Some questions?

[johnny250]

I'm about to remove the radiator and engine pulley to fit a toothed sensor wheel for the distributorless ignition set-up.....

Q1: whilst it's all out I was considering fitting an electric fan too..... can I just remove original plastic fan and extension piece? (change bolt)...I have heard of potential problems with a 4 cyl. engine but 6 OK?

Q2: Why does the front engine pulley have a rubber damped outer section?.....just driving the water pump and alternator and does it have to?

Q3: I seem to remember seeing somewhere a timing mark 'strip' that can be printed out and attached to the pulley for checking/adjusting ignition timing...or am I dreaming?

 

thanks in advance as usual

 

john

[Tom Fremont]

Hi John,

 

Re: Q2 - the pulley incorporates a harmonic balancer, or damper, to absorb vibrations which would otherwise resonate destructively. Probably less necessary than on the 4-cyls, but certainly a plus. Most TR 6-cyls I've seen use originals, a testament to their durability since they've been out of production for a long time. New ones are available from MOSS in the 'States at least, although they're not balanced nor do they have timing marks.

 

I am the proud owner of (2) of the MOSS type, since balanced and marked, but never used since I subsequently found a NOS pulley on ebay and my driver's car has one of the last new originals from the sometime in the last century

[Andy Moltu]

1) just need a shorter bolt. Same applies to removing the fan on the 4 cylinder cars -removing a bent old, unbalanced metal fan isn't going to be detrimental to the life of the crank.

2) This acts as a damper to help damp resonance in the crankshaft.

3) Once you have identified top dead centre make a mark(on the pulley) with a hacksaw blade or even a chisel that aligns with the pointer on the timing cover. You don't need the other timing marks if you use a strobe with an adjustable advance setting. Filling the mark with white paint or Tippex makes it easier to see.

[johnny250]

Talking with TRGB this afternoon seems as though they don't recommend removing the original fan...only adding another (electric) on to the front of the rad....???

 

john

[david ferry]

John,

 

The next question to them has to be, 'Why?', or in this case, 'Why not?'

 

Regards

 

David

[88V8]

I've posted before about ye olde fan and its detrimental effect on the crank thrust bearings, OK perhaps it's marginal, but also the power absorbed, plus the delayed warm-up, bin it I'd say. My car has had no mechanical fan since 1978, and a rather smaller Kenlowe than I would fit, yet it never gets anywhere towards hot - about the second mark on the gauge, that's it.

 

However............ if you have carbs, as I think you do, and if you have an air intake under the bonnet, perhaps worst of all an intake above the hot exhaust manifold, then perhaps there is a case for keeping the mechanical fan, as it does at least provide a steady supply of cold air to the carbs.

 

Ivor

[Tom Fremont]

However............ if you have carbs, as I think you do, and if you have an air intake under the bonnet, perhaps worst of all an intake above the hot exhaust manifold, then perhaps there is a case for keeping the mechanical fan, as it does at least provide a steady supply of cold air to the carbs.

 

My thoughts in the matter too

 

If I remember Racetorations have worked out a little bitty fan for just that purpose on Webered cars that have an electric fan instead of the mechanical one.

 

The stock fan also comes in handy when doing valve adjustments.

[BrianC]

When my TR3A was being rebuilt, I asked TRGB about the wisdom of removing the mechanical fan when fitting an electric fan and they advised replacing the wobbly metal fan with a lighter, more efficient plastic fan (I think from a Spitfire). They had been running this setup successfully on a customer's rally car and it seemed the safest way to go, bearing in mind I wanted to retain the dynamo rather than upgrade to alternator.

 

The dual fan approach has the benefit of continuous cooling air to the carbs and minimal current drain as the electric fan only comes on in heavy traffic, or when stopping after a long run. I guess it's less of a benefit for the six-cylinder cars which already have an alternator and plastic fan and I'm certainly not qualified to say whether or not the fan should go. However, for the four-cylinder cars I would definitely recommend it. Lynda's TR4A will probably get the same treatment sooner or later.

[johnny250]

Yep, all good points..... I phoned with credit card in hand all set to order a Pacet..... but think I'll be putting it all back as before... except that now it'll have a toothed sensor wheel on the crank pulley....A bit of hassle getting it off as you also have to remove the radiator, chassis cross brace and the steering rack to get clearance.... these cars may not have been designed by the mechanics who used to work on them!

TRGB did say that they normally run at above halfway on the temp gauge..... I haven't yet used the car on the road and it hasn't boiled with a couple of hours running stationary whilst setting engine up in the garage...i'll see how I get on in 'standard trim' when it's rolling,

 

john...... getting fed up waiting for my bonnet sun's out too....

Edited June 27, 2008 by johnny250