Pulley goes wibble wobble CRACK !

[Crayden]

Went for a short spin with Mrs. Crayden yesterday to the shopsand noticed some vibration at around 2k!
Had a look this morning and found that the front pulley on the crank was resonating.
I removed all the drive belts and found that I could rock the pulley up, down, and back and forth. Most odd (scratches head !)
So I jacked up the car and removed the pulley (easily said but a bugger to do) - it was cracked in two places and the woodruff key had also sheared!!
How the f**k can that happen ? So, I am off to Austechs tomorrow to see if we can cobble a new one!
Don't you just love the way TVRs keep you entertained.

P.S Any one know what the torque should be for the end bolt? Not half an inch/ounce as mine was!!

[k77-widow maker]

IMHO....it's FT

One for DustyC to work out!!!

[Crayden]

You lost me!

[mrmaggit]

Crayden said:

You lost me!

Either finger tight or f***ing tight. Boom or Bust!

[siwes]

slow down
you need to put a balanced new pulley on the car, obtained from TVR power .
If you are replacing the bottom pulley then fit a new high tensile bolt as the old ones can and do snap. the pullys are not that expensive and yes it happens quite a lot . were you giving it some licks?
good luck
simon

[Trefor]

You're lucky it didn't actually come undone completely while driving. I don't think it failing would have broken anything itself, but the resulting pulley debris and panic in the passenger cabin might have.

[Crayden]

A good point!
Fortunately, it may be possible to balance it at work as we build pumps that can run up to 25K RPM and have a state of the art balancing machine.
I have asked Austechs to supply a new end bolt and an oil seal.
It could have been quite catastrophic as the water pump drive would have failed which could have caused an engine meltdown, as well as damage to the crank, sump ECT as it rattled under the car.
I would also have pity on any poor car following me as it jettisoned !!!

[siwes]

Mine did break loose under power horrible bloody noise from the engine bay. Had to have the broken piece of bolt spark removed from the crank , I did drive the two miles home without any fan belt keeping a careful eye on the overheating engine. the tickover by the way climbs to around 1500 rpm without the pulley train
regards

[griffter]

Crayden said:

A good point! Fortunately, it may be possible to balance it at work as we build pumps that can run up to 25K RPM and have a state of the art balancing machine. I have asked Austechs to supply a new end bolt and an oil seal.

I think TVR balance the pulley to the engine - ie it's not balanced stand alone. The idea behind this is to 'balance' the engine. So just balancing the pulley may mean you end up with increased engine vibration. I think, as siwes says, it's a TVR job.

[DustyC]

griffter said:

I think TVR balance the pulley to the engine - ie it's not balanced stand alone. The idea behind this is to 'balance' the engine. So just balancing the pulley may mean you end up with increased engine vibration. I think, as siwes says, it's a TVR job.

Just read the thread and was going to say the same myself. Call round a few dealers and see what they say.

[siwes]

The pulley comes as a stand alone dynamically balanced item, so no trouble there, you can fit it yourself
if you have the new bolt!!
simon

[Mark Adams]

All TVR 5.0 Litre engines are balanced with their pulleys and flywheels, and they are an integral part of the overall balance when the engine leaves TVR (unless it is a Taraka upgrade).

If the engine is original, then it must have the correct pulley. Fortunatley those nice chaps at TVR Power (Dom, Jamie and co) keep records of each engine and can supply a replacement pulley.

Do NOT put on a neutrally balanced pulley, otherwise you risk breaking the crankshaft.

[Mark Adams]

I've just read my own post - and it sounds a bit crusty! Sorry if it comes over that way.

SiWes has given you the correct info...

[Crayden]

Thanks for ALL the advice

So please correct me if wrong the bottom line I can fit a new pulley provided

(A) The new one is balanced
(B) New H/T end bolt
(C) New nylock nuts
(D) New oil seal
(E new key

I was going to have the pulleys balance as an assembly checked at work anyway as I have had issues with supposed balanced items being well out of spec .

I have seen a “Competition harmonic damper for Rover V8 engines" on J.E.Developments
Any advantage on my Pre-serpentine over the standard cast iron hub?

Its running alternator, water pump and A/C pump (three belts)