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[rickmv6]

hi i have had a problem with the cylinder heads on my mv6 3.0 the engine place  has said my heads are beyond repair so they have gave me a recon set where  i will use my existing cams.  problem is just noticed the heads have 2.5  etched into the side of each head.  does anybody know if these will still work.

[rickmv6]

according to haynes manual valves are same size for both engines its the cams which have a different height. but i will be using the 3 litre cams any way.  just not sure if i will loose power.

[geoffr70]

A popular mod seems to be to replace 2.5 cams with 3.0 litre cams for a power increase. So it would obviously be a de-mod to go from 3.0 cams to 2.5 cams. But as you're keeping you 3.0 cams that won't be a problem.

What did the garage say is wrong with your heads? What is wrong with the heads?

[aaronjb]

I thought the 2.5 & 3.0 had different sized pistons and, thus, different size squish areas in the heads? (Which I'd think would create potential problems)

[rickmv6]

the heads where down on compression so took heads off. the outer half ring where water curculates was all blocked up when i cleaned them there was a big chunk of alloy that broke away. he said 2 much alloy would need to be welded in and he couldnt guarantee the work. so he got me these ones saying they where for the 3.0 litre

[feeutfo]

There was a member at Newent with 2.5 heads on a 3.0, so it will physically fit. Can't tell you the power output but I would not do it myself. It was frowned upon by those present as I recall. Probably due to reasons given above.

[albitz]

If he told you they were 3.0 heads and you have discovered for yourself that they are 2.5 heads, I would take that as a sign that he is incompetent/ dishonest, or both, and would take the car somewhere else.

[fiend61]

If he told you they were 3.0 heads and you have discovered for yourself that they are 2.5 heads, I would take that as a sign that he is incompetent/ dishonest, or both, and would take the car somewhere else. 

i wouldnt go elsewhere, i would be straight back to the garage to demand that he puts 3.0l heads on 

[rickmv6]

heads are not on engine yet they are still sitting in the kitchen  didnt want to fit them and find out it goes bang
.

[TheBoy]

I'd stick to 3.0l heads.  Given the hassle and expense of fitting them, may as well put the proper ones on.

The 3.0l also has sodium filled valves (exhaust only?)

[MutantCav]

Well I have a pair of 3 ltr heads here mate, still on the car which runs perfectly...I would take the 2.5 heads back to the garage point out they are clearly not what you paid for and get your money back...

[rickmv6]

Is their anyway of checking weather thay have been labled the heads up wrong. one head had has code 90412231 and the other head has code 90412232. Not sure what this bloke has done with my original heads. thanks mate for the offer will speak to the garage and let you know.

[sassanach]

if i recall correctly, the 2.5 heads will raise the compression ratio to unacceptable levels.if you are convinced they are 2.5 heads then do not fit!!!

[sassanach]

just checked some 2.5 heads i have here, the numbers you have are for 2.5 heads, take them back!!

[rickmv6]

thanks for the help everyone will phone the garage tomorrow and see about a refund and thanks pete have sent you a reply. thanks all. rick.