I think I'm doing this right... Options

[vw_porsche]

Okay, I know this topic has been covered before. But, I'd like you guys opinion. I built a 2056cc engine and have installed a taller cam and the swivel head valve adjustment screws.
I understand that the way to set the valve geometry is to make the adjustment screw straight with the valve stem at half throw. I have shimmed up the rockers and I am using the stock push rod for now. (I don't have the push rod measure tool). It seems to me that I need longer push rods. But, is it normal to use this many spacers? I'd like to not use the spacers if possible. Am I missing something?

Valve at seat


Half throw


Full throw

[pilothyer]

You really need the adjustable push rod before you can do this job correctly. You may not need to shim the rocker stands much if any being that you didn't stroke the motor.

[tomeric914]

Did you grind back any of the rocker where the swivel foot is? I had to take a decent amount off to keep the swivel foot from hitting the rocker and to get the geometry right. As I recall, it didn't take a lot of shims.

[jimkelly]

WHAT?

a 914world member that has a camera that takes CLEAR pics (IMG:style_emoticons/default/smile.gif)

[AE354803]

Did you grind back any of the rocker where the swivel foot is? I had to take a decent amount off to keep the swivel foot from hitting the rocker and to get the geometry right. As I recall, it didn't take a lot of shims.

Looks like you didn't machine the rocker arms. That will allow you to remove the shims. I'd probably cut them back by the amount of shims you have under the rocker arms right now, but I'd work my way up to it removing little by little. Always easier to remove more than put some back.

See Van's rebuild (http://www.ephotomotion.com/914engine/page26.html)

[7TPorsh]

WHAT?

a 914world member that has a camera that takes CLEAR pics (IMG:style_emoticons/default/smile.gif)

Yeah I noticed that too...and clean parts. What's the deal? (IMG:style_emoticons/default/biggrin.gif)

[stugray]

I took off a little over .060 from the face of the rockers and then countersunk the holes a little to help the feet clear.

You can run the feet in some more and that will help.

Even with my adjustable pushrod tool, the custom cut pushrods were very close to the stock length (length is recorded at home, can post later).

I shimmed up the rockers by .049.

Stu

[Valy]

The nuts on the rocker shafts are only holding on half the threads. You need to see the stud protrude through the nut at least one full thread to ensure the engaged threads are not over stressed.
Use longer studs or backoff the one you have a bit.
If you run the engine like this, you'll strip the studs or nuts and that's not fun.

[DBCooper]

Every time I see that thread title "I think I'm doing this right" it reminds me of teenage sex.

[vw_porsche]

I took off a little over .060 from the face of the rockers and then countersunk the holes a little to help the feet clear.

You can run the feet in some more and that will help.

Even with my adjustable pushrod tool, the custom cut pushrods were very close to the stock length (length is recorded at home, can post later).

I shimmed up the rockers by .049.

Stu

Are you talking about shaving off this face? And, how did you do it?


I tried using the stock pushrods, but like you said the swivel head hits the rocker. If you could post your pushrod length, that would be a great help.
And yes, I will get longer studs before I run the engine.

Thanks,
Jon

[r_towle]

yes, then lose the shims to setup your valve geometry.

Using the stock rods (or the wrong length) will be a waste of your investment in the new camshaft.

Get the adjustable rod, or buy one extra rod and make one.

rich

[vw_porsche]

yes, then lose the shims to setup your valve geometry.

Using the stock rods (or the wrong length) will be a waste of your investment in the new camshaft.

Get the adjustable rod, or buy one extra rod and make one.

rich

How is the best way to shave off the rockers?

I am not going to use the stock pushrods. I was just using them as a test. I have a set of cut to length to use. And, I have a pushrod tool coming in the mail. I knew someone locally I was going to borrow one from, but he's out of town. I'm now just going to wait til I get my tool in.

Thanks for all your help.
Jon

[stugray]

How is the best way to shave off the rockers?

I ground mine down with a benchtop belt sander and a set of calipers (set at .060) to check progress.

Stu

[vw_porsche]

How is the best way to shave off the rockers?

I ground mine down with a benchtop belt sander and a set of calipers (set at .060) to check progress.

Stu

Stu,
Can you post your pushrod length? That would give me a good idea where to start.

Thanks

[stugray]

I have a webcam 86b:
1.7L rockers w/ solid spacers & swivel foot

Int lift: ~.500
Exh lift: ~ .480

Rod length = 270mm
Rocker shim = .049

Stu

[vw_porsche]

I have a webcam 86b:
1.7L rockers w/ solid spacers & swivel foot

Int lift: ~.500
Exh lift: ~ .480

Rod length = 270mm
Rocker shim = .049

Stu

My stock pushrods are 270mm.

The cam I put in is:

Valve Lift: Intake 0.430----Exhaust 0.430
Duration: Intake 265°----Exhaust 265°
Duration @ 0.050": Intake 234°----Exhaust 234°
Lobe Center: Intake 108°----Exhaust 108°

Should I have gotten a bigger cam for a 2056cc with dual 44 idf carbs?
Jon

[stugray]

Valve Lift: Intake 0.430----Exhaust 0.430

is that measured or from the cam card?

Does the cam card show lobe lift vs valve lift?

Stu

[vw_porsche]

Valve Lift: Intake 0.430----Exhaust 0.430

is that measured or from the cam card?

Does the cam card show lobe lift vs valve lift?

Stu

yes, thats from the cam card.

All the paper that came with cam said about lobe was the lobe center of 108.

Jon