Author Topic: 836 deck height  (Read 2643 times)

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Offline Don R

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836 deck height
« on: August 22, 2012, 03:30:27 PM »
I have an Ebay 836 kit on a K4, engine. With the cylinder installed, not bolted down and a stock cylinder to block gasket. The pistons are slightly out of the hole leaving less than the gasket thickness for clearance. I know some measuring is needed but how much clearance should I be looking for?

 And no, I didn't check before putting on the rings dangit.
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Offline MRieck

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Re: 836 deck height
« Reply #1 on: August 22, 2012, 07:27:18 PM »
.040 for the street.
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Offline Don R

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Re: 836 deck height
« Reply #2 on: August 22, 2012, 09:22:38 PM »
With the gasket crush it's going to be close. I did rework the chambers for a quench band but it's still going to be  tight around the edges. Thanks. I have an old big bore gasket, might be a good time to sacrifice it.
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Offline Don R

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Re: 836 deck height
« Reply #3 on: August 24, 2012, 12:08:22 PM »
Pistons are .008 out of the hole, non compressed gasket is .060 thick If the gasket compresses .012 or less It should be fine.. the re-worked cylinder dome matches the piston dome pretty well too.
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Offline MRieck

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Re: 836 deck height
« Reply #4 on: August 24, 2012, 12:33:54 PM »
Pistons are .008 out of the hole, non compressed gasket is .060 thick If the gasket compresses .012 or less It should be fine.. the re-worked cylinder dome matches the piston dome pretty well too.
It should compress far less than that.... a couple of thou if it is good quality.
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Offline fang

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Re: 836 deck height
« Reply #5 on: September 15, 2012, 08:23:23 AM »
Good questions. I was thinking about these things again too, and I appreciate the info Mike.
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Offline Kemp

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Re: 836 deck height
« Reply #6 on: November 21, 2012, 01:01:56 PM »
A friend of mine bought the 836 E Bay kit also and had the same problem, pistons proud of the cylinder when assembled. In order to get enough clearance he milled the combustion chamber and the valve relief in the piston tops.

Offline Don R

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Re: 836 deck height
« Reply #7 on: November 22, 2012, 08:17:02 PM »
I  clayed mine with an F2 cam and a shave on the head, a little chamber work it runs great. I love the torque, a noticeable difference around town. Still working out oil leaks and carb issues but I did ride it before winter. Don't know the comp ratio but it's apparent when you kick start it. (Needed a battery.)
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Offline POPS 911

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Re: 836 deck height
« Reply #8 on: November 23, 2012, 07:09:46 AM »
POINT :     .040 in the hole = SAFE  or with rod stretch on out of the hole= bump and bump to breakage.  Use piston gauge with just the block bolted down to spec, and rock the piston back and forth to get correct  "IN THE HOLE " number with dial indicator.  Unless you got lots of cash and likes to tear motor down all the time just to get that tight squish [C-RATIO ]. Even with the best money can buy [ CARILLIO ]  ROD STRETCH [ read the instructions ] will kill your efforts if done wrong.

POPS BK911