Valve Spring Height Issues
Valve Spring Height Issues I couldn't help myself but to check the valve spring installed height on my 243 heads. I am in the middle of a heads/cam/supercharger install. I recently brought my stock 243's to a well known machine shop. They did a complete valve job, with larger 1.60 exhaust valves, light port work, milled them .004 and installed my valve springs, seats, retainers, locks and so on. Everything is from Lunati,... The springs are double springs. When I picked up the heads the machine shop told me that the installed valve spring height on each spring was between 1.82-1.83. Lunati calls for a 1.810 installed height. I was going to leave it and just finish bolting it all together, but I can't leave well enough alone, so I ordered a proform valve spring height micrometer part# 66902. I wanted to check to make sure they were all no more than .020 out of spec.
Needless to say I am pulling my hair out of my head. I am having a really hard time getting an accurate measurement. I think I know what MIGHT be wrong, but of course this mic comes with no instructions. I think the retainer needs to sit on top of the tool however, it does fall flush and sits nicely in the tool as well. And the measurements do look like they start below the retainer even when flush. I did get a 1.830 reading when I cocked the tool sideways but that's so inaccurate. Otherwise my readings have ranged from 1.850-1.870
Take a look and tell me what I am doing wrong please and tell me how I can get an accurate measurement....
DG
Needless to say I am pulling my hair out of my head. I am having a really hard time getting an accurate measurement. I think I know what MIGHT be wrong, but of course this mic comes with no instructions. I think the retainer needs to sit on top of the tool however, it does fall flush and sits nicely in the tool as well. And the measurements do look like they start below the retainer even when flush. I did get a 1.830 reading when I cocked the tool sideways but that's so inaccurate. Otherwise my readings have ranged from 1.850-1.870
Take a look and tell me what I am doing wrong please and tell me how I can get an accurate measurement....
DG
I knew something was wrong. I just got off the phone with proform. This tool although designed to work with all non-beehive engines actually won't work with my setup. The retainer is designed to sit ON TOP of the tool, not recessed in it. That is why my measurements are closer to what the machine shop got when they measured it after cocking the retainer. I asked Proform how to fix it, and they told me they have no idea. Excellent.
This whole project has been me chasing my tail....
DG
This whole project has been me chasing my tail....
DG
So another useless tool to add to my collection, comp cams recommends a "snap ring" gauge. I am going to take these measurements sideways and if they come in close to 1.82-1.83 I am going to leave it alone. No point in shimming anything if the measurements I am getting are not accurate anyway.
DG
DG
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I would like to shim these valves springs, however I do not want to accidentally over shim them.
DG
Unfortunately the base is too wide... That was a good though though,
Ill bet Lunati sells their own tool designed to deal with this issue. I will have to call tomorrow and find out.
DG
Lunati tech support states that I am "safe" to slide the tool over to one side a just grab the edge of the micrometer. Supposedly the keepers will keep the retainer from cocking to one side. Reading should be within .005 at the very most.
Now I have to see about getting some LSx shims. Are they any different from regular sbc shims?
DG
Now I have to see about getting some LSx shims. Are they any different from regular sbc shims?
DG
I turn down some shims to fit in the top of my spring mic to fit different retainers. The top to the step is about .120 IIRC so use a .125 shim with the ID to fit the retainer, then turn the OD to fit inside the mic top. I have a few for the common sizes.
and thouse springs to not install at 1.81 on stock heads like everyone thinks
and thouse springs to not install at 1.81 on stock heads like everyone thinks
Banned
Joined: Aug 2006
Posts: 326
Likes: 0
From: North Bay, CA
The retainer is going to lift up if you only load one side of it and will throw your number off by .010" or more.
If you want to shim them up to what is perfect in your mind, then get a pack of .015" shims and you'll end up at 1.805-1.815" according to the machine shop's measurement. They don't make them any smaller than .015", and really you're just chasing a few lbs.
Shim packs are available from Isky dealers, VSI should have them as well.
If you want to shim them up to what is perfect in your mind, then get a pack of .015" shims and you'll end up at 1.805-1.815" according to the machine shop's measurement. They don't make them any smaller than .015", and really you're just chasing a few lbs.
Shim packs are available from Isky dealers, VSI should have them as well.
The retainer is going to lift up if you only load one side of it and will throw your number off by .010" or more.
If you want to shim them up to what is perfect in your mind, then get a pack of .015" shims and you'll end up at 1.805-1.815" according to the machine shop's measurement. They don't make them any smaller than .015", and really you're just chasing a few lbs.
Shim packs are available from Isky dealers, VSI should have them as well.
If you want to shim them up to what is perfect in your mind, then get a pack of .015" shims and you'll end up at 1.805-1.815" according to the machine shop's measurement. They don't make them any smaller than .015", and really you're just chasing a few lbs.
Shim packs are available from Isky dealers, VSI should have them as well.
As I have done from the beginning of this project, I will take a little info from here, and a little from there combine it and hope for satisfactory results.
I will try the method mentioned above (using the edge of the retainer) to check to make sure all of my springs are consistent with one another, and add .015 shims to all of them.
DG
Banned
Joined: Aug 2006
Posts: 326
Likes: 0
From: North Bay, CA
I agree with you however, like with most of the questions I have asked so far, it seems as though there is no definitive answer. If you look in this thread you will see a few contradicting posts (by contradicting I mean one person agrees, one person disagrees,... its all be good information). Like I stated above I spoke with Lunati tech support; they are convinced it makes no difference. But when you are working in .001 you are splitting hairs so you would figure it would make a difference.
As I have done from the beginning of this project, I will take a little info from here, and a little from there combine it and hope for satisfactory results.
I will try the method mentioned above (using the edge of the retainer) to check to make sure all of my springs are consistent with one another, and add .015 shims to all of them.
DG
As I have done from the beginning of this project, I will take a little info from here, and a little from there combine it and hope for satisfactory results.
I will try the method mentioned above (using the edge of the retainer) to check to make sure all of my springs are consistent with one another, and add .015 shims to all of them.
DG
Slide it over to one side and check it. Make sure all heights are close. Yes you can tip the retainer by loading one side but when height mic is mocked up the retainer is pretty well locked. The mic pushing against one side of the retainer will cause it to engage the locks and get a good reading. That being said if you have access to a mill you could make a small insert for the height mic. That is what I did a few years back. It just makes for much faster checking of installed heights. If I wasn't an engine builder and just a DIY guy I would just slide the mic to one side, check it and forget it.
