Try 40% with OD 77t hot plug

Whole new engine......

2035 pipe

I have the 2035 pipe What brand of 40%

We run Byrons Gen2 with 9% oil

Big quantities of 121VR-ST engines are now on their way to distributors and dealers.

Good to know. I was wondering when that was going to happen

Well I read this entire thread yesterday,all 1200 posts!
I noticed no one is running this engine in an oval car.
Im running an Ofna ULTRA GTP DIRT OVAL Late model on a dirt track in So Florida. I broke in the engine like the manual suggested and have about 5 race weekends on it so far ( a little more than 1/2 gallon).
Its runs incredibly strong and I have actually posted the fastest lap time of the day twice with it. After reading the thread i get that in different conditions it may run what some would consider hot. Though I have been racing for some time, this is my first Nitro car so I can only go by what I hear or read.
Im running a 97t with Oddonel 30% and the stock pipe that came with the Ofna kit. The track I run at is a loose clay oval with a 250ft runline.
Since we are running oval i am running full throttle most of the time and the engine seems to run best around 280-290 deg after a 4 min race. last weekend however i came off at 325 and toward the end of the race i came out of turn 2 and lost all power.Power came back by the middle of the back straight. I managed to finish the last two laps by taking it easy and it was idling high.The LM body has a 3 in hole in the windshield right in front of the cooling head but i dont know if i need to make it bigger or maybe cut an exit hole in the back window to let some heat out.
I have smoke all the time and it very responsive.
What can I do to help bring down the temp?
What is too hot ? I dont want to hurt the engine but I really like how it runs at 280-290.
All the other drivers think Im crazy running it that hot since they are running mostly Vspecs and come off around 210-225.
Any advice would be greatly appreciated.

Mine ran hot for about the first 2L so I richened and it ran like a dog but kept temps down. But once it got 2-3L the temps came down when it was tuned for full power and now it's going awesome around the 260-270 mark. Just give it a bit more time.

I don't think it would hurt to give it a little more air and venting I know last summer I hit 300 on a really hot day with my buggy. It is funny when you tell people the temp your running and they look at you like your crazy. You could take a small oil funnel and cut a hole on the passenger side. Run some small flex tubing and aim it to the middle of the top of your cooling head. Something I did with my SC8 and it helped a lot actually. Just a thought good luck

Got a problem with my reedy. Sometimes when going over a jump it will act as though the throttle is sticking. Almost like an air leak.
Nothing is binding. I got it to do it on the bench ONCE. The throttle was closed yet the motor was still holding a high, steady rpm. Once i hit the brakes it goes away and the truck acts normal.
I really have no idea what it could be. Ive had motors with airleaks before but this sounds and acts different.
ANyone got any ideas? Am i just over thinking this? It doesnt happen down the straights either. Only in the air.

Not sure but could it be that the clutch is not disengaging at certain times?

sounds like it could be something as simple as your linkage being wrong based on that statement. Sounds like at the neutral position your linkage has the carb pulled slightly open, then when you hit the brake it closes the carb further to it's idle position. Watch the carb slide and boot when you give it brakes, does it close slightly when brake is applied. If so the return spring and/or the blue collet is not set correctly. Should be a lsight bit of daylight between plastic swivel and blue collet, and there should be slight preload on return spring.

Would that cause the RPMs to hang like they do?

I need to check everything again just to be sure. But wouldnt the throttle get stuck open more often? And why does this only happen on certain days? Like the weekend before last it didnt happen at all. Now this last weekend it happened quite often.
I mean could it be an airleak? I would think that it would happen more often than only when i hit a jump. And its a steady, high rpm that drops to normal once i hit the brakes.

Its really hard to explain for me here on the forums. lol. Ill have to try and maybe get a video next time im at the track if its doing it.

I dont know. Ill have to do more testing once i get my truggy back togather and get back to the track.

My experience is that air leaks are often overated, and blamed more than they should be, it's often a mechanical issue. If there is a lot of "mushroom" effect on your clutch shoes than dremel the edge off and start with fresh clutch bearings, and also double check linkage. Also make sure you have a slight bit of back and forth play on the clutch bell front to back on the bearings. The clutch bell shouldn't turn when you roll the flywheel back and forth slowly.

You can check the linkage without being at the track or even having the car running. If you hit the brake and the carb closes further, that's all you need to look for to see if that is it, takes 2 seconds.

Any one have the Engine at the track yet? or any videos of the engine in action? thanks