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Hydraulic head milling
https://slantsix.org/forum/viewtopic.php?t=43313		 Page 1 of 2
Author:  kennewick [ Thu Jan 20, 2011 1:05 pm ]
Post subject:  Hydraulic head milling
Yes I have used the search. For hours and hours :cry:

Anyway I have a 83 Miser pickup. Holley 2280, Exhaust mani outlet ported
to a full 2.25".

I had a bad valve and will be getting a valve job with stock valves new guides.

My question.. It had the steel shim but the new gasket is composite. Can I take 30 mils (or more) to compensate for the gasket and some componet wear and not have to use shorter push rods. Block and head are factory stock.
I don't have measurements but thought there has to be a operational range well established for a stock engine.

Thanks.
Author:  Joshie225 [ Thu Jan 20, 2011 1:23 pm ]
Post subject: 
When you grind valves and seats the stem ends up higher reducing valve lash and/or compressing the lifter farther. Hopefully the valve seats aren't too bad. .020" off the head should make up for the gasket difference and it's probably safe to take off .010" more. If you knew how much the lifter was compressed to start with and how much travel there is in the lifter we'd know for certain. Chances are you can have the head milled more and not run out of lifter travel, but it's a crap shoot without good measurements.
Author:  kennewick [ Thu Jan 20, 2011 1:51 pm ]
Post subject: 
Quote:
When you grind valves and seats the stem ends up higher reducing valve lash and/or compressing the lifter farther. Hopefully the valve seats aren't too bad. .020" off the head should make up for the gasket difference and it's probably safe to take off .010" more. If you knew how much the lifter was compressed to start with and how much travel there is in the lifter we'd know for certain. Chances are you can have the head milled more and not run out of lifter travel, but it's a crap shoot without good measurements.
I looked all over and could not find those tid bits. Thanks!
This may be a stupid question but do they grind all the seats to the same depth to keep the valve stem hieght as close as possible all the way across? I want to ask the right questions.
My guess is that for any hieght gained by valve and seat grinding is not linear the same amount at the lifter?
Author:  Joshie225 [ Thu Jan 20, 2011 1:56 pm ]
Post subject: 
Usually the machine shop grinds the seats until they clean up. It's possible with the newer Serdi machines to get all the seats the same depth, but you'd have to ask for it and it might cost more. It's possible to do it with old valve seat refinishing equipment too, but it's tedious. Unless a valve seat has receded or a valve has excessive wear the valve stem heights shouldn't be that far off from one to another.

If a valve stem is .015" higher the valve lifter will be compressed .010" more with a 1.5:1 rocker arm ratio.
Author:  kennewick [ Thu Jan 20, 2011 2:04 pm ]
Post subject: 
Quote:
Usually the machine shop grinds the seats until they clean up. It's possible with the newer Serdi machines to get all the seats the same depth, but you'd have to ask for it and it might cost more. It's possible to do it with old valve seat refinishing equipment too, but it's tedious. Unless a valve seat has receded or a valve has excessive wear the valve stem heights shouldn't be that far off from one to another.

If a valve stem is .015" higher the valve lifter will be compressed .010" more with a 1.5:1 rocker arm ratio.
I asked them if they make sure the valve length is the same when finished. I would guess to do this they would need to remove material from the ends. I have read on this forum that it is important to have the valve lengths the same with hyd lifters. Is that correct?

Looks good I think I'll have this truck on the road soon. This is my first \6. I just finished a 360 build and restore of a 88 Power Ram. This is way different.
Author:  Joshie225 [ Thu Jan 20, 2011 3:16 pm ]
Post subject: 
You cannot grind the valve stems to equalize the heights. The valve job has to be done correctly. If you grind much off the valve stems you go through the hardening and will tear up the valve stems and rocker arm pads.

The valve stem heights don't need to be super accurate. There is a fair amount of travel in the lifters. I'm tempted to go grab a new lifter I have on the shelf and see just how much travel it has.
Author:  Reed [ Thu Jan 20, 2011 3:54 pm ]
Post subject: 
Quote:
There is a fair amount of travel in the lifters. I'm tempted to go grab a new lifter I have on the shelf and see just how much travel it has.
:shock: Please do! :D
Author:  Joshie225 [ Thu Jan 20, 2011 5:30 pm ]
Post subject: 
Quote:
Quote:
There is a fair amount of travel in the lifters. I'm tempted to go grab a new lifter I have on the shelf and see just how much travel it has.
:shock: Please do! :D
OK! It has to be tomorrow though since I'm working swing shift.
Author:  kennewick [ Thu Jan 20, 2011 7:12 pm ]
Post subject: 
Quote:
Quote:
Quote:
There is a fair amount of travel in the lifters. I'm tempted to go grab a new lifter I have on the shelf and see just how much travel it has.
:shock: Please do! :D
OK! It has to be tomorrow though since I'm working swing shift.
I was making comment after pouring over tons of threads trying to figure out how to work with a \6 hyd cam and head. It was beginning to sound like the space shuttle by some of the posts and alot of conflicting and confusing info when the conversation turns to Hyd heads. So I thought I woud start this thread and ask more specific dumb questions that are rolling around in my head. I have already learned a bunch. Thanks and I can't wait to hear back about the operational range of the lifter.

PS this is some info that I got yesturday from another source:
"There's a relatively easy solution to ensuring you don't bottom the lifters and end up with a valve hung open...

When you have the valve job done, tell them to shorten the valve stems by .045, compared to the spec.

It means almost nothing to the valve or rocker geometry, but it'll ensure that you end up without having any issues with the pushrods being long.

Far better than shimming the dang rocker arm or anything like that."
Fine and dandy but I asked how much shaving this compensates for and no reply. It goes from casual info to space shuttle or she'll blow. Confuseing. Makes me long for an LA. lol I'm learning! It's like the info for valve length. Some say they all have to be the same. But how are you to do it unless you grind all the seats and valves exactly the same? Crazy. Seems there should be useable range of hydraulic operation and a moderate motor should be able to handle that with out calling Houston Mission Center. I have never seen any info on the .045 cut on the pushrods before and I have read alot of posts.
Author:  kennewick [ Fri Jan 21, 2011 8:40 am ]
Post subject: 
Any luck with the range on them lifters?
Author:  sandy in BC [ Fri Jan 21, 2011 5:37 pm ]
Post subject: 
Shortening the valve stems is not the same as shaving the pushrods.
Author:  Joshie225 [ Fri Jan 21, 2011 5:59 pm ]
Post subject: 
Quote:
Any luck with the range on them lifters?
Didn't get to it today, sorry.

As for you other post, shortening the valve stems is not an option. Pushrods are not that expensive. Want to mill a bunch? Here are .155" shorter pushrods for $32.95. http://www.summitracing.com/parts/CCA-7864-12/All/
Author:  kennewick [ Fri Jan 21, 2011 8:03 pm ]
Post subject: 
Quote:
Quote:
Any luck with the range on them lifters?
Didn't get to it today, sorry.

As for you other post, shortening the valve stems is not an option. Pushrods are not that expensive. Want to mill a bunch? Here are .155" shorter pushrods for $32.95. http://www.summitracing.com/parts/CCA-7864-12/All/
I was just trying to learn something :?
But thanks.
Author:  Joshie225 [ Fri Jan 21, 2011 9:26 pm ]
Post subject: 
And you haven't learned? :?
Author:  kennewick [ Fri Jan 21, 2011 11:13 pm ]
Post subject: 
Quote:
And you haven't learned? :?
Nice place.
I was asking "Can I take 30 mils " Not "want to mill a bunch here are shorter pushrods"
I have the info I need and talked it over with my machinist. I'll go away now.
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