Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Martin_1962 on 22 May 2009, 23:03:29

Title: Head removal - what position for crank?
Post by: Martin_1962 on 22 May 2009, 23:03:29
Cam belt is TDC, so what about when that belt is off?
Title: Re: Head removal - what position for crank?
Post by: VXL V6 on 22 May 2009, 23:15:59
Crank 30 degrees before TDC, pistons all in a safe position then.
Title: Re: Head removal - what position for crank?
Post by: Martin_1962 on 23 May 2009, 09:13:46
Quote
Crank 30 degrees before TDC, pistons all in a safe position then.


Thanks

WIll be starting just after a little shopping trip!
Title: Re: Head removal - what position for crank?
Post by: TheBoy on 23 May 2009, 10:37:23
Quote
Crank 30 degrees before TDC, pistons all in a safe position then.
Don't you mean 60 degrees BTDC :o
Title: Re: Head removal - what position for crank?
Post by: VXL V6 on 23 May 2009, 17:49:04
Quote
Quote
Crank 30 degrees before TDC, pistons all in a safe position then.
Don't you mean 60 degrees BTDC :o

Just double checked the 'Off with it's heads' thread:-

http://www.omegaowners.com/forum/YaBB.pl?num=1236287115
Title: Re: Head removal - what position for crank?
Post by: Martin_1962 on 23 May 2009, 20:46:23
Mine is about 45 BTDC as it was difficult to guess

Anyway looks OK on 135
Title: Re: Head removal - what position for crank?
Post by: Kevin Wood on 23 May 2009, 22:29:50
You have 6 cylinders, so 3 TDC points on each revolution of the crank. What is normally referred to as TDC when fitting cam belts is where no.1 and 4 are at TDC, but there will be another cylinder at TDC 120 degrees either side of this.

You need to be able to turn the crank to TDC on No. 1,4 with the valves set to that position, without bringing any other pots to TDC on the way, but you want all of the pistons out of the way when fitting heads and cams, hence the advice to be 30 or 60 degrees before TDC on No.1 & 4. In reality 90, 60, 30 degrees before are all fine. You just don't want to be any nearer than 30 degrees or  more than 90 degrees before in order to avoid any cylinders at  or near TDC.

Kevin