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Chat Area => General Discussion Area => Topic started by: JamesV6CDX on 10 August 2008, 20:37:05

Title: Valve timing and fuel economy
Post by: JamesV6CDX on 10 August 2008, 20:37:05
Currently economy is low.

Checked cambelt setup, cams 1 and 2 were about half a tooth too retarded, and cams 1 and 4 a couple of mm too advanced.

Likely to make a difference, or not? Some say a lot, some say none - what's your opinion?
Title: Re: Valve timing and fuel economy
Post by: Lazydocker on 10 August 2008, 20:39:56
I reckon you'll notice a difference... You'll be able to drive far more smoothly with the timing spot on  :y :y :y
Title: Re: Valve timing and fuel economy
Post by: tunnie on 10 August 2008, 20:40:22
half a tooth? hardly make a differnce really. other factors affect mpg, tyre pressure, breathers, oil changes and so on...

can't see 1/2 tooth making a difference.  :-/
Title: Re: Valve timing and fuel economy
Post by: STMO123 on 10 August 2008, 20:41:32
Economy not too good? On a 3 litre V6? Noooooo....... ;D
Title: Re: Valve timing and fuel economy
Post by: JamesV6CDX on 10 August 2008, 20:42:03
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half a tooth? hardly make a differnce really. other factors affect mpg, tyre pressure, breathers, oil changes and so on...

can't see 1/2 tooth making a difference.  :-/

In which case - why isn't it OK to setup valve timing without the kit ;)

(You can easily get it within half a tooth by eye, but many would say that's a no no!)
Title: Re: Valve timing and fuel economy
Post by: JamesV6CDX on 10 August 2008, 20:42:35
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Economy not too good? On a 3 litre V6? Noooooo....... ;D

Lol you silly old man, I am comparing with other 3.0 V6's I have owned :P
Title: Re: Valve timing and fuel economy
Post by: Taxi_Driver on 10 August 2008, 20:42:59
Me thinks it maybe to do with James has a 3L.......and he's having fun with the 'loud' pedal  :y :D
Title: Re: Valve timing and fuel economy
Post by: markey mark on 10 August 2008, 20:43:04
the timing is more for perfornance james and will help economy if it is spot on bud ! :y
Title: Re: Valve timing and fuel economy
Post by: STMO123 on 10 August 2008, 20:43:27
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Economy not too good? On a 3 litre V6? Noooooo....... ;D

Lol you silly old man, I am comparing with other 3.0 V6's I have owned :P


So you're getting 18mpg instead of 19? ;D ;D ;D
Title: Re: Valve timing and fuel economy
Post by: JamesV6CDX on 10 August 2008, 20:43:44
Also tunnie - I'd have thought cambelt setup being correct would have had a lot more impact on efficiency than changing the oil...  :-/
Title: Re: Valve timing and fuel economy
Post by: JamesV6CDX on 10 August 2008, 20:44:29
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Me thinks it maybe to do with James has a 3L.......and he's having fun with the 'loud' pedal  :y :D

Steady 70mph run give 25 mpg - we all know they will do over 30 in these conditions..  so something is amiss.
Title: Re: Valve timing and fuel economy
Post by: TheBoy on 10 August 2008, 20:45:05
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Currently economy is low.

Checked cambelt setup, cams 1 and 2 were about half a tooth too retarded, and cams 1 and 4 a couple of mm too advanced.

Likely to make a difference, or not? Some say a lot, some say none - what's your opinion?
That doesn't make sense.
Title: Re: Valve timing and fuel economy
Post by: STMO123 on 10 August 2008, 20:45:06
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Also tunnie - I'd have thought cambelt setup being correct would have had a lot more impact on efficiency than changing the oil...  :-/

I remember when Tunnie and James didn't know their borehole from their a***hole ;D ;D ;D
Title: Re: Valve timing and fuel economy
Post by: JamesV6CDX on 10 August 2008, 20:46:02
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Currently economy is low.

Checked cambelt setup, cams 1 and 2 were about half a tooth too retarded, and cams 1 and 4 a couple of mm too advanced.

Likely to make a difference, or not? Some say a lot, some say none - what's your opinion?
That doesn't make sense.

What doesn't? I thought it was quite a clear question?  ::)
Title: Re: Valve timing and fuel economy
Post by: TheBoy on 10 August 2008, 20:46:39
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Also tunnie - I'd have thought cambelt setup being correct would have had a lot more impact on efficiency than changing the oil...  :-/
Both can affect running, and both are part of the standard service schedule.
Title: Re: Valve timing and fuel economy
Post by: tunnie on 10 August 2008, 20:47:08
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Also tunnie - I'd have thought cambelt setup being correct would have had a lot more impact on efficiency than changing the oil...  :-/

i mean regular changes to keep the breathers clean.

I think cam timming is more for performance than mpg? Will help, but not that much.

Air leaks? dud sensor readings someware, under inflated tyres?

Sometimes just a few psi makes a big difference.
Title: Re: Valve timing and fuel economy
Post by: Taxi_Driver on 10 August 2008, 20:49:48
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Currently economy is low.

Checked cambelt setup, cams 1 and 2 were about half a tooth too retarded, and cams 1 and 4 a couple of mm too advanced.

Likely to make a difference, or not? Some say a lot, some say none - what's your opinion?
That doesn't make sense.

didnt to me either.....but

I read that as 1 and 2 too retarded 3 and 4 too advanced  :-/
Title: Re: Valve timing and fuel economy
Post by: TheBoy on 10 August 2008, 20:50:08
JamesV6CDX - before ripping engines apart, do the std service - fuel filters, ait filters, oil, breathers and so on.
Title: Re: Valve timing and fuel economy
Post by: Lazydocker on 10 August 2008, 20:52:02
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JamesV6CDX - before ripping engines apart, do the std service - fuel filters, ait filters, oil, breathers and so on.

And that's you told  :D :D :D :D

I agree... The standard service may well (and probably will) return the results you want :y :y :y :y
Title: Re: Valve timing and fuel economy
Post by: Kevin Wood on 10 August 2008, 20:59:52
Do the works, too. Run some injector cleaner through it because if the injector spray patterns are rubbish or the flow rates are all over the place that won't help. Change all the filters, clean the breathers, check for air leaks and make sure the multirams are behaving - you know the drill. :y

Cam timing will have an effect but I think what you're seeing is the result of neglect in every area - so make sure it's all tip top.

Kevin
Title: Re: Valve timing and fuel economy
Post by: JamesV6CDX on 10 August 2008, 21:00:39
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JamesV6CDX - before ripping engines apart, do the std service - fuel filters, ait filters, oil, breathers and so on.

All in the plan - in fact, is what I was doing tonight :y
Title: Re: Valve timing and fuel economy
Post by: TheBoy on 10 August 2008, 21:03:51
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JamesV6CDX - before ripping engines apart, do the std service - fuel filters, ait filters, oil, breathers and so on.

All in the plan - in fact, is what I was doing tonight :y
So stop moaning about economy until those basic steps have been done ;D
Title: Re: Valve timing and fuel economy
Post by: TheBoy on 10 August 2008, 21:04:23
Oh, and use genuine GM air filters, not come across a pattern one as good yet
Title: Re: Valve timing and fuel economy
Post by: JamesV6CDX on 10 August 2008, 21:06:34
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JamesV6CDX - before ripping engines apart, do the std service - fuel filters, ait filters, oil, breathers and so on.

All in the plan - in fact, is what I was doing tonight :y
So stop moaning about economy until those basic steps have been done ;D

Not moaning - but I see that having the valve timing right IS a crutial step towards getting it spot on, don't you agree? ::)
Title: Re: Valve timing and fuel economy
Post by: TheBoy on 10 August 2008, 21:09:13
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JamesV6CDX - before ripping engines apart, do the std service - fuel filters, ait filters, oil, breathers and so on.

All in the plan - in fact, is what I was doing tonight :y
So stop moaning about economy until those basic steps have been done ;D

Not moaning - but I see that having the valve timing right IS a crutial step towards getting it spot on, don't you agree? ::)
As is doing the basics.
Title: Re: Valve timing and fuel economy
Post by: JamesV6CDX on 10 August 2008, 21:21:04
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JamesV6CDX - before ripping engines apart, do the std service - fuel filters, ait filters, oil, breathers and so on.

All in the plan - in fact, is what I was doing tonight :y
So stop moaning about economy until those basic steps have been done ;D

Not moaning - but I see that having the valve timing right IS a crutial step towards getting it spot on, don't you agree? ::)
As is doing the basics.

Not disputing the basics make a difference -

But for the purpose of the question assume that is done, but the two cams are still slightly out.

Will half a tooth out make a noticable difference to either performance or economy,  in your experience, yes or no ;)
Title: Re: Valve timing and fuel economy
Post by: TheBoy on 10 August 2008, 21:25:35
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JamesV6CDX - before ripping engines apart, do the std service - fuel filters, ait filters, oil, breathers and so on.

All in the plan - in fact, is what I was doing tonight :y
So stop moaning about economy until those basic steps have been done ;D

Not moaning - but I see that having the valve timing right IS a crutial step towards getting it spot on, don't you agree? ::)
As is doing the basics.

Not disputing the basics make a difference -

But for the purpose of the question assume that is done, but the two cams are still slightly out.

Will half a tooth out make a noticable difference to either performance or economy,  in your experience, yes or no ;)
Slight difference, yes, but not enough to account for your economy.
Title: Re: Valve timing and fuel economy
Post by: JamesV6CDX on 10 August 2008, 21:26:42
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JamesV6CDX - before ripping engines apart, do the std service - fuel filters, ait filters, oil, breathers and so on.

All in the plan - in fact, is what I was doing tonight :y
So stop moaning about economy until those basic steps have been done ;D

Not moaning - but I see that having the valve timing right IS a crutial step towards getting it spot on, don't you agree? ::)
As is doing the basics.

Not disputing the basics make a difference -

But for the purpose of the question assume that is done, but the two cams are still slightly out.

Will half a tooth out make a noticable difference to either performance or economy,  in your experience, yes or no ;)
Slight difference, yes, but not enough to account for your economy.

Thanks :D

In which case, once that's done, COMBINED with a full service, it should be somewhere towards better :)
Title: Re: Valve timing and fuel economy
Post by: tunnie on 10 August 2008, 21:28:18
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JamesV6CDX - before ripping engines apart, do the std service - fuel filters, ait filters, oil, breathers and so on.

All in the plan - in fact, is what I was doing tonight :y
So stop moaning about economy until those basic steps have been done ;D

Not moaning - but I see that having the valve timing right IS a crutial step towards getting it spot on, don't you agree? ::)
As is doing the basics.

Not disputing the basics make a difference -

But for the purpose of the question assume that is done, but the two cams are still slightly out.

Will half a tooth out make a noticable difference to either performance or economy,  in your experience, yes or no ;)
Slight difference, yes, but not enough to account for your economy.

Thanks :D

In which case, once that's done, COMBINED with a full service, it should be somewhere towards better :)

Mixed 50 mile run, some sections in 3 figures, i averaged 27.6 in mother tunnies estate.
Title: Re: Valve timing and fuel economy
Post by: TheBoy on 10 August 2008, 21:38:00
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JamesV6CDX - before ripping engines apart, do the std service - fuel filters, ait filters, oil, breathers and so on.

All in the plan - in fact, is what I was doing tonight :y
So stop moaning about economy until those basic steps have been done ;D

Not moaning - but I see that having the valve timing right IS a crutial step towards getting it spot on, don't you agree? ::)
As is doing the basics.

Not disputing the basics make a difference -

But for the purpose of the question assume that is done, but the two cams are still slightly out.

Will half a tooth out make a noticable difference to either performance or economy,  in your experience, yes or no ;)
Slight difference, yes, but not enough to account for your economy.

Thanks :D

In which case, once that's done, COMBINED with a full service, it should be somewhere towards better :)
I would have done it the other way round - a known good service that then gives you a baseline to start from.
Title: Re: Valve timing and fuel economy
Post by: JamesV6CDX on 10 August 2008, 21:40:51
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JamesV6CDX - before ripping engines apart, do the std service - fuel filters, ait filters, oil, breathers and so on.

All in the plan - in fact, is what I was doing tonight :y
So stop moaning about economy until those basic steps have been done ;D

Not moaning - but I see that having the valve timing right IS a crutial step towards getting it spot on, don't you agree? ::)
As is doing the basics.

Not disputing the basics make a difference -

But for the purpose of the question assume that is done, but the two cams are still slightly out.

Will half a tooth out make a noticable difference to either performance or economy,  in your experience, yes or no ;)
Slight difference, yes, but not enough to account for your economy.

Thanks :D

In which case, once that's done, COMBINED with a full service, it should be somewhere towards better :)
I would have done it the other way round - a known good service that then gives you a baseline to start from.

I agree, but poor economy aside, I had a bigger concern, about no cambelt history.

I'm sure you'll agree that any Omega purchase with no cambelt history needs a kit put on there as a priority :y

And under the circumstances, it's a blessing I'm not driving it, given the state of the cambelt kit ;D
Title: Re: Valve timing and fuel economy
Post by: cem_devecioglu on 10 August 2008, 21:57:05
Omega ECU gives response to how you drive..if few hours you drive in sporty style ECU increases the fuel..This is my experience if I'm not wrong..

ps: assuming other engine parameters in good condition..


one thing to add , even a very small leak on exhaust line can effect

consumption
Title: Re: Valve timing and fuel economy
Post by: theowletman on 10 August 2008, 22:27:18
Always best to have all settings correct, as they say in Tesco, every little helps.