Has anyone tried out the head mod in the 03/07 XRC?

yes , will post pics later

Can you explain or post a link.

I can't find a link for you but it is in Xtreme RC Cars issue #136 (March, 07).
Look in the Nitro Tuner department. Basically, grooves are made in the head button from the plug to the outside edge to speed up and fully combust the fuel. They tried it and dyno'd it and it seemed to improve horsepower and torque.

yes ive done it to.

German, did it work for you? How much material did you need to remove to make it work? Any pics?

the results will be in soon, there wasnt much taken off, just a little bit.

As not to infringe any copyrights problems with xrc. You guys might have to get the copy of the mag yourself.

O.k i decided to go with the 3 groove boost >


Step one. Make sure my wife is sleeping

Step two get a beer and carefully pulled out a kyosho Vone RR
[ Was on ebay last week and not sold i took it off for this project what the heck. i can still drive it and break it] And aha it has a new engine.

Our subject a os .12 max 12TR(P)-T. Nib when installed 1 year back and i did a break in of two tanks and the yadadada and back to the bench err... floor.

The test subject and the rc bible that make made me do it.


The Warning


Ehhhwwww Green Stuff on piston and button head .The process is called oxidation i think , Common in nitro engines that are not used for a very long time.And the fools on ebay never believed me the engine is new.Altough old but still new...



O.k where is the boost port?.. if exhaust port is where the exhaust is and i'm pointing at the right direction.


Marking towards the boost port



More markings.. As they say measure twice cut once.


Ladies and gentlemen ...... start your engines.....




Honestly if there was improvement, it's unnoticeable. Maybe with a proper tool and the exact dimensions to create a proper fuel drain should be left to the experts .

But still i'll post here if i see any fuel savings or if i can flip the v one on a straight .

This is probably why you did not see any increase in power, these are the only way's I have see done:

I also have tried it my self: and have gotten some top end improvements

Its not off this button is for a axe rossi x3 engine so the bolt pattern is different.

Here is a whole thread on the head mod:
http://rctech.net/forum/showthread.php?t=124968

O.k i'm powering up the dremel

looks more like oil from your fuel, not oxidation. my engine never turns any colors aside from a golden brown after many gallons of fuel.

doing it that way requires a major gain in combustion chamber volume meaning you haft to totally reshim where as the other way you dont. Both will get you the same results though.

Here's one from Maximo:
MaXX LRP button MOD! **ignore the OS box!

nice,

We were actually try out the one from the magazine. where it's dyno'ed