20b front cover and CAS vs FD main pully!
 

So my plan (up till today) was to use the 20b from cover/stock CAS with my FD accessories. Unfortunately today i realized that the FD and 20b pulleys are not only different in width, but are also different in diameter. since the 20b main pulley is larger it would over drive the FD accessories (but its a moot point because the pulley is too wide anyway)

So i was hoping i could just bolt on the FD main pulley and be done with it, but i noticed the notch in the 20b pulley and the small pickup needle which reads it (i assume it verifies each crank revolution to keep the CAS honest?) . so what has everyone else done? the two obvious solutions are:

A) retain the 20b accessories - thats not gonna happen
B) upgrade to the FD front cover - i could but would really rather avoid the hassle if possible

is there another simpler solution that im missing? thanks, heath

i know when i build my 20b im just gona use an fd front cover and accessories. thats the only thing ive seen done when people put them in fd's

I'm using the 20b front cover, FD main pulley, and the Greddy water pump and alternator pullies. No problems whatsoever.

so are the pickup and two notches not needed for proper function of the CAS? what is the purpose of them? on the FD everything is done with magnetic pickups. thanks, heath
http://img.photobucket.com/albums/v2...r/DSC03164.jpg

thats so you can set the timing with a timing light...

if you're using the stock cosmo ecu, then you need to keep the cosmo CAS, if you're using an aftermarket ecu, then you might as well upgrade to the fd front cover/accesories

If you can use the FD front cover and CAS

IT IS FAR SUPERIOR!!!

I have had both, same car same haltech, so much less noise with the FD CAS that its ubelievable.

ok ive decided to just do it right and move over to the FD front cover. after digging through my garage for an hour i have finally found my FD front cover and (to my surprise) the FD pulley boss as well! i thought both were long gone :biggrin: now im in business!

so i was reading through some how-to's and ended up looking at this pineapple video. http://www.rebuildingrotaryengines.c...e_Modification
they recommend installing the thermal pellet defeater washers (which i have lost in my garage somewhere too :) ) while its apart. anyway, they got to the last bit about re torquing the e-shaft bolt and said FD = 200ft-lbs older 13b's = 90ft-lbs . whats the popper torque for the 20b? 90? thanks, heath

are the pulley bosses different? I have a handful of them but they could be from fd's or fc's....

You can skip the thermal bypass mod.....the 20b has no such pellet at all. Torque the front e-shaft bolt to 200ft-lbs.


Everything on the pulley bosses are identical, except the FD has two locator pins to make more precision in the timing wheel alignment.

thank you! yeah i was staring at that 32mm bolt and thinking that it MUST need more than 90ftlbs of torque lol

Are you sure? I noticed a difference in the 4 pulley bolt hole patterns between the two.

yeah i think the FD pulley boss has some offset bolt holes so you can only line the pulleys up one particular way

They all feature non-symmetrical bolt holes, so it can only go on one way. 86 and later all have the same bolt pattern. Including the 20b. Just the FD has the locator pins.

Yea your right I had to re check it. Previously I think I was using my Fd's trigger wheel to compare the 2 but I think I fliped the wheel around while checking the other (which changes the bolt hole patters). This is what made me think the bosses where different. Ooops! :D

fuck, is this nut reverse threaded or something??? i just bought a 750 ftlb impact gun and nothing is happening... ive tried heating it too (i believe theres threadlocker on it correct?) but still nothing.

EDIT: sorry false alarm...... i got it REALLY hot and it SLOOOOOWLY backed its way out. :biggrin: ive dealt with some crazy frozen bolts before but nothing that put up such a fight and didnt break lol. the last thing i had this much trouble with was a reverse threaded MGB wire wheel knock off (which had been rusted on there since the mid 80's!)

I had similar issues - it is fing tough.

ok so i just got the front cover off and found some interesting things. first is there is an insane amount of what looks like burnt on oil film... i can scrape it off with my finger but what caused this? there must be something wrong, or something happened to this motor at some point?
http://img.photobucket.com/albums/v2...s/IMG_2517.jpg

and a little bit of this gunk on the bottom of the motor as well:
http://img.photobucket.com/albums/v2...s/IMG_2457.jpg


also, my motor is #466 (all the plates/housings match)... but i see a 3 digit number stamped on the front counter weight which is not #466. has this motor been rebuilt? is that number supposed to match the rest of the engine? the number on the front counterweight is 307.
http://img.photobucket.com/albums/v2...s/IMG_2519.jpg

I have opend a couple 20b's that looked close to that. That is preaty bad.

Cheap oil, high heat and driving realy hard on that motor.

Hmmm mine came off pretty easily.

i drive harder on my 13b than anyone must have on this car... and ive never opened a motor and found something like this. i wonder if its some strange additive?? oil, even really hot oil shouldnt do this... especially on the front cover where there is relatively little heat.

the stock cosmo oil cooler is too small. Any time I push my cosmo around it is easy to get the oil temps up to 200 ~ 230 degs. if your running cheap oil / old oil I can see it doing this. Im going to be removing the stock oil cooler and installing 1 or maybe 2 FC coolers

so will the fd front cover and water pump fit right on cosmo 13b and 20b engine?

Yes it's a direct bolt on. That's what I'm running on my 20b. The only thing is, you have to use the longer 4 mounting studs that come on the fd front plate. The 20b's are too short.

so if you use FD front cover. do you still need to install the CAS gear on the eshaft?

on my project dont want to use the cosmo water pump and t-stats or a cas

I was having the same debate..

if I use the FD cover, I have the superior magnetic trigger..

but then I lose the OMP

and running premix in a gas guzzling DD is a PITA..

The gear must be used as it's apart of the end-play spacing.