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Author Topic: Cast in compression release  (Read 1202 times)

Offline BOREoffroad

Cast in compression release
« on: June 02, 2021, 04:49:25 PM »
Looking for some feedback on this idea.
This modification has been in the works with CPI to have a boss cast into the cylinder.
This improved compression release design allows for easier access and eliminates the need for a special head.
The cylinder pictured is a first test so its not centered and looks a little off.
If this is a desirable modification that people would like to have, the plan is to move it towards the intake for optimal clearance and access to choke and release in same area.

Online croat1

Re: Cast in compression release
« Reply #1 on: June 02, 2021, 07:28:06 PM »
I think it’s a great idea/option. 

Is anyone adding a decompression release to an existing CP cylinder?  I have a Sphinx that I’d like to add a release.

Joe

Offline BOREoffroad

Re: Cast in compression release
« Reply #2 on: June 03, 2021, 09:42:04 AM »
I think it’s a great idea/option. 

Is anyone adding a decompression release to an existing CP cylinder?  I have a Sphinx that I’d like to add a release.

Joe

I know a couple people that have cut into the cylinders and welded up an area for their personal use. But no one that I know of is offering it as a service.

Offline 2ndmoto

Re: Cast in compression release
« Reply #3 on: June 03, 2021, 05:35:17 PM »
So this goes in through the side of the sleeve? Seems like it is well below the combustion chamber.

Offline BOREoffroad

Re: Cast in compression release
« Reply #4 on: June 03, 2021, 06:20:51 PM »
So this goes in through the side of the sleeve? Seems like it is well below the combustion chamber.
It is, the concept in how they function are the same, bleeding off "xx" amount of volume before TDC, lowering the overall cranking compression while open.

Offline havinnoj

Re: Cast in compression release
« Reply #5 on: June 06, 2021, 01:09:35 PM »
I think it’s a great idea/option. 

Is anyone adding a decompression release to an existing CP cylinder?  I have a Sphinx that I’d like to add a release.

Joe

I know a couple people that have cut into the cylinders and welded up an area for their personal use. But no one that I know of is offering it as a service.

For the Sphynx, last I looked which was 8-12 months ago - there were 2 options.  Rob Selvy was welding them in the cast CP head.  I had concerns about warpage - they were my concerns though, as Rob said he didn't have any related issues.  The second options was from Bob Albright - who offered them with his 2 piece head.  Those were spendy.  And Elaine @ CP told me they wanted to offer a cast head option with the boss option for the release, but to this day I still have not seen it. 

@BOREoffroad  - I like the option.  But for me it would be an aesthetic choice - the head-mounted compression release I run on my PUMA might be harder to 'find' but it does, to me anyways, look cleaner to my eyes.
« Last Edit: June 06, 2021, 01:11:12 PM by havinnoj »

Offline Hawaiiysr

Re: Cast in compression release
« Reply #6 on: June 06, 2021, 10:33:07 PM »
Not to sound like a beauty queen but I like the decomposition in the head for aesthetics as well. I'm no engine builder but going through the cylinder doesn't appeal to me

 

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