NR 5port head button

[Ted buckley]

Thanks Rodney, Never can tell these days. :lol:

 

[Richard Dahlheimer]

the so called "hybrid" is pretty much the good old nova that they sold for many years.they did make the sleeve o.d. larger,and have eliminated the stupid o rings in the water jacket( still too much water volume),but it's my favorite 21 engine to date,and modded runs like stink

"but it's my favorite 21 engine to date,and modded runs like stink" Trying to figure out if "Stink" is a good thing? :blink: Does this mean the Hybrid is better "Not Modded" or does Stink Run Fast? I just bought a Hybrid P/L that I want to send you - but now Don't know? ipb.global.registerReputation( 'rep_post_438821', { domLikeStripId: 'like_post_438821', app: 'forums', type: 'pid', typeid: '438821' }, parseInt('') );

LOL Yes Ted, that would be a good thing for sure. For best results, have Steve do the complete motor, not just the liner. Maybe 90% is in the props, though. Richard D

 

[RodneyPierce]

Induction timing, head volume/clearance and PROPS PROPS PROPS. I have the first couple under control, the last one is where I need to do my work at. :lol:

 

[Charles Perdue]

brass!

Steve, I am confused, why make a head button from brass or bronze instead of aluminum?

 

[RodneyPierce]

Charles, it expands at a much more similar rate to the sleeve then aluminum. So keeps a tighter fit in theory to the sleeve then aluminum. Also apparently cuts down on the deto.

 

[Chris Wood]

Put it this way. U can run compression ratios not even heard of with alum. Works great

 

[Charles Perdue]

Charles, it expands at a much more similar rate to the sleeve then aluminum. So keeps a tighter fit in theory to the sleeve then aluminum. Also apparently cuts down on the deto.

I am not trying to start anything, I am naturally curious as to why thing work as they do, just would like to be educated. Different expansion can be taken care of with different clearances between the head and sleeve and the different types of aluminum. How does it cut down on detonation.....different thermal transfer rates.... faster removal of heat from the combustion chamber??????

 

[RodneyPierce]

I cant honestly answer that as I have not experimented nor done enough research to give you a factual answer, so I will let Steve Wood or Marty Davis chime in on that one.

 

[RodneyPierce]

Charles, after some quick research, it appears that brass has a LOWER thermal conductivity rate then Aluminum does. So im not sure what the advantage would be there. Let me do some more research.

 

[Chris Wood]

Hi charles

You know me i am cut and dried. I am not a metal ergy person a scientist ect. I can tell you that with brass it shows No detination Weither good bad or indifferent but we have run buttons around 11 to 1 compression pull the head it looks

like new. So to say it is good or bad not sure all i can say is i like it for sure other than the weight

 

[steve wood]

brass!

Steve, I am confused, why make a head button from brass or bronze instead of aluminum?

i don't have a clue why the brass(NOT bronze) works the way it does.i just read about it,and tried it.it works so well on the nova we won't use anything else on those motors.more compression,without detonation(at least that one can see,i guess that doesn't mean it's not),more torque,more rpm with shorter pipe= fastest 20 boat we ever had(new boat maybe helps too)

 

[steve wood]

do you have numbers on the brass used ?

Greg

360

 

[steve wood]

the so called "hybrid" is pretty much the good old nova that they sold for many years.they did make the sleeve o.d. larger,and have eliminated the stupid o rings in the water jacket( still too much water volume),but it's my favorite 21 engine to date,and modded runs like stink

"but it's my favorite 21 engine to date,and modded runs like stink" Trying to figure out if "Stink" is a good thing? :blink: Does this mean the Hybrid is better "Not Modded" or does Stink Run Fast? I just bought a Hybrid P/L that I want to send you - but now Don't know? ipb.global.registerReputation( 'rep_post_438821', { domLikeStripId: 'like_post_438821', app: 'forums', type: 'pid', typeid: '438821' }, parseInt('') );

LOL Yes Ted, that would be a good thing for sure. For best results, have Steve do the complete motor, not just the liner. Maybe 90% is in the props, though. Richard D

i won't do just a liner

 

[Ian Inverarity]

More compression without deto? Sounds good to me! Another project to try.. B)

 

[Ian Inverarity]

Greg,

I'll check but I think I have 360 brass at work. I'll let you know if I dont, thanks!

 

[RodneyPierce]

Ian, I seen your name posted on here, and figured I would be coming into a technical discussion on why brass worked the way it did. You surprised me man not to see anything I figured you guys would be all over this. You, Aaron, TD. Thats cool though, I havnt yet tried one, but if Steve and Chris Wood, and Marty Davis say its better, then Im sure it probably is. Thats good enough for me. I just dont have any brass bar stock laying around here, so I will continue to use the aluminum blanks that I have cut here.

 

[ace]

does it work on bigger sized engines and with higher comp did the elements in the plug last? just wondering cheers Ace

 

[Ian Inverarity]

Ian, I seen your name posted on here, and figured I would be coming into a technical discussion on why brass worked the way it did. You surprised me man not to see anything I figured you guys would be all over this. You, Aaron, TD. Thats cool though, I havnt yet tried one, but if Steve and Chris Wood, and Marty Davis say its better, then Im sure it probably is. Thats good enough for me. I just dont have any brass bar stock laying around here, so I will continue to use the aluminum blanks that I have cut here.

Rodney,

I know someone who has tried the brass head buttons and recommended I try it, that was maybe a couple of years ago. His findings seemed more that the brass head button was less damaged by deto rather than had less deto. If I can get less deto then I have a couple of applications for that, simply less damage from deto isnt what I want. So I havent tried it yet either. I will now tho. From my reading and understanding of deto I dont know why a brass head button would help.

 

[Ian Inverarity]

does it work on bigger sized engines and with higher comp did the elements in the plug last? just wondering cheers Ace

Ace,

When I try one in the cube I'll let you know if it works!

 

[Charles Perdue]

does it work on bigger sized engines and with higher comp did the elements in the plug last? just wondering cheers Ace

Just curious as to how brass is better than aluminum. If we knew why, then maybe there is a better material than brass. Not showing the deto would not account for the increase in performance.

Some of the dirt bikes have a copper insert in the top of the combustion chamber????