500 - stress and reliability
Discussion
Dont forget that the 5.0 is almost at the limit of the bore size that you can get away with. They will use more oil and generate more heat - hence the potential decreased reliabilty.
My take on this would be that you need to be a little more vigilant with a 5.0 - it will use oil and water and you need to keep on top of this. If you do then there is no reason why it will be any less reliable than a 4.0 or 4.5....
Cheers,
Paul
My take on this would be that you need to be a little more vigilant with a 5.0 - it will use oil and water and you need to keep on top of this. If you do then there is no reason why it will be any less reliable than a 4.0 or 4.5....
Cheers,
Paul
quote:
Dont forget that the 5.0 is almost at the limit of the bore size that you can get away with. They will use more oil and generate more heat - hence the potential decreased reliabilty.
My take on this would be that you need to be a little more vigilant with a 5.0 - it will use oil and water and you need to keep on top of this. If you do then there is no reason why it will be any less reliable than a 4.0 or 4.5....
Cheers,
Paul
Surely the recent '450' and '500' Griff and Chimaera engines were all based on the later Rover 4.6 block anyway, the 500s just being stroked to get the extra capacity. (In contrast, the earlier non-cross-bolted 450s used in Wedges and so on were based on a 3.9 block and I wouldn't be at all surprised if these *were* bored out.) There are probably other significant differences between the 450 and 500 such as piston rings, cam, valve sizes and spring rates and so on that could affect durability quite significantly though.
As I understand it the 4.0 is basically the 3.9 or 4.0 litre Range Rover Engine and all the 4.3, 4.5 and 5.0 versions of TVR Rover Engines are drived from this. The 4.6 is a much stronger later block and crank, and I also believe - check your manuals that they are ALL the same bore (the are not as a rule bored to get the cc's) but all engines over 4.0 have different through cranks, the 5.0 being the longest and there for best for torque and the worst (per cc for BHP - it has more but not as much more as you would expect - but alot of torque). Change up in a 500 at 5.5 and thats about as fast as they go - fairly quick (at the top end - but not great - but excellent at the bootom end).
quote:
Change up in a 500 at 5.5 and thats about as fast as they go - fairly quick (at the top end - but not great - but excellent at the bootom end).
Sir My Griff 500 demands satisfaction as this is both an insult to my car and others.
Crankshafts at Dawn.
My peak power is at 6050. I see no reason why I should change up early.
Joking aside, I have found in my experience, it is the smaller 4.x cars that tend to run out of puff while the 5 litre is still pulling. With the "go faster by changing at these revs" analysis based on the power curves I have got and a 5500 change up is considerably slower. Change when I get blinded by the hi intensity change lights.
Steve
www.tvrbooks.co.uk
quote:
Surely the recent '450' and '500' Griff and Chimaera engines were all based on the later Rover 4.6 block anyway, the 500s just being stroked to get the extra capacity. (In contrast, the earlier non-cross-bolted 450s used in Wedges and so on were based on a 3.9 block and I wouldn't be at all surprised if these *were* bored out.) There are probably other significant differences between the 450 and 500 such as piston rings, cam, valve sizes and spring rates and so on that could affect durability quite significantly though.
Not sure about the full technical details - but it is my understanding that the 500 engines are getting close to the edge on tolerances for the standard components. Rather than go the full hog with real specialist pistons and rings the tolerances are quite a bit bigger than that of the 4.0 and 4.5. I am not sure if I am making myself understood here
... sorry if it doesnt make sense.... But ask a couple of 500 owners and they talk of oil usage. Talk to 400 owners and they talk of very little - with the notable exception of some who get the same oil usage. But almost all 500 owners report some oil usage in some form or another - the tolerances are a little larger and hence some oil loss....
Just re-read that message - what utter bollox I can type sometimes! Doesnt make sense and cant be bothered to re-type it. Sorry. In the vain attempt that it does make sense then great - if not then oh well...
Cheers,
Paul - back hurts and want to go home - its funny how pain distracts the brain!!!
1. Tower View are probably still in shock with what they found in my Griff 500 caused by no preload set on the cam when it was changed in a previous existence.
2. Oil consumption is caused by the use of slippy rings to reduce friction on the 500. Well known ploy used by TVR on the big enegine Wedges that have attracious oil consumption in some cases.
3. I don't thing the 500 is any worse. There are more of them and they probably have been used more than the 450 so you see more problems.
4. The 500 does develop more power and therefore there is probably a bit more strain but non-sympathetic driving in a 450 is probably a lot worse anyway.
5. Accept no substitute for cubic inches...
Steve
www.tvrbooks.co.uk
2. Oil consumption is caused by the use of slippy rings to reduce friction on the 500. Well known ploy used by TVR on the big enegine Wedges that have attracious oil consumption in some cases.
3. I don't thing the 500 is any worse. There are more of them and they probably have been used more than the 450 so you see more problems.
4. The 500 does develop more power and therefore there is probably a bit more strain but non-sympathetic driving in a 450 is probably a lot worse anyway.
5. Accept no substitute for cubic inches...
Steve
www.tvrbooks.co.uk
The Configuration of the 4.0L makes it the best and safest for revving, of course the fuel map runs out at 5500 rpm so they don't so much run out of puff as run out of fuel, we chipped a bog standard non gas flowed 4.0L and it revved to 6000 very easily, The 500's have big valve heads with very large porting which work very well with hotter cams, with such they will rev well beyond 6500 but with the standard TVR bottom end not advisable,
The 4.6 as in the Chimaera won't rev so freely as it has a almost standard inlet system, maybe this helps to preserve them, as well as a more sensible stroke.
Tim
The 4.6 as in the Chimaera won't rev so freely as it has a almost standard inlet system, maybe this helps to preserve them, as well as a more sensible stroke.
Tim
quote:
As I understand it the 4.0 is basically the 3.9 or 4.0 litre Range Rover Engine and all the 4.3, 4.5 and 5.0 versions of TVR Rover Engines are drived from this. The 4.6 is a much stronger later block and crank, and I also believe - check your manuals that they are ALL the same bore (the are not as a rule bored to get the cc's) but all engines over 4.0 have different through cranks, the 5.0 being the longest and there for best for torque and the worst (per cc for BHP - it has more but not as much more as you would expect - but alot of torque). Change up in a 500 at 5.5 and thats about as fast as they go - fairly quick (at the top end - but not great - but excellent at the bootom end).
So I could put a 5 Litre crank in my 4.6 and have 5 Litre performance without boring out the cylinders?(obviously, big valve heads and injection and airflow modifications would need to be made but...)
AND don't forget the brakes, suspension etc.
But how much would it cost to stick a 5 Litre crank in a 4.6 if it can be done?
Not definitive proof, but when I was chatting to Ben Samuelson at this years back home, he mentioned that the factory had a 5L Chim' that did 130K. In addition, I feel that my 5L Chim is running better now at 38K than it did when I bought it (24K). If you look after it, then there's no reason to expect that a 5L won't last.
Just my two cents,
Steve.
Just my two cents,
Steve.
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So I could put a 5 Litre crank in my 4.6 and have 5 Litre performance without boring out the cylinders?(obviously, big valve heads and injection and airflow modifications would need to be made but...)
AND don't forget the brakes, suspension etc.
But how much would it cost to stick a 5 Litre crank in a 4.6 if it can be done?
Not that simple, to my knowledge TVR modify the pistons and block (as they retain standard bore)so that the con-rods don't hit , other engine builders however use a larger bore than TVR for the 5.OL
Tim
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quote:
So I could put a 5 Litre crank in my 4.6 and have 5 Litre performance without boring out the cylinders?(obviously, big valve heads and injection and airflow modifications would need to be made but...)
AND don't forget the brakes, suspension etc.
But how much would it cost to stick a 5 Litre crank in a 4.6 if it can be done?
Not that simple, to my knowledge TVR modify the pistons and block (as they retain standard bore)so that the con-rods don't hit , other engine builders however use a larger bore than TVR for the 5.OL
Tim
this must surely be a money issue then? .. since unless you use a longer conrod and move the gudgeon pin up the piston (bringing it's own problems) longer stroke means greater rod angularity, greater side thrust and greater frictional losses..and a lower rev limit. Presumably they keep the same pistons across the larger engines for economy of scale when purchasing ...? strange.
this must surely be a money issue then? .. since unless you use a longer conrod and move the gudgeon pin up the piston (bringing it's own problems) longer stroke means greater rod angularity, greater side thrust and greater frictional losses..and a lower rev limit. Presumably they keep the same pistons across the larger engines for economy of scale when purchasing ...? strange.
It was Al Mellings idea, There has to be more friction and wear, I had a Nash 5.0L, which has the larger bore, it produce a good 25 bhp more than the Griff with the same cam but the engine would cost £12,000.
Tim
Thank you for your replies. I should have expected the 'go for more power and sod the reliability' stance 
My Cerbie (RIP) certainly fell into that category. I strongly agree that a little TLC goes a long way to keeping tivvers on the road and out of the garage. 130k miles on a TVR must be some kind of record?
My Cerbie (RIP) certainly fell into that category. I strongly agree that a little TLC goes a long way to keeping tivvers on the road and out of the garage. 130k miles on a TVR must be some kind of record? shpub - yours is a long way from a std 500 so may make more power at 6 that 5.5 / 5.6k - all figures and from the feel of the thing show that the power a pusg in the back drop dramatically after these speeds. Longer the crank though the less it is gonna like being rev'd.
Nitros may be an option!
Have you had a new paint job on the 520 yet?
Nitros may be an option!
Have you had a new paint job on the 520 yet?
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