Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: toj28 on 14 January 2008, 20:46:46

Title: 2.5 heads on a 3 ltr
Post by: toj28 on 14 January 2008, 20:46:46
can i put 2.5v6 heads on to a 3ltr omega and can someone tell me the diffrence thanks ;)
Title: Re: 2.5 heads on a 3 ltr
Post by: Dazzler on 14 January 2008, 21:14:04
You probably can but you will lose alot of power, approx 30bhp... :o
Title: Re: 2.5 heads on a 3 ltr
Post by: MutantCav on 14 January 2008, 21:30:36
Why would you want to? You can but there may be compression issues...you will lose power as a result of the cams being 1mm different in size (about 20bhp), I think the block is the cubic capacity bit so you wont lose all your power?? Or is that the heads too???
Title: Re: 2.5 heads on a 3 ltr
Post by: Marks DTM Calib on 14 January 2008, 21:34:54
It ups the compression ratio into the 11's......so not advisable!
Title: Re: 2.5 heads on a 3 ltr
Post by: markey mark on 14 January 2008, 21:50:43
i have heard its a power upgrade putting 2.5 heads on 3.0 !! carnt understand why the 3.0 heads have 1mm bigger valves and sodium filled exhaust valves !! :-?
Title: Re: 2.5 heads on a 3 ltr
Post by: Marks DTM Calib on 14 January 2008, 21:52:55
The valves are the same size.....the cams have slightly higher lift (but could be swapped) and the exhaust valves are sodium filled to give better thermal properties.

As for a performance upgrade, its fine if you are going to use high octane fuel all the time.
Title: Re: 2.5 heads on a 3 ltr
Post by: Essex_Andy on 14 January 2008, 22:43:52
I have no proof but have read on here that 2.5 heads fitted with 3.0 cams offer a sizeable performance gain when fitted to 3.0 engines.
Something about increased compression ratio? ? ? ? ?
Title: Re: 2.5 heads on a 3 ltr
Post by: toj28 on 14 January 2008, 23:11:15
it does increase the compression and ive been advised not to go a head as it woint run right and will most likely blow gaskets so i woint bother
Title: Re: 2.5 heads on a 3 ltr
Post by: MutantCav on 15 January 2008, 08:52:30
Thinking about it, my mutant cavalier had a 3.0 v6 omega engine with 2.5 top end fitted and messed about with by Courtney, reportedly produced 270bhp although that couldnt be verified as the clutch couldnt cope with the power and slipped all the time I had it...@I guess with the 3.0 block capacity and the 3.0 cams there would be no real loss in power from the 2.5 heads, and increased compression could add power IF done correctly so the compression didnt blow the gaskets...also remapping the ECU may help.