Two-bladed radiator fan

[Andrew]

The holed-piston and head engine I got last week (see post below) came with a two-bladed plastic fan on the water pump. It looks like a factory fan, not a modified one, but I've never seen or heard of one before with fewer than six blades. I know people modify them at home, but I don't see any evidence of home-trimming on this one. Anyone know?

Andrew

[rockiemosley]

Oh but of course that is the famous Autodelta racing fan. (har, har) Somehow telling that it came from a motor with a holed piston.

[Andrew]

I was going to use it, but on close inspection it had so many cracks I threw it away. Quality merchandise all around.

Andrew

[lowmileage]

I've read (as you have too probably) that you can pick up a few HP by doing this mod at the expense of getting an overheated engine if you're not careful. Not worth it IMHO. Then again, it could be that Autodelta fan mentioned above.

[Andrew]

The car I would have used it on is mostly a track car, so I wasn't worry about overheating really. I may go to an electric fan. Autodelta made fans with six blades, but very short, like 1" long.

Andrew

[lowmileage]

Your are correct and I should have said that. I was referring to a road car about the possible overheating issue.

[Gordon Raymond]

Here's an Ausca Autodelta fan from about 1968. No cracks, not hard, and will be used again on an Ausca 1600 single plug.
Never have seen a 2 blade though. The Short blade was to both save Hp where a fan was required, and to avoid the explosive() result of centrifugal forces at high rpm.

[la_strega_nera]

Just out of curiosity, whats the diameter of that thing?

[Gordon Raymond]

Ah... Lets see.. 170 mm. 'bout 6 1/2 inches.