10:1 or 11:1

[1red400ex]

will a stock 400ex rod work fine with 416 or 426 piston on either of these pistons. They make a kit for 10:1 or 11:1, is 11:1 too much for a stock rod

[khen]

I run the stock rod with the 11:1 416 and it's fine. A lot of others on here do as well and I haven't heard of any problems.

[400exrider707]

yeah if its a wiseco its not even 11:1 so dont worry. Either way you should be fine.

[rr4406pak]

If it is not 11:1 then what is it???
How can they false advertise? That would be illegal!

Thanks...

[cals400ex]

it will be less than 11:1. one problem lies with the stock ex gaskets themselves. these pistons were actually designed for the xr dirtbike in mind. they use thinner gaskets. however, with thinner gaskets, i have heard the wiseco's are still a ways off. i don't really know though. they may have fixed this, they may not have. look into je or ross if your not happy.

[rr4406pak]

OK, what if one uses aftermarket gaskets, like Cometic, rather than stock replacements? Would different brands of aftermarket gaskets be different in thinkness?

[khen]

When I bought my gaskets I emailed C&D and asked them if they sold gaskets that make the Wisco 416 piston a true 11:1 and they said they did so I purchased mine from them(Cometic steel). I've also heard that the Wisco 440's are further off than the 416's. :confused:

I need to test my compression one of these days to see where I'm at.

[400exrider707]

They are still off. To get the 11:1 with a wiseco you have to run NO base gasket and one pieve of the three piece head gasket. Then it is right around 11:1. Technically its not false advertising because like cal said it was made for the XR. Technically speaking you purchesed the XR piston. Im pretty sure C&D has a standard gasket kit and a "thin" one. Or you could buy the XR head gasket to raise it a little bit. I'm running the 11:1 wiseco in mine and it did make a big difference.

[BIGRED400]

I have a 416 JE 11:1 w/stock rod, I think alot comes in to play with detonation,Run good gas ,I run 93 w/octane boost or straight 100 octane race fuel, I did a search on this and alot of engine rods get stressed when engine detonation occurs from poor octane levels and then engine damage happens, I think it is cheap insurance for your motor. Airplane fuel is not a good alternative either, it is made for low RPM's at high altitude, Race fuel is made for high RPM's at low altitudes,kinda makes sense .Go to Articles up top, click on it ,go to Mickey Dunlap 2, at the bottom he discusses head gasket's and "flame quench".

[400exrider707]

Originally posted by BIGRED400
I have a 416 JE 11:1 w/stock rod, I think alot comes in to play with detonation,Run good gas ,I run 93 w/octane boost or straight 100 octane race fuel, I did a search on this and alot of engine rods get stressed when engine detonation occurs from poor octane levels and then engine damage happens, I think it is cheap insurance for your motor. Airplane fuel is not a good alternative either, it is made for low RPM's at high altitude, Race fuel is made for high RPM's at low altitudes,kinda makes sense .Go to Articles up top, click on it ,go to Mickey Dunlap 2, at the bottom he discusses head gasket's and "flame quench".

For someone who is so up on the subject I surprised you run octane boost. You should have found in all of your "research" that octane boost isn't good for an engine and causing gumming.

[Jake250ex]

how high comp. can you go on the stock rod (stock bore)?

[400exrider707]

Originally posted by Jake250ex
how high comp. can you go on the stock rod (stock bore)?

I wouldn't go more than 11:1, but you should be ok with 11:1

[BIGRED400]

Originally posted by 400exrider707
For someone who is so up on the subject I surprised you run octane boost. You should have found in all of your "research" that octane boost isn't good for an engine and causing gumming.


Only in a pinch .I've read where some people actually make a high octane home brew from hi test w/ 30 % toluene mixed in and some add a small bit of transmission fluid for lube, I agree the best is good race fuel or a good mixture of 93 mixed with race fuel, a good article is this , click on the "custom blending chart" in this article for desired octane

http://www.osbornauto.com/racing/dragster.htm