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Posted by: vw_porsche Aug 8 2013, 12:55 AM

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

Posted by: pilothyer Aug 8 2013, 07:20 AM

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.

Posted by: tomeric914 Aug 8 2013, 01:45 PM

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.

Posted by: jimkelly Aug 8 2013, 01:49 PM

WHAT?

a 914world member that has a camera that takes CLEAR pics

Posted by: AE354803 Aug 8 2013, 01:49 PM

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)

Posted by: 7TPorsh Aug 8 2013, 02:25 PM

Yeah I noticed that too...and clean parts. What's the deal?

Posted by: stugray Aug 8 2013, 03:00 PM

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

Posted by: Valy Aug 8 2013, 05:23 PM

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.

Posted by: DBCooper Aug 8 2013, 05:50 PM

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

Posted by: vw_porsche Aug 8 2013, 10:19 PM

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

Posted by: r_towle Aug 8 2013, 11:48 PM

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

Posted by: vw_porsche Aug 9 2013, 04:39 PM

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

Posted by: stugray Aug 9 2013, 04:56 PM

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

Stu

Posted by: vw_porsche Aug 9 2013, 08:21 PM

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

Thanks

Posted by: stugray Aug 9 2013, 09:39 PM

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

Posted by: vw_porsche Aug 11 2013, 05:06 PM

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

Posted by: stugray Aug 11 2013, 06:10 PM

is that measured or from the cam card?

Does the cam card show lobe lift vs valve lift?

Stu

Posted by: vw_porsche Aug 11 2013, 08:00 PM

yes, thats from the cam card.

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

Jon