Overheating Damage?

[rovanmadlunatic]

hi. I have an OBR zenoa ful mod g340 .34cc. I us castor 927. This is what OBR recommends. They want me to run 32:1. I ask them few times and they insist on 32:1. They say it is the best oil and at 32:1 it will be cleaner. What do you think.

Just remember that A leaner fuel mixture leaves less margin for error when tuning. Settings you could get away with at 25:1 you wouldnt at 32:1. You could always go 28 or 30:1 and see how it goes then up to 32:1 if you feel comfortable with it. Less scrupulous engine builders might tell you that because it will likely make slightly more power which makes them look better and also might bring you back for a replacement that much sooner. I don't think that Is the case with OBR.They seem to have a good rep and want to keep it that way. Thats just a thought really as I have no experience yet with leaner fuel mixtures.

 

[atom3624]

I was simply saying nearly all who run for 'extended periods' run 25:1.
Boats will probably be at high throttle settings for a higher %age of the time, but perhaps the load on the motor is less, than a land motor encounters - could be an interesting comparison for someone.
On-/Off-ROAD installations for extended periods people prefer 25:1.

Al.

 

[MonsterAir]

Not speaking for Al, but remember the comparisons.
Boat guys run decent periods of time, and 90% of it nearly wide open.
They will mix 8 - 10 oz of oil per gallon in order to keep their engines cool, and keep them from having lean engine issues.

Higher RPM will require more fuel, which carries the oil, which cools the engines and lubricates under high heat conditions.

Other question is where are you taking your temp reading at, because that alone can be giving you false High temp readings ?

3 or 4 fins above the exhaust port. After talking with you in the other thread about where to take readings I got a little unsure where the best place was so I gave OBR a call and he told me to take it there

 

[looker2756]

I was simply saying nearly all who run for 'extended periods' run 25:1.
Boats will probably be at high throttle settings for a higher %age of the time, but perhaps the load on the motor is less, than a land motor encounters - could be an interesting comparison for someone.
On-/Off-ROAD installations for extended periods people prefer 25:1.

Al.

I agree with you, and I have always ran 25:1 with Never a lean problem ever in my land based models.

3 or 4 fins above the exhaust port. After talking with you in the other thread about where to take readings I got a little unsure where the best place was so I gave OBR a call and he told me to take it there

I would still question the temp readings you are getting.
Not saying you are doing it wrong, or definitely not saying OBR is telling you wrong.
Base of the spark plug right at the center of the combustion chamber is where you will get the true reading, Just saying ... LOL
In the few times that I have been exposed to overheating engines, somewhere around 280 the engines I have seen lose performance bad, and start to have vapor locking type symptoms, due to fuel boiling in the carbs, or the inability of the engine to keep a fuel air mixture due to Extreme cylinder temps.
The one specifically that we got to see had a radio with onboard temp sensor reading back to the transmitter, and it went from 270 to 280 Very quickly, and had these issues.
With that being said ...
Nearly all overheating issues are caused by one of 2 things.
Air leak causing the engine to run lean due to the inability of the carb to deliver fuel mix to the engine effectively.
OR
Needle tuning issue, and having a Mainly high speed needle in to far, causing a lean mix allowed to enter the engine.

I Highly doubt that an oil ratio is going to be an issue for the problem you are having.
That is what I was attempting to explain in my prior post about boats, but I feel like that point got lost.

Just to be clear, in Running a QSAC 1/4 scale car, I have actually ran a 100:1 mixture of Amsoil in it with Zero issues.
Tuning is going to be where I would look first.