TR2/3/3A " do not remove the fan as it is essential for establishing crankshaft balance"

[karls59tr]

This is what someone on a different TR3 site stated that Bill Piggot mentioned in one of his books? Not sure if the quote is accurate but I don't see how it could be true as many TR3 owners have been running electric fans for ages.

 

[Sarastro]

Naaahhhhh......

When I rebuilt my engine, I had the whole moving assemby--crank, pistons, rods, flywheel--balanced. If that is true, they should have needed the fan, too. The weight of the fan, and any minor imbalance it might have, is minuscule compared to the rest of the engine components.

 

[bobhustead]

I have built 2 TR3 engines that were balanced. The fan was balanced in the process both times. Why would installing an electric fan require removal of the crank fan?
Bob

 

[CJD]

I am sure it refers to the fact the balancing tabs are located on the fan. I don't know of anyone who knows how to use the tabs for balancing anyway!?! I had everything balanced individually on the last reuild.

 

[Hamish Racing]

This is what someone on a different TR3 site stated that Bill Piggot mentioned in one of his books? Not sure if the quote is accurate but I don't see how it could be true as many TR3 owners have been running electric fans for ages.

i guess that’s the issue. If you are not running the original fan and extension in favour of an elec fan (as I do) then the fan and extension shouldn’t be balanced with the crank etc.

and if you do use the fan and extension have it balanced AND mark its orientation to the crank in case you need to take it off so it can go back in the same place.

 

[bobhustead]

Machine shops mark the fan with a small drill hole in the hub and through far enough to mark the extension.
Bob

 

[mezy]

what about fan belt slip.
If the fan is balanced properly it would not need to be timed to the crank,
if it is not balance properly it would cause vibration where ever it was in relation to the crank and need balancing or throwing away.

 

[bobhustead]

The fan is bolted to the crank on these cars.
Bob

 

[karls59tr]

I'm running a TR6 yellow fan. to replace the useless stock fan (useless in terms of moving enough air for cooling on a 30 c day....may have been OK for British climate back in the day) . No electric fan. Haven't had any issues. I don't believe fan balance is a serious issue on these motors. Am I wrong?

 

[JFS]

You can convert to a harmonic dampener to replace the two piece stock crank pulley. I converted to the wide belt kit from British Frame and Engine many years ago and my modified engine revs happily with it. BFE lists two kits, $255 for the less expensive kit. I thought Moss also sold a kit but could not find one listed on their site. I use an electric fan with it. Great conversion.