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tips, technology, tools and techniques related to vehicle driveline components

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NixVegaGT
Nicolas Wiederhold
Minneapolis, MN
(659 posts)

Registered:
10/16/2007 05:30AM

Main British Car:
'73 Vega GT 4.9L Rover/Buick Stroker

authors avatar
Re: Hydraulic Lifter Preload (Buick/Rover)
Posted by: NixVegaGT
Date: June 05, 2009 05:50PM

I was about to bring up that I had to add shims for my cam but then I realized my valves are also a lot longer so different problem, LOL. SO, yes if you are using the stock valve length you have to remove some material off the bottom of the rocker pillars.

I'm using the Harland Sharp roller rockers for the buick 215...


donkelly23
Don Kelly
Charleston, SC
(89 posts)

Registered:
07/21/2011 05:13PM

Main British Car:
1980 TR7 V8 Z28 FI ECM 4.0

Re: Hydraulic Lifter Preload (Buick/Rover)
Posted by: donkelly23
Date: October 17, 2017 10:01AM

Gentlemen, It has finally turned from Summer to winter overnight and the garage is hospitable again. Time to get back to work
Quoting Jim Blackburn (Blackwood, sorry Jim) here

" Most common is to use an adjustable pushrod, take up the play, do a direct length measurement, add your preload and order the next longer size pushrod. Typically they come in .050" increments, that should be a clue."

Sp basically put the adjustable in and lengthen it until the slop is gone.
Question on this ...When the slop is gone will it still spin but not move up and down???

Then measure and add, WHAT?, .040???



Edited 1 time(s). Last edit at 10/18/2017 09:06AM by donkelly23.


donkelly23
Don Kelly
Charleston, SC
(89 posts)

Registered:
07/21/2011 05:13PM

Main British Car:
1980 TR7 V8 Z28 FI ECM 4.0

Re: Hydraulic Lifter Preload (Buick/Rover)
Posted by: donkelly23
Date: October 17, 2017 03:57PM

OK, if I would have know how to do this it would have been done 2 yrs ago.

20171017_153247_resized (Small).jpg

So if I average them I get 7.935
If I throw out the high and low I get 7.936.
Pretty close.
SO I add .040 to that for a push rod length?
That's 7.975 for optimal preload..
My existing PR's I had built from Smith Bros. are 8.027.Which mean's I would need to shim.052 for them to work



Edited 1 time(s). Last edit at 10/17/2017 04:05PM by donkelly23.


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5343 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Hydraulic Lifter Preload (Buick/Rover)
Posted by: BlownMGB-V8
Date: October 17, 2017 09:52PM

Blackburn huh? Well, that's a less common corruption of Blackwood at least. But still not right.

OK, why was it you didn't like the existing pushrods again? For these aluminum V8's I like to go .060" on the preload just to cut down the likelihood of lifter tap. Which leaves you .030" long or .090" of preload. Your lifters can easily accommodate that, and the only reason not to use them would be if you planned to redline the engine and wanted to avoid lifter pump-up, which depending on many factors such as valve spring pressure could potentially reduce your redline a bit by causing valve float.

Was this why you were installing new pushrods? Because if the symptom you are fighting is lifter tap you'd be going the wrong way and the pushrods aren't the problem. If anything they are partially masking some other cause.

Jim


donkelly23
Don Kelly
Charleston, SC
(89 posts)

Registered:
07/21/2011 05:13PM

Main British Car:
1980 TR7 V8 Z28 FI ECM 4.0

Re: Hydraulic Lifter Preload (Buick/Rover)
Posted by: donkelly23
Date: October 18, 2017 09:12AM

Jim, thank you for your post...And I apologize for bastardizing your name and have corrected it).
I have read and heard that when adding a non stock cam to a motor that you need to redo the push rod lengths.
Not sure if that was causing my tappet noise on my old 3.5 or not.
As I am not the sharpest engineer out there please all do chime in and straighten me out on this.


MGBV8
Carl Floyd
Kingsport, TN
(3232 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
79 MGB, Buick 215

authors avatar
Re: Hydraulic Lifter Preload (Buick/Rover)
Posted by: MGBV8
Date: October 18, 2017 10:47AM

Never hurts to double check, but I have never had to change pushrod length when swapping in a bigger cam (provided that cam's base circle is the same).



Edited 1 time(s). Last edit at 10/18/2017 12:28PM by MGBV8.


donkelly23
Don Kelly
Charleston, SC
(89 posts)

Registered:
07/21/2011 05:13PM

Main British Car:
1980 TR7 V8 Z28 FI ECM 4.0

Re: Hydraulic Lifter Preload (Buick/Rover)
Posted by: donkelly23
Date: October 18, 2017 10:51AM

I talked about that with a friend who wiped a cam on his 3.5.
This cam came from Woody and I think he said Woody does change the base circle..

Not that it matters, I don't think, but I'm going from a TR8 block to a brand new 4.0 short block.
Cam was in the 3.5 for about 7K and 4.0 heads for the same amount



donkelly23
Don Kelly
Charleston, SC
(89 posts)

Registered:
07/21/2011 05:13PM

Main British Car:
1980 TR7 V8 Z28 FI ECM 4.0

Re: Hydraulic Lifter Preload (Buick/Rover)
Posted by: donkelly23
Date: October 18, 2017 12:02PM

My friend did am Excel spreadsheet with my measured lengths and you can see possible preload by changing "G"
Try this
[1drv.ms]

Dang, can't figure how to edit in the cloud version



Edited 3 time(s). Last edit at 10/18/2017 12:08PM by donkelly23.


donkelly23
Don Kelly
Charleston, SC
(89 posts)

Registered:
07/21/2011 05:13PM

Main British Car:
1980 TR7 V8 Z28 FI ECM 4.0

Re: Hydraulic Lifter Preload (Buick/Rover)
Posted by: donkelly23
Date: October 18, 2017 02:03PM

Got it
Just go to the "Edit Workbook"
Hit the arrow and edit in Browser

So basically you can input any length in the "G" field


donkelly23
Don Kelly
Charleston, SC
(89 posts)

Registered:
07/21/2011 05:13PM

Main British Car:
1980 TR7 V8 Z28 FI ECM 4.0

Re: Hydraulic Lifter Preload (Buick/Rover)
Posted by: donkelly23
Date: October 19, 2017 03:41PM

So using the chart I posted if I use 7.985" pushrod my preload will rang from a low of .023 to a high of .095
A little high on the low high end but id I go a little it drops the low below .020.

I plgged in the "stock" pushrod value and thought the preload values over 100 were a little to high


Need to soak my lifters before I finish up the top end.
I have always just used my engine oil.
Any reason I should use my break in oil to soak them?



Edited 1 time(s). Last edit at 10/19/2017 04:31PM by donkelly23.
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