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
> valve adj night mare, grr
rhodyguy
post May 29 2004, 06:01 PM
Post #1


Chimp Sanctuary NW. Check it out.
***************

Group: Members
Posts: 22,072
Joined: 2-March 03
From: Orion's Bell. The BELL!
Member No.: 378
Region Association: Galt's Gulch



just let me know if i'm reading this right. two colored marks on fan. one red, on white behind it, or to the right while looking down. wanye writes in the pp artcile, "on most cars, there will be a paint mark at tdc, as well as a timing mark elsewhere on the fan. do not confuse the 2 marks, as it will lead to confusion later. additionaly on the impeller there is a notch that also indicates tdc for cly #1" ok, i see no notch and i presume the white mark is tdc. i have an 009 and i can see that the rotor is at approx the #1 plug wire on the cap. with all other rockers tight and a small amount of free play on the #1 rockers, is it safe to say i'm ready to go forward? i see to remember that the vw emblem was to be upside down on the valve covers upon reassembly, correct? mine didn't come off that way.

kevin
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
anthony
post May 29 2004, 06:08 PM
Post #2


2270 club
****

Group: Benefactors
Posts: 3,107
Joined: 1-February 03
From: SF Bay Area, CA
Member No.: 218



I always find TDC by the distributor rotor. It should be pointing at the line etched on the distributor body. Just like in waynes picture:

(IMG:http://www.pelicanparts.com/techarticles/914_valve_adjust/914_valve_adjust_pic4_big.JPG)


I have no idea though is the 009 would have that line.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
lapuwali
post May 29 2004, 06:25 PM
Post #3


Not another one!
****

Group: Benefactors
Posts: 4,526
Joined: 1-March 04
From: San Mateo, CA
Member No.: 1,743



I think the various PP articles have caused more confusion than not...

The key to remember is that there are only four lobes on the camshaft. One intake shared by 1 & 4, one exhaust shared by 1 & 4. Ditto for 2 & 3. So, the opposite cylinders are 180 camshaft degrees apart. If the intake valve on cylinder 1 is open, the intake valve on cylinder 4 MUST be closed. Same on the exhausts, and same for 2 & 3.

You don't have to find the EXACT TDC to measure valve clearance. With the valve covers off, if you rotate the engine and watch the intake valve on cylinder 1, as soon as it opens, the valve on cylinder 4 is off the lobe on the camshaft, and can be checked. For sticklers, if you want the rocker until it pushes the valve open, pauses, then JUST starts to close the valve, you'll be within a few degrees of TDC, and plenty close enough to measure the clearance on the opposite valve within 0.001", which is plenty good enough.

Repeat for all of the valves, and you never have to look for those hard to see marks on the fan, or even remove the distributor cap. You never even have to get out from underneath the car. Just watch the rockers. If you use a remote starter button, which is absurdly easy to wire from under the car given the location of the starter, you can bump the engine forwards and not even have to go through the trouble of jacking up the car and immobilising one wheel to turn the engine over with the tire.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
machina
post May 29 2004, 06:37 PM
Post #4


Advanced Member
****

Group: Benefactors
Posts: 2,030
Joined: 21-June 03
From: Miami Beach, FL
Member No.: 848



QUOTE(lapuwali @ May 29 2004, 08:25 PM)
The key to remember is that there are only four lobes on the camshaft.

what about with a split duration cam?

my RAT motor has one.

I've only done a valve adjust on a flat 6 up until now.

dr
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
lapuwali
post May 29 2004, 07:07 PM
Post #5


Not another one!
****

Group: Benefactors
Posts: 4,526
Joined: 1-March 04
From: San Mateo, CA
Member No.: 1,743



No idea on the split duration cam. The above certainly works on a stock or near stock engine, though.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
McMark
post May 29 2004, 07:35 PM
Post #6


914 Freak!
***************

Group: Retired Admin
Posts: 20,179
Joined: 13-March 03
From: Grand Rapids, MI
Member No.: 419
Region Association: None



I never have and never will use the distributor to find TDC. Too many cars have the cam drive installed incorrectly to trust it. If you've checked that it's in the right place then you could use the distributor, but I still wouldn't (sorry anthony). The problem with writing a tech article about this is that there are SO MANY impeller variations. You just have to learn what works for your engine/impeller and then use that. If you have a helper it can make things easier. Tell them to get under the car, point their nose at the cylinder 1 intake valve and have them watch for when that valve opens and then closes. Once it has fully opened and then fully closed you know you're coming up on #1 TDC. (Note: Make sure the car is in 5th gear, one wheel is on the ground, you're turning the other wheel in the direction of travel, as if the car was driving forward.) Turn the wheel slowly and climb inside the engine bay so you can see everything there is to see inside the inspection hole. Get really close to it. Turn the wheel really slowly and look for the marks. As you're turning you'll see the FI/27 degree timing mark come up first, and then the 0/TDC mark later. Some impellers have extra marks. As I recall, 0/TDC is right next to one of the fat pulley supports (the ones that aren't fan blades). If I get less lazy, I'll walk out and take a picture.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
URY914
post May 29 2004, 07:37 PM
Post #7


I built the lightest 914 in the history of mankind.
****************************************************************************************************

Group: Members
Posts: 120,356
Joined: 3-February 03
From: Jacksonville, FL
Member No.: 222
Region Association: None



I've marked my flywheel at 90, 180 and 270 degrees. It is MUCH easier to see.

Try it. (IMG:style_emoticons/default/biggrin.gif)

Paul
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
anthony
post May 29 2004, 07:41 PM
Post #8


2270 club
****

Group: Benefactors
Posts: 3,107
Joined: 1-February 03
From: SF Bay Area, CA
Member No.: 218



My engine is still original so I know the cam drive is in the right place. I also just use the distributor to get it in the general vicinity of TDC and then use the marks on the flywheel to know where I'm at while under the car adjusting.

The other thing to mention is that if you regularly adjust your valves you'll develop a sense of how much they go out of adjustment. Usually I only need to adjust half of the valves because the rest are still in spec.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
rhodyguy
post May 29 2004, 08:30 PM
Post #9


Chimp Sanctuary NW. Check it out.
***************

Group: Members
Posts: 22,072
Joined: 2-March 03
From: Orion's Bell. The BELL!
Member No.: 378
Region Association: Galt's Gulch



well i conceded some ground. between neck cramps i cleaned the k&n's, letting them dry and will oil them up tomorrow. i was going to tune it so the plugs came out. easier to turn with them out anyway. they we suprisingly unfouled for a carbed car save for the one that had a plugged idle jet on that cylinder a while back, the rest were a light brownish. the exhausts were all a tight five-loose six, but the intakes all seem to be incredibly tight. i'll attack on all fronts tomorrow and be hard at it as late as i need to on monday night. stay by your computers. (IMG:style_emoticons/default/wink.gif)

kevin, always waiting to the last minute
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
ChrisReale
post May 29 2004, 08:41 PM
Post #10


Sleazy
****

Group: Members
Posts: 2,665
Joined: 20-January 03
From: San Francisco
Member No.: 176



QUOTE(URY914 @ May 29 2004, 05:37 PM)
I've marked my flywheel at 90, 180 and 270 degrees. It is MUCH easier to see.

Try it. (IMG:style_emoticons/default/biggrin.gif)

Paul

I hope you didnt use paint to mark it, that would add dead weight (IMG:style_emoticons/default/biggrin.gif)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
URY914
post May 29 2004, 08:46 PM
Post #11


I built the lightest 914 in the history of mankind.
****************************************************************************************************

Group: Members
Posts: 120,356
Joined: 3-February 03
From: Jacksonville, FL
Member No.: 222
Region Association: None



Used a grease pencil.
Very slippery. (IMG:style_emoticons/default/biggrin.gif)

Paul
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: 4th May 2024 - 04:41 PM