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Post by shakerdriver on Apr 5, 2014 17:35:53 GMT -5
I installed a 70cc bbk on a taotao thunder and now the intake valve hits the piston, barely but it does. Would it be safe to stack another base gasket on there for more clearance?
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Post by Upgrayedd on Apr 5, 2014 17:57:45 GMT -5
I have zero experience in trying that, but I read on the old scootdawg forum where others do just that and have success/no problems with it. My only concern would be potential oil leaks - I was prepared to use 2 base gaskets on my kit if needed, I would have added a real thin layer of ultra copper RTV both in between the two gaskets and on both metal mating sides, maybe overkill but I'd rather that than have a leak.
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Post by shakerdriver on Apr 5, 2014 19:07:08 GMT -5
The copper rtv was an automatic for me if I stacked gaskets. There's no compression there so I shouldn't have to worry about that.
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Post by 90GTVert on Apr 5, 2014 19:12:24 GMT -5
I would try to verify that the cam is right on and the flywheel is machined correctly. I constantly had valve clearance issue on my old SunL. Once I used a flywheel that wasn't 30 degrees off most valve clearance issues disappeared.
Stacking a base gasket is fine. If there's plenty of meat I have enlarged valve reliefs on these before just using a large flat dremel stone. If your compression figures are good now, that will keep them closer. If compression is high, the gasket would prob solve 2 problems at once.
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Post by shakerdriver on Apr 5, 2014 19:36:59 GMT -5
Compression does seam quite high but not 100% sure because of the valve clearance issue.
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Post by craisin on Apr 6, 2014 2:29:31 GMT -5
you could dremel the releif and set a big gap on the rocker as thing stretch out with revs. or double up base gasket
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Post by usmcdoc on Apr 6, 2014 7:46:30 GMT -5
I would try to verify that the cam is right on and the flywheel is machined correctly. I constantly had valve clearance issue on my old SunL. Once I used a flywheel that wasn't 30 degrees off most valve clearance issues disappeared. Stacking a base gasket is fine. If there's plenty of meat I have enlarged valve reliefs on these before just using a large flat dremel stone. If your compression figures are good now, that will keep them closer. If compression is high, the gasket would prob solve 2 problems at once. @ shakerdriver Bingo..as Brent said..read my post above called..--> I don't care what China sez.. TDC is not always TDC... Cause I found that for the second time last night! Also what BBK are you using?.. Just curious.. |
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Post by craisin on Apr 6, 2014 13:36:03 GMT -5
every other time the piston is at tdc the valves should be at overlap eg there should be clearance on both valves.
when i was young a friend messed up the timing on his OHC Hillman Imp the first OHC i had seen and i timed it liked that.
He kissed me when it ran. First time a man kissed me turned me off OHCs
Screwdriver in the sparkplug hole to find TDC
Unless you want to get a degree wheel a piston stop and a dial indicator.
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Post by craisin on Apr 6, 2014 14:06:14 GMT -5
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Post by craisin on Apr 6, 2014 14:53:36 GMT -5
correction overlap is when both valves are open so the stroke 180% from overlap is when there should be clearance on both rockers.
On inline engines they say when number one is knocking [firing] the back one is rocking [you can rock the rockers] but on these there is only one piston
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Post by craisin on Apr 11, 2014 12:33:49 GMT -5
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Post by craisin on Apr 12, 2014 3:38:44 GMT -5
 do you get anything like this for gy6 |
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