[BruceWilkie]

I like the 2 stroke idea... 100 hp per 500 cc on 89 octane on modern 2 stroke snowmobile engine from the factory... 1400 hp 428 or 1750 hp on a 535 anyone. Good luck keepin it cool...

You can test coatings while your at it.

[David Holmberg]

Paul Gast tried to race a two stroke in Pro Stock motorcycle in the 70's and 80's.
While he tried very hard, he finally gave up and went 4 stroke.

His efforts were very impressive, just never found much success. Was it rules or potential, I don't know.

[455firebird1969]

http://m.youtube.com/watch?v=EmnsXTMLzCE

V8 two-stroke with expansion chamber exhaust.

[455firebird1969]

Originally Posted by David Holmberg

Paul Gast tried to race a two stroke in Pro Stock motorcycle in the 70's and 80's.
While he tried very hard, he finally gave up and went 4 stroke.

His efforts were very impressive, just never found much success. Was it rules or potential, I don't know.

"Fast by Gast"- I still have one of his small catalog/pamphlet advertisements from the eighties, when I had an H-1.

[janderson]

[QUOTE=mike leech;5104899]No he highlighted it. $500 in coatings 10-20 hp. He got it and so did I. I too would get right off of $500 for 20 hp. NOT GONNA HAPPEN WITH COATINGS!!!!!!!


Don't beat me up too bad, actually spent $800.00 in coatings:

Combustion chambers
Exhaust ports
Both sides of exhaust valves
Face of intake valves
Piston tops & skirts
Wrist pins
Main, Rod and Cam bearings
Windage Tray

Can't be specific on any gains (if any at all), but sure not 20 hp, was a fresh build so no baseline to compare.
Hopefully will see some benefit when it comes apart to freshen.

Jess

[Half-Inch Stud]

Originally Posted by 455firebird1969

http://m.youtube.com/watch?v=EmnsXTMLzCE

V8 two-stroke with expansion chamber exhaust.

seems unreal to have a 2-stroke V8 behave while resting on a dolly. looks like it works.

[mike leech]

[QUOTE=janderson;5106548]

Originally Posted by mike leech

No he highlighted it. $500 in coatings 10-20 hp. He got it and so did I. I too would get right off of $500 for 20 hp. NOT GONNA HAPPEN WITH COATINGS!!!!!!!


Don't beat me up too bad, actually spent $800.00 in coatings:

Combustion chambers
Exhaust ports
Both sides of exhaust valves
Face of intake valves
Piston tops & skirts
Wrist pins
Main, Rod and Cam bearings
Windage Tray

Can't be specific on any gains (if any at all), but sure not 20 hp, was a fresh build so no baseline to compare.
Hopefully will see some benefit when it comes apart to freshen.

Jess

please keep us posted with your findings Jess. I truly am interested.

[janderson]

Will do Mike, should have something this spring/summer.

[Bob Crueger]

Originally Posted by Bob Crueger
Why again does an aluminum head need slightly higher in compression than an iron head to create the same power?

Originally Posted by Aaron Quinton

Because aluminum transfers heat better than iron. The aluminum head dumps more heat to coolant keeping less in cylinder for power. Consequently, you have bump the compression on the aluminum head to maintain similar power (efficiency).

As a side note, I've not tested coatings on combustion chambers to measure the efficiency improvement. In theory it should help. Is the cost worth the improvement? It likely depends but if it was a big deal, I think you'd see it a lot more.

I do know that surface area will change the heat transfer significantly. Anyone with CNC machined chambers would be wise to smooth them out. The surface area is ~2x as compared to a smooth surface. I'm not sure what its worth on power but I don't want all of that heat dumping into my radiator.

If you want to talk piston skirt coatings, I have some experience there.

My original question was rhetorical, no-one really bit. Again, rhetorically, perhaps coat your aluminum parts with iron.... seems to me that if "materials" matter, how could coatings not? If you say "not enough to matter", ok..but no difference? Not possible.

[Bob Crueger]

Originally Posted by BruceWilkie

I like the 2 stroke idea... 100 hp per 500 cc on 89 octane on modern 2 stroke snowmobile engine from the factory... 1400 hp 428 or 1750 hp on a 535 anyone. Good luck keepin it cool...

You can test coatings while your at it.

Evinrude ETEC Outboard motors. The bugs are worked out...

[Half-Inch Stud]

Originally Posted by Bob Crueger

Originally Posted by Bob Crueger
Why again does an aluminum head need slightly higher in compression than an iron head...
My original question was rhetorical, no-one really bit. Again, rhetorically, perhaps coat your aluminum parts with iron.... seems to me that if "materials" matter...

Hmmm yea, my can Red Oxide Primer spraycan may have value afterall.

[Aaron Quinton]

I'm sure coatings do something, it's just hard to tell how big of an impact they make. If they were very effective for their costs, every production engine on the planet would have coated parts. They don't.

People don't use aluminum heads because they are less efficient. They use them because they are lower weight and easier port.

Originally Posted by Bob Crueger

Originally Posted by Bob Crueger
Why again does an aluminum head need slightly higher in compression than an iron head to create the same power?





My original question was rhetorical, no-one really bit. Again, rhetorically, perhaps coat your aluminum parts with iron.... seems to me that if "materials" matter, how could coatings not? If you say "not enough to matter", ok..but no difference? Not possible.

[Half-Inch Stud]

Originally Posted by Aaron Quinton

...People don't use aluminum heads because they are less efficient. They use them because they are lower weight and easier port.

Stability of Cast Iron, integrated valveseats, really good Street/Strip flow for HP, etc has my attention. so if an OPTIMIZED high HP aluminum head was DONE, then implemented in as-cast CAST iron, would it sell. i think so.

[Aaron Quinton]

I am a BIG fan of cast iron. Your points are right on HIS. And don't forget they are low cost.

Originally Posted by Half-Inch Stud

Stability of Cast Iron, integrated valveseats, really good Street/Strip flow for HP, etc has my attention.

[john marcella]

Cast iron sucks, I want heat in the cyl not the head. JMO

Real question, why don't most OEM still use iron heads?

[cptinjak]

Originally Posted by john marcella

Cast iron sucks, I want heat in the cyl not the head. JMO

Real question, why don't most OEM still use iron heads?

Cost of machining.

Jack

[Region Warrior]

Weight savings vs cost of material.
Don't forget plastic intakes since the 90's.

[Bob Crueger]

[QUOTE=john marcella;5107891]Cast iron sucks, I want heat in the cyl not the head. JMO

So is it accepted or not, that at a given compression and all things else equal, a cast iron head will make more power that an aluminum head? I've been reading it here, and everywhere else, for years.

If that's the case, YOS.

[john marcella]

[QUOTE=Bob Crueger;5107960]

Originally Posted by john marcella

Cast iron sucks, I want heat in the cyl not the head. JMO

So is it accepted or not, that at a given compression and all things else equal, a cast iron head will make more power that an aluminum head? I've been reading it here, and everywhere else, for years.

If that's the case, YOS.

What does YOS mean?

Truth is I don't really know for sure. But my logic says that iron will not make any more hp. But I don't want to get in that debate.

[Bob Crueger]

[QUOTE=john marcella;5107972]

Originally Posted by Bob Crueger

What does YOS mean?

Truth is I don't really know for sure. But my logic says that iron will not make any more hp. But I don't want to get in that debate.

Your opinion sucks.