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Scott

Compression Figs for VR6

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Anyone know the book compression figs for a VR6 or has had good figures from their VR and know what they are....???

 

Obviously its more important that they are consistant but Im after a ball park figure.......

 

Cheers

 

Scott

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Im getting 10.5 bar on cylinder one......... others seem to be around 11.5 bar...

 

So thats about 155psi in cylinder one and about 165 psi in rest?

 

mmmmmmmmmmmmm :cry:

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You've got 147 and 161psi respectively. I would guess your car isn't idling well due to number 1 cylinder being down. That's odd as it's normall cyl no 6 that goes first on the VR.

 

Might just need a head job to reseal the valves. The exhaust valves on the VR are known to crack with age. Could be that, may not be, only one way to be sure! Your compressions are within tolerance though.

 

Kev

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Off with its head then :lol:

 

Surprised compression is low when I got 192bhp ??? - standard - no mods...... :?

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Don't take a compression test as gospel, it's just a rough indicator. Seek a second opinion. Oil tends to fill the gap between piston ring and bore anyway, so a traditional spark plug guage is not the most reliable way of telling.

 

If it's still producing 192bhp, I personally wouldn't worry about it too much.

 

Kev

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Yup 192bhp and 185lbft torque.... 8)

 

Cheers Kev - just need to sort this smoke problem out *:(

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Is it blue smoke you've got? Does it smell of burnt oil? If it only does it when you pull away after a lengthy idle or when booting after a period of over-run, it's just valve stems and seals as the cylinders are in a state of vacuum in those conditions and suck oil through the stems. If you've got oil smoke when accelerating....bore wear :(

 

You did say some time ago you've always had problems with number 1 spark plug being oil fouled and smelling rich etc, so I think it's a head job for you my man!

 

Very unusual that as Vince reckons number 6 is always the first cylinder to go!

 

Let us know how you get on with that. How many miles has the engine done?

 

Kev

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Engine has done 103k *:)

 

Well after a lengthy idle - I boot it and it smokes then clears.... when moving it only ever smokes on the over-run after booting like you say... even then not all the time...

 

So it looks like a valve stem seal job which to be honest I'm not worried about - will do the job myself as its pretty common on these engines to need valve stem seal jobs around the mileage I have.......

 

Any ideas how much to re-con a VR head?

 

Cheers Kev!

 

Scott

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Have a look here:- http://www.hiflowheads.co.uk

 

Very reasonably priced although I have no idea of their workmanship or reputation.

 

Most decent tuners charge around £800+VAT inc fitting for a good job, best to shop around. I can vouch for Stealth heads though. Graham there, an ex-Bentley engine builder apparently, builds all their engines and the workmanship is awesome.

 

If you have the tools to press in new guides, then there's no reason why you can't do it yourself but personally I'd have one done professionally with a 3 angle valve cut and perhaps fit it myself, saving around £300 in labour and VAT.

 

Cheers

Kev

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Cheers mate - am going to do the stripping / fitting myself to save on the labour plus never worked on a VR6 before so will be experience :D

 

I want to send the head to someone who knows what they doing - so will give Stealth a call and see how much they want and how long it would take although I have a superb engineering guy up here who only works for trade and would sort me out....

 

You reckon would be worth replacing tappets? - or can they be cleaned out on these engines? - Ive cleaned a few on a C20XE engine.....

 

Cheers

 

Scott

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Yeah you may aswell stick some new tappets in. I wouldn't have thought their is much you can do with worn ones.

 

Cheers

Kev

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