what valve seals after machining guides?

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turboking15

turboking15

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Im getting ready to send my heads to the machine shop for a valve job and have the guides cut down and have a couple questions.

First- max lift on the cam will be .568, now this is theoretical lift 1.6 rocker with .355 lobe lift so actual lift will probably be less due to the roller lifters and the pushrod angle, so how much should i have the guides cut down?

Ill be running the 1110 springs and 1286r retainers, measured retainer to seal clearance before the valve job is .540.

Second- what seals do i need to go with after having the guides cut? Ive searched and couldnt find much info on this one. Also based on this seal is there any other machining i need to have done to the guides for them?

If theres anything ive missed let me know. Thanks
 
Any good machine shop should have all those answers for you, I had mine done this spring and my machine shop was really on top of things, thank god.
 
turboking15 said:
Im getting ready to send my heads to the machine shop for a valve job and have the guides cut down and have a couple questions.

First- max lift on the cam will be .568, now this is theoretical lift 1.6 rocker with .355 lobe lift so actual lift will probably be less due to the roller lifters and the pushrod angle, so how much should i have the guides cut down?

Ill be running the 1110 springs and 1286r retainers, measured retainer to seal clearance before the valve job is .540.

Second- what seals do i need to go with after having the guides cut? Ive searched and couldnt find much info on this one. Also based on this seal is there any other machining i need to have done to the guides for them?

If theres anything ive missed let me know. Thanks
Click to expand...

Info is a little vague. What heads?

Read this thread, might help you with what you are doing.

http://www.forabodiesonly.com/mopar/showthread.php?t=83860
 
Have the guides cut to .630" outside diam(IF STOCK HEADS ARE USED), have them cut down about .100", this will give you plenty of room with the seal installed. Make sure the guides are not too loose, if they are just have them install some liners.

Dont use the stock type seals and definitely use seals on all 16 valves. I like to use seal like the one here in the pic. Its called a Metal Body Vition. They last a long time and work well.
 

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turboking15 said:
Heads are magnum heads
Click to expand...

Iron? Factory? RHS? EQ?

MRL gave some good info on the valve seals.

However, you still need to do some measuring yourself or verify the measurements when you get the heads back from the machine shop. If you are trying to 'blueprint' the heads then naturally the goal is to have everything measure the same wherever possible. If it's just a basic rebuild, it's probably not that important.

Do you have a checking spring? What about a valve spring height micrometer? You may (or not) have to shim the springs to get the installed height you need. Probably should also check retainer to guide clearance once the machining is done.
 
rmchrgr said:
Iron? Factory? RHS? EQ?

MRL gave some good info on the valve seals.

However, you still need to do some measuring yourself or verify the measurements when you get the heads back from the machine shop. If you are trying to 'blueprint' the heads then naturally the goal is to have everything measure the same wherever possible. If it's just a basic rebuild, it's probably not that important.

Do you have a checking spring? What about a valve spring height micrometer? You may (or not) have to shim the springs to get the installed height you need. Probably should also check retainer to guide clearance once the machining is done.
Click to expand...

Factory magnum heads, basic port work and a valve job. I do have a checking spring but not a vs mic.

I think MRL was referring to LA heads as i just measured the guides and they are .530" in diameter and .372" from the spring seat to the top.
Already measured current ret to seal is .540"

From what i have read there is generally a .020" to .025" lift loss from advertised lift on the roller setups, does this sound about right?

I appreciate all the help, still kinda new to the machine work side of engine building and want to make sure i cover all my basses and learn everything i can.
 
turboking15 said:
Factory magnum heads, basic port work and a valve job. I do have a checking spring but not a vs mic.
Click to expand...

Verifying installed height and checking for coil bind would be a good thing to do especially with 1.6 ratio rockers and if you trim the seats. You can get cheapo height mics. from all the usual sources.

turboking15 said:
I think MRL was referring to LA heads as i just measured the guides and they are .530" in diameter and .372" from the spring seat to the top. Already measured current ret to seal is .540"
Click to expand...

I would wait to buy seals until you know exactly what you are dealing with. Again, verify after the machining is done and then order the parts. Valve seals are not a big deal. Are you using aftermarket valves or factory? Do the springs specify a specific inside diameter?

turboking15 said:
From what i have read there is generally a .020" to .025" lift loss from advertised lift on the roller setups, does this sound about right?
Click to expand...

Sounds like you are referring to valve lash? Magnums generally use hydraulic roller lifters though so let us know if you have switched to a solid roller. A hydraulic will have preload but no lash.

You generally follow the cam card for the valve lash specs. Once it's dialed, you can adjust somewhat to fine tune. Tighter valve lash can increase top end performance slightly and looser can have the effect of more torque. (I think that's how it works, could be backwards but you get the idea).

turboking15 said:
I appreciate all the help, still kinda new to the machine work side of engine building and want to make sure i cover all my basses and learn everything i can.
Click to expand...

Sounds like you are on the right track. What are your performance goals with these heads?
 
Not lash, the actual lift loss due to the extreme pushrod angle induced by the roller lifters due to their height.

Springs will be the hughes 1110

Stock valves

I would like to see how close i can get to 400 on just motor with what i feel to be a very basic combo and just paying attention to the details, then i will put a little gas on it for so fun to see what the magnum can handle.
 
On the metal body seals do you have to cut the seal base as well to make up for the cut guide or do they machine a groove for the seal to fit all the way down?

Thanks again for all the info and advice.
 
turboking15 said:
Not lash, the actual lift loss due to the extreme pushrod angle induced by the roller lifters due to their height.
Click to expand...

Are you using the factory roller lifter or aftermarket? The factory ones are as stout as any brand name. Theoretically those should not cause any geometry issues from being too tall.

Get a checking pushrod and order custom ones to ensure proper lift and the best possible geometry.
 
Yes they are factory roller lifters. Theres no geometry issues persay, its just the fact that the lifters are so tall it put the pushrods at more of an angle so you are not transfering all of the lift in the vertical axis, some is absorbed into the horizontal axis aswell.

I was just trying to get an idea how much lift is soaked up by that to get a good ballpark for total lift at the valve.
 
Your over thinking it. Set everything up for the Theoretical lift and you will be safe all the way around. You end up losing 2-3% lift on a SBM.
 
turboking15 said:
Yes they are factory roller lifters. Theres no geometry issues persay, its just the fact that the lifters are so tall it put the pushrods at more of an angle so you are not transfering all of the lift in the vertical axis, some is absorbed into the horizontal axis aswell.

I was just trying to get an idea how much lift is soaked up by that to get a good ballpark for total lift at the valve.
Click to expand...

You seem to have a figure in mind based on things you've read, maybe use that as a general idea and go from there. You're probably aware that there is no way to possibly know for sure until you actually measure. Plus, every combination of parts is going to yield a different answer, especially when dealing with production tolerances.

Regardless, if you are concerned about poor geometry by eyeballing the pushrod angle, you should know that you can correct it by getting the proper length pushrods.

In lieu of that, AR Engineering makes an inexpensive fixture to facilitate checking valve train geometry/lift. See here. I would think that plate is exactly what you need if you want an accurate answer.

That's what I would do; get a pushrod checking tool and the AR valvetrain plate since those are a minimum expense. The labor would cost nothing except your time. Install your parts and run the valve with the pushrod tool in place. Take an initial reading to see how close or far off you are to the desired lift. Adjust pushrod length until you find the sweet spot.

Here's a pic of the plate in use.
AR319aP1.jpg
 
I wanted to check back here and make sure I wasn't totally out in left field with the lifter angle thing you were asking about. Turns out its a well known quirk. Sorry for any wrong/incorrect info or suggestions.

The only thing that really has to do with pushrods here is that they are what connects the lifter to the rocker. Using a checking pushrod holds some merit in a general sense but really has nothing to do with what you are asking here and could not possibly solve the issue.

I didn't find anything specific about how much lift is lost due to the angle but I think the general consensus is like MRL said, not much. Maybe a few percentage points or like you stated earlier, a few thousandths.

Back in the 70s Dick Landy and Bob Glidden were plugging/sleeving the lifter bores on small blocks to get better angles.
 
All is good, discussing things is how we learn and leave info for others down the road. After looking at the heads and what MRL said i realized that as he said i was over-thinking it. All that needs to be done is cut the inner seat down .100" and then have that much shaved off the valve guide as well and the heads will be good to .600" lift safley, which is more than likely way out of the flow range of a set of home ported magnums anyway. But its always nice to have that insurance.

Also the pushrod length shouldnt be much of an issue as i decided to go with the crane conversion and 1.6 chevy rockers to simplify things.
 
And i appreciate all the info rmchrgr and MRL have provided in here, its always nice to hear from people who have been there. Makes the learning curve a little less steep :thumbrig:
 
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