Any update?
Have you stuck with the Himalayan map?
I’ve got all the parts and prepping the install myself.
J-Engine 500cc Thread
- Thread starter sam2019
- Start date
Have you stuck with the Himalayan map?
I’ve got all the parts and prepping the install myself.
500 cc install complete. I’ve been testing it for about a week and a half.
The bullet is running wonderfully! The power gain and added torque is a huge upgrade. I did install the V4,and FuelX Pro. I did not dish my head.
I’m running 91 octane with Boostane octane booster bringing it to about 98. I’m experiencing no knocking with the booster, I did experience knocking under heavy acceleration with a straight 91 octane.
However, considering that these motors are designed for fairly low compression, I am somewhat concerned about the ability of motor to handle such high compression overtime. I’m considering open it back up and dishing the head. Although I’m also reluctant to give up the gains that the extra compression achieves.
I will continue testing and update.
The bullet is running wonderfully! The power gain and added torque is a huge upgrade. I did install the V4,and FuelX Pro. I did not dish my head.
I’m running 91 octane with Boostane octane booster bringing it to about 98. I’m experiencing no knocking with the booster, I did experience knocking under heavy acceleration with a straight 91 octane.
However, considering that these motors are designed for fairly low compression, I am somewhat concerned about the ability of motor to handle such high compression overtime. I’m considering open it back up and dishing the head. Although I’m also reluctant to give up the gains that the extra compression achieves.
I will continue testing and update.
About that: In my experience the loss of gains weren't perceivable - I am sure they can be measured but I had to do the compression reduction bc fuel here is very bad - and after i did I lose the knocking but not the power.
That’s good to know.
Estimated power gains from one point of compression are estimated between 2% and 4%. Although you also need to calculate dimension return. So you’re right it’s probably not a significant loss.
I think I’ll be cautious and go ahead and dish out the head. This will save me from using octane booster as well.
Thank you Sam,
When you compare the combustion chamber design of the J to the 411 Himalayan you see huge differences.
I did anyhow
Start with the 410, the piston was not designed for the J combustion chamber, the Himalayan piston has a more symmetrical crown where as the J piston is obviously designed for the J head having a raised area that is aligned with the combustion chamber.
This pic is stock J head after being removed from my 410 build gasket is in place.
there is a 6mm Squish ring formed which may or may not be of benifit, certainly it was not designed to be like this.
My latest build is same cc as yours albeit my piston is different, this what my combustion chamber looks like now ( well not now as it is bolted to the cylinder
)
Plenty of room there for 4 valves?
Gets Dynoed 27 October, chances are it will produce about as much as a Himalayan 411cc with minor mods, I'm guessing 24 on the same dyno my Himalayan stock produced 22 at the back wheel!
I did anyhow
Start with the 410, the piston was not designed for the J combustion chamber, the Himalayan piston has a more symmetrical crown where as the J piston is obviously designed for the J head having a raised area that is aligned with the combustion chamber.
This pic is stock J head after being removed from my 410 build gasket is in place.
there is a 6mm Squish ring formed which may or may not be of benifit, certainly it was not designed to be like this.
My latest build is same cc as yours albeit my piston is different, this what my combustion chamber looks like now ( well not now as it is bolted to the cylinder
)Plenty of room there for 4 valves?
Gets Dynoed 27 October, chances are it will produce about as much as a Himalayan 411cc with minor mods, I'm guessing 24 on the same dyno my Himalayan stock produced 22 at the back wheel!
The QS connector is for the optional quick shifter.
