30.5 OBR Prostock

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Rep732 said:
I have to say I'm perplexed at your statement @Troopermaniac , how is it a air cooled harley engine can go 100k miles but a "model" engine cannot go a full race? The concept of an engine needs to work in the real world and if it does congrats you just made a functional object called an engine. Yes you can slap cheap metal together and make it run but it won't last and that's seen with the clone engines but for an obr I think they use better metals so they don't kick the bucket on the first heat. And really the 3rd thing in mind is fuel economy? If I run through a gallon of fuel on a bash outing I'd be ok with that. Hell I'd be happy with better fuel economy on my raptor but I didn't buy it to get fuel range a Honda does.
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Less pit stops the better tbh the power to weight ratio is already amazing even with stock Zenoah engines. I think these OBR engines are just a small step beyond which is probably perfect for racing.

In terms of heat, the hotter the engine the more fuel consumption it will have. Dunno if this would make a difference in circuit racing due to the fact that I am not sure they even run long enough for heat or even for that matter fuel consumption to be an issue.

The more realistic answer probably comes down to race rules on engine size and tune.
 
Troopermaniac said:
Less pit stops the better tbh the power to weight ratio is already amazing even with stock Zenoah engines. I think these OBR engines are just a small step beyond which is probably perfect for racing.

In terms of heat, the hotter the engine the more fuel consumption it will have. Dunno if this would make a difference in circuit racing due to the fact that I am not sure they even run long enough for heat or even for that matter fuel consumption to be an issue.

The more realistic answer probably comes down to race rules on engine size and tune.
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My 2pence take on this.

In bashing we tend to run WOT across fields etc for long periods of time, normally up to a minute at a time sometimes longer if running in an oval, on a track the throttle is constantly varied with WOT only being 2-5 seconds so heat shouldn't be an issue for fuel consumption.
Also while bashing I know I use more fuel than at the track, but at the track I use more of my battery pack due to the amount of corners and braking.
On my truck with the 32 Zen I get 45mins+ from a tank of fuel, bashing is about 30mins to a tank, my tank is 750ml if my memory is right.
 
Since I have this thread started Ill just post here. Was having a stall issue at 10 minutes of run. Fuel bulb was dry so I went ahead and replaced the aluminum carb isolator with a plastic zenoah piece. After reassembly it kept flooding. Had to turn the low screw in and choke it to get it started and then quickly backed out to around 1-1/8 turns. Tuned in great and beat on it real hard for about 15 minutes. Thought maybe on the lean side but the power and rpms were clean. Started to bog and figured it was low on fuel, then it stalled. Added fuel and would not start back up, fuel in the bulb. Pulled the plug (was brand new) it looked absolutely terrible. Real dark with debris that appeared to be pieces of carbon on the electrode. Brushed it off real quick and went to start it. Same flooding condition as before and a no start. The plug looked similar to when I got it, but the difference being the electrode was completely missing then. Want to rebuild the carb but am having a bit of a time figuring out how to identify the model. It is a Walbro with a choke, do they have numbers on them anywhere? The rest of the motor appears fine.


Thanks
 
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