GET EM JOEWell I was hoping that the Brass Head Button Topic would not come up till after the next couple of BIG Races!!!!! Steve is making them & I have never seen anything like them as for Performance they Provide. There is NO DOUBT that they Allow the Engine to Burn More of the Nitro Percentage that is Already in the Fuel by providing a higher heat to the prechamber. They are made out of what ever Steve Wood says they are made out of?? But the Alum ones will NEVER be back on my RS101s. & You better hope you got a pair or two for Hobart in a few weeks?? & Ralph already has some for Charleston........ Thats all I`am saying for now!! Done.....Now Back to the original reason for this thread!!!
Hi David,So to get back to the piston fit.
I have ordered a custom 29mm hone from Brush research.
It is a 800 grit Levigated Alumina compound. there specks for the surface finish are RA 3-10 (.05-.2 micrometer)
My intent is to polish the cylinder. Don't know how it will work till I give it a whirl. for $32 have nothing to lose testing it on old liners.
Will give it a try this weekend.
David
Mr Hargett:Mr Davis im really not tyring to be an azz but if detonation is a problem and I dont know that it is in a 2 stroke why would you want to hide it? How will you know its going on to correct it.Mind you im very dumb coz I dont even understand how a 2 stroke has detonation. I thought some of its(detonation) principles are what made these type engines run. Thought thats why we used glow plugs - beacause the latent heat of the last combustion event plus the compression gave me fire for the next revolution.Im really learning something here. About the dyno Joe W tells me that some of their crews record boats times will drop because of the button change. All of them(RR CREW) are making the change. Strong statement but Joe really believes in theese things so until someone confirms it on a dyno we will have to see. One thing I do know- they are very speed greedy so if it doesnt make the boat faster they wont stay with them long.
Hugh
Good call! Awesome pictures there as well.Nah it not standard heres what it says " The cylinder sleeve/liner is chromed brass with an ergal aluminum sleeve as in "bimetal" heres the blog http://www.bing.com/...6911D26C3DE6F3E
that should "really" make finding the expansion rate quite complicated.
Ergal is a trade name used for 7075 aluminum alloys. Other 7000 series alloys used for moulds had names such as Alumould, Alumec, etc.Lets just leave it alone youre sneaky Julian extremely!! But im watching ya move in the shadows. :huh: .
Jim , Marty, Andy, someone lets go back to the ops. Whats "ergal" aluminum and what were they trying to accomplish with the P/L here if anyone knows?
Absolutely yes.Jim based on whats been said here is it a fair statement to say that with the right combination of materials you can get almost any expansion rate you want? though you may not be able to calculate it based on the different alloys alone you certainly can just put it together and put it on a dyno run it and see how it goes? That requires the ability to make your own piston liners and that means alot of testing . It would be a pain in an actual boat coz if it cuts off then you got to retrieve yady ya! Seems like you have to have the proper equipment and toolery to really get in to the design aspect of motors versus go fast mods.
My intent with this is to just get a good surface finish. Not trying to change the tapper.Hi David,So to get back to the piston fit.
I have ordered a custom 29mm hone from Brush research.
It is a 800 grit Levigated Alumina compound. there specks for the surface finish are RA 3-10 (.05-.2 micrometer)
My intent is to polish the cylinder. Don't know how it will work till I give it a whirl. for $32 have nothing to lose testing it on old liners.
Will give it a try this weekend.
David
We used a copper plug lap and diamond dust to lap more taper in the liners, also used a jig grinder with borazon carbide wheels to get them round and add taper. You might want to consider using a support sleeve around the liner when working it.
John
Hi David,My intent with this is to just get a good surface finish. Not trying to change the tapper.Hi David,So to get back to the piston fit.
I have ordered a custom 29mm hone from Brush research.
It is a 800 grit Levigated Alumina compound. there specks for the surface finish are RA 3-10 (.05-.2 micrometer)
My intent is to polish the cylinder. Don't know how it will work till I give it a whirl. for $32 have nothing to lose testing it on old liners.
Will give it a try this weekend.
David
We used a copper plug lap and diamond dust to lap more taper in the liners, also used a jig grinder with borazon carbide wheels to get them round and add taper. You might want to consider using a support sleeve around the liner when working it.
John
My thinking is to give the piston a better chance of seating good.
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