Thinner head gasket = more power... but???

Waterfoul

Waterfoul

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Dec 13, 2004
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Location
Grand Rapids, MI
I understand the principle behind the thinner head gasket: Raise the compression a little bit and you get more power. But, on my 600 Vmax would this require a change to higher octane fuel? Gas prices being what they are, the extra dime a gallon at the station isn't something I'm willing to pay for an extra couple hp. If you can make this change without compromising reliability on regular (87 octane) gas, I might be willing to turn a few wrenches.

Thoughts??

'Foul
 

Higher rated fuel may not be required if your comp is only increased a bit. Im sure there are people on the site that have learned the hard way exactly how high you can go with your comp using reg fuel in a 600 trip, maybe they will chime in with their experiences.
 
It's not an exact science...Gas will vary a lot from station to station.. I would not change the compression at all if you do not want to run premium. I know gas prices are through the roof...but I look a it this way... Figure a dime more per gallon... then figure about hom many miles you will ride and MPG... then you can see what it would actually cost for the season...and see if it is worth the couple extra ponies to ya.. Personally I would do it because we only put on about 1000 miles per year...@ 13mpg that is about 80 Gal....@ .10 more a gal....= 8.00 for the year.. It's worth 8 bucks to me.. All depends what a few extra HP are worth to ya. :)
 
I have run a 600 and 700 triple (the 700 was piped) with a layer out of the gasket for several hundred miles on regular without a problem, that is no guarantee that nothing could, but its more of a safety cushion obviously to run the premium. Only problem I ever had was the gasket on the 700 started leaking after about 3,000 miles, had to replace, and didn't do it again.
 
Wait until you have to pull start it cold once. It'll rip your arm off. I removed the center layer on my sx700r. I haven't had any problems at all, except on cold mornings. It takes a few pulls just to get the pull cord to come out far enough to start her.

Crazy
 
you'll get better mileage (in the form of kg of fuel/kw/h anyways, meaning drive it with the same acceleration and speed as before, and you'll use less fuel, mash your thumb into it and use the extra power and it'll probably be worse) with the extra compression. usually enough better to make it cheaper, higher gas goes, the better off you are to do this mod, since the price difference between regular and premium is usually a set amount, the % difference between the 2 is therefor smaller the higher the overall price is.

sorry it's late and that's probably jumbled, coles notes version: if you want it to be cheaper to run, mod the gasket and use better fuel, odds are it's cheaper/mile
 
Today: 87 octane 2.69 per gallon 93 octane 2.89 per gallon. That's a .20 difference. I ride about 1500 miles a season or so... get 10 miles to the gallon ( it's a 600 twin by the way) so that's 150 gallons x .20, or $30 a year in fuel to do the mod. I guess it might be worth it because most of the trail side stations on the UP offer the higher octane only. Hmmmm... decisions... decisions...

Any other opinions?
 
I thinned the head gaskets out on my ’99 SX 600 by replacing them with a custom set of Cometic gaskets (0.015” thick). I have about 6,200 miles on this sled with the mod and use what ever gas is available (not much option in northern Wi. some times). I have never had a problem with this engine. In fact, I have yet to re-ring it and the compression is still in the 120’s.
 
I would have to disagree with spartasxr, I have a 600 twin that I race and trail ride and I have whipped plenty triple's with it, It currently run's 6.0's in 500 ft. and 6.9's in 660 ft. and that's in trail form! remember, it's not alway's hp. that win's races, sometimes it,s knowledge about what makes a sled move efficiently without cheating. email me if you need help. R.J. rj21@charter.net
 
rj21, spartasrx is just picking on me... we are friends who have fun jabbing eachother! He'd probably like to sell me his viper so he can get a new sled....

But like I said it's all about the $$ with me!!!
 
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