Pump Gas & Booster for 0540

[WallyGator]

I have never run any gas but av gas in my 0540 but I am finding harder to get to the airport.Will it hurt me to run pump gas with octane booster .If not what does everyone run?
Input please
History
0540 Jr J motor
28 hours still on mineral oil

Thanks

 

[Daddy Dave]

There is still reasonable AV Gas in Polk County at Wally's in Dundee and off 540 in Eloise.

Hard to stomach airport prices.

I have run my 0-540 on Chevron 93 Octane with Marvel Mystery Oil added. I am very careful to watch my engine temp and to never cut if off after any hard running. I try to run easy when on that mix.

 

[blackpowderscout]

I read an article that someone here had a link to...I believe it was Jim...anyways, it was showing how ineffective the octane booster was. What I got out of it was that you would have to use a bunch of bottles to make it worthwhile and for that price you might as well buy avgas.

I've run 93 in my 0470 and can't really tell much difference. It might get a little warmer after extended running. I'd follow BigDaddy's advice and you should be ok.

Adam

 

[cfth]

Wally,

I spoke in length with Jr. about this as he rebuilt my 540. There are a couple of factors to take in consideration but as bigdaddy said you have to watch the temps. Per Jr. the straight valves run cooler then the angle valves. In addition do you have a shroud. I try to run 50/50 av and pump gas because of the price but I also just put a shroud on my boat and I do have an angle valve.

Thunder or one of the good mech. on here can correct me if I am wrong but I believe that the advantage of the av gas is not really the oct. but the lead. So would be better to go with 93 octane and a lead additive. I have heard of the Marvel Mystery oil as an additive but never used it. Also as Bigdaddy said let the motor idle for a few minutes and cool down before you shut it off. I always lean mine (vs. shutting off with mags.) out but I think that's another issue to discuss later.

 

[WallyGator]

I would hate to tear up a new motor for a few pennys. It is just a 20 mile ride for fuel here.But it sounds like it is the best thing for it to stay with av gas.
This being the first real airboat I have owned I am going to treat it well.After I run for a long time my guage gets to about 160 I have not checked it with a heat gun to see if it correct.I do not have a shroud on my motor.
Hey,I have a question!!! When I put mufflers on will that change the temp?.
I have gotten on the list for suppertraps for now.

 

[jim]

I have never tried this stuff. It's hard to believe that it is really lead. Maybe you can check it out.

http://tetraboost.com/

Jim

 

[marshmaster pat]

I was doubtful about those shrouds, but at least one person (Duckhunter ?) from LA that posts here has one from Marks. Mark and Duck ?? said the same thing, they drop temperatures on the cylinders about 100 degrees. That would be something to really consider if you were running 93 octane and follow what Big Daddy said. You should stay out of trouble doing that.

For around $120.00 you can get a cylinder head bayonet attachment, wire lead, and a cylinder head gauge from Chief Aircraft. You can play around and fine out which cylinder is your hot one and leave it mounted on that cylinder. Or if you know someone with one of the Temperature detectors that you point at something and it gives you a reading, use it to determine the hottest cylinder and go from there.

This way you could keep an eye on at least one cylinder's temperature (most the aviation guys claim one is always hotter than the others) and it would give you some satisfaction that you know what you cylinder heads are running. Jurnigan can tell you what he would consider the max CHTs should be.