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Omega Help Area => Omega General Help => Topic started by: Ianb on 01 May 2010, 11:05:24

Title: Cam shaft timing
Post by: Ianb on 01 May 2010, 11:05:24

Morning all
Just completed head gasket replacement, but on start up a misfire (loud bangs) - obviously won't start. I thjink the timing is incorrect. I replaced the cam sprockets without moving the crank. That was with the notch at the 4pm position. However, the marks on the sprockets didn't align with marks on the rear cover. Could one of you kind souls confirm the correct positon of the notch on the crank, so that I can align the sprockets with the timing marks on the rear cover.  A little knowledge and all that . . .

Title: Re: Cam shaft timing
Post by: Andy B on 01 May 2010, 11:18:47

Quote

Morning all
Just completed head gasket replacement, but on start up a misfire (loud bangs) - obviously won't start. I thjink the timing is incorrect. I replaced the cam sprockets without moving the crank. That was with the notch at the 4pm position. However, the marks on the sprockets didn't align with marks on the rear cover. Could one of you kind souls confirm the correct positon of the notch on the crank, so that I can align the sprockets with the timing marks on the rear cover.  A little knowledge and all that . . .

did you use a locking kit  :-/

Title: Re: Cam shaft timing
Post by: TheBoy on 01 May 2010, 11:24:54

Quote

Quote

Morning all
Just completed head gasket replacement, but on start up a misfire (loud bangs) - obviously won't start. I thjink the timing is incorrect. I replaced the cam sprockets without moving the crank. That was with the notch at the 4pm position. However, the marks on the sprockets didn't align with marks on the rear cover. Could one of you kind souls confirm the correct positon of the notch on the crank, so that I can align the sprockets with the timing marks on the rear cover.  A little knowledge and all that . . .

did you use a locking kit  :-/

I think the op was asking how the cam spockets lock on. Inlet is 1, ex is 2 iirc on these.

If these are wrong, and its been turned over, budget on at least a few valves....

Title: Re: Cam shaft timing
Post by: Ianb on 01 May 2010, 12:12:02

Andy B
Didn't use locking kit. But was careful in not moving cams whilst tightening.  Need to start from scratch and retime. Does anyone have a guide?

Thanks

Title: Re: Cam shaft timing
Post by: Andy B on 01 May 2010, 12:18:09

Quote

Andy B
Didn't use locking kit. But was careful in not moving cams whilst tightening.  Need to start from scratch and retime. Does anyone have a guide?

Thanks

There are various guides here ..... http://www.omegaowners.com/forum/YaBB.pl?num=1259003779

Title: Re: Cam shaft timing
Post by: Ianb on 01 May 2010, 12:29:30

Just to clarify.  When the cam sprockets are lined up with the marks on the rear casing, where is the cutout on the crank positioned?  Is it at the top or at 4pm position?

Title: Re: Cam shaft timing
Post by: Welung666 on 01 May 2010, 12:31:08

Quote

Just to clarify.  When the cam sprockets are lined up with the marks on the rear casing, where is the cutout on the crank positioned?  Is it at the top or at 4pm position?

Cams are marked seperately for inlet and exhaust as TB has already said :y

Title: Re: Cam shaft timing
Post by: Ianb on 01 May 2010, 12:36:29

Wellung - The sprockets are on the correct camshafts, 1 inlet 2 exhaust etc.  What I wish to understand is at what position is the crank when the sprockets are lined up with the cutouts on the rear cover.  At the top or at the 4pm position (which is 60 deg BTDC) I am let to believe.  Cam shafts are on correctly with the dowels in the right positions, and the sprockets are in the correct psotion. It is just the position of the crank when the sprockets are lined up with the marks on the cover.
 

Title: Re: Cam shaft timing
Post by: Welung666 on 01 May 2010, 12:38:30

Quote

Wellung - The sprockets are on the correct camshafts, 1 inlet 2 exhaust etc.  What I wish to understand is at what position is the crank when the sprockets are lined up with the cutouts on the rear cover.  At the top or at the 4pm position (which is 60 deg BTDC) I am let to believe.  Cam shafts are on correctly with the dowels in the right positions, and the sprockets are in the correct psotion. It is just the position of the crank when the sprockets are lined up with the marks on the cover.
 

Spelling  ::) tut tut ;D

I highlighted the 4pm position in my last reply ;) The notch on the crank pulley lines up with the notch on the oil pump housing at the bottom for TDC. :y

Title: Re: Cam shaft timing
Post by: Ianb on 01 May 2010, 12:45:18

Sorry - spellchecker obviously not functioning!! Thanks for the info. Just to be absolutely sure - be patient!! - when the crank is at 4pm position camshaft sprockets should be aligned with the marks on the rear cover.  Is that correct?

Title: Re: Cam shaft timing
Post by: Welung666 on 01 May 2010, 13:04:25

Sorry, wasn't very clear :P The notch on the crank sprocket is at TDC when lined up to the cut-out in the oil pump housing below. 60 deg BTDC is the 4pm position.

EDIT: pictures on page 2C.9 in the Haynes book of lies for clarification :y

Title: Re: Cam shaft timing
Post by: Ianb on 01 May 2010, 13:12:21

Thanks.  That's clear now. rgds

Title: Re: Cam shaft timing
Post by: Ianb on 11 May 2010, 14:35:06

For anyone interested.  I reset the sprokets to align with the marks on the casing, but weas unable to find a locking kit.  To keep the sprockets in the correct position whilst fitting the cambelt, I locked them together with mole grips!!  Worked perfectly. Probably not recommended by the experts but happy to report that it worked, and the engine sounds sweet!!

Thanks to those who replied to my original posts.

Title: Re: Cam shaft timing
Post by: Andy B on 11 May 2010, 14:38:29

you can only set your cams & crank something like without a locking kit. It's possible to get cams 1 & 2 out of time with cams 3 & 4 and both out of timewith the crank. The way you have done it can only be regarded as best guess!  :y :y