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Thu Jan 30, 2014 1:49 pm

Doing a search on going from hydraulic to solid lifters/cam, I found some useful info. What I didn't see mentioned was any difference in push rod length between the two. I'm comparing my old hydro push rods with the used set that I bought and the solids(aluminum) are about 3/8" longer.

Is this the way they are? Also, I didn't see anything mentioned about changing rocker arms. I'm guessing they're the same. Is that right?

Thu Jan 30, 2014 2:32 pm

http://ratwell.com/technical/HydraulicLifters.html

Halfway down

Solids 271mm
Hydro 262mm

Thu Jan 30, 2014 3:49 pm

rocker arms themselves are the same, the spacers and springs between the arms are different. use the hydraulic rocker spacers if you have them.

Thu Jan 30, 2014 4:22 pm

Thanks guys. Scott, if I read you right, I'll go ahead and use my old hydro rocker shaft assemblies on the new solid lifter cam that I'm installing.

Thu Jan 30, 2014 4:28 pm

yes the hydraulic assemblies have the thick spacers and wave washers between the rocker arms which are more robust than the coil springs.

Thu Jan 30, 2014 4:29 pm

FNGRUVN wrote: Thanks guys. Scott, if I read you right, I'll go ahead and use my old hydro rocker shaft assemblies on the new solid lifter cam that I'm installing.

yes - the solid spacers and shims hold the rockers better than the springs of the older style. They went to solid spacers because the Hydro springs are much heavier than solid lifters. In fact if you have new /E genuine VW springs they work better with a solid camshaft than the heavier springs which cause more cam and cam bearing wear. The /E were also used in 912's and 914's so they are no slouch. They have about the same rate as Isky racing springs for the street.

You can flip the rocker shafts over and use the non-galled sides if you don't have new ones. Do inspect the spacer shims to be sure none are about to wear thru.

Thu Jan 30, 2014 5:01 pm

Thanks again guys. I wish I had known about the Samba when I was doing the engine on my '80 Vanagon.

I'm waiting for a cam plug, otherwise I would have the case together by now. In the mean time Ive been busy with all the busy work. My idea of hell would be a mountain of rusty, greasy engine tin that you had to clean, fix, and paint. You'd get to the top of the mountain only to find a sea of mountains behind it.

Thu Jan 30, 2014 10:03 pm

I may be talking out my ass here but it may be worth a look at measuring for proper length needed for your application.

Thu Jan 30, 2014 10:54 pm

SGKent wrote: yes - the solid spacers and shims hold the rockers better than the springs of the older style. They went to solid spacers because the Hydro springs are much heavier than solid lifters.

With solids the rockers tend to walk sideways against the spring each time the valve it opened, but are pushed back into their proper position when the lifter is on the base circle and there is slack in the valve train. With hydraulic lifters the valve train is under continuous pressure with would cause the rockers to walk their way further and further into the spring until the rocker pops off the end of the valve stem or the push rod unseats.

Using solid spacers with solid lifters lessens the chance of the rocker being pushed too far to the side which can easily happen if valve train recession has taken place the the lash is gone.

Thu Jan 30, 2014 11:17 pm

X-2 Wildthings
Solid rocker arm spacers were designed and sold by many type 1 and type 4
engine builders long before VW adopted them to their 1st hydraulic cam
air cooled engines.

this is only 1 item that VW knew from listening to other engineers would work with the increased valve spring pressure used in the later years of the air cooled engine.

Wed Apr 04, 2018 8:35 am

Quick question on this topic.... I have hydraulic lifters in my type 4 2000cc engine. Is there a difference between stock pushrod lengths for hydraulic lifters for type 4 engines as opposed to type 2?

I am aware of the previous posts pointing to Ratwell’s 262mm length for hydraulic lifters, but I don’t think he specifies type 2 or type 4 engine. Maybe it’s all the same?

Currently the length of my rods is 259mm total outside length end to end (strange, but that’s what was in there)

Planning to measure with a tool, but opinions are welcome.

Donovan

Wed Apr 04, 2018 8:44 am

Navonod123 wrote: Quick question on this topic.... I have hydraulic lifters in my type 4 2000cc engine. Is there a difference between stock pushrod lengths for hydraulic lifters for type 4 engines as opposed to type 2?

I am aware of the previous posts pointing to Ratwell’s 262mm length for hydraulic lifters, but I don’t think he specifies type 2 or type 4 engine. Maybe it’s all the same?

Currently the length of my rods is 259mm total outside length end to end (strange, but that’s what was in there)

Planning to measure with a tool, but opinions are welcome.

Donovan
I believe these are the part numbers. 3 different parts. Someone can double check me

type 1 engine - 043-109-301A
type 4 engine solid lifter - 021-109-301A
type 4 engine hydraulic lifter - 071-109-301

Wed Apr 04, 2018 9:43 am

The hydraulic lifters are effectively longer than solid lifters and thus require a shorter pushrod. Hydraulics pushrods are also made with a steel shaft verses the aluminium shaft used with solid lifter pushrods.

Wed Apr 04, 2018 9:54 am

Navonod123 wrote: Quick question on this topic.... I have hydraulic lifters in my type 4 2000cc engine. Is there a difference between stock pushrod lengths for hydraulic lifters for type 4 engines as opposed to type 2?

I am aware of the previous posts pointing to Ratwell’s 262mm length for hydraulic lifters, but I don’t think he specifies type 2 or type 4 engine. Maybe it’s all the same?

Currently the length of my rods is 259mm total outside length end to end (strange, but that’s what was in there)

Planning to measure with a tool, but opinions are welcome.

Donovan

To answer the exact question you asked....yes....type 2 and type 4 engines are the same basic engine case, crank castings etc.....from August 1972 and on. Previously to that mark the "type 2" engine was based on the type 1 case. After that the "type 2" engine was based on the type 4 case (in the US).
And....any type 4 based engine you find that has hydraulic lifters...came in a type 2 vehicle (unless they were installed by a previous owner). The type 4 cars...411/412/914 never used hydraulic lifters (thankfully).

So if you are somehow finding pushrods that came from a hydraulic lifter engine based on a type 1 case...do not use them.

The odd 3mm shorter length? Hmmmm. Its possible that someone had new pushrods made on a previous rebuild to correct geometry...and its also possible they are worn on the tips.
What do the tips look like? Also....are they steel? they should be. Put a magnet on the middle of the rod.

Ray

Wed Apr 04, 2018 9:57 am

I have an adjustable pushrod that I used to build my Camper Special engine. It was handy as Boston Bob and I set the valve train geometry and then cut the chromemoly pushrods to the correct length.

Looks sort of like this....

http://vwparts.aircooled.net/Adjustable-Pushrod-Tool-Each-p/adjustable-pushrod.htm