Cam with compression release, a bit confused about valve lash
because the compression release has more than .005" of lift on the exhaust valve.
thats how.
the compression release is a spring loaded nub on a pivot point connected to counter weights on the camshaft. when the motor reaches a low rpm, the compression release and its aforementioned counter weights allow it to move out of the way via centrifugal force from the lifter.
pull the valve cover off, pull the spark plug wire off, and gently pull start the motor. you will see the exhaust valve slightly open when pull starting it on the compression stroke. you will be able to visibly see that it moves more than .005".
i went into my garage just now and did a very quick and inaccurate eye ball measurement with my digital mitutoyu calipers. .135" was what a quickly saw. again, not accurate at all, but a quick eyeball job with them. so as you see, .135" of lift is a touch more than the .005" valve lash you quoted.
:thumbsup:
thats how.
the compression release is a spring loaded nub on a pivot point connected to counter weights on the camshaft. when the motor reaches a low rpm, the compression release and its aforementioned counter weights allow it to move out of the way via centrifugal force from the lifter.
pull the valve cover off, pull the spark plug wire off, and gently pull start the motor. you will see the exhaust valve slightly open when pull starting it on the compression stroke. you will be able to visibly see that it moves more than .005".
i went into my garage just now and did a very quick and inaccurate eye ball measurement with my digital mitutoyu calipers. .135" was what a quickly saw. again, not accurate at all, but a quick eyeball job with them. so as you see, .135" of lift is a touch more than the .005" valve lash you quoted.
:thumbsup:
tear the thing off and throw it away it's only robbing you of power. It's the same as cutting the ez spin off of a briggs cam. I had one of those compression releases on my h60 and took it off . At least that cam type stops holding the valve open once the engine runs fast enough. Without the compression release the engine will have alot more low end power and compression. To start it just pull it to the beginning of the compression stroke [you will feel it with the pull start] then just pull it through the compression stroke. My two h60s will both start cold on the first or second pull. I put a video of my h60 running if you want to hear it. It is all stock except for removing the compression release and advancing the timing all the way.
I have to type this one handed as my right hand is still grabbing the pull start handle out in the garage.
And you want me to remove the compression release?
It's not that it's just hard to pull, it pulls back. And it's pissed.
I have 130 PSI compression just pulling the rope.
I should note that there's an Isky cam in there, aluminum flywheel with 8 degree key, and the head is missing .065.
Something ain't letting that pressure out.
And you want me to remove the compression release?
It's not that it's just hard to pull, it pulls back. And it's pissed.
I have 130 PSI compression just pulling the rope.
I should note that there's an Isky cam in there, aluminum flywheel with 8 degree key, and the head is missing .065.
Something ain't letting that pressure out.
You failed to mention any of this in your original post, removing the compression release on a stock engine will make a difference. It doesn't sound like your compression release is working anyway. It might have already been disabled on the aftermarket cam that you have. Add the milled head, the light weight flywheel and a lot of timing advance and of course it will kick back on you. I don't have that problem with the h60 because like I said the engine is basically stock