3) Anyone know parts numbers for the water and oil pumps from the 20B or
maybe a supplier you've used that caries them?

Jay


Hi Jay;
From what little I remember, the 20B's were somewhere between 2nd and
3rd gen.
A good place for used parts and information is rx7club.com.  See also
nopistons.com
There are several forums you can search or post a want to buy thread:
http://www.rx7club.com/forumdisplay.php?f=95
http://www.rx7club.com/forumdisplay.php?f=99

http://www.mazdamotorsports.com

You can supposedly still order Cosmo/20B parts through your Mazda
dealer.  Some people seem to have a full Cosmo parts fiche.  See this
thread for hints (I should have bought that car):
http://www.rx7club.com/showthread.php?t=788077&highlight=cosmo

Some of the engine parts are here:
http://cp_www.tripod.com/rotary/pg20.htm
Cosmo:
http://cp_www.tripod.com/rotary/pg09.htm

possibly:
http://www.partsnet.com.au/members.html

Cheers
Cary

Paul,
Here are some photos of the original water pump and housing side by side
with the one I got from Atkins. I also included one of the front end
housing. The oil pump is going to fit. So for now I'm just dealing with the
water pump issue. Dan at Atkins suggested an 86'-91' pump and housing would
fit the 20B without any fabricating or cutting. Can you corroborate this?

Thanks
Jay

Your original pump is fine Jay. No need for the 3rd gen cartridge besides
the
that fact that it does not fit the 20B water pump housing. I'll take a
closer look at my
20B out in the hangar and see if I can find any disadvantages to sticking
with the
original pump.

You may have to cut it down to fit under your cowl but that would be true
of a 2nd or
3rd gen water pump housing as well.

Paul Lamar

The front cover looks unique to the 20B but I am not sure. Mainly in the
area of the oil drain back for the sequentially turbos.


Please take a picture of the front cover both from the front and rear so we
can tell if it will fit a 2nd gen water pump housings. Also please take a
picture of the 20B front end housing from the front.

The cartridge Dave Atkins sent you is a 2nd gen 8 bolt version. In order to
use that you would need a 2nd gen water pump housing which may or may not
fit your front cover.

The only drawback I can see  sticking with the 20B WP pump is the
difficulty in finding a new cartridge if it develops a leak or the bearings
go out. They can be pressed apart and the bearings replaced but that is
what
most people don't do. They just replace the cartridge.

Paul Lamar


Paul,
The 13b water pump housing will fit on the 20b, but the 13b's impeller is
smaller.  Also, the Renesis water pump (removed from the front cover) will
also fit the 20b. The Renesis entire front cover will fit, but it requires
some machine work for it to clear the 20b front counterweight which
is larger than the Renesis' counterweight and it interferes with some of
the
front cover casting.  If you machine it for adequate clearance, then you
are
into the bolt head recesses which then must be welded up, but by this
point,
we're probably beyond what most people would be willing to do for the
limited benefits of the Renesis front cover.  Also, the Renesis front cover
has a different shape and spacing around the oil pan.  Not a problem if
you're building a custom oil pan anyway.  The easiest route is to cut the
Renesis pump housing from the front cover (if you want to run the Renesis
water pump).

Who was it that commented about removing and replacing the 20b exhaust
inserts.  Having gone down that road, my recommendation is DON"T DO IT
unless you're planning on turbo-charging your engine.  I changed out the
20b
exhaust inserts for 13b turbo inserts.  Now I'm pulling my hair out trying
to get a muffler that will handle the torture of the rotary's exhaust and
still quiet things down.  Word has it that the splitter inserts are good
for a 5db noise reduction.  I constantly get the comment from people that
they can hear me coming long before they can see me.  Not exactly the image
I want to portray. You can be sure that my new engine will retain the stock
exhaust inserts.

Mark S. Texas

Are you talking about removing the RX8 engine water pump housing from
the RX8 engine front cover? In other words sawing it off? That sounds
like a good idea except for the cost of an RX8 front cover.

The RX8 WP cartridge will not fit the 20B water pump housing.

Paul Lamar

The only drawback I can see sticking with the 20B WP pump is the difficulty
in finding a new cartridge if it develops a leak or the bearings go out.
They can be pressed apart and the bearings replaced but that is what most
people don't do. They just replace the cartridge.


Will the bearing from a 13B WP fit a 20B pump? Exactly how do you get the
WP
bearing out? Do I need a special Mazda tool? How about the impeller?
What I'm getting at is could I use 13B water pump parts (bearing and
impeller) and fit them into the original 20B WP housing?

Jay


It can be pressed apart and the bearings replaced with off the shelf
bearings I am sure. You may need to make some tools to press it apart.

It may be possible to just press the shaft down and  out from the impeller
side.

A 13B front cover and pump may fit the 20B front end housing.
I am not sure the 20B front end housing is different than a 13B
front end housing. I could be wrong. My 20B is not apart
so it is hard to tell.

Paul Lamar

3) Anyone know parts numbers for the water and oil pumps from the 20B or
maybe a supplier you've used that caries them?

Jay


Hi Jay;
From what little I remember, the 20B's were somewhere between 2nd and
3rd gen.
A good place for used parts and information is rx7club.com.  See also
nopistons.com
There are several forums you can search or post a want to buy thread:
http://www.rx7club.com/forumdisplay.php?f=95
http://www.rx7club.com/forumdisplay.php?f=99

http://www.mazdamotorsports.com

You can supposedly still order Cosmo/20B parts through your Mazda
dealer.  Some people seem to have a full Cosmo parts fiche.  See this
thread for hints (I should have bought that car):
http://www.rx7club.com/showthread.php?t=788077&highlight=cosmo

Some of the engine parts are here:
http://cp_www.tripod.com/rotary/pg20.htm
Cosmo:
http://cp_www.tripod.com/rotary/pg09.htm

possibly:
http://www.partsnet.com.au/members.html

Cheers
Cary

Paul,
Here are some photos of the original water pump and housing side by side
with the one I got from Atkins. I also included one of the front end
housing. The oil pump is going to fit. So for now I'm just dealing with the
water pump issue. Dan at Atkins suggested an 86'-91' pump and housing would
fit the 20B without any fabricating or cutting. Can you corroborate this?

Thanks
Jay

Your original pump is fine Jay. No need for the 3rd gen cartridge besides
the
that fact that it does not fit the 20B water pump housing. I'll take a
closer look at my
20B out in the hangar and see if I can find any disadvantages to sticking
with the
original pump.

You may have to cut it down to fit under your cowl but that would be true
of a 2nd or
3rd gen water pump housing as well.

Paul Lamar

The front cover looks unique to the 20B but I am not sure. Mainly in the
area of the oil drain back for the sequentially turbos.


Please take a picture of the front cover both from the front and rear so we
can tell if it will fit a 2nd gen water pump housings. Also please take a
picture of the 20B front end housing from the front.

The cartridge Dave Atkins sent you is a 2nd gen 8 bolt version. In order to
use that you would need a 2nd gen water pump housing which may or may not
fit your front cover.

The only drawback I can see  sticking with the 20B WP pump is the
difficulty in finding a new cartridge if it develops a leak or the bearings
go out. They can be pressed apart and the bearings replaced but that is
what
most people don't do. They just replace the cartridge.

Paul Lamar


Paul,
The 13b water pump housing will fit on the 20b, but the 13b's impeller is
smaller.  Also, the Renesis water pump (removed from the front cover) will
also fit the 20b. The Renesis entire front cover will fit, but it requires
some machine work for it to clear the 20b front counterweight which
is larger than the Renesis' counterweight and it interferes with some of
the
front cover casting.  If you machine it for adequate clearance, then you
are
into the bolt head recesses which then must be welded up, but by this
point,
we're probably beyond what most people would be willing to do for the
limited benefits of the Renesis front cover.  Also, the Renesis front cover
has a different shape and spacing around the oil pan.  Not a problem if
you're building a custom oil pan anyway.  The easiest route is to cut the
Renesis pump housing from the front cover (if you want to run the Renesis
water pump).

Who was it that commented about removing and replacing the 20b exhaust
inserts.  Having gone down that road, my recommendation is DON"T DO IT
unless you're planning on turbo-charging your engine.  I changed out the
20b
exhaust inserts for 13b turbo inserts.  Now I'm pulling my hair out trying
to get a muffler that will handle the torture of the rotary's exhaust and
still quiet things down.  Word has it that the splitter inserts are good
for a 5db noise reduction.  I constantly get the comment from people that
they can hear me coming long before they can see me.  Not exactly the image
I want to portray. You can be sure that my new engine will retain the stock
exhaust inserts.

Mark S. Texas

Are you talking about removing the RX8 engine water pump housing from the
RX8 engine front cover? In other words sawing it off? That sounds like a
good idea except for the cost of an RX8 front cover.

The RX8 WP cartridge will not fit the 20B water pump housing.

Paul Lamar


Paul,

If you don't want to go through the trouble of machining an RX-8 front cover
to fit the 20B, you can saw off the water pump housing and use that on the
20B, along with the RX-8 cartridge.  This would necessitate using the 20B
front cover.  The benefit to using the Renesis front cover would be for the
crank mounted CAS arrangement.

Mark S.
Austin

Given the trouble you had with the RX8 CAS  and if you have a 20B
crank angle sensor you might as well stick to it. Less to do.

Paul Lamar