heads up

[iwanajohnson]

I was looking at the second effort performance catalogue and saw a double plug head and a high compression head. Does anyone know what this does or how it enhances performance. I also have heard about milling out the heads to different cc's. How does this work and what does it do. i'm really interested in 3 hole omc motors but info on any other motor would be helpful. Anyone know anything about shaving the flywheel on 3 bangers?

[Jeff Akers]

Checkout this thread at hydroracer

http://www.hydroracer.net/forums/sho...light=flywheel

The photos have been deleted to save server space...I'll see if I can find an old pic and post it later.

[Roy Hodges]

I was looking at the second effort performance catalogue and saw a double plug head and a high compression head. Does anyone know what this does or how it enhances performance. I also have heard about milling out the heads to different cc's. How does this work and what does it do. i'm really interested in 3 hole omc motors but info on any other motor would be helpful. Anyone know anything about shaving the flywheel on 3 bangers?

You've been warned about milling flywheels , i know. You can mill a head , like on a 70 horsepower ,up to 3/16 ", (As long as you have flat top pistons) but you will need hy octane gas ,also the edge of the combustion chamber should be chamfered (beveled). The only double plug heads i saw was for big bore v-6's or v-8's .

[iwanajohnson]

You've been warned about milling flywheels , i know. You can mill a head , like on a 70 horsepower ,up to 3/16 ", (As long as you have flat top pistons) but you will need hy octane gas ,also the edge of the combustion chamber should be chamfered (beveled). The only double plug heads i saw was for big bore v-6's or v-8's .

I have only saw the double plugged heads on a v-6 also. wonder if it would be possible for a 3 banger, hehe. how much more does milling the heads out help compared to shaving the head? and can anyone explane a cc cut to a head to me. just tryin to learn some new stuff. And how are you guys talking about cutting a flywheel? I've saw them shaved down on the bottom , which makes the teeth thinner. I've heard of teeth chipping but i've never saw one esplode. I don't know how much it will help me so I don't think I'll shave it, but the heads, still interested.

[Roy Hodges]

I have only saw the double plugged heads on a v-6 also. wonder if it would be possible for a 3 banger, hehe. how much more does milling the heads out help compared to shaving the head? and can anyone explane a cc cut to a head to me. just tryin to learn some new stuff. And how are you guys talking about cutting a flywheel? I've saw them shaved down on the bottom , which makes the teeth thinner. I've heard of teeth chipping but i've never saw one esplode. I don't know how much it will help me so I don't think I'll shave it, but the heads, still interested.

Milling or shaving =same thing -=you do it with a mill.
I guess on some heads (cast iron CAR heads ,) they could be "surfaced" to reduce the combustion chamber

[iwanajohnson]

I had heard of miling and I have shaved heads before but I didn't know if milling ment milling out the domes. is that even possible? Nebody ever tried nitrous or a turbocharger on a 3 banger. it's all about the 1/4 mile

[Roy Hodges]

I had heard of miling and I have shaved heads before but I didn't know if milling ment milling out the domes. is that even possible? Nebody ever tried nitrous or a turbocharger on a 3 banger. it's all about the 1/4 mile

Sorry to correct you, Nitrous HAS been tried on a 3 banger. Out here in region 11. Back in late 70's. was sent out here by omc factory. It gave an instant 30 EXTRA horses. gave great accelleration out of corners ,installed on a SPORT E tunnel. If you're using flat top pistons , just mill whole head, on gasket side, of course.

[Skoontz]

You can take 36 grit sandpaper on a straight 2x4, clamp the head in a vice and take off all you need, then go to finer paper to clean it up. Just keep using modeling clay to tell how close you are getting. As long as you use even smooth strokes, it works slicker than snot on aluminum. Accurate? Not to far off what a mill would do as long as you move the paper correctly.

Sound butcherous, but when you are a kid with no money, lots of parts and time, anything for a mile an hour!

[iwanajohnson]

How about reliaility on a nitrous shootin motor? I would like to have that extra little shot of power but I don't believe it would be too practicle. would be nice put prolly not now. Sandpaper to a head, that takes some big ones. I understand the resource thing but don't think I could do it. so besides the chance of it exploding does shaving the fly wheel improve performance any at all? What kind of fuel pumps do yall run on your hopped up 3 cyl. omc's. I'm thinking of going with a electric holley.

[Skoontz]

You can also use an aluminum bastard and make sure you card file it after every 2nd stroke. Once again, make sure your strokes are even, using similar pressure across the whole thing. In Chicago, we called it a Pollack Powered milling machine.