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Re: 360 heads redone, valve stem heights are different?
[Re: John_Kunkel]
#1688847
10/22/14 10:11 PM
10/22/14 10:11 PM
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Joined: Jan 2003
Posts: 27,421
Balt. Md
383man
Too Many Posts
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Too Many Posts
Joined: Jan 2003
Posts: 27,421
Balt. Md
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Quote:
When I was taught to do valve jobs it was accepted practice to adjust the valve stem length so that all the valve stem tips were at the same height....there is an attachment on the valve grinder for grinding the valve stem ends. Some FSM's show a tool that is used to measure the height of the installed valve stem tip above the spring seat.
A good machinist will deliver heads that have the correct valve stem height and equal heights so that a straight edge laid across the stem tips will show no daylight.
This is just what I was taught in high school auto shop and my brothers valve grinder has the tool to grind the valve stem ends. Ron
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Re: 360 heads redone, valve stem heights are different?
[Re: dvw]
#1688848
10/22/14 10:25 PM
10/22/14 10:25 PM
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Joined: May 2008
Posts: 958
eastern, pa.
cudabitten
OP
super stock
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OP
super stock
Joined: May 2008
Posts: 958
eastern, pa.
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Ok, Thanks Everyone.
I did a little more research on this...I've been building this car for seven years and just fired her up on Friday, so I am on the home stretch with this project. Anyway, The Spec on the valve spring height is, for a 1978 360 2 bbl (I converted to a 4bbl which has a tighter spec) is 1 5/8 to 1 11/16 which converts to 1 40/64 to 1 44/64 which is easy to work with since my calipers are in 64ths.
So here is what I measured just for the record. I could not get to all off the spring seats on the passenger side, so here is the drivers side...
from front to back: E 1 38/64, I 1 43/64, I 1 43/64, E 1 37/64, E 1 37/64, I 1 43/64, I 1 42/64, E 1 37/64.
So all of the E's (Exhaust valves) are out of spec. All of the I's (Intake Valves) are right on.
So I dont think I can use the lash caps as was stated, they are way too thick. And as was stated, NO I do not want the same guy grinding on these anymore. As long as I dont have any valves not closing or not opening all the way, I am cool with going with something adjustable. Or maybe using some longer push rods on the Exhaust valves.
Can you please look at my numbers and tell me if the valves will be opening enough and closing enough? And will longer pushrods on the exhaust valves be a solution, or adjustable rockers?
Thank you for all this help.
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Re: 360 heads redone, valve stem heights are different?
[Re: cudabitten]
#1688849
10/23/14 09:10 PM
10/23/14 09:10 PM
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Joined: Sep 2014
Posts: 4,457
Washington
madscientist
master
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master
Joined: Sep 2014
Posts: 4,457
Washington
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Quote:
Ok, Thanks Everyone.
I did a little more research on this...I've been building this car for seven years and just fired her up on Friday, so I am on the home stretch with this project. Anyway, The Spec on the valve spring height is, for a 1978 360 2 bbl (I converted to a 4bbl which has a tighter spec) is 1 5/8 to 1 11/16 which converts to 1 40/64 to 1 44/64 which is easy to work with since my calipers are in 64ths.
So here is what I measured just for the record. I could not get to all off the spring seats on the passenger side, so here is the drivers side...
from front to back: E 1 38/64, I 1 43/64, I 1 43/64, E 1 37/64, E 1 37/64, I 1 43/64, I 1 42/64, E 1 37/64.
So all of the E's (Exhaust valves) are out of spec. All of the I's (Intake Valves) are right on.
So I dont think I can use the lash caps as was stated, they are way too thick. And as was stated, NO I do not want the same guy grinding on these anymore. As long as I dont have any valves not closing or not opening all the way, I am cool with going with something adjustable. Or maybe using some longer push rods on the Exhaust valves.
Can you please look at my numbers and tell me if the valves will be opening enough and closing enough? And will longer pushrods on the exhaust valves be a solution, or adjustable rockers?
Thank you for all this help.
Be careful here. Stem height and spring height are NOT the same thing.
The best solution is to use pushrods that are longer on the valves that have the STEM HEIGHT too short. You only need to have .040-.060 preload on the lifter. If you have that you are golden.
Just because you think it won't make it true. Horsepower is KING. To dispute this is stupid. C. Alston
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