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Author Topic: Potential Valve Dammage ?  (Read 3856 times)

rf

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Potential Valve Dammage ?
« on: June 17, 2009, 03:57:51 AM »
I've been playing with my new toy, an Indian built 12/2. (Bharti Brand)
 After polishing the lifter bowls, rods and threaded tips to the rods I noticed upon turning the fly wheel with the decompression levers in place that there seemed to be a slight sense of compression at TDC on both cylinders.
 After a little poking around I noticed that the castings for the decompression stops were too long and the pistons were indeed hitting the valves forcing the flanges on the exhaust lifters to bend.
 The fellow I bought my engine from mentioned that his had broke also on another engine but he wrote it off to poor craftsmanship. He made an exact duplicate and we discovered today that that was in fact the same problem that broke his original.
 It's a problem I wouldn't expect but it may be worth looking for.


Regards
RF

mobile_bob

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Re: Potential Valve Dammage ?
« Reply #1 on: June 17, 2009, 04:34:10 AM »
what kind of valve clearance are you running?

it might be something as simple as not enough clearance and a misprint in your instruction booklet?

bob g
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rf

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Re: Potential Valve Dammage ?
« Reply #2 on: June 17, 2009, 04:53:54 AM »
Valve clearance is in excess of the book recommended .017" intake / .032" exhaust clearances.

RF

xyzer

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Re: Potential Valve Dammage ?
« Reply #3 on: June 17, 2009, 06:40:35 AM »
It's a problem I wouldn't expect but it may be worth looking for.
Definatly one of those Indian things that needs to be checked out. I freshend up one up my 6/1's and noticed a clear spot on the piston where the exhaust valve was jus missing the piston. If the decompression height is too tall it will hit the piston for sure. Less valve clearance will get it closer and loose will give it more clearance. I fixed mine so it clears what ever the clearance is.
Dave
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cujet

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Re: Potential Valve Dammage ?
« Reply #4 on: June 18, 2009, 08:03:16 PM »
You can reduce the lift of the compression release by changing the shims under the removable upper section of the exhaust lifter. The compression release should lift the ex valves so they are very close to, but not touching the piston. They will touch the carbon. It's just the way it is......

Every time these engines are overhauled this needs to be adjusted.

Chris
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12 gauge

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Re: Potential Valve Dammage ?
« Reply #5 on: July 04, 2009, 06:54:11 PM »
About 2 weeks after I read this thread I noticed a new "ticking" sound when engaging the compression release on shutdown.  So I allready knew what the problem was.  Fixed it by removing the valve lifter pin and removing about .030" from it in the lathe.  Now the exhaust valve has a small amount of clearance from the piston when the valve lifter is engaged.  Thanks to all.
RH