SXVChris
New member
I checked the compression on the viper and got 125-125-110. Is this ok? I installed new rings last year. I did notice a small scratch on two of the cylinders - one of which is the lower compression cylinder. Is it time for a whole top end rebuild? There is approx. 6800 kms on the machine.
Thats good to go the pto cylinder comes stock lower than the rest so it.makes it easier to jwt by being able to jet the same across all three cylinders
snoprokidf6
Member
Same ordeal with my sled, did rings last year, and have 125-125-110. Staggered compression as stated above on the viper motors.
super1c
Super Moderator
X3 and if you go to an opticool head gasket take another 5psi off that across the board.
SXVChris
New member
Thanks for the replies everyone!
Agpetro
Member
super1c said:
Thats odd. I have the opticool head gasket on my viper and it was 125psi across the board. Must be because of the head mod i had done by bender.
super1c
Super Moderator
Agpetro said:
The head mod will even out the comp. All three of mine with the opticools are now down 5psi across. Last year there was a post about this and it seemed to be the same with everyone else.
Agpetro
Member
I know that it evens out the compression. I was just saying that bender must up the compression on their head mods so it ends up at 125psi with the opticool because mine never dropped the 5psi with the opticool.
ottawaair
New member
Yes, they have to open the 2 smaller chambers to match the pto chamber, then machine head surface to get back to desired volume. Knowing you're going to use the opticool. You can also remove the middle layer of gasket to tighten it backup some.
Agpetro
Member
ottawaair said:
how much do you think it will raise the psi if i take out the middle gasket?
ottawaair
New member
I would check the squish before deciding to remove anything. Depending on that number, you can decide to remove layer or even cut the head a bit. To answer your question tho, it prob won't raise the cranking compression maybe only a few points. Will change installed cyl volume and should result in better throttle response. Chech squish first tho, to see where at right now.
dubla92
Member
Thinning the head gasket will result in the squish being too tight on the center and mag. It will be good on the PTO though. Best way is to have the head machined for even compression and stagger the jetting.
Agpetro
Member
dubla92 said:
My head has already been machined and has even compression across the board. Ran it the last two years with no problems. I was just wondering how much my compression would go up or would it even make a difference if i took the middle layer out. I did notice the opitool gasket is a bit thicker then the shock oem gasket when i switched them. Might try it and see what i come up with.