Jeff20B

iTrader: (13)

Could you or anyone else tell me all you can about the oil pickup tube and oil pan of a 20B?

Firstly, I want to install a 20B into an automatic '76 Cosmo. Yeah yeah yeah, but at least it's a freakin' barge! It'll take the extra weight and like it! Erm, I'm still not sure about the sway bar, but every other measurement I've taken looks like it will allow a 20B to fit pretty nicely. I'll need to see if I can get a newer shorter starter motor because the old one is really long. Too long for a 20B anyway. If the 4 and 5 speed starters of the day when compared to the mid to late '80s are any indication of downsizing and lightening, then I hope the automatic starters were also made smaller.

I may go to a T2 tranny someday, but the stock Jatco auto is actually very strong and, according to Cal at Rx5 CENTRAL, can handle 400HP+ and all the torque a turbo charged 13B can throw at it. So can the unibody. He does, however, think the tranny will break if he upped it to 600HP. Well, I know a 20B will produce more torque at the same HP level and RPM as the 13B (5252RPM? Ted? Wanna straigten me out? ), but I was only shootin' for a maximum of 400HP in the begining (or even less because anything over stock power levels will be a great improvement regardless).

If I start out NA, it'll have a bit more power than stock, and I won't even need to upgrade the big juicy 3 core radiator, or the large oil cooler (Mazda's largest stock unit as far as I know). But then again, aftermarket water and oil temp guages are going in just to be sure. I guess I'll cross that bridge when I come to it.

So, do any of you know if a '74-'85 front cover will work well on a 20B? I'd like to use this style because it has threaded holes for a front crossmember mount. I'll have to repostion the perches the stock mounts sit on, but that's not a big deal. I'll also be using the stock 20B motor mounts for a four mount system. It ought to hold the 20B well enough.

Does the pickup tube connect to the front cast iron housing? Or does it come down from inside the front cover like on this 13g?

http://cp_www.tripod.com/rotary/pg19.htm

Just scroll down a little to this side view cut-away which shows the oil pickup tube. http://cp_www.tripod.com/rotary/images/pg19_04b.jpg (pic may no work due to tripod)

The big sump will be moved forward a little to clear the main crossmember between the front wheels. What I'll need to do is find out how hard it would be to run the oil pickup tube from wherever it connects to down to the sump and clear the swaybar in the process. The rest, even the exhaust, should be easy compared to this. Please could someone explain how the oil stuff works on a 20B? Thanks!

Bitchn7

check out www.badrotor.co.nz Andrew who runs this site has am early cosmo that he has also fitted a 20B too, still in the build.
tubbed etc.

HyperRex

Not related to the post but...I read this topic and I thought it said "Evil Ted, please help me!"

zyounker

You can use a 12A/13B front cover but you will not have the oil outlet you need for the turbos.. this can be solved bt putting an inlet directly on the oil pan

-Zach

Evil Aviator

I don't remember exactly where the pickup tube originates. I'll check my pics to see if I can find out. I do know that it is in the front lobe of the oil pan which interferes with the sway bar. This is an oil pan pic from Ted's project where you can see the lobe forward of the steering rack:
http://www.k2rd.com/Projects/20B/EngineBay/Bay5.jpg

A stock 20B (276bhp @ 6500rpm rating) makes about 288 lbs-ft at 2000rpm, is rated for a peak torque of 296 lbs-ft @ 3000rpm, and it only drops off to about 267 lbs-ft at its 7000rpm redline. This thing is a torque monster.

j9fd3s

iTrader: (3)

the stock cosmo starter actually sits on the engine backwards (well when you compare with a manual)
http://www.fc3s.org/20BT3rotor694.jpg the starter is not mounted in that pic but you can see the aluminum bracket that holds the starter. if the bellhousings on the trannies interchange an fd/jc one will let you use the 20b starter (it's the same as an at fd). the swap actually shouldn't be that bad, i wonder if it clears the hood??

mike
running 20b fc

Jeff20B

iTrader: (13)

Thank you all for repsonding! You've given me some new ideas of problems to try to work around. By the way, the engine was originally going to be moved back by 100mm, leaving 60mm in front. Then I found some sets of threaded holes for different Tranny mount positions under the tranny tunnel and there is a set at approx 97mm further back than the stock ones. I'd imagine these were there for the 121 piston variant as well as stickshifts and possibly an early 3 rotor engine? Well, anyway, I've taken plenty of measurements using 100mm as my model and so far there are only minor probs to deal with.

Thanks Bitchn7. Andrew actually contacted me quite a while ago about my Cosmo. This was when he was finishing construction of his first website. Then he redid his site, but he didn't add any new pics of the Cosmo. I hope he can get it done soon.

Heh, Ted probably has a little evil in him hehehe!

Zach, could I add an oil fitting to the front cover like how Atkins does their SC oil return lines? http://www.atkinsrotary.com/DanielA.htm (scroll down near the bottom. the pics aren't clickable, but if you save them they'll display at full size on your computer).

Evil, thanks for the pic. Ah, I can see the round indentation for the front pressure regulator. That thing was going to cause a problem when I was first thinking of how to install a 13B in my formerly twin dizzy 12A powered MG Midget. I decided to keep the front where it was and moved the rest back by 20mm. The top mounted starter tranny was replaced with a bottom mounted starter tranny (ribcase 4 speed). There was barely enough room for an '86 NA starter. I have a little experience with fitting starters in tight situations, but the 20B sure is a lot longer than 20mm

Anyway, if you could find a pic of a stock 20B pickup tube or where it connects to (front cast iron housing?), I'd really apreciate it. I'll also be taking some measurements of my sway bar and '76 oil pan to see if I can get away with a mostly stock 20B oil pan and oil pickup tube near my sway bar.

Wow, that's some healthy torque!

j9fd3s, thanks for the pic. I have no idea if the bellhousings will interchange. Or would it be possible to modify my bell housing? If the starter's strength comes from mounting on the the cast iron rear housing, then the bolts on the bellhousing aren't expected to handle as much torque. That's how it is on my top mounted starter tranny at least. (even the 13G used a top mounted starter). Hmm, if the '76 flex plate is the same diameter and tooth count as the '73 flywheel, I may just be able to use my top mounted starter on the side! Well, that is if the steering box isn't in the way. Yep, good old recircualting ball steering box and centerlink to deal with. That and the main crossmember are why I'm interested in learning about how the oil pickup tube fits in the pan so I can modify it without getting oil starvation.

Please keep the excellent info coming!

Jeff20B

iTrader: (13)

Oh yeah, the top of the Cosmo air filter canister is around 9" above the engine. I believe the top of the upper plenum of a 20B is also 9" above the engine. There shouldn't be any hood issues with this project.

now

iTrader: (1)

j9fds3 > you are looking at,, what i had first thought
was a bracket to hold the starter, but its not, that is the
motor mount which fits around the starter, and is not
attached to that bracket at all...


matt


QUOTE]Originally posted by j9fd3s
the stock cosmo starter actually sits on the engine backwards (well when you compare with a manual)
http://www.fc3s.org/20BT3rotor694.jpg the starter is not mounted in that pic but you can see the aluminum bracket that holds the starter. if the bellhousings on the trannies interchange an fd/jc one will let you use the 20b starter (it's the same as an at fd). the swap actually shouldn't be that bad, i wonder if it clears the hood??

mike
running 20b fc [/QUOTE]

Jeff20B

iTrader: (13)

My Cosmo starter is attatched in the back to an 'L' bracket.

So, now, you're saying the JC starter just kinda sits there within the aluminum motor mount bracket? Upon closer inspection of that area of my Cosmo, it looks like a stock JC starter will probably have enough room. Only my bell housing will need to be modified. I'll need to just try to install it to be sure though.

RETed

Hmmm...I swear I thought I got my reponse to go through, but I don't see it.&nbsp Oh well...

It looks like the other took care of the other questions, so I might as well try and tackle this one.

This is pretty vague in my mind, but I do remember this.&nbsp Yes, the oil pick-up tube starts out from the front-most side housing.&nbsp The tube actually goes down into the front oil pan section and goes back up to snake over the "dent" into the main, rearward oil pan section for it's strainer end.&nbsp There is a reason why that front "reservior" is there - it's so the oil pick-up tube has enough space to curve back around so it can finally end up in the larger/rear oil pan reservior section.



-Ted

now

iTrader: (1)

you can take a look at what the starter looks like with
that bracket off, its near the bottom of this page..

http://www.agt.net/public/nowback/rx7club/20b/4/
matt

Jeff20B

iTrader: (13)

Thanks Ted! That makes sense to me!

I'll most likely cut out the 'dent' and the sump together, rotate them 180º, then weld them back in. Or do a sump swap with an old 13B pan. I've currently got one (13B pan) lined up next to a mock 20B I have sitting on my garage floor (made from 13B rotor housings). If I can keep the 13B sump in its stock position relative to the crossmember, but move the engine to wherever it'll fit best (60/100 split), that would be best. These old 13B pans can hold something like 5 quarts (6 if you count the tall filters, which I hope to use). I'm just glad that the pickup tube should be fine with a simple cut and reweld.

Cool! One problem solved! Now on to the next one.

now, thanks for the pic! Wow, that starter isn't very big. I'm just not sure if I'd be able to use it since my '76 flex plate is probably a different diameter. Could I bolt my torque converter to the JC flex plate? Hmm, my bellhousing is probably too small. Or maybe not?

Does anyone here know if Mazda kept the flex plates and ring gears the same diameter? I'd also like to know if the torque converters have the same bolt pattern.

Again, thanks to all who've posted. This info has been perfect for my project!

zyounker

Yep, you should be able to do that, if you don't want to dump it into your oil pan.


-Zach

Kurgan

Yeah, the oil pickup starts in the front most housing on the passenger side of the engine. it drops down into that front area and then back up and over the flat spot into the main area....

Don't quite understand why they did this, but there HAS to be a way to modify the oil pickup and remove that stupid front "bubble" from the oil pan.... Maybe running an AN line from the front of the block in the oil pan area and over over the flat spot directly to the oil pickup and screen filter would work... seems to be enough room to do this... Custom oil pan would be called for, but that is not a big deal. you could just cut your 20b pan and weld it flat there... I've been considering doing this to retain the stock swaybar on my FC....

Do you have any empty engine bay shots of your Cosmo? I think those cars are pretty damn cool, almost bought one a couple of years ago... I love old school rotaries....

So, you are going NA for now? May not be a bad idea and is definitely easier than turbocharging it. The stock exhaust sleeves on the 20b are pieces of **** that direct the flow of the exhaust to optimally (yeah right) use the stock twin turbo setup. When I had mine rebuilt, the 20b exhaust sleeves were removed (which was a bitch and a half!) and replaced with S6 sleeves.

Are you planning on turbo charging in the future?

Jeff20B

iTrader: (13)

Thanks Zach! I'll most likely do that then.

Kurgan, maybe they added that elbow as some sort of antidrainback thing, so it holds a little oil in it (like a kitchen sink drain). Maybe this is so oil ends up getting to the turbos a little sooner?

Nope, no pics of the empty engine bay, but you could check out these pics:
http://www.geocities.com/cd23c/pics/ignition19.jpg
http://www.geocities.com/cd23c/pics/ignition20.jpg
(they work, just use the geocities pic viewing method, or copy and paste if you don't know).

Yeah, I'll be going NA at first. Is it possible to grind on the sleeves to get rid of those flow directors?

I may turbocharge in the future, or possibly supercharge using Atkin's 9 inch kit. It's sort of a made to order type thing since he doesn't sell very many. There's one on Mazdatrix's drag car so it ought to have enough power for me. I haven't decided yet.

There's tons of room in front of the radiator for a big FMIC heheh!

Kurgan

Are you going to be rebuilding the motor, or just dropping a jspec engine in?

If you are going to rebuild the engine, yes, you could either grind out the flow directing POS exhaust sleeves, or just replace them with T2 or FD exhaust sleeves.

If you are dropping a used engine in, I personally would grind the sleeves for fear of getting metal in the rotor housing and scaring the surface.

I thought about the sump idea of the elbow.. but what I have been thinking about relocating the elbow to the other part of the oil pan.... Not something I'm going to do right now, but a project I plan on hitting up this fall.

Right now, priority is getting my car running in the next 1.5 weeks

peejay

Here's a thought Jeff... AFAIK all rear counterweights have the same bolt pattern that the flexplate bolts to. You're trying to mate the 20B with your Cosmo's automatic, yes? Why not just use the Cosmo's flexplate? That way you could also use the Cosmo's starter (hopefully it'll have enough torque to spin the engine!) and eliminate that problem too.

Hey if it all works out okay, and I happen to win the 5-digit lotto or something, I'll try stuffing a 20B in my FC. It's automatic already, you know.

j9fd3s

iTrader: (3)

the flexplates will interchange no problem, but it might be easier to use all the jc stuff. the jc engine has a different bolt pattern to use a side mount starter, but the older cosmo stuff would work fine too

mike <---using stock t2 starter

Jeff20B

iTrader: (13)

Just dropping it in. If I did decide to grind on those sleeves, I'd make sure to seal the exhaust ports so no metal bits would get into the rotor housings. Or not. It's one of those bridges I'll cross when I get to it.

Relocating the elbow itself is an interesting idea. If it's gotta be there, then its exact location probably isn't all that important, just as long as it's inline somewhere. If that will eliminate that little buldge, then this would be a very good idea to look into further. Anyone wanna experiment?

1.5 weeks? Do you have a video cam or a good stero mic for some audio clips? Heh, I love the sound of a 20B! I'm doing this project at least 50% for the sound alone. The fringe benefit is greater torque

peejay, I think the JC flex plate is larger than my Cosmo flex plate. I also think my bellhousing would be too small. The reason why I don't think I'll be using my stock starter is because it is very weak. I need to check the wiring, but two different new batteries hooked up at different times have yeilded slow cranking both times. It's either the wiring or the starter. I'll be relocating my battery to the trunk so I'll need to rewire it anyway. The stock starter is also very huge. Imagine a '74 stickshift starter and add a few inches to its length. It is too long and will interfere with my gas pedal if I move the tranny back by 97-100mm. The front also bolts to the bellhousing differently, so I won't be able to use a stickshift starter.

Does anyone know if an '86 automatic starter will work on a '76 auto tranny?

If the flex plate will bolt to my torque converter and fit inside the bellhousing, I'll be able to use a JC starter.

Hmm, gotta figure this stuff out. I wonder how hard it is to get a JC starter?

Thanks!

j9fd3s

iTrader: (3)

the jc starter is the easiest part # NF01-18-400R its the same as an automatic fd

mike

Kurgan

I'll give you my JC starter for $8.99 plus shipping. Just enough to buy a 12 pack of rolling rock.

Jeff20B

iTrader: (13)

Wow! At least I now know there's no shortage of JC starters out there! Now I've really got to find out if the JC flex plate will fit inside my '76 bellhousing and if it will bolt to the stock torque converter. If so, Kurgan, we may be in business!

Jeff20B

iTrader: (13)

I've got another question. Does anyone here know of anyone who's ever installed a 20B in a CD Cosmo before? For those who don't know, the CD series ran from '76-'78 (then it went to HB and JC). I've seen pics of Lance's and Rob's HB Cosmos with 20Bs, but never seen anything about a 20B in a CD Cosmo. Will I be the first?

Evil Aviator

I found a picture of the 20B with the oil pan removed. You can see the routing of the pickup. I guess you could reroute it and then make the front part of the oil pan flat, but then there may be issues with the chain getting oil and with the purge valve having some place to discharge. I think that a dry sump would work better than trying to rig the wet sump.
http://www.geocities.com/mcgumrapper/20B