Start with a 41021 (medium) or a 41020 (long) header with the 9901 pipe. There are big differences with those headers :nod:

Questions about BTTA.
 

I have a BTTA with about a gallon break-in on it and its runs good but last race it was hard keeping the temps up. The motor is coming off at about 180 but almost seems like its lean bogging on the bottom but it runs good on top. When I try to richen the bottom a hour or so it loads too up quickly but when I lean it a hour or two the idle shoots up even with proper gap. My needles are both just about a half to quarter turn above flush. Anyway what I'm asking is where is a good spot to start with needles on my BTTA when race tuning also what carb insert do you recommend for a tight technical track? Thanks for any replies!

A good place to start is flush on both, You'll probably turn the top in more than that. Check and make sure the carb is not loose, that can screw with the tuning. 180 is way too cold. We were running 220-230 in 20 deg weather. Something does not sound right with what your doing.

Lean lsn , adjust idle then try again , probably have to richen hsn :nod:

Yeah it's probably closer to 200 I use a cheap Duratrax temp tool and I also seal all my motors as soon as I get them. I preheat to 200 before each run and I ran a sock on the head during first couple quarts to keep temps over 200. Our track is pretty big but real tight and technical so I think that has alot to do with low temps but I am going to flush the needles and check idle gap then test and tune some more. Thanks for the info guys!

any new, exciting , 2012 off-road engines coming down the pipeline? :tire:

How fast you wanna go ? ;)

lol,,,i want A Smooth, reliable race engine, for my new xray xb9 buggy when it gets here, last buggy motor i had was a houston tuned plus4c-team, and that was smooth as butter!!!! Not sure on the current crop of motors, is nova putting out a new lineup for 2012?

Have a look on the Novarossi web site there new line of 2012 are up same engines just a few changes.... The BTT in standard form is a perfect power plant for the XB9 All Tho a filled crank would make it just that bit nicer....

What does a silicone filled crank do?
If you remove material from the crank, the crank would be lighter if you add silicone instead and with or without material removal the flow through the crank must be better with the gentle curve the silicone makes.
But, can you feel the difference at all?

you cannot push mixture..the silicone does nothing for the flow.....mixture will naturally follow the shortest path on its own...putting filler there can actually slow it down as it creates drag.....short side radius is what matters....... putting filler in the crank just stuffs the crankcase volume a little...

If you want smooth AND powerful across the entire RPM range, you should take a hard look at the CRE BTT. It is the perfect buggy engine IMO.

If you want something that is more punchy down low but doesn't rev out to the moon, the FM X3 is also very nice.

I have a CRE Nova P5 otw and I am told it is the perfect balance between the two mentioned above.

Of course I prefer modified engines over stock units, so I have no idea how they compare in stock trim.

Nice Neal!

Thanks a lot :nod:

silicone filled intake ramp does do a few things , most noticeably the reduction of the staged idle by filling an airpocket that completely disrupts incoming flow of air/fuel when going from high vacuum to low vacuum on the intake of the crank , noticed a HUGE difference in the way the engines tuned off throttle and it threw me for a loop back in '06-'07 ish when the 821b was the first engine to come with the lightened crank that was unfilled . one thing i can tell ya is every single one of my multi repeat customers from all over the world have tried both and prefer a filled crank , we all do things a lil differently , we all have different opinions , we all feel things that others dont .


i have met well educated people in all different fields who thought they were the masters of what they studied in miss even the simplest of things looking a project over because they were too concentrated on the "deeply technical" aspect of the job ;)

If im running a BTT on 30% should i remove any of the head shims?