Snowmobile World banner

1 - 7 of 7 Posts

·
Registered
Joined
·
343 Posts
Discussion Starter #1
Does anybody know how much you could safely shave off the head on this motor ? The compression is 115 on both cylinders and thats my next question , how much more psi could you go ? The reason why I ask is because my other machine has 140 psi in both and it runs find on regular fuel . ???
 
5

·
Guest
Joined
·
0 Posts
have a 93 indy500 classic and last year have the engine rebuilt .20 over and i am running @ 140lbs each cylinder and it run fantastic although i have not had to have the head shaved at all i would expect your could probably take .10 to .20 off of it
 

·
Registered
Joined
·
179 Posts
:devil: I have a 145+ compresion out of mine 6 pull's when the engine is cool i had the hole engine rebult last year bored 10,000 over had her blue printed ect. I would recomend that if you have any more that 5000 to 6000 miles on the engine to change the rings and posibley the pistions or put a thinner head gasket in her made by legand performance. And don't cut anymore than 15000 of the head if you still want to run 92 octane hope this helps and you don't want to have any more than 150 psi in each cylinder
 

·
Registered
Joined
·
343 Posts
Discussion Starter #4
I was talking to people with the same sleds and they said 110-125 psi was the norm on these motors ! :nervous:
 

·
Registered
Joined
·
49 Posts
skimikedoo, You have to calculate your instlalled head volume divided into your displacement to find compression ratio and then use a formula in the performance handbook to find out how much to cut off. I'd give you the formula, but there's not room or time to expain it. Just be cautious before you lop off .015" or you might end up with a detonation problem. As for the compression differences, not every guage reads the same. 110- 115psi is normal. - XCorcist
 

·
Registered
Joined
·
4,869 Posts
I owned two Indy 500s :D

Compression was 115lbs on each same as my Indy 4 :)

Skidoo has always had more compression :thumbsup:

Lot easier to pull over a Poo :sly:
 

·
Registered
Joined
·
343 Posts
Discussion Starter #7
thanks everybody i think i will leave well enough alone , and sell it to get a bigger sled . to save this post from mad argument i will not tell what sled i'm eyeing next . :p :D
 
1 - 7 of 7 Posts
Top