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2 minutes ago, greenhuman said:

Anyone had experience with O ringing a head and cylinder on a CRF230?

For what porpoise?

The shop in Arizona makes any size copper gasket you desire for any bike.

Edited by Baja Rambler

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Anyone had experience with O ringing a head and cylinder on a CRF230?


Yes, 69.5 and 70 mm bores have been known to require a Stainless steel "O Ring between the copper head gasket and cylinder if the cylinders are NOT offset bored to keep the sleeve from being to close to the flywheel side rear stud.

Compression will travel down that stud and pressurize the crank case because the OEM base gasket has a slot in it from the factory.

One can custom build a copper base gasket to cure this problem in conjunction with offset boring the cylinder (and cases) to give adequate margins for the top end oil supply and that one stud.
Then the stainless "O, Ring" will not be required

There are other things that can be done with the head gasket to give it more surface area around the one stud.

Why do you ask?
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In the quad world o-ringing is quite common in the big builds on the 450s... Lots of nitrous on big bore/stroker 500cc+ setups for the drag race crowd....

Sredrum Performance is quite experienced in machining head gasket surfaces for o-rings... if anyone needed it done from a shop...

I have recently wondered at what point would the 230 need either bigger diameter and/or better steel for the cylinder studs??

Edited by mixxer

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He's building a 277 and then a 320cc after that! mmmmmmm TORQUE  


He is not building a 320 with all 230 components
Like 230 stud location or cylinder and head.

More than likely based with China made components
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In the quad world o-ringing is quite common in the big builds on the 450s... Lots of nitrous on big bore/stroker 500cc+ setups for the drag race crowd....

Sredrum Performance is quite experienced in machining head gasket surfaces for o-rings... if anyone needed it done from a shop...

I have recently wondered at what point would the 230 need either bigger diameter and/or better steel for the cylinder studs??

 

Well, so far, a 269 with over 13-1, the std studs with std torque applied are holding as well as a stocker.

On 273cc engines, I have added another ft lb torque to the head studs over stock and at 13-1... so far so good.

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26 minutes ago, adnohguy said:

 


He is not building a 320 with all 230 components
Like 230 stud location or cylinder and head.

More than likely based with China made components

 

He also is using more stroke😁

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I have been thinking...

You know BBR made all the aluminum crf framed 230s

So I was thinking for ultimate suspension I should put my 230 engine in my yz450 frame... Since the suspension is lowered 1 inch front and rear... Correct race tech springs ... And triple rate valving from Pro Action suspension.... 

And then to have the most brutal big bore monster power.... Torque for days on end...

I will pull 230 engine back out and put the 450 engine back in😎👍🤘

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He also is using more stroke

 

More stroke than stock for a 320.... thats a given.

 

74mm X 74mm = 318.3 cc with 15mm piston pin

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2 minutes ago, adnohguy said:

 


More stroke than stock for a 320.... that a given.

74X74= 318.3 cc

 

More than what's readily available here😎

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More than what's readily available here

 

Your saying that Zongshen China made engines, 4mm off set crank pins, and 74mm pistons cannot be sourced here. Where is "here" located?

One does not need an offset pin to increase stroke by 8mm

One does not need a 74 mm piston to made in Taiwan. They can be sourced in the USA.

But on a 230f, one does need different stud spacing, case welding and a cylinder and head to match the stud spacing to go as large as 74 mm bore, such as a Zongshen engine would provide.

 

Now if most all components were based on a crf230f and made into a 494cc V Twin engine,

That would be much more impressive and fun to ride, talk about an accomplishment.

 

But that's just me.

 

And it's up to Greenhuman, for he has the ability to build it.

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I can use all crf components to build a 320 but for now Ching Chong top end parts will do to gauge if it's all worthwhile. I am all for buying local but with our exchange rate, waiting times and freight charges from the U.S to take into consideration these evil Asian parts are worth looking at for me plus there thousands of times more bikes racing and getting around with these parts in them with reliability than anywhere else.

I can go as large as 370cc's using these parts but I don't need negative comments so I may as well keep it to myself.

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I can use all crf components to build a 320 but for now Ching Chong top end parts will do to gauge if it's all worthwhile. I am all for buying local but with our exchange rate, waiting times and freight charges from the U.S to take into consideration these evil Asian parts are worth looking at for me plus there thousands of times more bikes racing and getting around with these parts in them with reliability than anywhere else.
I can go as large as 370cc's using these parts but I don't need negative comments so I may as well keep it to myself.



Ahh, to each his own, but where is the fun in that, when your 40 miles away from your truck in the fifth Canyon where your bike cannot be even pushed started let alone be towed out of there when it breaks....
I think I can, I think I can, I think I can... maybe I can not

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I have not O ringed my 254cc but had to do it. To my TT600 bore and stroke to 680cc. Frame flex was the problem on head gasket. So we made a sub frame on bottom welded it in,O ringed Sleeve fixed.  Was a bitch to put in O ring.

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I don't know about the zongshen engine parts but these ads for Asian dating service keep popping up on TT.  Just click to view more ladies.  I thought they had a shortage of women over there.

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37 minutes ago, bajatrailrider said:

Where are the Adds Baja Hooter. Maybe I can add on another room here to house them.

It's called iDateasia.com

Also Russian women keep popping up for some reason.

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I have been wondering where I am supposed to be going to have dramas using the zongshen top end on the 320.

Resleeved using an LA sleeve

Stainless steel valves and bronze guides

Forged piston

CRF rockers

Crf cam chain

After market CRF cam

Pro X rod

CRF top timing sprocket

Copper head gasket

CRF studs

Basically the only ZS parts I am using is the bare cylinder shell, the bare head and rocker cover. 

Currently I am using a ZS top end on my hybrid ATC200X/CRF 247cc and constantly rev the piss out of it for hours at a time with absolutely no problems at all and that is using all the ZS components. And not to forget my cylinder head is laying down with no oil bath to help lube the cam and rockers. 

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