Do I have hydraulic lifters or not?

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Do I have hydraulic lifters or not?

Post by Jleedog » Fri Feb 26, 2016 4:09 pm

Hi guys, I am new to your board. I would like to ask for your help to determine if I have solid lifters or hydro in my type 4 motor. I have a sand rail that I purchased several years back and I am in the process of doing some maintenance on it. I was replacing my valve cover gaskets due to a leak, and I thought I should go ahead and adjust the valves while I had everything opened up. My problem is, I don't remember if the guy I got the sandrail from said if it had hydro lifters or solid? I know he said that it was a built engine from a reputable shop and it was a 2.0 liter. I did some reading and checked the pushrods and they appear to be aluminum (magnet will not stick to the shafts). Does this mean that I have to have solid lifters? Is there any more things I can check besides pulling the pushrod tubes and removing a lifter to find out. Can I just set the valves to .006 and run the engine and if it makes horrible noises from the head it tells me that I have hydraulics. Will this hurt the engine? What is my best option? I would rather not pull the pushrod tubes if at all possible. Thanks for your help.

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Re: Do I have hydraulic lifters or not?

Post by SlowLane » Fri Feb 26, 2016 10:47 pm

Well, if the engine has been running well enough up until now, save for the oil leaks, then you can pretty much take it for granted that the existing valve clearances are close to correct for the type of lifters you have.

Solids are set with a smidgeon of free clearance, or "lash", typically around .006", Hydraulics, on the other hand, are set by screwing in the adjustment screws some number of turns past the contact, or "zero lash" point. The two settings should be quite easy to distinguish.

If you can't tell if a valve has any lash, try backing it off by half a turn. Even a tight valve on a solid lifter should have noticeable lash after half a turn. If there is still no lash, then suspect hydraulics. Try backing it off another half a turn to double-check. Keep track of how many turns you are backing.

Depending on your source of information/opinion, hydraulics should be set to one or two full turns in. I split the difference and use 1.5 turns in. Ratwell did some decent analysis of the subject and also settled on 1.5 turns.
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Re: Do I have hydraulic lifters or not?

Post by the miz » Tue Mar 01, 2016 2:05 pm

I feel your pain on not knowing for sure what type of lifter you have.
Fwiw: the full Colin method for hydraulic adjustment...and a little background on solids can be found here:

1982 Westy- Vana White

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Re: Do I have hydraulic lifters or not?

Post by honeybus » Thu Mar 03, 2016 10:09 am

OK, I am a novice here, but how about this test?

if your 'choice or target' cylinder is positioned at TDC, and if the rotor arm is pointed to that particular cylinder for firing, then loosen up both adjusting screws until they are relatively 'free', each not touching their respective valve's stems.

Observe that the top of both valves are even, and darn near straight across. Hopefully. If not, GO TO JAIL; DO NOT PASS GO, DO NOT COLLECT $200!

Now, loosely tighten both adjusting screws until they just touch each valve stem, Tighten one of the two adjusting screws two more full turns.

If you can see that both rocker arms have not changed their relative (mirror image and level) position, then you have hydraulic lifters / cam followers.

If tightening of the adjusting screw does cause the rocker arm to push against the valve stem (not against the push rod), it will have pushed that valve OPEN (evidence of solid lifter), and not have pushed (compressed) the hydraulic lifter.

This is just a basic observation. There are other considerations which may come into play here (collapsed hydraulic lifters; stretched valve stems; sunk valve seat; the law of mechanics becoming declared unconstitutional and voided).

Also consider that the length of the hydraulic lifter is different from the length of the solid lifter; the length of the hydraulic lifter push rod [[Hydraulic: 1-piece steel (262mm long)]] is different from the length of the solid lifter push rod [[Solid: Aluminum with steel tips (271mm long)]] .

RAtwell says this: "Two turns of the 10mm valve adjusting screw with 1mm threads will preload the lifter ~1.5mm " So, IMHO, the 9mm difference between the push rod lengths is very significant, and almost demands that the push rod / lifter be a family.

To have a hydraulic lifter push rod almost REQUIRES that you have the matching hydraulic lifter. There is no mixing of the two. Of course, unusual circumstances might discard this theory.

Thanks for listening.
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