Which flywheel?
Discussion
I have 2 flywheels here.
The one i just pulled from the car is badly scored and needs a skim.
11kg = 24lb here..
The other is from a previous engine and is a little heavier at 12.38kg = over 27lb but has an undamaged face.
Which one would you use.
Shall i just have the lighter one skimmed and refit or use the heavier one.
Thoughts on the choice of light and heavy would be of interest too please.
The one i just pulled from the car is badly scored and needs a skim.
11kg = 24lb here..
The other is from a previous engine and is a little heavier at 12.38kg = over 27lb but has an undamaged face.
Which one would you use.
Shall i just have the lighter one skimmed and refit or use the heavier one.
Thoughts on the choice of light and heavy would be of interest too please.
Chilliman said:
Well googled Chilli 
That's the question (and answer) that matters.
The flywheel as fitted to 500 TVRs weighs about 19lb compared to 21 for a 400, which is a derivative of the Rover 2wd unit. There is a gotcha in that 500s were balanced as a built unit (ie with clutch, flywheel, crank and pulley all assembled). Balancing is contentious
taken from a post in 2009
taken from a post in 2009
db418BHP said:
Yeah, doesn't matter what you fit you're gonna break it you nutter 
db418BHP said:
Are the shafts the same size? I seem to remember being told TVR spec T5s had a larger dia than cossie but was ages ago so may be misremembering... Pupp said:
Are the shafts the same size? I seem to remember being told TVR spec T5s had a larger dia than cossie but was ages ago so may be misremembering...
That needs checking. Too easy for these sellers to just add TVR into the title to hit more searches. The outer diameter could be different also.With the noises mine has been making it would be nice to fit a roller bearing to eliminate that.
Ive had the same noises with 2 clutches now and altho wear on the old spigot seems minimal it might be enough to be the cause.
I got a lightened flywheel on an exchange basis from Rob Robertson when I fitted my Helix clutch.
Even after sending the old one back (sorry for the delay Rob) the whole exercise was just shy of £100.
What amazed me was the hernia inducing weight of the original, from memory it was almost 30 lbs!!!
That's what you got in a 4.0 litre, pretty much a Rover SD1 flywheel from what I could tell.
I believe Rob took a good 6-7 lbs out of it to take it closer to what TVR gave you in the 5.0 litre.
As we know, from 4.0 litres up the bore always remained the same in a Rover V8, to build the bigger engines TVR just stroked them.
My guess is TVR Power used the lighter flywheel in the 5.0 litre as an attempt to counter the inevitable lazy nature of a longer stroke configuration.
In theory the smaller stroke 4.0 litre should rev significantly better than the 5.0 litre, but sadly it's burdened with that 30lb millstone on the back of it, so you lose much of this advantage.
However, take a 5.0 litre flywheel or just machine a fat chunk of weight out of your original 4.0 litre millstone, & you instantly release the fun that's been hiding within
Well that was my experience, as soon as Rob's Weight Watchers flywheel went in my 4.0 litre it completely changed it's character, in a very good way.
Throttle response was instantly improved with no loss of drivability or ability to maintain speed as you face an incline.
Suddenly the car went from truck, to a proper sports car
A 30lb flywheel is probably ideal for a heavy four seater saloon car like a Rover SD1, but it really has no place in a 1060kg sports car.
The short stroke TVR 4.3 RV8 was famed for it's ability to rev, it was Peter Wheeler's favourite RV configuration.
And while I believe the heads saw extra work I'd put money on the 4.3 also having a much lighter flywheel.
If you own a 4.0 litre like me, you owe it to yourself to ditch that 30lb mill stone and get something a lot lighter in there.
If you need to replace the clutch a lightened flywheel is an absolute no-brainer.
It wont add horse power as such, but boy it will feel like you have.
You'll be bringing your 4.0 litre a significant step closer to the fabled 4.3 in one easy £100 step.
Like I say, it's a no-brainer, try it
I grantee your first drive on the lightened flywheel will have you grinning like a loon
I hope this helps some other owners of the baby 4.0 litre
Even after sending the old one back (sorry for the delay Rob) the whole exercise was just shy of £100.
What amazed me was the hernia inducing weight of the original, from memory it was almost 30 lbs!!!
That's what you got in a 4.0 litre, pretty much a Rover SD1 flywheel from what I could tell.
I believe Rob took a good 6-7 lbs out of it to take it closer to what TVR gave you in the 5.0 litre.
As we know, from 4.0 litres up the bore always remained the same in a Rover V8, to build the bigger engines TVR just stroked them.
My guess is TVR Power used the lighter flywheel in the 5.0 litre as an attempt to counter the inevitable lazy nature of a longer stroke configuration.
In theory the smaller stroke 4.0 litre should rev significantly better than the 5.0 litre, but sadly it's burdened with that 30lb millstone on the back of it, so you lose much of this advantage.
However, take a 5.0 litre flywheel or just machine a fat chunk of weight out of your original 4.0 litre millstone, & you instantly release the fun that's been hiding within
Well that was my experience, as soon as Rob's Weight Watchers flywheel went in my 4.0 litre it completely changed it's character, in a very good way.
Throttle response was instantly improved with no loss of drivability or ability to maintain speed as you face an incline.
Suddenly the car went from truck, to a proper sports car
A 30lb flywheel is probably ideal for a heavy four seater saloon car like a Rover SD1, but it really has no place in a 1060kg sports car.
The short stroke TVR 4.3 RV8 was famed for it's ability to rev, it was Peter Wheeler's favourite RV configuration.
And while I believe the heads saw extra work I'd put money on the 4.3 also having a much lighter flywheel.
If you own a 4.0 litre like me, you owe it to yourself to ditch that 30lb mill stone and get something a lot lighter in there.
If you need to replace the clutch a lightened flywheel is an absolute no-brainer.
It wont add horse power as such, but boy it will feel like you have.
You'll be bringing your 4.0 litre a significant step closer to the fabled 4.3 in one easy £100 step.
Like I say, it's a no-brainer, try it
I grantee your first drive on the lightened flywheel will have you grinning like a loon
I hope this helps some other owners of the baby 4.0 litre
But what are these actual weights?
My already lightened flywheel weighed 24.2 lb and is currently getting a reface and a bit more of the back. I will weigh it again when i pick it up.
The theory is that a kilo taken off the fly = the same effect as 40 kg off the weight of the car. This is from standstill and as you pick up speed and throught the gears the effect lessens.
All i care about is getting off the line as swiftly as possible on the dragstrip to keep me ahead of the big power NA guys. Ive managed it upto now but Phazed is very close. Big respect for his 12.5. Alex claims a 12.48 but we never did see the ticket
My already lightened flywheel weighed 24.2 lb and is currently getting a reface and a bit more of the back. I will weigh it again when i pick it up.
The theory is that a kilo taken off the fly = the same effect as 40 kg off the weight of the car. This is from standstill and as you pick up speed and throught the gears the effect lessens.
All i care about is getting off the line as swiftly as possible on the dragstrip to keep me ahead of the big power NA guys. Ive managed it upto now but Phazed is very close. Big respect for his 12.5. Alex claims a 12.48 but we never did see the ticket
Chilliman said:
The wait will soon be over......
I wish you all the best in your quest ChilliYou only need to run sub 12.5 to get my respect.
Under 12.41 will get you the fastest NA Chimaera record and
To run that 11 you predicted will take every bit of your 370bhp and some decent rubber on the rears. Maybe get your flywheel lightened to 10lb, may help
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