hi comp piston !!!

[pro-rider46]

i have the money for a hi comp piston and i only want to go to 12:1. what piston should i go with and do i need to rebore a little or can i just put the stock bore on.

ps i have around 100 hrs on it

[ghott]

CP makes a great shelf piston - 12:1 compression.

Great features, stock bore, and it can be run on pump gas.

www.cppistons.com

[DirtDevilBT]

second

no need to bore the cylinder if it still looks good. If there is still crosshatching. It will be ok with a 12:1 piston running 3 rings.

It'll be fine

[pro-rider46]

thanks

[450R_lover]

If i were you, i'd get a Venom 12.25:1 piston. It is one of the best from what i hear, and you can run pump fuel. I have heard that it out performs JE 13:1 on 50/50 mix. Just what i've heard.

[juspifool]

I give another nod to the Venom. I have one and it is pretty darn nice.

[400exrider707]

Originally posted by 450R_lover
If i were you, i'd get a Venom 12.25:1 piston. It is one of the best from what i hear, and you can run pump fuel. I have heard that it out performs JE 13:1 on 50/50 mix. Just what i've heard.

How is that possible?

[DirtDevilBT]

^^^ piston design. Lower weight, low tension rings, 2 ring less friction, and dome design

Among other things, those are the contributing factors
I haven't raced a 13:1 equiped R yet, not that I know of, so I can't really give you a real world race.

I have the HH version, the first one, but it's supposidly a little more wild than the Venoms, but I think the venoms just have 3 rings instead of 2 and possibly a longer skirt, or maybe it's an option. Don't really know, but I like my HH, going strong, easy to kick over....

[400exrider707]

Originally posted by DirtDevilBT
^^^ piston design. Lower weight, low tension rings, 2 ring less friction, and dome design

Among other things, those are the contributing factors
I haven't raced a 13:1 equiped R yet, not that I know of, so I can't really give you a real world race.

I have the HH version, the first one, but it's supposidly a little more wild than the Venoms, but I think the venoms just have 3 rings instead of 2 and possibly a longer skirt, or maybe it's an option. Don't really know, but I like my HH, going strong, easy to kick over....


cool thanks for the info....

also it shouldn't be any harder to kick over no matter what you have in there, it has auto decompression...

[sandmanblue]

The Venom BW is an updated and renamed HH piston. Single ring "full race" CP with several other features added.

It's worth the $ if you have it. They are about $250.

[400exrider707]

Didn't the HH pistons have a lot of problems?

[DirtDevilBT]

nope
at least none that I know of or experienced

[400exrider707]

Originally posted by DirtDevilBT
nope
at least none that I know of or experienced

When they first came out everyone on .org was having problems with their bikes eating oil up. They traced it to the piston ring design I thought. Seems the two ring design just eats a little more oil. I remember they were hot for about a month and then everyone was selling theirs... I'll search and see what I come up with.

[Rulz]

Originally posted by pro-rider46
i have the money for a hi comp piston and i only want to go to 12:1. what piston should i go with and do i need to rebore a little or can i just put the stock bore on.

ps i have around 100 hrs on it

No need to rebore, but definitely ball hone the cylinder before installing any new piston/rings.

[400exrider707]

Originally posted by Rulz
No need to rebore, but definitely ball hone the cylinder before installing any new piston/rings.

You are not supposed to hone the 450R cylinders, it will eat through the NiCaSil coating


I did a little reasearch on the HH pistons, it brought back too many memories of bashing and thrashing, so if you want to know about it just search it yourself...nuff said.

[Rulz]

Originally posted by 400exrider707
You are not supposed to hone the 450R cylinders, it will eat through the NiCaSil coating


I did a little reasearch on the HH pistons, it brought back too many memories of bashing and thrashing, so if you want to know about it just search it yourself...nuff said.

WRONG!!! These cylinder will not be affected by ball honing them. You should always ball hone before installing new pistons. You need to remove the small metal particles inside the cross hatch area and then clean up with warm soapy water and wipe dry with white paper towels to ensure all material is gone. If you do not do this, the rings will not "cut" into the cross hatch, thus ensuring the best possible ring seal.

[400exrider707]

How will the coating not be effected? How is it possible to cut into the surface of the cylinder wall and not effect a coating on it???

[FireFighterI]

Do any of you guys know the web site where I can order the HH hi comp piston that you guys are talking about? I have the money for one and that sounds like what I want...thanks

[GPracer2500]

Rultz is correct.

When you run a ball hone through a Nikasil bore you're not actually honing it. What your doing is deglazing it. Deglazing is basically just cleaning--removing carbon and piston/ring material that has transfered onto the bore.

Nikasil is so hard the only way to actually hone it (that is to say, dimentionally change the bore and install cross-hatch) is with specialized diamond hone tools.

You are not going to harm a Nikasil bore with a ball hone or any other method your likely to do in your garage. The exception might be with two stroke cylinders. If you catch the edge a port with the hone in just the wrong way it's possible to chip the coating off. No issues there with a four stroke.

A coated bore should be deglazed with every new ring/piston install. This restores the original cross-hatch and gives the rings the best chance to seal completely. I deglaze my Nikasil bores by wetsanding them in my sink. If I had the right ball hone I'd use that instead.

[400exrider707]

Originally posted by GPracer2500
Rultz is correct.

When you run a ball hone through a Nikasil bore you're not actually honing it. What your doing is deglazing it. Deglazing is basically just cleaning--removing carbon and piston/ring material that has transfered onto the bore.

Nikasil is so hard the only way to actually hone it (that is to say, dimentionally change the bore and install cross-hatch) is with specialized diamond hone tools.

You are not going to harm a Nikasil bore with a ball hone or any other method your likely to do in your garage. The exception might be with two stroke cylinders. If you catch the edge a port with the hone in just the wrong way it's possible to chip the coating off. No issues there with a four stroke.

A coated bore should be deglazed with every new ring/piston install. This restores the original cross-hatch and gives the rings the best chance to seal completely. I deglaze my Nikasil bores by wetsanding them in my sink. If I had the right ball hone I'd use that instead.

good info... what would you consider the "right" ball hone... I am going to be putting my 450 back together tonight hopefully and honestly hadn't planned on honing, from what I've heard. Also, all of the cross hatching is still in the original cylinder... would you still recommend honing?

[GPracer2500]

A Flex-Hone in 320 to 240 grit in the appropriate diameter.....

http://imageserver.isnweb.com/KDT2492.jpg

Flapper type hones work too and they're prefered on 2 smokes because the risk of chipping the bore coating at a port edge is reduced compared to a Flex-Hone.

Really though, you don't need either. Wet sanding with medium and/or mild sand paper works well. I've tried a Scotchbrite pad too and many recommend that. It just didn't seem to have enough "bite" when I tried it though. Wet sanding worked better.

Advantages of wet sanding are you probably already have sandpaper in your garage and it's easy to focus on certain areas where you might be able to see a little extra build-up. A Flex-Hone can't really zero in on one area. A Flex-Hone is probably faster though--chuck it in a drill and after a handful of passes your done.

If you wetsand by hand you'll see what I mean about not being able to harm the Nikasil. It will seem like you could rub with max pressure in one spot all day long without eating into the coating at all. Nikasil is like magic. I've got a 1995 CR250R with a Nikasil'd bore that's had who knows how many pistons in it. The bore is original and is still in good condition.

Make sure to clean the bore very well when your done. After cleaning, clean it again...and again for good measure. Use brake or carb cleaner and wipe out the bore with clean paper towels until they keep coming out perfectly white. It's important to get all foreign material out of the cross-hatch.

I'd deglaze a cylinder even if it looks clean to the eye.

[sandmanblue]

Originally posted by FireFighterI
Do any of you guys know the web site where I can order the HH hi comp piston that you guys are talking about? I have the money for one and that sounds like what I want...thanks

As stated above, the HammerHedz piston is no longer available. The company that was offering them split up. The same guy that designed that piston designed and is now offereing Black Widow pistons or Venom (which is what is etched on the top of the piston).

You can order them through a company in Utah - KBR or www.kylebaldwinracing.com.

[FireFighterI]

Thanks a bunch... I have heard alot of people talking about them and they sound pretty good so I am willing to give the (venom) piston a try.. I will call that number from that website you gave me.. Thanks again:)

[DirtDevilBT]

Originally posted by 400exrider707
When they first came out everyone on .org was having problems with their bikes eating oil up. They traced it to the piston ring design I thought. Seems the two ring design just eats a little more oil. I remember they were hot for about a month and then everyone was selling theirs... I'll search and see what I come up with.
I remember that. It's just a bunch of horsecrap. It's because people were putting race pistons in warn cylinders and not making sure proper clearances were met. Plus folks seemed confused about ring gaps and so on. I dunno. I bought mine from Lukestar and my springs from Woodward.

!!!!!!!! I have had my HH 12.25 for some time now. Many many sand trips and drag races, one right after the other. I took it out to Glamis with a little over an hour of break in and it ran GREAT. It burns no more oil than anyones stock engine. I can go an entire weekend at Glamis without having to top off. I have only had to add the rest of the quart (what was left over from .89) once. It wasn't neccessary however, but I had the room so I dumped it in. The Venoms wont be any different, they use the same ring pack and gas ports for sealing.

Venom gives you a choice between 2 rings or 3 rings. I have the HH 2 ring piston, which was the only option available at the time. If you are dropping the piston into the cylinder without getting a new one or de-glazing it, buy the 3 ringer. There's nothing wrong with that and some people can't stand to burn oil.....I however don't mind....then again I don't. :D

[hy250r]

has anyone tried Baldwin Motorsports hi-compression piston? Just curious how good they are..

[400exrider707]

Originally posted by GPracer2500
A Flex-Hone in 320 to 240 grit in the appropriate diameter.....

http://imageserver.isnweb.com/KDT2492.jpg

Flapper type hones work too and they're prefered on 2 smokes because the risk of chipping the bore coating at a port edge is reduced compared to a Flex-Hone.

Really though, you don't need either. Wet sanding with medium and/or mild sand paper works well. I've tried a Scotchbrite pad too and many recommend that. It just didn't seem to have enough "bite" when I tried it though. Wet sanding worked better.

Advantages of wet sanding are you probably already have sandpaper in your garage and it's easy to focus on certain areas where you might be able to see a little extra build-up. A Flex-Hone can't really zero in on one area. A Flex-Hone is probably faster though--chuck it in a drill and after a handful of passes your done.

If you wetsand by hand you'll see what I mean about not being able to harm the Nikasil. It will seem like you could rub with max pressure in one spot all day long without eating into the coating at all. Nikasil is like magic. I've got a 1995 CR250R with a Nikasil'd bore that's had who knows how many pistons in it. The bore is original and is still in good condition.

Make sure to clean the bore very well when your done. After cleaning, clean it again...and again for good measure. Use brake or carb cleaner and wipe out the bore with clean paper towels until they keep coming out perfectly white. It's important to get all foreign material out of the cross-hatch.

I'd deglaze a cylinder even if it looks clean to the eye.


Ok well then from what you're saying I should be able to just clean it then... I still have all of my original cross hatching, with no signs of wear at all.

[dobo450r]

I have the baldwin 14:1 and i have not had any problems with it, i dune ride and race mx at times, baldwin piston are cut by wisco!! a very very good company, the baldwin piston also has the teflon panels in the skirt to reduce fiction. But keep in mind that most high compression piston will burn a little bit of oil to do to the fact that a larger tolerance is used for thermal expansion of the piston, so on start up you will burn a little oil till you are warm, but the lil i am talking about is not noticed if you do regular maintenance on you quad (I.E oil changes and stuff like that).

Peace

BRIAN

[chad502ex]

Originally posted by hy250r
has anyone tried Baldwin Motorsports hi-compression piston? Just curious how good they are..

Baldwin makes a great piston... and so does CP...

[GPracer2500]

Originally posted by 400exrider707
Ok well then from what you're saying I should be able to just clean it then... I still have all of my original cross hatching, with no signs of wear at all.

If it where mine, I'd deglaze regardless of how it looked. There could be lots of stuff you can't see. I figure it can't hurt and might help. If the bore looks new then it may not make much difference one way or the other so it's up to you. But my thinking is that ring seal is such an important aspect of a strong running engine I'm going to do everything I can do to assure that seal is the best it can be.

I'm not trying to push you into taking unecessary steps; just giving you my $0.02.

[400exrider707]

Originally posted by GPracer2500
If it where mine, I'd deglaze regardless of how it looked. There could be lots of stuff you can't see. I figure it can't hurt and might help. If the bore looks new then it may not make much difference one way or the other so it's up to you. But my thinking is that ring seal is such an important aspect of a strong running engine I'm going to do everything I can do to assure that seal is the best it can be.

I'm not trying to push you into taking unecessary steps; just giving you my $0.02.

No I appreciated the input, I've heard so many different conflicting stories on the honing of NiCaSil cylinders that it makes my head spin. Just the short time you've been here its quite apparent you know your stuff though. So some medium sandpaper and a little wetsanding and then multiple cleanings and I should be good to go then!