engine cover and electric fan

[Guest teigan]

there is a 10" elecric fan made by sanden attached to the engine cover of federal S3s. lotus mounted it upside down because sanden's mounting holes were not in the proper place to allow mounting right way round. by also reversing the wires, lotus concluded it was circulating air correctly. however, ducted fans are designed assymetrically to draw air most efficiently in one direction and not the other. the result is the fan draws more power from the battery to circulate less air. i've yet to find another 10" fan unit which is the required under 2.25" height. thus i'm making a new fan bracket out of alluminum and a new duct out of carbon fiber. i'll reuse only the electric motor from the stock unit. by having the fan mounted correctly, i should expect 20-40% more volume of airflow. why couldn't lotus have done it correctly in the first place? i sometimes wonder if their engineers grasp even the basics of grade school physics.

[Richard S3T]

Just a thought, I had been looking at Motorcycle radiator fans off ebay for exactly that purpose.

Richard

[Guest teigan]

you'll definitely want a ducted fan, and a single large fan will be more efficient than multiple small ones. at some point i want to put a camera in the engine bay to see the airflow with streamers. i'm guessing it's a big mess. smaller fans blowing up from below may help. i'll post a photo of the custom aluminum bracket i've made for the original fanmotor if you're interested.

[Richard S3T]

A picture of your bracket etc would be really usefull. I don't know about the shape of the federal engine cover, but mine has a rectangular slot set in the top edge towards the rear. I was looking at my Triumph S3 fan, which has a cort nozzle / shroud which would help ducting, this looks like quite a compact design and given the rectangular shape of the hole, I was thinking that 2 fans would fit the existing shape better. What do you think?

[Guest teigan]

if you must use multiple fans, you need to array them tightly. having a fan on either side won't be effiecient. i'll post photos of the federal variation tomorrow when i have daylight again. panasonic computer fans may work for you. they have a range with alluminum cowls which tile nicely. they work on 12V, so you won't need to modify anything. you really won't know until you try though. little adjustments make a huge difference.

[Guest teigan]

here are the photos for comparison. the minimalist motor bracket fits snugly under the right hand side of the grill pictured. no modification of the engine cover was necessary to fit the improved bracket. i'm as yet uncertain why the left hand side of the grill has that square section blocked off. i doubt lotus could tell us. my upgrade is yet incomplete, because i still need to fabricate the fan shroud to properly duct the blades.

[AJay]

here are the photos for comparison.  the minimalist motor bracket fits snugly under the right hand side of the grill pictured.  no modification of the engine cover was necessary to fit the improved bracket. i'm as yet uncertain why the left hand side of the grill has that square section blocked off.  i doubt lotus could tell us.  my upgrade is yet incomplete, because i still need to fabricate the fan shroud to properly duct the blades.

<{POST_SNAPBACK}>

The left hand side of the grill is blanked off to stop rain water from entering the Spark plug holes and causing a miss fire.

The Domestic car has a similar arrangement on the grill. i removed it and after a few rain storms had a miss fire problems. I have now re installed a similar device and have cured the problem.

[Guest teigan]

thank andy. i love that answer, because it is so ironic. i've left things stock, and i still had rain going into the spark plug wells causing misfire. i just live with the problem now, by making sure the rubber plug boots are always very nearly new.

[Guest Troy Halliday]

I figured out what the problem is with your cars.

Some one has nicked the glass out of your tailgates and boarded them up

New sheet of glass and your engines won't get wet anymore

[Guest teigan]

what if i place a cocktail brolly over each spark plug well? the car is english after all.

[Guest Troy Halliday]

Just don't go out and buy any all us brits have some laying around for when we have BBQ's. It rains so much here we have to do something to stop our drinks gettin watered down