valve float with comp XE-R lobes
The 833's will sit at about 145 or so on the seat with no shims (can't remember the "K" value for them, but the installed height on stock heads is about 1.765" as I measured it this past winter. I would think this should be plenty of seat pressure but Roger is the best guy to ask on this, he knows his stuff.
Originally Posted by LSXSeven
I hear what you're saying but they may already be shimmed from the guy who built the heads. This brings up the real question, how much psi do I need.
well, for those of you who have been folowwing along, I did the leak test tonight and checked all the spring heights. All is good on the leak test, so no bent valves. After checking the height on all the springs, I came up with an average of about 1.827. the highest was 1.835 and the lowest checked in at 1.820. This is more than the 1.8" where the springs are rated for 112#'s. This is obviously low.
Now here is what I can see. After pulling the locks and retainers, we removed the springs. The valve seals were next and then the spring seats which were located under the valve seal. There seemed to be an additional washer/shim under the spring seat. Is this where you normally shim the springs? The only way to get to them would be to remove the seals and seats 1st. Do the shims you guys reffer to go on top of the seats? If so this would get around pulling the seals. Also to get my installed height down to 1.775, I will need to shim an additional .050. Where should I put the shim?
Mike
Now here is what I can see. After pulling the locks and retainers, we removed the springs. The valve seals were next and then the spring seats which were located under the valve seal. There seemed to be an additional washer/shim under the spring seat. Is this where you normally shim the springs? The only way to get to them would be to remove the seals and seats 1st. Do the shims you guys reffer to go on top of the seats? If so this would get around pulling the seals. Also to get my installed height down to 1.775, I will need to shim an additional .050. Where should I put the shim?
Mike
Ok, the ball of thread unravels even more. Took one of the valves seals off to get at the spring seats and shims. The crane seats measure .050 as confirmed by the website. Under the seat was a .050 shim. Under that shim was a .017 shim. So my installed height of only 1.830" was after the crane seat and .067" worth of shims. Now to get to a 1.780 height I will need an additional .050 shim. This is a lot of shiming. I thought I should be at this # with just the spring seats. This leads me to believe that my valves are either sunk pretty far into the head or these REV valves have long stems.
Anyway, my new problem is this. From what I have read, the valve seal is supposed to push all the way down until it bottoms out on the guide. This normally leaves a small gap between the bottom of the seal and the top of the spring seat collar. In my case they are already flush. The valve guide without the seal on it protrude .275" above the seat collar. The valve seal has .330 worth of depth inside. Therefor when pushed onto the guide, there is a gap of .055 left unsupported in the top of the seal. If I put another .050 shim under the spring seat, this gap will increase to .105. That is a third of the seal unsupported.
Is this a problem? How much valve seal needs to be in contact with the guide?
Anyway, my new problem is this. From what I have read, the valve seal is supposed to push all the way down until it bottoms out on the guide. This normally leaves a small gap between the bottom of the seal and the top of the spring seat collar. In my case they are already flush. The valve guide without the seal on it protrude .275" above the seat collar. The valve seal has .330 worth of depth inside. Therefor when pushed onto the guide, there is a gap of .055 left unsupported in the top of the seal. If I put another .050 shim under the spring seat, this gap will increase to .105. That is a third of the seal unsupported.
Is this a problem? How much valve seal needs to be in contact with the guide?
The shims go under the seat, as you found. I can't believe how much installed height you have, can you find out the REV part number and then pull the valve information from REV to compare to stock length? You might want to do this to confirm what is going on and why. I would be concerned with the seat not sitting all the way down, the service manual has a specific measurement that is made to ensure the seal is down all the way. Also, I had this problem on a Nissan, the seal may come off the guide if not fully seated and ride up and down with the valve.
With the 833',s you may not need to decrease the installed height as low as you are planning, they set up with pretty good seat numbers at 1.8".
With the 833',s you may not need to decrease the installed height as low as you are planning, they set up with pretty good seat numbers at 1.8".
You may be able to get by with a 0.030" shim to squeek under 1.800", but you may want to verify with the camp manufacture by giving your seat and over the nose pressures.
One other option, contact Joe or Roger Vinci and find out if Crane makes the retainers with a 0.050 set lower, this would preclude the need for more shims. I know they make them, just not sure on the LSx motors if they do or not.
One final option, I believe the LS7 sets up with a rather large height, you might look into this and see if there are springs for the LS7 that will fit your need.
One other option, contact Joe or Roger Vinci and find out if Crane makes the retainers with a 0.050 set lower, this would preclude the need for more shims. I know they make them, just not sure on the LSx motors if they do or not.
One final option, I believe the LS7 sets up with a rather large height, you might look into this and see if there are springs for the LS7 that will fit your need.
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Verdad Gallardo I ended up going with the Patriot dual extremes instead of the cranes. They are a little more but come with everything. The main thing is that they setup at 150# at 1.8. This way if I don't change my install height at all, I am still over 140#. If the seats are close enough, I might be able to just leave the crane seats and everything installed and just throw on the new springs and retainers. Otherwise, I will have to pull all the seals and swap seats. We shall see tommorrow when the springs arrive.
Mike
Mike
Originally Posted by Ryan02SS
With his cam he's on the limit of the 918's capability IMO. If he did want to run the 918's he should shim up the spring pressure to get the pressure up to be safer.
Originally Posted by vettenuts
I believe the Patriots come with new seals. You may want to change the seals so you can pull the Crane seats and sell them as a complete set.
You asked about the valve info. Here it is.
Exh REV CL-1168 1.600” 4.930” 8MM .170” TIP 24 ½ RADIUS GRV #239
INt REV CL -1175 2.055” 4.915” 8MM .170” TIP 10 3/8 RADIUS GRV #230
Let me know how this compares to stock.
Thanks
Mike
Originally Posted by PREDATOR-Z
That is the issue of many problems (mismatching components).
Replace with COMPLETE set is more favorable.
Replace with COMPLETE set is more favorable.
update; I'm an idiot!!!!
Remeasured the installed height with the springs out with a propper height checking tool using the new retainers and come up with 1.78. So I say to myself "self... these retainers must be lower..Great". Then I decide to check with the old retainers, same results. Then it hit me. When I originally checked the height with the springs in, I was using my digital caliper and extending it down to where the spring was sitting and measured from there to the underside of the retainer. The problem was that I was missing the top of the spring seat all together and actually sitting on top of the 1st shim. This was putting me .050 lower than actual. Now all makes sense.
Since the spring base is very tight to the spring, I missed it all together. Now with the new measurment, I can install everything as shipped from Patriot. I am going to use their base(.060) and their shim (.060) to get 1.20 worth of base height. This will give me an installed height of 1.787. The springs are rated at 150# at 1.8 so I should be golden. Also, this drop in shim height will help me with the valve seals.
Anyone want some used 832's
Mike
Remeasured the installed height with the springs out with a propper height checking tool using the new retainers and come up with 1.78. So I say to myself "self... these retainers must be lower..Great". Then I decide to check with the old retainers, same results. Then it hit me. When I originally checked the height with the springs in, I was using my digital caliper and extending it down to where the spring was sitting and measured from there to the underside of the retainer. The problem was that I was missing the top of the spring seat all together and actually sitting on top of the 1st shim. This was putting me .050 lower than actual. Now all makes sense.
Since the spring base is very tight to the spring, I missed it all together. Now with the new measurment, I can install everything as shipped from Patriot. I am going to use their base(.060) and their shim (.060) to get 1.20 worth of base height. This will give me an installed height of 1.787. The springs are rated at 150# at 1.8 so I should be golden. Also, this drop in shim height will help me with the valve seals.
Anyone want some used 832's
Mike
I almost asked how you were measuring but didn't want to insult you.
Don't feel bad, I have a special shim for my valve spring micrometer that I use for beehive retainers because they fall into the top of the micrometer. Last time I checked, my installed heights were coming out huge and I posted a question, of course someone said you have to compensate for the retainer going into the top of the micrometer and I had the shim sitting right there on my work bench the whole time
Don't feel bad, I have a special shim for my valve spring micrometer that I use for beehive retainers because they fall into the top of the micrometer. Last time I checked, my installed heights were coming out huge and I posted a question, of course someone said you have to compensate for the retainer going into the top of the micrometer and I had the shim sitting right there on my work bench the whole time
Ok, got the new springs installed. I used a snap gauge to do all my measuring and set them up around 1.78. Took the car out for a spin and low and behold, 7k no float. Looks like the crane springs were under gunned for my setup. I plan on having a couple tested to see what the spec out at.
I did notice that the Patriot retainers sit further down on the stem than the crane's. This is most likely why the cranes reuired more shim height to get to 1.78 than the Patriot springs did. I ended up with just the base and a .030 shim to get right around 1.78 installed.
Now all that is left is to figure out if this ticking noise is normal or if I too have a bad Caddy lifter.
I did notice that the Patriot retainers sit further down on the stem than the crane's. This is most likely why the cranes reuired more shim height to get to 1.78 than the Patriot springs did. I ended up with just the base and a .030 shim to get right around 1.78 installed.
Now all that is left is to figure out if this ticking noise is normal or if I too have a bad Caddy lifter.
Originally Posted by LSXSeven
Now all that is left is to figure out if this ticking noise is normal or if I too have a bad Caddy lifter.
