Home  |  Forums  |  914 Info  |  Blogs
 
914World.com - The fastest growing online 914 community!
 
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG. This site is not affiliated with Porsche in any way.
Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners.
 

Welcome Guest ( Log In | Register )

 
Reply to this topicStart new topic
> Embarrassed, Lifter Geometry
Wew
post Jun 22 2022, 12:33 PM
Post #1


Member
**

Group: Members
Posts: 227
Joined: 17-January 15
From: Novato, ca
Member No.: 18,335
Region Association: None



Hi all,

I have watched Ian's valve geometry video many times. Thank you Ian.

I have my side to side movement on the valve train set with .004mm of movement and things lined up very nicely. Even ordered some shims from Tabari to help.

Now comes the part that just isn't working for me and must be some type of simple oversight on my part.

I know in the video they start with the adjustable pushrod and .271mm in length and then work from there.

My cam grind also has me at a .426mm lift for intake.

I even purchased the digital dial and arm mechanism Ian uses in his video.

I am working off of the intake cylinder 1.

Here's the crazy part: When I turn my motor manually the mic shows a travel of over 1.0300mm? I do rotate my drive shaft 360 degrees twice in order to get this measurement. The first 360 degree rotation I barely get any movement, the second 360 degree movement back to TDC is what really moves the dial and I end up at over 1,000mm which really sends me for a loop. I am more than double the travel that Ian has got and the recommended travel.

(IMG:style_emoticons/default/WTF.gif) (IMG:style_emoticons/default/confused24.gif) (IMG:style_emoticons/default/headbang.gif)

I am super perplexed? I know it has to be user error and there is just no way it could be so far off.

I would appreciate all input and recommendations.


Thanks much,

Gary
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
sportlicherFahrer
post Jun 22 2022, 12:42 PM
Post #2


Nothing to see here.
***

Group: Members
Posts: 1,078
Joined: 18-April 05
From: Tacoma, WA
Member No.: 3,945
Region Association: Pacific Northwest



Have you tried measuring the lift in thousands of an inch? Pushrod length is usually measured in mm, and the lift measured in inches.

Also, the rocker sideplay should be .005 inch as well.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Wew
post Jun 22 2022, 12:47 PM
Post #3


Member
**

Group: Members
Posts: 227
Joined: 17-January 15
From: Novato, ca
Member No.: 18,335
Region Association: None



QUOTE(sportlicherFahrer @ Jun 22 2022, 11:42 AM) *

Have you tried measuring the lift in thousands of an inch? Pushrod length is usually measured in mm, and the lift measured in inches.

Also, the rocker sideplay should be .005 inches as well.

Oh my.... This may be the simple solution I needed. (IMG:style_emoticons/default/idea.gif) (IMG:style_emoticons/default/pray.gif)

Thank you. When I get home this evening I will make the change on the mic when I do the lift measurement in inches.

Thank you much.

Message received on the sidepaly of .005 inches as well.

Sucking at math has really come back to bite me hard when it comes to engine building.

This forum is my savior and has helped me from grenading my engine a few times.

Thanks again,

Gary
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
sportlicherFahrer
post Jun 22 2022, 12:52 PM
Post #4


Nothing to see here.
***

Group: Members
Posts: 1,078
Joined: 18-April 05
From: Tacoma, WA
Member No.: 3,945
Region Association: Pacific Northwest



Worked through a few "user issues" on my valve train recently as well. (IMG:style_emoticons/default/biggrin.gif) Hope you're able to get it dialed in as quick as they make it look in the videos! (IMG:style_emoticons/default/aktion035.gif)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Dave_Darling
post Jun 22 2022, 10:21 PM
Post #5


914 Idiot
**********

Group: Members
Posts: 14,982
Joined: 9-January 03
From: Silicon Valley / Kailua-Kona
Member No.: 121
Region Association: Northern California



QUOTE(Wew @ Jun 22 2022, 11:33 AM) *

My cam grind also has me at a .426mm lift for intake.


Are you sure it is 0.426mm? That's an awful lot of precision, and a pretty small number. We are much more used to seeing cam lift numbers in inches, which are 25.4 times as large as millimeters.

--DD
User is online!Profile CardPM
Go to the top of the page
+Quote Post
stownsen914
post Jun 23 2022, 06:32 AM
Post #6


Senior Member
***

Group: Members
Posts: 913
Joined: 3-October 06
From: Ossining, NY
Member No.: 6,985
Region Association: None



The lift at valve is almost certainly .426" (not .426 mm).

I'm not quite following what the 1 mm measurement is. Can you post a pic of your measuring setup?
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Wew
post Jun 23 2022, 09:29 AM
Post #7


Member
**

Group: Members
Posts: 227
Joined: 17-January 15
From: Novato, ca
Member No.: 18,335
Region Association: None



You are all correct.

I had my dial set at millimeters.

Measuring the pushrod prior was in mm so I "ASSumed" it was a mm measurement for the lift.

WRONG! (IMG:style_emoticons/default/chair.gif)

Now that I am straightened out proper I will address the lift and the side to side play on the rockers at inches.

Thank you much everyone and hope to have this completed by the end of the weekend.

Thanks again!!

Gary
User is offlineProfile CardPM
Go to the top of the page
+Quote Post

Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 



- Lo-Fi Version Time is now: 7th May 2024 - 03:09 PM