How to trash 4 pistons

[Dr. Thunder]

Bump ... just because I didn't want my questions to get lost ...

[smittythewelder]

Ron, I've never used walnut shell and don't know.

[Skoontz]

We always shot peen piston tops, then porcelin coat the top to deflect heat. The poor mans way of doing that is to powder coat the tops, which gives the same effect, just won't last as long.

What it does, is simply this. Combustion chamber temps are kept in the chamber, and, the piston itself can run 100° cooler so you can wind the motor tighter and not worry about sticking the pistons.

I got two porcelin coated pistons in a 340cc Rockwell JLO sitting in a Max ATV that makes 50HP at 9200 RPM. Since that motor is air cooled, 100 degrees is huge. You can gain 200° difference in the combustion chambers simply by leaning the jets down. So, if you want to lean the motor down to go screaming up Oldsmobile hill out in Glamis on a 90°-100° day, the porcelin helps this engine do it's job by giving an extra 100°. It's not as big of a deal when we drive down the Mission Bay launch ramp much to onlookers dismay because you only run half throttle in water.

We porcelin coated a Tecumseh lawn mower piston after we had heat problems from the supercharger we installed. Seemed to help it from sticking a piston, but what really helped was water cooling the cylinder head.

Since outboards are running open cooling systems ( direct feed from the lake, then out again) porcelin won't be as big of a help as in air cooled and closed cooled systems motors. The thermostats of the V-4 OMC box motors were preset to 140° if my memory serves me right, then they boosted them on the race motors to 160°. Still not hot enough internally to see any benefits from porcelin. Unless of course you add a little nitrous to the mix

Most motors running compressed aspiration systems that I've seen apart are running porcelin topped pistons. Volvo took it a step further rumor has it, they have a porcelin engine.

BTW, coating one piston, $150.00, plus the piston cost.

Opinions on glass beading and coatings will differ, and it comes down to what works best in your situation. Anywho, my two centabos.

[smittythewelder]

Skoontz, I hadn't heard about powdercoating for that purpose. The poor man's piston top coating used to be Sperex "1200-degree" exhaust pipe paint, sprayed on and baked in your toaster oven. I did it to a DT-175 Yamaha, but it didn't make up for my lousy riding. Wartinger once stated what I consider the ultimate judgement on one of these little speed secrets: "Well, it won't make up for a bad start."

[Skoontz]

There is a power coat available used on exhaust parts that works well on piston tops.

As for pores in metal may I add this. We use a product called "Energy Release" in all crankcases and in the oil mix of two strokers.

What it does is this...It is a metal conditioner that coats all the pores of the metal. In engines that turn over 6500 RPM, we see an 8 to 14% increase in horsepower, which helps us when we break the draft and take on all our own air. My daughter is running it in her car, it looks just like oil, so the inspectors can't see it when they wire the engine shut. The difference we see is about a 1 second faster lap time and on a 330' long track, that's significant.

Sorry to side track to cars....I plan on running it in the 4-60 I'm building because I can't find any of the old Ramco we used to run.


Try it help with the metal pore friction.

[smittythewelder]

Never heard of it. Do they have a website?

[Skoontz]

www.energyrelease.com


That stuff is bitch'in! We started loosing a hundreth of a second off index each run we made. Knowing we did not have any spare engines until the next week, and that loosing a hundreth conssitently is a sign of a bearing starting to twist, we added a 10 oz. dose into the crankcase of a 606 cubic inch Arias motor in the car. It stopped loosing time, we took a 2nd place that day, and, the bearing was in fact starting to go. It will set you back about $120.00 a gallon. Who cares, the stuff works right????