Posted By: dusterjp
Valve Cover Bolt - 08/06/12 01:45 AM
How far should a valve cover bolt go into the head (Edelbrock).
Valve Cover Bolt
Posted By: MLR426
Re: Valve Cover Bolt - 08/06/12 01:52 AM
Guess would be at least a 1/2 minimum.
MLR426
Posted By: Supercuda
Re: Valve Cover Bolt - 08/06/12 03:06 AM
minimum thread effective engagement for any bolt is the same as the diameter.
So a valve cover bolt is 1/4-20, which means minimum engagement should be 1/4"
So a valve cover bolt is 1/4-20, which means minimum engagement should be 1/4"
Posted By: dusterjp
Re: Valve Cover Bolt - 08/06/12 03:22 AM
Thanks for the help!
Posted By: MLR426
Re: Valve Cover Bolt - 08/06/12 03:28 AM
effective engagement ?? 
no disrespect and don't take it that way but with only a 1/4 inch effective engagement it would be tough to draw down a valve cover with gasket with only a 1/4 inch depth of thread in the head. You need more effective thread depth to pull down the valve cover. Compression of the gasket and the bolt will bottom out. Also for example when talking about effective thread depth with a certian diameter you have to take the torque of the bolt into consideration in certian applications, for 3/8 intake bolt tapered on the starting threads and sticking below the gasket surface I wouldn't torque the bolt to 25/30 ft pds and expect the threads to hold in the heads with a 1/4 inch of bolt thread taking the load. I would be afraid the the threads would pull in the heads.
MLR426
no disrespect and don't take it that way but with only a 1/4 inch effective engagement it would be tough to draw down a valve cover with gasket with only a 1/4 inch depth of thread in the head. You need more effective thread depth to pull down the valve cover. Compression of the gasket and the bolt will bottom out. Also for example when talking about effective thread depth with a certian diameter you have to take the torque of the bolt into consideration in certian applications, for 3/8 intake bolt tapered on the starting threads and sticking below the gasket surface I wouldn't torque the bolt to 25/30 ft pds and expect the threads to hold in the heads with a 1/4 inch of bolt thread taking the load. I would be afraid the the threads would pull in the heads.MLR426
Posted By: Supercuda
Re: Valve Cover Bolt - 08/06/12 03:51 AM
Quote:
effective engagement ??
MLR426
Effective engagement has NOTHING to do with a valve cover gasket.
It has to do with having enough engagement to proper stretch the bolt for it to do it's job and that MINIMUM is the same as the diameter of the bolt in question.
In case you haven't clued in it's NOT the maximum, it is the minimum required. You can have more and still be affective, you cannot have less though.
To further elucidate, that minimum is what is actually threaded into the hole, it does not include the portion that passed thru the gasket or the valve cover, that would be extra.
Ever notice how a standard nut will be as thick as the diameter of it's threaded hole? Now you know why.
Posted By: MLR426
Re: Valve Cover Bolt - 08/06/12 04:01 AM
Quote:Quote:
effective engagement ??
MLR426
Effective engagement has NOTHING to do with a valve cover gasket.
It has to do with having enough engagement to proper stretch the bolt for it to do it's job and that MINIMUM is the same as the diameter of the bolt in question.
In case you haven't clued in it's NOT the maximum, it is the minimum required. You can have more and still be affective, you cannot have less though.
To further elucidate, that minimum is what is actually threaded into the hole, it does not include the portion that passed thru the gasket or the valve cover, that would be extra.
Ever notice how a standard nut will be as thick as the diameter of it's threaded hole? Now you know why.
If effective engagement has nothing to do with a valve cover gasket then why would you use the term of effective engagement on the original posters question ? He's asking about thread depth on the valve cover rail in which the gasket compression and correct thread depth will come into play correct ?
MMLR426
Posted By: Supercuda
Re: Valve Cover Bolt - 08/06/12 04:04 AM
Quote:
If effective engagement has nothing to do with a valve cover gasket then why would you use the term of effective engagement on the original posters question ? He's asking about thread depth on the valve cover rail in which the gasket compression and correct thread depth will come into play correct ?
MMLR426
Go reread his original post.
To be honest I would NOT use a bolt in aluminum threads, I would use a stud and a nut.
Posted By: tboomer
Re: Valve Cover Bolt - 08/06/12 04:07 AM
Quote:
Go reread his original post.
To be honest I would NOT use a bolt in aluminum threads, I would use a stud and a nut.
What the small weasel guy says!! 
Posted By: JohnRR
Re: Valve Cover Bolt - 08/06/12 04:19 AM
Quote:
Quote:
Go reread his original post.
To be honest I would NOT use a bolt in aluminum threads, I would use a stud and a nut.
X3 ...
otherwise , carry on ...
Martin , you need to understand , the small weasel guy is NEVER wrong ... in his little world anyway ...
But , he is correct about the effective engagement principle ...
Posted By: MLR426
Re: Valve Cover Bolt - 08/06/12 04:23 PM
Wasn't trying to offend anyone guys. I took it as though the poster must have had very sallow threaded holes in the cover rail, and with the compression of the gasket it would be impossible to compress the gasket before bottoming out with the 1/4 inch engagement rule to take effect with that depth. I didn't mean to give you a wedgey dude!!! I didn't think engagement had anything to do with proper thread depth to compress the gasket.
MLR426
I didn't think engagement had anything to do with proper thread depth to compress the gasket.MLR426
Posted By: Supercuda
Re: Valve Cover Bolt - 08/06/12 06:17 PM
To answer the question you thought was asked you would have to also know what gasket he's running and what valve cover. The bolt hole is blind so there is a limit to how long the bolt can be and have it still work.
As for you John, it isn't that I am always right, it's more that you are wrong so often.
As for you John, it isn't that I am always right, it's more that you are wrong so often.
Posted By: MLR426
Re: Valve Cover Bolt - 08/06/12 06:23 PM
Quote:
To answer the question you thought was asked you would have to also know what gasket he's running and what valve cover. The bolt hole is blind so there is a limit to how long the bolt can be and have it still work.
As for you John, it isn't that I am always right, it's more that you are wrong so often.
Doesn't matter what gasket or cover,,,John you were right.
MLR426