air cooled buggy engines

[jken1995]

I know some guys are using air cooled buggy engines in their boats. I noticed that some of the fins were cut off so I was wondering how many air cooled fins are left on to still have enough cooling. I understand that it may vary from engine to engine, but if there is a general rule of thumb. Also, if you are running a cowl how much of the fins are exposed? The engine I have is a .18 Traxxas. I am just doing this for fun not for racing. Thanks for any help.

Jeff

 

[moparbarn]

i would go conservative. easier to block or tape off fins than to add more later......testing now would be way different than summer, ambient temp will play a big part in temps B) .

 

[jken1995]

I never thought about taping fins off. Good idea. I will wait until it gets warmer out and use a temp. gun to dial it in. Anybody with other ideas or experience with this type setup would be great also. Thanks again.

Jeff

 

[Glenn Quarles]

Jeff, I have always left 3 fins and have had no problems even on the hotter Texas summer days. During cold/cooler weather, you can take the air-cooled head off completely and just run the plan head button.

Glenn

 

[jken1995]

Thanks for the info. Glenn. I will leave 3 fins on the engine. Did you run some type of cowling? If so, did you leave all 3 fins exposed for cooling? Or did you partially cover some? Thanks again.

Jeff

 

[Glenn Quarles]

Thanks for the info. Glenn. I will leave 3 fins on the engine. Did you run some type of cowling? If so, did you leave all 3 fins exposed for cooling? Or did you partially cover some? Thanks again.

Jeff

Jeff, I ran without a cowling. My best guess is you would want about two fins sticking above the cowling.

Glenn

 

[jken1995]

Thanks for the help. Time to do some work.

Jeff

 

[Mike Hughes]

I run 3-4 fins. This is on the 18TZ and a MAC21OB. They both have tape on them because it does not get that hot here in the NW.

Mike

 

[Bob Morton]

i would go conservative. easier to block or tape off fins than to add more later......testing now would be way different than summer, ambient temp will play a big part in temps B) .

Robin,

That's a great idea

Bob

 

[moparbarn]

it's an idea i may get to test, bob. i've got a .21 mac buggy engine coming. i'm gonna stick it in my rc buggy, but i'm not beyond trying it in my jae h34r: .

 

[Ron Olson]

With the RC car guys buying aftermarket heat sinks for their engines or if someone has had their trucks on its roof too many times, you might be able to find some used ones so if you go too far then you'll have a replacement.

On my .12's I keep 3 fins on.

Boats don't need all of that extra cooling if the engine is exposed to the air. It's not stuck under a Lexan body running at low speeds plus you're catching the cooler air off the water.

 

[byron westman]

hay mike, can you explain how to you cut down the heat sink on your 18 tz? i'm interested to do mine

 

[chris armstrong]

The easiest way is to take a hacksaw and a fine blade and then cut as close to the bottom as you can.

Then use a bench grinder or file to grind them nice and flat.. Do this lightly and delicately.

Once done, you can give it a sand with paper and pollish like a prop.

Then hit it with a buff and some green rouge (Pollish compound) and the finish will be a polished top fin.

It may not be the best way but worked out fine for me and got a great finish

 

[BlueBlaster]

Just a thought couldn't someone who wants to run a .18 Tz car motor take the cvr marine head and just swap it from the air cooled head.