Factory valve seal question
08-01-2006, 05:35 PM
#1
Factory valve seal question I'm in the process of shimming my Crane 832's, but I notice after installing the shim there is very little guide left for the seal (pre-01' style) to grab onto (others have had this problem after searching previous posts). The black, shorter intake seals still has enough rubber to guide contact and should be just fine, but the exhaust seals don't have as much grip on the guide. The exhaust seals will and are installed, but I'm just nervous if they might come off later down the road.
When looking at the factory seals the exhaust seal seems to be taller and the rubber that contacts the guide inside of the seal doesn't start untill 1/16" or so up from the base compared to the intake seal. I was thinking of getting some new exhaust seals and trimming down the base just enough to get them to look like the intake seal (1/16" or so) unless a vendor has an easier solution.
When looking at the factory seals the exhaust seal seems to be taller and the rubber that contacts the guide inside of the seal doesn't start untill 1/16" or so up from the base compared to the intake seal. I was thinking of getting some new exhaust seals and trimming down the base just enough to get them to look like the intake seal (1/16" or so) unless a vendor has an easier solution.
08-01-2006, 07:29 PM
#3
Old style. When I removed the 832's to shim them they had a spacer that went between the head and the spring locater plate. I installed the shim between the spacer on the head and the spring locater. Origionally the springs were at 1.790"-1.800" installed height (what Crane lists for them). Now with a .060" shim they are at 1.730"-1.740". Don't get me wrong the seals fit on and have plenty of clearance to the retainer, but with the exhaust seal being slightly taller it seems to not make as much contact.
If I used all intake seals I wouldn't worry (fit wise), but since the exhaust seals are slightly taller they don't press down as much. I guess it's hard to describe without pictures, but think of it this way. When I removed the old seals (same as new ones) the black intake seal was fully installed and had a gap between the spring locater and bottom of the seal. The exhaust seal was touching the spring locater before shimming. The shimming only made the locater rise up .060" and I lost that much exhaust seal to guide contact.
If I used all intake seals I wouldn't worry (fit wise), but since the exhaust seals are slightly taller they don't press down as much. I guess it's hard to describe without pictures, but think of it this way. When I removed the old seals (same as new ones) the black intake seal was fully installed and had a gap between the spring locater and bottom of the seal. The exhaust seal was touching the spring locater before shimming. The shimming only made the locater rise up .060" and I lost that much exhaust seal to guide contact.
08-02-2006, 05:36 AM
#4
What is the spacer between the retainer (spring locator plate) and the head? Sounds like they were installed with the original spring seat left in place. Do you have a spring micrometer to measure your installed height? Almost sounds like too many parts in there.
08-02-2006, 03:59 PM
#6
It looks like spacer and one side says "this side up" and the other side that faces the head has some lines stamped into it. The installed height I listed above without adding shims is what the springs were set up origionally ( 1.790"-1.800" with the origional spacer and spring locator plate). I used my machinest's spring caliper to measure that height and he verified I am correct. Thats the way I purchased the car (h/c etc, etc) so I have never seen anything else to compare it to.
Everything as far as rocker/valve tip alignment are perfect so the valves can't be that recessed into the head from a bad valve job or anything. Maybe I do have to many spacers in the head, but the installed height doesn't lie
Everything as far as rocker/valve tip alignment are perfect so the valves can't be that recessed into the head from a bad valve job or anything. Maybe I do have to many spacers in the head, but the installed height doesn't lie
Originally Posted by vettenuts
What is the spacer between the retainer (spring locator plate) and the head? Sounds like they were installed with the original spring seat left in place. Do you have a spring micrometer to measure your installed height? Almost sounds like too many parts in there.
08-02-2006, 04:05 PM
#7
Originally Posted by GuitsBoy
If i recall the grabby part of teh seals dosnt start right at the bottom... Maybe you could shave or grind .050 or so off the bottoms of the seals?
I was thinking about shaving of some of the seal, but it might be a little tricky as to keep the seal from being damaged due to heat and particles during the grinding.
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08-04-2006, 05:37 PM
#9
I have a set of GM's here and just did some measuring. Seems to me that you can take about 0.030" off the bottom of the intake seal and about 0.080" off the bottom of the exhaust since the rubber is recessed from the bottom of the metal housing. You would have to flush them really good afterwards, but it should work. If you have an old set you can practice on, that might help just to prevent getting them out of round and making sure you can get them clean. Under the seal spring might be a little tough and you could pack that with grease before sanding and then just flush the grease off before installing.
08-04-2006, 07:47 PM
#10
Wow thanks for the info. I'm glad we are on the same page now. I was beginning to think some of you thought I was crazy
I might check them out at the machine shop tomorrow. I'll try to pull one off and if it pulls easy I'll try to remove some material. The intake seals went on with enough force that I'm not worried about them, just the exhaust. Even with the seals standing up high I still have plenty of seal/retianer clearance. I think I have the taller installed height Crane retainers, but not sure. I almost just bought different springs due to all of this, but they are low milage and I want to reuse what I can for the buildup.
I might check them out at the machine shop tomorrow. I'll try to pull one off and if it pulls easy I'll try to remove some material. The intake seals went on with enough force that I'm not worried about them, just the exhaust. Even with the seals standing up high I still have plenty of seal/retianer clearance. I think I have the taller installed height Crane retainers, but not sure. I almost just bought different springs due to all of this, but they are low milage and I want to reuse what I can for the buildup.
08-05-2006, 06:01 PM
#12
Well I shaved the bottom of the exhaust seals down on a belt sander and cleaned them good with carb spray. Everything worked out well. I took off most of the excess metal before the inner rubber starts. I'm gald I looked at them again because the first spring I removed had the seal off already without me even trying to pull it.
