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  #11  
Old 08-30-2014, 10:39 AM
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ericg ericg is online now
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Quote:
Originally Posted by Bashby View Post
So your question is about how valvetrain wear can make clearance tighten asopposed to loosen?
Valve seats can wear causing the valve to recess in the head andthe valve itself can deform. Id adjust it to spec and run it. Maybe check it again in a couple hundred hours to see if ittightens up again.
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Here is a thread from Garage Journal that deals with a B&S engine that had similar issues and valve growth is discussed.

http://www.garagejournal.com/forum/archive/index.php/t-118796.html
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  #12  
Old 08-30-2014, 10:51 AM
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Originally Posted by ed2hess View Post
It wasn't hot I pulled it in shop and took awhile to get plugs out and covers off. If it was hot it should have clearance right? The unit got to the point that it would only start cold. It is propane. When really hot I could hear a pop which was probably ignition with the exhaust open a little. It bothers me that it would wear in and get tighter? The adjusting nut was tight.
Are you running propane specific oil? Propane can produce allot of deposits on the valves and lead to overheated valves if they are held off the seat.
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  #13  
Old 08-30-2014, 04:09 PM
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Originally Posted by tigerepairdotcom View Post
Ed2hess here is my suggestion. Adjust valves cold and then run a compression test just to make sure they match. And let us know what you find
ok I will have to get fitting for that size plug. Think I will let unit set until I can run test and use backup.

Quote:
Originally Posted by Bashby View Post
So your question is about how valvetrain wear can make clearance tighten asopposed to loosen?
Valve seats can wear causing the valve to recess in the head andthe valve itself can deform. Id adjust it to spec and run it. Maybe check it again in a couple hundred hours to see if ittightens up again.
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now that makes sense.I remember grinding valves on FB460 and then would have to remove the valve and grind the tip to get clearance. Kinda makes me wonder about how running propane affects engine. I thought I was doing a good thing that would increase life.
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  #14  
Old 08-31-2014, 12:33 PM
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jkilov jkilov is offline
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Originally Posted by Bashby View Post
Valve seats can wear causing the valve to recess in the head
A local guy does LPG conversions and said valve problems are quite common on converted engines.

Intake valves rely on gasoline for cleaning. When converting to LPG some sort of auxiliary valve lubrication system is added.

Unlike gasoline, propane burns hotter and slower on richer fuel/air ratios which can cause exhaust valve/seat wear. I believe most OEM propane engines come with hardened valves and seats.

What Ed2Hess need to do is have his regulator checked. Next take a compression reading and if low a valve job needs to be done.
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  #15  
Old 08-31-2014, 01:05 PM
Tcartwri Tcartwri is offline
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This is an example of LPG specific oil;

http://www.valvoline.com/products/co...engine-oils/71
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  #16  
Old 09-01-2014, 04:39 PM
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Originally Posted by tigerepairdotcom View Post
Ed2hess here is my suggestion. Adjust valves cold and then run a compression test just to make sure they match. And let us know what you find
Well they don't match......120 and 165. The 120 is on the side where I apparently had valve wear. Sure would like to run until winter before I pull that head. Sure hope the seat is not damaged.
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  #17  
Old 09-02-2014, 12:43 AM
tigerepairdotcom tigerepairdotcom is offline
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Quote:
Originally Posted by jkilov View Post
A local guy does LPG conversions and said valve problems are quite common on converted engines.

Intake valves rely on gasoline for cleaning. When converting to LPG some sort of auxiliary valve lubrication system is added.

Unlike gasoline, propane burns hotter and slower on richer fuel/air ratios which can cause exhaust valve/seat wear. I believe most OEM propane engines come with hardened valves and seats.

What Ed2Hess need to do is have his regulator checked. Next take a compression reading and if low a valve job needs to be done.
Not exactly but close!

http://www.transtechenergy.com/LPG-N...alve-Recession
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  #18  
Old 09-02-2014, 01:51 PM
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Not that it matters but I think it was the exhaust that was tight. Having the valve seats replaced would be costly and new heads probably cost
An arm and leg. As long as compression holds I am going to run it.
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  #19  
Old 09-02-2014, 03:49 PM
Bashby Bashby is offline
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I found some used heads on ebay a while back for my ch25. Might be worthwhile to try to find something cheap to have in inventory. Go ahead and get some head gaskets too... that should guarantee your old one will last forever.
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  #20  
Old 09-02-2014, 04:31 PM
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Quote:
Originally Posted by tigerepairdotcom View Post
Thanks for help.

Quote:
Originally Posted by Bashby View Post
I found some used heads on ebay a while back for my ch25. Might be worthwhile to try to find something cheap to have in inventory. Go ahead and get some head gaskets too... that should guarantee your old one will last forever.
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Thanks for help....lesson learned on doing aftermarket propane install.
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