Question about cutting valve guides 4 seals

Is there a better way of doing this?

  • Yes. Please explain

  • No

  • I'm hungry. Going to eat and think about life.


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Jadaharabi

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Okay I am cutting on a pair of 308 heads for the valve stem seals. I am installing the Howard dual Springs for a roller hydraulic cam. I have a couple of questions that maybe some of you fellows can answer that work on heads for me.
Okay do I remove the step next to the valve stem on the head for my innerspring to sit flush with my outer spring?
I am cutting these for the .531 seals. They have already been cut for a bigger seal when they were done by Indy aero heads.
I have cut down to the step on the head on the end 2.

16018876918188247620725061957816.jpg


As you can see whoever prep these heads cut all the guides down short.

1601887769532265720543189281860.jpg


16018879085343350861262251453145.jpg


The set I bought. Howard's 98438-K32 for 3/8 stems.

98438-K32.jpg


Screenshot_20201005-043430_Chrome.jpg


The close out sheet has a 100 of these seals for $22.68.
 
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Yes, you want both springs to set flush with each other at the bottom of the spring pad. Otherwise, the inner spring may coil bind.
 
I leave it if there is room, helps keep the bottom of the spring from walking around, if you cut it you should use a spring locator, plus it gives you more spring pressure

4704-16_600.jpg
 
Have you checked the inner spring only for coil bind with the step? Does the outer spring fit around the step? Inner springs are typically a thinner wire so they will not bind at the same height. It might be beneficial to leave it to keep the springs separated. If the inner are wound the opposite direction from the outer coils it might not be such a big deal. Also some spring sets have a counter-wound flat spring to keep the coils from getting caught in each other.
 
Thanks to all. I called Howard Cams. Was told to remove the step and the spring is big enough that it fills the pocket in the head so it won't be going walk about.
 
I should have added above that your seat pressure #s from the spring manufacturer are spec'd with the springs setting at the same height on the bottom.
 
I'm not sure about where some manufactures base their spec #s , they don't print th correct info..or they base it off using the step, because the seat psi is light 15 lbs with a set I just checked. Comp cams.
Most inner coils have more room to collapse than the outer. I was always thought to cut the inner step to locate the innner spring . It's easier on the guide and less spring harmonics... But ultimately the goal is to obtain a particular seat and open pressure of said spring...so if it takes leaving the step to attain that advertised pressure... and you have plenty of clearance to...then leaving it could be an option...or getting a better spring that physically specs as advertised.
Typically you cut them to fit to locate the inner.
 
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I think you should get yourself a spring pressure tester and not just guess because you could find out you have a lot less or more than you thought
 
ixnay on the teflon seals
what size now
I like the 031 better than the 000 but nothing wrong with 9/16
use biggest that will fot in your inner spring
get viton seals
 
Thanks to all. I called Howard Cams. Was told to remove the step and the spring is big enough that it fills the pocket in the head so it won't be going walk about.

That was going to be my recommendation. To call the manufacturer. Depending on the spring I have seen some recommend removing the step and some not. Good call.
 
What do you see wrong about the teflon seals?
As I've said before, they wear the stems and dont really meter the oil once you have some miles on it. We know seals let some oil in, They have to , there is vacuum on the guide...but some do better than others at metering it.
 
what size now
I like the 031 better than the 000 but nothing wrong with 9/16
use biggest that will fot in your inner spring
get viton seals

Inner spring ID is .807
.562 seal OD is .665
Differance of .142
Divide by 2. = .071. Clearance

Is that enough?

I know the .531s have plenty of clearance but if the .562 will work I would like to save some guide metal.
 
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good moove
make sure you have a good finish on your valve stems
some cheap valves have the finish of files
I put a fine finih with a Sunnen stem hone to give a nice crosshatch but a few strokes with some wet or dry paper works
 
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