Flaps

[Mr Pharmacist]

I've lost one of my flaps - the curved one on the right of the image below.

has anyone got one they dont need? Or a full set of flaps even? I need it to get back on the track before the end of the season...



Thanks

[jwhillracer]

Hi Stuart,

If I recall correctly, the flaps purpose is to restrict the air flow and warm the engine up faster, so they are not really necessary on a semi-competition engine. I'm fairly sure that I took them out of mine when I rebuilt it, but
a/ it was over 35 years ago.........!
b/ the whole engine had been cooked by an engine fire, so the thermostat was toast anyway.......

Cheers!

JW

[Bruce M]

You need to leave in the one by oil cooler as it splits the air correctly (even when open). Without it, the air is not correctly distributed.

I should have a spare set of flaps including the curved piece. I'm away this weekend (at the F1) so it might be the following weekend before I get a chance to dig it out.

[Mr Pharmacist]

Hi JW

That is what I thought, however it turns out that the flaps start off diverting the air away from the oil cooler to let the engine warm up, and once its warm the bellow thermostat close the flap which diverts air over the oil cooler to provide cooling.

I did leave them out but have now realised I actually need them (or at least the oil cooler side flap)

[davep]

Whatever you do, make sure that the pulley shaft bolt is still in place on the side of the crankcase. A friend forgot that bolt and was spewing oil like a well blowout.

[914 KEV]

Hi Stuart,

If I recall correctly, the flaps purpose is to restrict the air flow and warm the engine up faster, so they are not really necessary on a semi-competition engine. I'm fairly sure that I took them out of mine when I rebuilt it, but
a/ it was over 35 years ago.........!
b/ the whole engine had been cooked by an engine fire, so the thermostat was toast anyway.......

Cheers!

JW

They are a must, common mistake in removing them; they not only help the engine to warm up quicker but once in the hot position guide the air to where it is needed, without them the engine will run hotter and have a shorter life.

If no thermostat is fitted make sure they are set in the hot position, the spring is a fail safe device as well so when the cable or thermostat fails the flaps stay in the hot position.

[Mr Pharmacist]

I'm sorted now thanks

[jwhillracer]

Happy to be corrected! Hope you get going again soon, Stuart.

JW

[Mr Pharmacist]

Thanks JW - aiming to get to harewood in August!