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The Wife and the Car
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Discussion Starter #1
Looking for valve clearances on a cold engine Intake and Exhaust for a Bisi Cam.
Randy told me to use the stock clearances. In another e-mail Bisi mentioned a number of 0.010. Im some how not convinced with Randay's recommendations of using the stock clearances.
Id ask on their support forum but most of the posts never seem to get a reply.

So Im a bit confused. With the group buy and all Im sure tons of guys have installed their Bisi Cams so any help would be great. And please dont ask me to read the cam card LOL.
Im talking about the clearance between the rocker and the valve stem.
 

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See above...
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Intake - .007 Exhaust - .009 is stock, and what I used on my Comp 59300 cam. Perhaps the .010 was to recommend a looser tolerance for the larger lobes.
 

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del Sol si '94
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Off my level 2 Bisi cam card



Cam specs for Bisimoto level 2 n/a cam.

Valve lash Intake .006 Exhaust .007

Duration In 264 degrees Ex 244 degrees

Lift In .420 inch Ex .420 inch

Lobe center In 110 degrees Ex 110 degrees

Intake valve opens 7.5 degrees before tdc
Exhuast valve opens 38.5 degrees before bdc
Intake closes 47.5 After bdc
Exhaust closes -1.5 after tdc
__________________
 

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1988 Honda CRX
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I would NEVER buy a cam from someone who will not provide a proper cam card.

Having said that, I never saw a reason not to run stock tappet clearance on any solid lifter cam on any NA engine. I always give a bit more on boosted engines to compensate for extra expansion in the exhaust valve stem.

The only need to change tappet clearance is poor accuracy of the base circle or a change in maximum valve stem temperature or head temperature.
 

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1988 Honda CRX
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Also, if they are to tight you will quickly find out as it loses all power on the first hard pull. If so just back them off 0.002"
 

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The Wife and the Car
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Discussion Starter #7
Thanks guys.
Well I have to say I was quite impressed with at least one aspect of the cam.
When installed it almost looked like the engine needed no adjustment.
Which means they have not ground the hell out of the base circle.
With most after market cams. I land up with the adjuster all the way in.
This is the first cam where the adjuster is almost close to stock. So we have not given up the base circle to make lift.

I did find it odd that when measuring the base circle the values kept changing.
Normally one would expect the base circle to be constant. But Ill only get into detailing this issue latter after I re-confirm my measurements.
 

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Also, if they are to tight you will quickly find out as it loses all power on the first hard pull. If so just back them off 0.002"
hm, my car ran perfekt up until the first autobahn run where the one
valve with improper clearance melted away :-(

nearly half of the valve disc was gone and i never found out where the material went, lol
 
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