Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: P6UL K on 05 October 2013, 20:25:55

Title: Air Intake/Plenum Length
Post by: P6UL K on 05 October 2013, 20:25:55
Did all V6 engine sizes (2.5, 3.0 & 3.2) across the FL range have the longer plenum?

Was it just the PFL & MFL that had the shorter length plenums?

Thanks  :y
Title: Re: Air Intake/Plenum Length
Post by: tunnie on 05 October 2013, 20:32:57
Facelift or not is irrelevant. It's the engines.  :y

2.5 all Short, Early 3.0s short, until mini facelift when it went long.

All 2.6/3.2s long
Title: Re: Air Intake/Plenum Length
Post by: joshwyatt on 05 October 2013, 20:33:44
All DBW V6's have the long plenum, as do later 3.0's in both MFL and FL. I don't know if the early 3.0's had short plenum's like the 2.5?

So in short, no all FL's didn't have long plenum's as the 2.5's always had short one's if fitted to PFL, MFL or FL.
Title: Re: Air Intake/Plenum Length
Post by: P6UL K on 05 October 2013, 20:37:00
Hi chaps.... I've just gained a headache  :D :-[

So in short (excuse the punn) Only cars - pretty much with DBW had the long plenums?
Title: Re: Air Intake/Plenum Length
Post by: joshwyatt on 05 October 2013, 20:39:43
I may have confused it with my overly long answer tbh, Tunnie's was better. All DBW's without exception are long plenum. Only later 3.0's are long. So, early 3.0's and all 2.5's are short.
Title: Re: Air Intake/Plenum Length
Post by: P6UL K on 05 October 2013, 20:47:40
I may have confused it with my overly long answer tbh, Tunnie's was better. All DBW's without exception are long plenum. Only later 3.0's are long. So, early 3.0's and all 2.5's are short.

Thanks both, I'm a simpleton at times so short answers work best  :D ;D

Josh, i don't suppose you have any background info on my Omega from when it was in service do you?
Title: Re: Air Intake/Plenum Length
Post by: joshwyatt on 05 October 2013, 22:14:29
I may have confused it with my overly long answer tbh, Tunnie's was better. All DBW's without exception are long plenum. Only later 3.0's are long. So, early 3.0's and all 2.5's are short.

Thanks both, I'm a simpleton at times so short answers work best  :D ;D

Josh, i don't suppose you have any background info on my Omega from when it was in service do you?

The reg is OY53 URM from memory? I'll find out if you want? Did you buy it direct?
Title: Re: Air Intake/Plenum Length
Post by: P6UL K on 06 October 2013, 00:05:53
I may have confused it with my overly long answer tbh, Tunnie's was better. All DBW's without exception are long plenum. Only later 3.0's are long. So, early 3.0's and all 2.5's are short.

Thanks both, I'm a simpleton at times so short answers work best  :D ;D

Josh, i don't suppose you have any background info on my Omega from when it was in service do you?

The reg is OY53 URM from memory? I'll find out if you want? Did you buy it direct?

That would be amazing - Thank you!!  :o 8) :y

Unfortunately no, i bought it from our dear friend 'Simon' lol

If you happen to come across any photos too I'd be forever grateful  ;) :D :)
Title: Re: Air Intake/Plenum Length
Post by: TheBoy on 06 October 2013, 09:20:06
To clarify:

All 2.5 - short
3.0 up to and including 1997 - short
All other V6 - long
Title: Re: Air Intake/Plenum Length
Post by: BazaJT on 06 October 2013, 13:02:40
As a point of interest[and because I'm a dummy]what was the reasoning behind the change of length?Or put another way what if anything does the longer length achieve over the short one?
Title: Re: Air Intake/Plenum Length
Post by: Andy H on 06 October 2013, 13:29:45
As a point of interest[and because I'm a dummy]what was the reasoning behind the change of length?Or put another way what if anything does the longer length achieve over the short one?
My assumption has always been that the longer inlet would resonate at a lower frequency but I am not confident that this applies here :-\ When the throttle is open the inlet tract carries on down to the bottom of the bagpipes (or halfway down if the valve is open). I can't see that moving where the transition from alloy inlet manifold to plastic bagpipes occurs makes much difference :-\

I haven't checked but I don't think there is space for the DBW throttle motor to clear the cambelt cover if it were fitted to a short inlet manifold. The 2.5 probably had the short inlet because it cost less to make.......
Title: Re: Air Intake/Plenum Length
Post by: TheBoy on 06 October 2013, 17:37:29
I believe the longer one was a better length for 3.0l, and DBW 2.6 had the longer one for the DBW rather tha optimal performance.
Title: Re: Air Intake/Plenum Length
Post by: 05omegav6 on 06 October 2013, 17:48:24
What effect would removing the flaps from the multirams have?