 Deck height measurements driving me crazy, Need advice |
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| stugray |
 Oct 14 2012, 02:06 PM
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#1
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Advanced Member  Group: Members Posts: 3,825 Joined: 17-September 09 From: Longmont, CO Member No.: 10,819 Region Association: None  |
Ok, so I bought the deck height measurement tools from the group buy.
But I cannot figure out exactly how the OP intended to use the middle plate. I have been trying to measure my deck height accurately for weeks now and I either am not doing it right, or I have a problem. I have the EMW AA cylinders & KB Hypereutectic pistons - brand new. I am measuring with no shims under the cyls. I bolt the holddown tool on two cyls with pistons installed and torque to spec (24 ft-lbs) I set TDC on the cyl I am about to measure with a mag base & dial indicator using the middle of the piston as reference. I then set a VERY straight edge across both cylinders and clamp it down. I then measure the top of the cylinder mating surface down to the very edge of the piston using a dial indicator/depth gauge. I repeat the measurement at least 5 times and average the results. I am getting measurements that vary from .022 to .032 and they can vary by up to .0067 across a single piston (front to rear). (IMG:style_emoticons/default/WTF.gif) (measurements at the same spot are repeateable within less than .001) When we are trying to get these deck heights to match to within a few thousandths, I cannot see how that can be done when the piston can be off by more than 5 thousandths front to rear. Does this mean I have bent rods or misaligned wrist pin bushings? I had the entire rotating assembly balanced, so I would hope they would have caught something bent. I guess my next steps will be to shuffle the pistons around and see if the measurements follow the pistons. If they dont, I might need to move rods. Can all 4 rods be removed & replaced without splitting the case again? Stu |
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| EdwardBlume |
Dec 25 2012, 06:59 AM
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#2
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914 Wizard Group: Members Posts: 12,338 Joined: 2-January 03 From: SLO Member No.: 81 Region Association: Central California 
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Any news or update?
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Posts in this topic
stugray Deck height measurements driving me crazy Oct 14 2012, 02:06 PM
Vacca Rabite Shim the base of the cylinders.
Don't start m... Oct 14 2012, 04:28 PM rick 918-S Just a guess but sounds like maybe collapsed regis... Oct 14 2012, 05:46 PM Valy Are the rings on?
The pistons will rock a bit in ... Oct 14 2012, 10:26 PM yeahmag Are you using the tool I built?
-Aaron Oct 15 2012, 11:11 AM McMark Did you have the cylinder spigots machined? Oct 15 2012, 11:36 AM stugray 1- Just curious, why would shims make a difference... Oct 15 2012, 01:42 PM yeahmag The plate simply sits on top of the cylinders loca... Oct 15 2012, 02:15 PM r_towle I measure at the side of the piston directly above... Oct 15 2012, 03:15 PM yeahmag Rich,
I think you mean above the piston "wri... Oct 15 2012, 03:24 PM
r_towle
Rich,
I think you mean above the piston "wr... Oct 15 2012, 04:08 PM Vacca Rabite When I did mine I measured from the exact center o... Oct 15 2012, 03:39 PM stugray I have all of the rings on and I measure in line w... Oct 15 2012, 03:40 PM yeahmag Do you understand how to use the tool now? If not ... Oct 15 2012, 03:45 PM stugray
The .006 difference is across the same piston wi... Oct 15 2012, 09:19 PM wndsrfr [quote name='stugray' date='Oct 15 201... Oct 16 2012, 11:31 AM yeahmag Which direction are you measuring the piston? Acro... Oct 16 2012, 10:55 AM r_towle If those measurements are at the top of the piston... Oct 16 2012, 12:59 PM stugray
This is a vintage race engine that is carbed and... Oct 16 2012, 04:54 PM bobhasissues
You have mentioned this cam in several of your t... Oct 17 2012, 08:03 PM yeahmag Measure using the slot on the inner edge of each c... Oct 16 2012, 04:56 PM stugray yeahmag,
I only see the large difference in side-... Oct 16 2012, 05:18 PM yeahmag That stinks... Sounds like something is messed up. Oct 16 2012, 05:22 PM r_towle Have you tried a simple feeler gauge and a straigh... Oct 16 2012, 05:25 PM stugray
Yes and it showed a difference from side to side... Oct 16 2012, 10:22 PM Vacca Rabite Please put up some pictures of what you are doing.... Oct 17 2012, 06:42 AM Randal
Please put up some pictures of what you are doing... Dec 25 2012, 10:31 AM stugray Bob - I would post a link to Jakes Type-IV store t... Oct 18 2012, 10:24 AM Vacca Rabite
Bob - I would post a link to Jakes Type-IV store ... Oct 18 2012, 12:00 PM stugray The cam is a: "Super 9700 Cam Kit", incl... Oct 20 2012, 08:17 PM stugray Ok, got the new tools to do this right, and the re... Oct 22 2012, 11:16 PM rick 918-S What happens of you swap cylinders? I would invest... Oct 23 2012, 07:03 AM yeahmag Flip the plate end for end so the overhang "t... Oct 23 2012, 08:28 AM Valy What is your deck height right now? You should hav... Oct 23 2012, 01:29 PM jmalone Have you measured from the top of the problem pist... Oct 23 2012, 02:05 PM stugray I will do the suggestions above, but for now I rep... Oct 27 2012, 12:04 PM Joe Sharp Pull the crank and lay it on the bench with all th... Oct 27 2012, 05:00 PM stugray Joe,
Thanks! but I was hoping to do as many s... Oct 28 2012, 11:18 AM wndsrfr
Joe,
Thanks! but I was hoping to do as many ... Oct 28 2012, 04:27 PM stugray Not sure what this means.
I flipped the #4 Rod an... Oct 28 2012, 09:36 PM yeahmag Did you measure the cylinder height differences wi... Oct 28 2012, 10:36 PM stugray Yes, less than 0.001 between the two.
Stu Oct 29 2012, 07:16 AM stugray Bump!
So the only things I can find say that ... Oct 29 2012, 09:29 PM yeahmag I would suspect the rods first. You can snake them... Oct 30 2012, 10:00 AM r_towle You need to open up the case and send everything t... Oct 30 2012, 10:27 AM brant I would have a shop check the registers and also f... Oct 30 2012, 10:37 AM Valy Measure the piston travel. If it's as expected... Oct 30 2012, 10:38 AM yeahmag I agree in principal, but there is no reason not t... Oct 30 2012, 10:41 AM stugray I will go over all of the suggestions above but he... Oct 30 2012, 02:34 PM r_towle Crank was balanced at a shop? then its straight.
R... Oct 30 2012, 02:37 PM yeahmag Actually, the rods can be in balance but different... Oct 30 2012, 02:40 PM r_towle
Actually, the rods can be in balance but differen... Oct 30 2012, 02:44 PM yeahmag Agreed, but the one thing I have taken to heart fr... Oct 30 2012, 02:46 PM stugray
I would agree that the MAIN journals would need ... Oct 30 2012, 04:53 PM stugray ok, latest update.
I took all four rods off witho... Nov 3 2012, 09:57 PM yeahmag RIMCO or EMS can do it. Nov 3 2012, 10:57 PM Valy You should have measure the piston travel before t... Nov 4 2012, 10:45 AM stugray Ok, talked to a two local machine shops who claim ... Nov 7 2012, 10:17 PM McMark Remember that each case half must have matching re... Nov 8 2012, 09:58 AM stugray Thanks - he said that he would machine all four re... Nov 8 2012, 12:58 PM Racer Chris
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If the #1 & 2 side is perfect, is there a... Nov 8 2012, 04:20 PM Harpo
Thanks - he said that he would machine all four r... Nov 8 2012, 04:33 PM stugray David - Sorry, but what is "EMS"?
I kno... Nov 8 2012, 06:28 PM Dr Evil EBS, not EMS. Engine Builder's Supply in Spark... Nov 8 2012, 06:41 PM stugray I had the cases decked and did another measurement... Dec 25 2012, 01:35 PM |
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