M20 converted to Serpentine belt - Adding supercharger - Take 2

whodwho · 10-18-2019, 05:41 AM

Looking for that picture I had seen this picture from after finally stuffing a new motor in it (might make a new thread for that) and seen the spider webs hanging off it and thought I would share

Waiting so patiently for some attention 8^(

It had been a spider factory for a while now but now they are getting eviction notices, she was not thrilled I was messing with her nests! (being a black car it should make black widows but these are brown widows)

whodwho · 10-18-2019, 04:52 AM

Originally posted by digger

i just want to see which part is rubber and some basic dimensions will probably do if it is cut up a bit

i think i have a solution for the ATI option for the M20 that retains all the pulleys locations with little more than some modified front covers. there are a couple of options i came up with based on ATI's initial work to fit their recommended Inertia ring.
- one option allows the stock OE crank gear (albeit the new version) and 24V 95mm long centre bolt used for a typical stroker which is ideal. will be discussing with them in coming weeks.
- another options a new gear that integrates to the damper but means the big M18 bolt needs to be removed to change the timing belt which is not ideal. this will add a fair bit of cost to the already expensive price so fingers crossed the first option can be taken from concept design to a detail design.

Are you looking at using the thin style(VAC) shell with the trigger wheel?

whodwho · 10-17-2019, 06:04 PM

Originally posted by digger

Is the water pump directional ? Have you checked the overall drive ratios the different components?

Highly directional. These are matching sizes from a M5x, the crank and WP are the same size as the stock M20(145/130mm) but the alternator is ~20mm smaller but thinking of running a larger diameter clutch pulley and slow it down some. I probably will be running a newer alternator so won't be an issue running it as is.

The belt routing is exactly the same as a 24v setup and the same as the M20 they all rotate the same direction.

digger · 10-17-2019, 12:56 PM

yeah eyes painted on at the moment

ForcedFirebird · 10-17-2019, 12:23 PM

Water pump is directional, but if you look close, it is driven off the ribbed side of the belt (clockwise when facing the engine). The time you would need revere rotation is when water pump is driven off the smooth side of the belt (counterclockwise).

digger · 10-17-2019, 12:02 PM

Is the water pump directional ? Have you checked the overall drive ratios the different components?

whodwho · 10-17-2019, 07:21 AM

Originally posted by ForcedFirebird

Would be best to see a sensor on there. Looks can be deceiving in pics, but appears that the bracket will be too close. Now you have me thinking, I do happen to have an m20 (or 15) laying around the shop, along with 24v crank hubs...

I'm not finding a spare sensor in my piles, I can make a spacer easy enough if so. Looking forward to your take on it 8^)

Originally posted by lukeADE335i

Are you using M50 pulleys and tensioners?

Yes all I believe all the pulleys are all M50 ones, I have a box of different ones so not 100% without looking up numbers. Everything but the tensioner is BMW

lukeADE335i · 10-17-2019, 04:18 AM

Are you using M50 pulleys and tensioners?

ForcedFirebird · 10-16-2019, 07:12 AM

Would be best to see a sensor on there. Looks can be deceiving in pics, but appears that the bracket will be too close. Now you have me thinking, I do happen to have an m20 (or 15) laying around the shop, along with 24v crank hubs...

whodwho · 10-16-2019, 06:12 AM

Originally posted by ForcedFirebird

I see the bracket on there, but appears to be the one for m20.

I am going to run the M20 sensor

Updated and posted pics in the last post

ForcedFirebird · 10-16-2019, 06:06 AM

I see the bracket on there, but appears to be the one for m20.

whodwho · 10-16-2019, 05:56 AM

Originally posted by ForcedFirebird

What did you do for the CPS?

I still need to find a sensor and see how it will work. easy enough to make a bracket if not

For timing, I would be running MS or something I can alter the timing wheel configuration, for running a stock ECU I think you could carefully weld up the missing teeth and grind down the new location related to the m20 timing wheel location but not sure how close it would get. something I still have to look into.