Author Topic: Hydraulic, Solid Lifter (Read 8310 times)

HP · « **on:** February 25, 2006, 10:58:46 am »

I'v read many times here on this forum these type of heads: Hydraulic and Solid Lifter.
It seems these are the 2 type of 1.6L heads, right? What's the difference?! I didn't know there was different heads! :?

HP · « **Reply #1 on:** February 25, 2006, 05:12:29 pm »

humm... I see.
The question now is: what is a lifter?
And is my '89 JR a hydraulic (which is the *best* one, I suppose) or a solid one?!

VWDieselDoc · « **Reply #2 on:** February 25, 2006, 06:08:32 pm »

A lifter, tappet, or 'cam follower' is the barrel-like object that sits between the cam and the top of the valve stem. It serves two purposes. First, it provides a wide surface for the cam to contact when opening the valves. Second it provides a means to adjust the clearance between the the camshaft lobes and the valves.

The difference between the hydraulic and mechanical tappets is the way the clearance adjustment is made. Hydraulic tappets use the hydraulic pressure from the engine's oil system to maintain a 'zero' clearance between the tappet and the cam lobe. They also adjust themselves as the engine expands and contracts from heat. Self adjusting, they never need to be adjusted at all.
Mechanical lifters are adjusted manually through disks of different thicknesses. When the clearance between the tappet and cam lobe becomes too great, the disk is removed and a thicker disk is inserted to decrease the clearance. Same when the clearance becomes too small... a thinner disk is inserted to increase the clearance. Since the mechanical tappens cannot adjust themselves 'on the fly', they are pre-set with a certain amount of clearance so when the engine heats and expands, that clearance will close and be as close to 'zero' as possible.

HP · « **Reply #3 on:** February 25, 2006, 06:35:06 pm »

Thank u guys, for clearing that out.

I, now, only fail to know:

Quote from: "HP"

And is my '89 JR a hydraulic (which is the *best* one, I suppose [??]) or a solid one?!

jtanguay · « **Reply #4 on:** February 26, 2006, 06:55:29 am »

hydraulic is easier to maintain but mechanical has a bit more power :wink:

oh yea. hydraulic lifters can get stuck over time from buildup - so you have to change your oil a bit more than regularly if its a worn down engine.

MacGyver · « **Reply #5 on:** February 26, 2006, 10:35:51 am »

Quote from: "HP"

Thank u guys, for clearing that out.

I, now, only fail to know:
Quote from: "HP"

And is my '89 JR a hydraulic (which is the *best* one, I suppose [??]) or a solid one?!

In North America, the switch from solid to hydraulic was made mid-1986.
I've see 86's with either.

Your 89 should definitely be hydraulic unless vw did things way differently in Portugal than here.
Identify your head for sure as per libbybapa's instructions above.
As for hydraulic being the best, well, they're definitely easier. No periodic adjustments to make.

HP · « **Reply #6 on:** February 26, 2006, 02:21:27 pm »

Well, the car was actually imported from Germany and was made in Wolfsburg.

Quote from: "libbybapa"

The difference is significant in that the hydraulic lifter heads have an additional oil drain hole that runs through the head between the #1 and #2 injectors. Externally there is a vertical hump in the casting instead of a depression there in the solid lifter ones.

I'll try to notice that. And report it here.

texaseric · « **Reply #7 on:** February 26, 2006, 04:25:58 pm »

I heard that you can put a hydraulic head on an older (solid lifter) bottom end if you seal off the additional oil return passage on the head. What is the downside of this approach?

texaseric · « **Reply #8 on:** February 26, 2006, 04:48:57 pm »

Larger-geared oil pump is any pump that goes with post-1986 1.6 diesel engine? Not sure if this is what I have on my rebuild. What sort of pressure should I be looking for?

HP · « **Reply #9 on:** March 05, 2006, 04:54:38 pm »

Quote from: "HP"

I'll try to notice that. And report it here.

Hydraulic head.

Thanks to those who responded.

HP · « **Reply #10 on:** March 06, 2006, 02:00:52 am »

Quote from: "libbybapa"

Take a peek next time you have the valve cover off to make sure you don't have adjustment discs in that head.

I don't think that's gonna happen that soon! :lol: I hope not. Even if it would, I don't mess with the engine. I'm a 0 in mechanics and stuff.. :oops:

Thanks, Andrew.

texaseric · « **Reply #11 on:** March 27, 2006, 07:34:47 pm »

Aren't the 36mm pumps for gassers only, or does it matter? Do these pumps require larger (5-qt) oil pans?

AllanJetta · « **Reply #12 on:** October 27, 2006, 02:04:13 am »

I have a different problem, can I use mechanical head on what used to be hydraulic head engine? Hydraulic head is broken and I can't get new one where I am or at least with good price. What else needs to be replaced when I want to make that swap?

Author Topic: Hydraulic, Solid Lifter (Read 8310 times)

AllanJetta