Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > Porsche Forums > 911 Engine Rebuilding Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered User
 
adomakin's Avatar
 
Join Date: Mar 2002
Location: Essex UK
Posts: 2,194
Garage
for gods sake please someone help me before i cry

cam timing. its getting silly now. two of us have been on it since 7pm tonight and its now 2am. we get the left cam dot facing up, we take the pin out, we get z1 to line up, we put the pin in and nip up the cam bolt. we set the overlap at 1.26, we back off the cam bolt. everything goes fine up unitl this point. when we try to remove the pin the cam rotates as if the intake valve spring is pushing the cam round due to the preload in the valve spring. it ends up sending the overlap back to approx .9

please help!
__________________
Andy

1980 SC soon to be big hp 3.3t powered 73RSR Replica (well, I'm keeping the engine but everything else is going )
Old 03-11-2006, 06:09 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
Registered User
 
Join Date: May 2002
Location: Up North
Posts: 1,446
I feel for you Andy...
Similar thing happened to me when I did my top end a few years back. In my case, luckily it was the left cam so I used the scavenge pump pulley to hold the cam and set it.
I was thinking about same thing if it happened on the right side...
__________________
87 930 K27HFS/B&B/Twin-Plug... Megasquirted
Old 03-11-2006, 07:07 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Registered User
 
Join Date: May 2003
Posts: 3,232
What I do is:

Check the overlap reading, back the engine off from Z1 to where the rocker isn't pushing on the cam. Remove the pin and decide which way to move the cam to correct my error. Turn the cam the direction it needed to go so the pin goes in a couple of holes away. Repeat as needed. After the first go you can figure out how many holes to move for a given correction. As I recall it's about 3 pin holes for .5mm of overlap change on my SC cams.

-Andy
__________________
72 Carrera RS replica, Spec 911 racer
Old 03-11-2006, 09:08 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Registered User
 
ischmitz's Avatar
 
Join Date: May 2002
Location: Santa Barbara, CA
Posts: 4,526
Garage
Send a message via Skype™ to ischmitz
Here is what I do: I set the cam with the dot up, find Z1 TDC and put the pin in (corase adjustment step). Then I turn the engine over a couple of times and set the crank so that the lift is 1.26mm. Next I gauge how far the Z1 mark is off the case center line and make a mental note. Then I rotate until both valves are closed (#1E & #4E). That's when I pull the pin and bump the crank by as much as Z1 was off. After a couple of itterations you'll get real good at this.

BTW: I assume that only #1 intake and #4 intake are set for proper valve lash. No other rockers should not be present or their adjuster backed out all the way.

Good luck,
Ingo
__________________
'74 Targa 3.6 (not stock ) - '01 C4 (almost stock) - '00 ML430 (stock)

I repair/rebuild Bosch CDI Boxes and Porsche Motronic DMEs
Porsche "Hammer" or Porsche PST2 - I can help!!
How about a NoBadDays DualChip for 964 or '95 993
Old 03-11-2006, 09:50 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
Registered User
 
adomakin's Avatar
 
Join Date: Mar 2002
Location: Essex UK
Posts: 2,194
Garage
thanks blokes, new day today with fresh eyes so fingers crossed ill get it done....bloody cam timing!
__________________
Andy

1980 SC soon to be big hp 3.3t powered 73RSR Replica (well, I'm keeping the engine but everything else is going )
Old 03-12-2006, 12:19 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Registered User
 
adomakin's Avatar
 
Join Date: Mar 2002
Location: Essex UK
Posts: 2,194
Garage
yes!!!! yes yes yes yes!!! i got 1.28 and i think im gonna leave it at that. im reading in other posts that slightly more cam advance gives better bottom end and im building a laggy turbo so it should help a little-trouble is im assuming that i now HAVE to get 1.28 on the right side? is there any generally acceptable discrepancy levels between sides or is it just the +/- .1? seems like a lot of difference to me but what do i know
__________________
Andy

1980 SC soon to be big hp 3.3t powered 73RSR Replica (well, I'm keeping the engine but everything else is going )
Old 03-12-2006, 04:31 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
 
Registered User
 
adomakin's Avatar
 
Join Date: Mar 2002
Location: Essex UK
Posts: 2,194
Garage
dont bother answering that question, 1.28 per side spot on! im so happy I might come out of retirement and roll myself a fat one!

Andy and Ingo, thanks very much for your help!

now its just exhaust, intercooler, efi, learing how to program efi, rebuilding gbox, fuel system, cage, suspension, brakes, interior, body mods, prep and paint, wheel finish, trim......................hmmm...
__________________
Andy

1980 SC soon to be big hp 3.3t powered 73RSR Replica (well, I'm keeping the engine but everything else is going )
Old 03-12-2006, 04:45 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)
Registered User
 
Ken911's Avatar
 
Join Date: May 2005
Location: Loxahatchee, florida
Posts: 2,708
I had the same problem I took the large washer off of the bolt in the end of the cam, then bottomed out the bolt in the hole, that allows you to put a wrench on the cam to hold it while adjusting the sprocket with the sprocket tool. then put in the pin. then rotate the crank a couple turns then recheck the dial indicator. when it's ok then place the sprocket tool back in the sprocket to hold the cam then remove the bolt replace the washer then torque it down. when you bottom the bolt out in the hole tighten it just tight enough to hold the cam to avoid damaging the threads. I didnt have to tighten it very tight. and both sides are set EXACTLY the same.
__________________
88 turbo Guards red Targa slant nose, and yes I am a horsepower junkie, 3.4liter,7.5 to 1 JE pistons, Adjustable WUR, Imagine fuel head, 1 bar waste gate headers,allthe cis toys. Now apart to become the next EFI monster. fabbing my own intake, headers Individual throttle bodies, MS-3, pauter rods, Xtreme twin plugged heads, gt-2 evo cams cop's.
05 Cayenne S lapis blue

Last edited by Ken911; 03-12-2006 at 07:03 AM..
Old 03-12-2006, 06:55 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #8 (permalink)
Registered User
 
Join Date: Jul 2002
Location: Canberra Australia
Posts: 440
Had the same issue. I chose to time from a degree wheel rather than from the overlap. It means that you do not have to hold or turn cams when the pressure is on them. Much easier but still a very fiddly job.

Will have the motor in next weekend so the proof of this it still to be realised.

Cheers

Mark....
Old 03-12-2006, 03:37 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #9 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 09:52 PM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.