Blown O-ring

Message

Kuma · #21 Post by **Kuma** » Thu Apr 16, 2009 5:58 pm

QUOTE (Canniboomer @ Apr 16 2009, 09:17 AM) <{POST_SNAPBACK}>

Here are dimensions from a few sleeves that are close by to my desk:

1.733" LA Steel Sleeve, used (uses thin O-ring version)
1.733" LA Steel Sleeve, used (uses thin O-ring version)
1.732" OEM Aluminum Sleeve, new
1.730" OEM Alumimum Sleeve, used

In your situtation, it seems that using some silicone under the bottom lip may be required. For normal practice, we don't add silicone down there,....... since it has been known to cause over-compression of the Sleeve in some installations.....But your measurements indicate a need for more sealing cushion. Also, I can fix you up with a special-order Higher Durometer O-ring. It will cost less actually. I have some on order for stock -- they are 20% stiffer Viton, and could work better with your particular sleeve-case combo.

Is your sleeve a bored-out Aluminum one?

I'll be ordering parts from you shortly, are the new orings shore 90?
The cylinder is from Timbo, I would assume that he starts with a stocker but I don't know for sure, it is aluminum.

I don't feel too comfortable with the idea of using RTV to lift the cylinder, do you know of any shims that would work? my other option would be to remove some material from the top of the case but that would be adding to my compression, I will already have to take some off of the head to clean it up.
I'm hopeing that Tim will have a replacement that I can trade that will give me the correct crush.

claas900 · #22 Post by **claas900** » Thu Apr 16, 2009 8:29 pm

None of the CP piston kits use stock sleeves. That's why they coast so much, the piston isn't any more money then any other brand its the sleeve that gets it.

cannondale27 · #23 Post by **cannondale27** » Fri Apr 17, 2009 12:24 am

All my aluminum sleeves were 1.730-1.732

Looks like your sleeve is the issue.The two sleeves I got 1.732 on were both new so they must lose the .002 when used.Overheating could possibly cause a bigger loss since it could temper the metal.

rayspeed · #24 Post by **rayspeed** » Fri Apr 17, 2009 4:38 am

QUOTE (claas900 @ Apr 16 2009, 01:29 PM) <{POST_SNAPBACK}>

None of the CP piston kits use stock sleeves. That's why they coast so much, the piston isn't any more money then any other brand its the sleeve that gets it.

It doesnt have anything to do with this issue but...
Not quite so... my short stroker has a cp stock size piston with a stock liner making it a 450.

SlOoT · #25 Post by **SlOoT** » Fri Apr 17, 2009 6:33 am

I have measured 7 engine cases here, 4ssm, 2 unicorn and 1 cable.
All are in the 1.728-1.729 range.

claas900 · #26 Post by **claas900** » Fri Apr 17, 2009 9:34 am

QUOTE (rayspeed @ Apr 16 2009, 09:38 PM) <{POST_SNAPBACK}>

It doesnt have anything to do with this issue but...
Not quite so... my short stroker has a cp stock size piston with a stock liner making it a 450.

Hmm I didn't know cp made a stock bore size piston, I thought only 97 and 98mm?

claas900 · #27 Post by **claas900** » Fri Apr 17, 2009 9:35 am

QUOTE (SlOoT @ Apr 16 2009, 11:33 PM) <{POST_SNAPBACK}>

I have measured 7 engine cases here, 4ssm, 2 unicorn and 1 cable.
All are in the 1.728-1.729 range.

Did you use the same tool to measure all of them or do you have more then one tool?

SlOoT · #28 Post by **SlOoT** » Fri Apr 17, 2009 10:43 am

I used the same tool on all of them.

Kuma · #29 Post by **Kuma** » Fri Apr 17, 2009 2:44 pm

QUOTE (SlOoT @ Apr 16 2009, 11:33 PM) <{POST_SNAPBACK}>

I have measured 7 engine cases here, 4ssm, 2 unicorn and 1 cable.
All are in the 1.728-1.729 range.

That is the exact measurement that I got on my cable clutch case. I used a depth micrometer, it is difficult to get this type of measurment with calipers.

claas900 · #30 Post by **claas900** » Fri Apr 17, 2009 3:39 pm

QUOTE (Kuma @ Apr 17 2009, 07:44 AM) <{POST_SNAPBACK}>

That is the exact measurement that I got on my cable clutch case. I used a depth micrometer, it is difficult to get this type of measurment with calipers.

See I used calipers. It's the only tool I have other then dial indicator.