 8
Joined: Thu Jun 05, 2003 6:01 pm

head-skimming

Post by yzf 1 »

Yes, No, Yes, No, & YES<br>Its the off-season here, so time to go make some power!<br>Safe riding<br>C.U.<br><!--EZCODE EMOTICON START :evil --><img src=http://www.ezboard.com/images/emoticons/devil.gif ALT=":evil"><!--EZCODE EMOTICON END--> <p></p><i></i>

Post Reply