Board index Flathead Power-Technical Questions, Answers, and Suggestions Pans Hydraulic Lifters

Hydraulic Lifters

Post Thu Oct 05, 2017 3:37 am

Posts: 188
Location: Radolfzell, Germany
Hi Guys,

I know this was discussed endless times in all kind of forums, but I am still puzzled with what is the right way to properly adjust my hydraulic lifters on my 57 Pan.
I hear of 4 turns (not bleeded) or 1,5 turns (bleeded) and when do I need to start the turns? I have no problems with my solid ones on my Knuck but here, I struggle!

Can anyone give my a idiot proof (for me) method to adjust these biests? (donT' know what brand my lifters are but they have OEM thread)

thanks a lot
Klaus

Post Thu Oct 05, 2017 1:02 pm

Posts: 3539
Location: Central Illinois, USA
Klaus!

If they are not washed out "dry" (I used only a light film of petrolatum off of my fingers for lube), then it becomes a tedious, and sometimes dangerous task to determine if they are 'pumped' or conversely "bled", and giving a false adjustment.

So I suggest following the Service Manual's instructions of extending the pushrod to where it takes up all slack, and then four turns down on the washed-out "dry" hydraulic, when on the 'heel' of the cam of course.

Please do them in order without turning the motor fully through each time, or it will fill the installed units, and cause more confusion.

Hope this helps,

....Cotten
PS: The Service Manuals were certainly written for "idiots", and sometimes by "idiots". It seemed to balance out...

Post Fri Oct 06, 2017 1:15 am

Posts: 188
Location: Radolfzell, Germany
Thanks Cotten,

will give it a try. I feel its difficult to get the starting point for the 4 turns right ...!?

I have a set to convert them to solids ... What do you think? does it make sense if I put them in? Then I would at least know what I`m doing. But I dont want to create another issue. The bike is bone stock (to my taste ... never opened) and has 60k km on it.

thanks
Klaus

Post Fri Oct 06, 2017 7:26 am

Posts: 3539
Location: Central Illinois, USA
Klaus!

Unless you have a "performance" cam that requires 'solids', I'm sure you would be happier with hydraulics.

Unless you have the Colony "slugs" that use the hydraulic pushrods, most solid replacement kits have aluminum pushrods, which are just another confusion, as they must be far tighter than your Knuck's.

There is a little gauge on the market for setting hydraulics, but I've never used one as it seems gimmicky and awkward.

....Cotten

Post Fri Oct 06, 2017 12:57 pm

Posts: 15
Location: Bussum, The Netherlands
If possible (stock cams, FLE FL or FLH) use hydraulics. They give a wonderful quiet valve operation...
For first-time adjustment: pull out the hydraulic units (match them fr ex, fr in, rr in, rr ex), remove all oil from the inside of the cam followers, pull the pistons out of the units (keep pistons and unit bodies paired), fill a plastic disposable syringe (with the needle removed) with gasoline, flush the units with gasoline by purging with the syringe on the little tube that extends from the unit, let the units dry (purging is o.k. when you can hear the little ball rattle in the units), remove all oil from the pistons, put the pistons back in their original units, put the units back in their original cam followers, select high gear, remove sparking plugs, turn the engine BACKWARDS (so no oil is pumped into the cam followers) by the rear wheel until one of the pistons is at TDC of its compression stroke, install the pushrods of the corresponding cylinder with their covers, unscrew the adjuster bolts until the unit pistons bottom out in the units (that is when you can't turn the pushrods with your fingers any more), turn in the adjuster bolts four turns (24 flats of the bolt head), tighten the locknuts without changing the positions of the adjusting bolts relative to the pushrods, turn the engine BACKWARDS by the rear wheel until the other piston is at TDC of its compression stroke, repeat the adjustment steps for this cylinder, measure with the aid of a pair of compasses or similar the distances between the locknuts and the heads of the adjuster bolts, note the four distances in your workshop manual.
Later adjustments: don't remove the hydraulic units from the cam followers, install the pushrods with their covers in their original positions, unscrew the adjuster bolts until the measured and noted distances between locknuts and adjuster bolt heads are reached, tighten the locknuts without changing the positions of the adjuster bolts relative to the pushrods (work slowly in order to prevent the valves being lifted too far, the hydraulic units should be given time to bleed off excess oil - it helps if the corresponding piston is at TDC of its compression stroke, engine can be turned forwards in order to reach TDC).
If the hydraulic units fail it is mostly either dirty engine oil, a blocked oilscreen or excessive play between the cam followers and their housing (mostly noted for the front exhaust, because of heavy side thrust due to an unfavourable angle between pushrod and cam follower).
JW
JW

Post Fri Oct 06, 2017 2:31 pm

Posts: 170
Location: Carver, MN

As it happens, I wrote a piece on Panhead/Shovelhead hydraulics a while back (can it really be 5 years already?). Anyway, you might find it worth taking a look. Here is a link:

http://knuckleheadtheology.blogspot.com ... ulics.html

Post Fri Oct 06, 2017 2:45 pm

Posts: 3539
Location: Central Illinois, USA
I forgot to mention, Folks...

When you flush out the hydraulic "cups", it is easiest when using a blunt toothpick to open the valve from the bottom.

Its tragic that wasn't in the Service Manual.

....Cotten

Post Sat Oct 07, 2017 8:17 am

Posts: 188
Location: Radolfzell, Germany
Thanks Guys,

now I think, this is the point where i am getting confused. Cotten, according to your "instruction I should lengthen the pushrod by 4 turns once the slack is gone. JW, according to yours, I should shorten the rod by 4 turns once the piston is bottomed out in the lifter unit ...
Does this mean that it takes 8 turns from "slack gone" to "bottomed lifter piston"?

JW, how do I feel the moment when the piston bottoms out in the lifter unit ... doesn't at one point in time the rod lift the valve ...?

thanks again and sorry for the questions
KLaus

Post Sat Oct 07, 2017 9:12 am

Posts: 15
Location: Bussum, The Netherlands
I found the instructions in Chilton, Clymer and Harley' Shope Dope # 341 very confusing, so I followed the instructions made by a dutch Harley dealer in the sixties. These are based upon the fact that the piston in the hydraulic unit should be lifted 1/8" from its bottom position. This corresponds with 4 turns of the adjuster screw from the situation that the pistin bottoms in the unit. This situation can easily be detected, as it corresponds with the transition from pushrods that can be turned by hand to pushrods that can notbe turned by hand.
JW

Post Sat Oct 07, 2017 11:57 am

Posts: 3539
Location: Central Illinois, USA
JW!

1/8" is probably what the gauge is.

But my instincts Folks,..
Is that I want to error on the loose side of its travel, rather than risking damage from the units becoming "solid" with no where to go.

I just bring the pushrod down to where it reasonably "takes out the shake", and have never had a problem (as long as the unit is "dry").

One of my '65s doesn't have the overhead oiler screen in the case, and it became obvious why a screen was a good thing.
Stuck on the side of the road in the 'boonies' from it suddenly hammering, I had to remove the unit to un-stick it, and had no can of spray or anything to clean it, or the others.
So, yes, I had to sit patiently and let all of the others "bleed down" before I could turn it oh-so-slowly through to intall the lifter swabbed out the best I could. Good thing I had a kicker.

It worked.
But I would rather play it safe....

....Cotten

Post Sat Oct 07, 2017 1:52 pm
Pa Site Admin

Posts: 6226
Location: Ohio USA

I've used your lifter method on many a v-8 engine Cotten. And it worked without harming any pushrods. Once the lifters were completely pumped up, I readjusted the pushrods to compensate for the loose ones.

Post Sat Oct 07, 2017 2:34 pm

Posts: 3539
Location: Central Illinois, USA
Pa wrote:
I've used your lifter method on many a v-8 engine Cotten. And it worked without harming any pushrods. Once the lifters were completely pumped up, I readjusted the pushrods to compensate for the loose ones.
Uh,...

What's a "v-8"?

Nevermind,

...Cotten

Post Sun Oct 08, 2017 7:38 am

Posts: 15
Location: Bussum, The Netherlands
Klaus,
I assembled a clean and dry hydraulic unit and measured its length at different positions of the piston or plunger. When the piston spring rests upon the unit cylinder: 62,7 mm (plunger uppermost position). When the plunger is lowered a little bit, the spring clicks into a recess of the unit cylinder: 61,7 mm (plunger upper position). When the plunger is lowered until it bottoms: 55,7 mm (plunger lower position). So the difference between the uppermost and lower position is 7 mm or 9/32" or 9 turns of the adjuster screw, and the difference between the upper and lower postion is 6 mm or 15/64" or 7,5 turns.
The 9 turns seem to correspond neatly with Shop Dope #341 and the method published in the monthly of the dutch Harley-Davidson Club, cited by me above (5 turns pushrod extension starting from the uppermost plunger position, and 4 turns pushrod shortening starting from the lower plunger position, respectively).
The advantage of the Shop Dope method is that it can be applied to an oil-filled hydraulic unit. The disadvantage is that it is more difficult to detect the moment when the pushrod has lost its shake than to detect the moment when the pushrod can not be turned any more with your fingers. I have always been using the dutch method, without any problems over more than a quarter of a million kilometers with my old faithfull Duo Glide. And I think that the necessary drying and cleaning of the hydraulic units and the oil reservoir in the cam follower does not harm...
JW

Post Sun Oct 08, 2017 10:51 am

Posts: 188
Location: Radolfzell, Germany
Thanks JW,

That helps a lot. Do I also need to clean the cam follower before adjusting and if yes, how would I do that?

Cheers

Post Sun Oct 08, 2017 11:19 am

Posts: 15
Location: Bussum, The Netherlands
You can leave the cam followers in their housings, you only need to remove all of the oil that is in the cam followers. I use pieces of rags to absorb the oil and, when most of the oil is removed, cotton buds/swabs to remove the last traces. Take care not to turn the engine over as the cam follower oil reservoirs will be filled with oil again. Also take care that the reservoirs are perfectly clean. It is like medical surgery....
JW

Post Mon Oct 09, 2017 3:09 am

Posts: 188
Location: Radolfzell, Germany
Cotten,

given JW's measurements, this would assume that your method starts with the spring "clipped" in the shoulder of the cylinder ... JW calls it the plunger upper position. Would that be correct?
That would make the difference between both method's starting point a 7,5 turns ... from there 4 turns in or out leaves half a turn variance?

thanks
KLaus

Post Mon Oct 09, 2017 7:36 am

Posts: 3539
Location: Central Illinois, USA
Yes, Klaus!

The spring should be seated in its counterbore of course.

Four turns down has always been trouble-free for me (as long as the units are dry), so I cannot judge the other method.

....Cotten

Post Mon Oct 09, 2017 11:05 am

Posts: 104
Hydraulic lifters aren't complicated. The piston has a travel of about .200". Four turns of the adjuster puts the piston within that range. The position will change with engine temperature. It is not precise.

Post Tue Oct 10, 2017 5:06 am

Posts: 188
Location: Radolfzell, Germany
Thanks Guys,

guess I'm good with that. Will play over the weekend

all the best
Klaus


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