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-   -   Need more P/V clearance in a BB mopar (https://classracer.com/classforum/showthread.php?t=69617)

Glenn Briglio 04-19-2018 10:26 AM

Re: Need more P/V clearance in a BB mopar
 
Quote:

Originally Posted by ss3011 (Post 561098)
Indicator method is good , but usually gives the closest value . When the real springs are used the clearance will be greater . Would be nice to be able to run the cam advanced , but that would be based on dyno testing .

As Russ says, check with actual spring pressure. You'll have more p to v clearance.

GallopinGhost 04-19-2018 02:09 PM

Re: Need more P/V clearance in a BB mopar
 
I think for now we'll leave the valve job as is, I'd hate to lose anything there. I really just need to decide how much to deck the head. Once I get the head from the shop, I'll check it with race springs and see where it's at. Then I'll just get a gasket that will give me what is needed. This project is taking forever and I just want it on the track. Next winter I can do some of the trimming of the valve head and maybe re-grind the cam, hopefully that will enable me to then get a thinner gasket and get some of the compression back. thanks all

Larry Hill 04-21-2018 08:15 AM

Re: Need more P/V clearance in a BB mopar
 
While you are waiting on next winter find out what is available for gaskets, pistons, rods, and block deck height. In your spare time learn how to juggle. lol

Patric Fox 04-21-2018 08:28 AM

Re: Need more P/V clearance in a BB mopar
 
The Steel Shim head gaskets for a small block are very hard to find, the Mr. Gasket head gaskets are .028, about as thin as I have found. Might not be able to get the .021 gaskets you mentioned. I was taught not to sink the valves. So I wouldn't personally do that if there was another solution.

Coleydog 04-21-2018 12:23 PM

Re: Need more P/V clearance in a BB mopar
 
Well Brian looks like we're in the same boat. Someday you and I will get these cars done. Look out world. LOL
I need to get down there a take a look see.
Mike

GTX JOHN 04-21-2018 05:16 PM

Re: Need more P/V clearance in a BB mopar
 
I am confused.......How can you tell piston to valve clearance BEFORE
you CC Heads and know how much they will be milled. It is not unusually
to mill BB Mopar heads .060 or more to get the correct specs.
Every thousand you mill them bring them closer to piston.
How can you measure accurately piston to valve prior to finishing the heads
that are actually being used on engine

What did I misread on this post?

randy wilson 04-21-2018 07:57 PM

Re: Need more P/V clearance in a BB mopar
 
Quote:

Originally Posted by GTX JOHN (Post 561292)
I am confused.......How can you tell piston to valve clearance BEFORE
you CC Heads and know how much they will be milled. It is not unusually
to mill BB Mopar heads .060 or more to get the correct specs.
Every thousand you mill them bring them closer to piston.
How can you measure accurately piston to valve prior to finishing the heads
that are actually being used on engine

What did I misread on this post?

If you angle mill, it does funny things, and can give you a slight larger valve to piston clearance. I’ve also seen it stay near exactly the same. But beings you have zero valve reliefs, I don’t know how that’ll work.

GallopinGhost 04-21-2018 08:21 PM

Re: Need more P/V clearance in a BB mopar
 
John,

Maybe I didn't explain very well what I'm doing. The whole purpose of this exercise is to figure out how much to machine the heads. I have a finished block with the crank, 1 rod/piston, cam, head gasket, and a spare assembled head, with valves and rockers, and an adjustable pushrod. I then take P/V measurements. Then measure the valve drop on my spare head, which is the travel of the valve to the head deck. Next I compare the valve drop on my new head at the shop to mine. If the new head had .010" more valve drop, I should have .010" more P/V clearance.

The steel shim gaskets are mopar performance and are available from mancini, for $20/set. Felpro 1009 is what I'll probably use though.

Not angle milling the heads.

GallopinGhost 04-21-2018 08:27 PM

Re: Need more P/V clearance in a BB mopar
 
I'm enjoying the juggling match now, but then again, I don't have a running engine yet. Lol

Quote:

Originally Posted by Larry Hill (Post 561249)
While you are waiting on next winter find out what is available for gaskets, pistons, rods, and block deck height. In your spare time learn how to juggle. lol



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