Old 03-24-2020, 10:02 PM
arbys's Avatar
arbys arbys is offline
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Join Date: Jun 2010
Location: Richland Mi.
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Default How to measure valve lift 326 HO

I've had some questions if I may have worn off the a lobe on the cam. I have a dial indicator gauge and tried measuring the rise of the push rod but it keeps slipping off the push rod. Should I loosely install the rocker arm and try to measure that way? Any suggestions would be welcomed.

Old 03-25-2020, 08:07 AM
cold coffee cold coffee is offline
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Join Date: Apr 2017
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Do you have one of the weak valve springs installed ?

Old 03-25-2020, 08:26 AM
arbys's Avatar
arbys arbys is offline
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Join Date: Jun 2010
Location: Richland Mi.
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Yes, valve springs are installed. The engine is in the car and I basically removed the valve covers. I don't know why valve springs being installed would make a difference. At this point I just want to see that the lift is the same on all the cylinders.

Old 03-26-2020, 03:43 AM
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lust4speed lust4speed is offline
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A quick cheat is to look at the witness marks on the pushrods above the guide plates. If the lobes are equal then the wear pattern should be the same on all the pushrods. Along with this you can check for excess play on one or more rocker arms if they haven't been adjust lately - but for this to work there has to be enough wear that you would be hearing the tapping.

If you want to use the dial indicator, the stem will sit better if you unscrew the bottom tip with the roller ball. It then should stay pretty much in place on top of the rocker arm above the pushrod.

Mick Batson
1967 original owner Tyro Blue/black top 4-speed HO GTO -- 1967 red GTO drag car (best pass on old .030 over 455 was 10.28 at 131 on 91 octane pump gas) / 1968 Firebird has moved on to another owner, 1965 2+2 survivor AC auto.

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