Head button material preference?

[Jeff Lutz]

Going down this road of different head material, Ampcoloy #940 will retain heat better than brass and will expand less. You shouldn’t have over expansion with it in our brass/chrome sleeve setups. Jeff Lutz

 

[LohringMiller]

I think that in theory the head shouldn't conduct heat well around the combustion chamber. In a little larger engines an effort is made to cool the squish area and the plug without cooling the combustion chamber. See below:

Lohring Miller

 

[Charles Perdue]

What fuel does the engine that this head belongs to use?????

 

[RaceMechaniX]

Looks like a QD Pioneer head button.

 

[John Beardslee]

Looks like a QD Pioneer head button.

Back in the late 60’s I did an independent study research project, supercharging 2 cycle engines. Pioneer was building chainsaw engines at the time. Power products, Westbend, Macs all sent me multiple engines to test. Yup, I granaded the best of them. In a nutshell it’s better to add another cylinder instead of supercharging,
Thanks John

 

[LohringMiller]

That head button is probably from a 125 cc motorcycle engine. The idea is to only have small passages that flow the water from the squish to the plug area. the cap closes the space over the combustion chamber leaving most of the water over the squish and around the plug threads.

Lohring Miller

 

[LohringMiller]

It's always less expensive to get power by adding displacement. A tuned pipe is a less expensive power boost than a turbocharger for small two strokes. That said, two strokes can gain a lot of power by turbocharging. The
turbocharged snowmobile engine below developed around 800 hp with nitrous injection.

Lohring Miller

 

[Wasted wages]

It's always less expensive to get power by adding displacement. A tuned pipe is a less expensive power boost than a turbocharger for small two strokes. That said, two strokes can gain a lot of power by turbocharging. The
turbocharged snowmobile engine below developed around 800 hp with nitrous injection.

Lohring Miller

View attachment 292061

I assume that the 800 hp was at peak rpm and a very narrow power band ????

 

[dwilfong]

I assume that the 800 hp was at peak rpm and a very narrow power band ????

Look up drag sleds on You Tube. Thy have bin using turbos on them for YEARS..........This ain't nothing new. Somevtimes every one has to look out at the real world.......LOL

 

[Jeff Lutz]

Back in the late 60’s I did an independent study research project, supercharging 2 cycle engines. Pioneer was building chainsaw engines at the time. Power products, Westbend, Macs all sent me multiple engines to test. Yup, I granaded the best of them. In a nutshell it’s better to add another cylinder instead of supercharging,
Thanks John

Mercury has about taken over the marine market with Supercharged outboards. They are very reliable and make the most power to weight of any Outboard. Even in 2005 when they made the first Verados they didn’t blow up , they just had sensor and electrical issues. Jeff Lutz

 

[LohringMiller]

If four strokes are so great, I challenge you to build or modify one and run it in a gas RC boat. We seriously considered doing just that, but there aren't any turbochargers small enough. We doubted that a small supercharger would be available. We could build a piston supercharger and that might work. Without serious supercharging, small four strokes can't come close to two stroke peak power at the same displacement and weight. Four strokes are ysed in models for better control and realistic sound.

Lohring Miller

 

[Jeff Lutz]

If four strokes are so great, I challenge you to build or modify one and run it in a gas RC boat. We seriously considered doing just that, but there aren't any turbochargers small enough. We doubted that a small supercharger would be available. We could build a piston supercharger and that might work. Without serious supercharging, small four strokes can't come close to two stroke peak power at the same displacement and weight. Four strokes are ysed in models for better control and realistic sound.

Lohring Miller

I did bring up a particular 4 stroke , and John was talking about super charged 2 strokes, but when I see ultra small supercharged displacement engines outperforming much bigger naturally aspirated engines, I pay attention. I’m not praising 4 strokes necessarily. Unfortunately no one tries to supercharge 2 strokes anymore (To my knowledge ) I wish they did. The tech still wouldn’t be there for our simple rc setups , but It would be cool to see the outcomes .

 

[LohringMiller]

Ski-Doo isn't anyone. For small supercharged four strokes look at YS engines. Maybe a racing version with overhead cams and bigger valves could get the rpm into the 20,000 rpm area for racing. I still think you would need an increased displacement to race against two strokes.

Lohring Miller

 

[dwilfong]

You know I posted a few years ago about using a roots super charger on a 1.01. Conley makes a nice one for his V8s. Even posted a video of bench running my 1.01 to prove it would start with no disk. I was thinking the roots blower would be the intake valve. May be some day I will do it just to see what happens. Got BIGGER fish to fry first.

 

[Jeff Lutz]

Ski-Doo isn't anyone. For small supercharged four strokes look at YS engines. Maybe a racing version with overhead cams and bigger valves could get the rpm into the 20,000 rpm area for racing. I still think you would need an increased displacement to race against two strokes.

Lohring Miller

Reread my post. I’m not talking about super charging a four stroke. Reread.

 

[Jeff Lutz]

You know I posted a few years ago about using a roots super charger on a 1.01. Conley makes a nice one for his V8s. Even posted a video of bench running my 1.01 to prove it would start with no disk. I was thinking the roots blower would be the intake valve. May be some day I will do it just to see what happens. Goy BIGGER fish to fry first.

Many of us knew that over 20 years ago, long before you tried it apparently. A guy pulled a engine down at the Nats and forgot to put his disc back in on a old CMB. It cranked up but didn’t launch. If you really know the whole system of our some what simple setups , it should not be a surprise why it does crank but doesn’t launch. I saw you reference how our engines are a few moving parts and not to over complicate it. (Pinckert saying ) . That sounds great until you see a boater taking plugs left and right and about to quit boating. And this can happen when it’s just the engine setup wrong, not the fuel system. There are some very crucial parts that sit still and never move. Back to before, I’m still all about trying out of the box setups to advance 2 strokes. Our tank pressure system needs serious improvement for a example.

 

[LohringMiller]

Look at the SkiDoo link for a commercial, turbocharged two stroke. The rest is a thought about how you might be able to build a competitive four stroke.

Lohring Miller

 

[Jeff Lutz]

Look at the SkiDoo link for a commercial, turbocharged two stroke. The rest is a thought about how you might be able to build a competitive four stroke.

Lohring Miller

I did see ski doo came out with what they called the first factory built turbo 2 stroke. Pretty cool. I run nitro only , and of course two stroke. Did you ever run nitro ? Jeff

 

[dwilfong]

WOW I see what you mean now............................

 

[Jeff Lutz]

You know I posted a few years ago about using a roots super charger on a 1.01. Conley makes a nice one for his V8s. Even posted a video of bench running my 1.01 to prove it would start with no disk. I was thinking the roots blower would be the intake valve. May be some day I will do it just to see what happens. Got BIGGER fish to fry first.

I don’t remember seeing your thread about the super charger. Where is more info on Conley ?