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cpi's vs shearer's


man27

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Stock "spec" is 22cc. I have milled more heads than i can count. CC'd them to begin with and they ranged from 20.7-24.2cc's before i milled them. production tolerances i guess. cast em, mill em drill em put them on.

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Stock "spec" is 22cc. I have milled more heads than i can count. CC'd them to begin with and they ranged from 20.7-24.2cc's before i milled them. production tolerances i guess. cast em, mill em drill em put them on.

 

Toybreaker, that makes 100% perfect since.

 

Some guys can mill .015 off and need to run a little race gas, some can mill off .030 and run pump.

I'd bet the majority of guys that get them milled:

 

a. Don't bother to cc the head, before or after and

b. Don't bother checking squish when putting it back together.

 

That is priceless info from experience right there...kudos to you...

 

--Daj...

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Hi guys I would like to know what pipes would work best for my mods.I'm running stock cylinders that have been bored 66mm and have been ported for a 4mm stroker crank .The crank is a hot rods 4mm 5mm long rod ,the pistons are wiseco pro lites ,reeds v force 3s ,vito's hemi head 24cc domes ,ricky stator 4+ timing advance,vito's water impeller,34mm mikuni carbs 390 mains 30 pilots clip in the 3rd position, tors removed,I 'm running 110 race gas 32:1,I 've been running pro curcuits.I want to run in frames if that makes a differance.I would like to know my hp but there 's not a dyno around so if someone could get me close I would appriciate it,I 'm thinking around 65 or so.Thanks for the help man27

The guy is saying he has a 4mm stroker crank and cylinders are 66mm with some porting. As for the 24cc domes, I've never heard of anyone using that size and getting 170 psi for there compression, but if thats what you're getting for your compression check its good your using race fuel.

 

I don't know how to quote what he wrote sorry

chris, your jugs have a aggressive dune port right? if your wanting a 50/50 duner/drag bike i think you would like the cpi.... they pull pretty hard but they peak off before the shearers, but they have a lower mid range which is great for dunning....only thing i dont like about cpi is they dont give much room to work on your carbs to chang jets... i mean you can get in there but it not ez... also you got to make sure you do something for your pods so they dont hit the stingers...

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chris, your jugs have a aggressive dune port right? if your wanting a 50/50 duner/drag bike i think you would like the cpi.... they pull pretty hard but they peak off before the shearers, but they have a lower mid range which is great for dunning....only thing i dont like about cpi is they dont give much room to work on your carbs to chang jets... i mean you can get in there but it not ez... also you got to make sure you do something for your pods so they dont hit the stingers...

yeah I'm really thinking about what pipes to get because my little bro might buy my fmf's for his new shee. i was thinking about the cpi's shearers, and someone was telling me about grand river racing pipes, which i don't know anything about the grr pipes.

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If you look on Dave Noss's site, it will tell you that stock is 22cc. However, I've read here and elsewhere that a stock head (OEM) is 23cc...so, I'm not 100%....and to be honest, I've never measured a stock OEM head for cc volume.

Either way...as said, 24cc should produce no where near that PSI...

I didn't even know they made 24cc domes...never seen 'em before!!

 

I should be getting my CPI's tomorrow. I can take pics after they are installed to show the amount of room there is with my filter pods etc...

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yeah I'm really thinking about what pipes to get because my little bro might buy my fmf's for his new shee. i was thinking about the cpi's shearers, and someone was telling me about grand river racing pipes, which i don't know anything about the grr pipes.

grr isnt for that motor... they make great pipes but they are for big motors for drag... youll like the cpi, but like i said before i dont like how they are hard to get to the carbs for jetting... but the performance are good... the shearers are better drag pipes and have a better design in the stingers too... either way you cant go wrong its just prefferance for the style riing you want the pipes for..

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Hi guys I would like to know what pipes would work best for my mods.I'm running stock cylinders that have been bored 66mm and have been ported for a 4mm stroker crank .The crank is a hot rods 4mm 5mm long rod ,the pistons are wiseco pro lites ,reeds v force 3s ,vito's hemi head 24cc domes ,ricky stator 4+ timing advance,vito's water impeller,34mm mikuni carbs 390 mains 30 pilots clip in the 3rd position, tors removed,I 'm running 110 race gas 32:1,I 've been running pro curcuits.I want to run in frames if that makes a differance.I would like to know my hp but there 's not a dyno around so if someone could get me close I would appriciate it,I 'm thinking around 65 or so.Thanks for the help man27

The guy is saying he has a 4mm stroker crank and cylinders are 66mm with some porting. As for the 24cc domes, I've never heard of anyone using that size and getting 170 psi for there compression, but if thats what you're getting for your compression check its good your using race fuel.

 

I don't know how to quote what he wrote sorry

I'm running a hot rods 4mm stroke 115mm long rod, sorry for the confusion, the gauge is brand new , like I said it's the first banshee I've ever built so when I got all back together I was expecting 140 or 150 on compression so I went and got a friends gauge and it was with in 2 or 3 psi so I check it again and it was the same,I did the research and I don't want just a drag bike I want a all around bike to have a blast on in the sand ,in the trails at st joe.I know from what you guys told me last spring that I didn't need a cub for my riding style so I took the advice' the bike runs better than what I was expecting ,the only thing is the oil coming out of the exhaust thats why I'm looking for drag pipes? The domes must be stamped wrong.What domes do you recommend for 155 or 160 psi.Thanks for the replies I'm just dumb ole hillbilly that needs all the help I can get and I'm at the wright place the hq is awsome!!! :laugh:

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Ive been waiting for a good thread on this topic.....

 

I have an agressive dune/trail port with 20cc domes, and 28mm keihins that pulls hard on pump gas, even with the FMF gold series I have on right now. Ive been wanting to switch up pipes, but how much will I gain in the drags or lose on the trails??

 

My top end seems to rip, i smoked a HRC kitted 450r up top, by at least 4 or 5 bikes.

 

I also ride a lot of trails, mostly in the U.P which are long and fast.

 

I cant complain about the FMFs, but want to see if im missing out on significant power gains.

 

Daj.. you mentioned a 2-5hp gain with shearers or CPI, u think I should just keep the FMFs if they are performing?

I guess you will see this winter on white lake (if we get a winter that is)....

 

Thanks,,

JD

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i went from fmf to shearers and it was night and day.... pulling up olds with fmf's i was lucky to hit 4th and pull it... with the shearers i can pull 5th no problem.... but your low end will definately suffer from the drag pipes... you can always advance your timing or gear a little differant if need be...

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i went from fmf to shearers and it was night and day.... pulling up olds with fmf's i was lucky to hit 4th and pull it... with the shearers i can pull 5th no problem.... but your low end will definately suffer from the drag pipes... you can always advance your timing or gear a little differant if need be...

 

 

No shit, and ive kinsa been doing more drag racing lately. Hmm, i think im guna have to save my pennies and get some.

 

But I traded some older T5s for these pipes since they are chrome. I hardly noticed any difference... although I did have the T5s on this bike before it was ported. Do I not know what im missing??

 

Ohh and im running a 15/41 gear right now, helped this bike a lot on the top end..

Edited by 87sheerips
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Don't take this the wrong way, but something doesn't add up. The domes are marked wrong (and you don't use big bore domes until you get into big bore pistons...which, I didn't read in your list of mods...just a 66 mm piston which is .080, not considered a big bore)...

IF those domes are 24cc and your gauge is accurate, there is no way it has 170PSI...no way.

 

Talk to Lane @ Vitos...he knows his shit and is a great guy to talk to.

 

 

 

 

 

They do make a 24cc. I have a set myself. I used them when I was .080 and .100 over.

 

 

Ditto on Lane too. Vito's is the only game in town IMO.

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Sorry JD...just parsed this thread again.

 

I think with 29mm carbs, FMFs are a better choice. If you wanted to get a drag port, then larger carbs...CPI or Shearer would be a good compliment. But...I think you're fine with FMFs...to be honest.

 

Yeah...I might have my 10 mil done sooner than thought....hopefully we get some ice!!

 

JMD...you bring up an interesting point. Normally, you want a tighter squish and more compression (smaller domes) when you go bigger bore....there is more piston surface to compress the mix, why did you get 24cc's for your .080 and .100 motor?

Just curious....not trying to be a smart ass at all....

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Sorry JD...just parsed this thread again.

 

I think with 29mm carbs, FMFs are a better choice. If you wanted to get a drag port, then larger carbs...CPI or Shearer would be a good compliment. But...I think you're fine with FMFs...to be honest.

 

Yeah...I might have my 10 mil done sooner than thought....hopefully we get some ice!!

 

 

 

 

Thx for the advice Daj, but as you can see in my avatar, the intakes are huge like a drag port ( i know it doesnt tell the whole story of the port though) the builder told me they are good for up to 75 horse with the right pipes. But, I am happy with the FMFs, especially for down low trails, I can put around all day with these.

 

And I have been beating bansees with T5s and some other mods. Shit last winter I was beating a 402 big bore with DMCs every time we dragged, and that was before I was ported, and I was at .100 over with a shaved head.

 

I dont know, maybe ill try some diff. pipes If i get the money.

 

If we get ice, well have to hook up so u can see my setup.

 

Thanks

 

JD

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