bonobo

Early or late?

bumpstart

water pump and rear inspection cover and the missing EGR thingy off the middle plate all scream early ( pre 1986 13b )

GSL-SE ( 1983-85 13b ) also have housing OMP points ,, and a wax cam feed off the top of the rear plate and a coolant sensor for ECU
--so that chucks yours back to the pre-80's if originally non imported

from here though,, the housing mazda font appears late style
( although its rather vague from this POV )


all up though,,,with more than enough indications so far
( without really having a great view of the font or if any housing OMP points, or the inlet pattern )
that this is an rx4/5 engine circa 1974- 1978

remove the water pump
and tell us what letter code is bossed onto the front plate under there
- also on the rear plate,, and visible near the oil filler base on the rear side of the middle plate

i am expecting one of three combos, but almost certainly yours will be R5, NO,R5
and is thus at the later end of the spectrum, call 76-78

( earlier motors got taller runner R5 middle plate ,, that lacks the EGR thingo on top )

2slow4stock

iTrader: (18)

Also S4's n/a of course did have an egr in the middle iron also. Take a picture exhaust side of the motor, and front cover.

bumpstart

i pretty much discounted the s4 6port,, and the 1983-85 RESI /GSL-SE 6 ports
due to the apparent lack of any wax cam water pipe from the rear plate

( and lack of OMP points )

however,, the front of the s4 6p centre plates ,, near the oil filler base will be bossed "E" beside a bossed replica of a Phillip's screw head for the mold tag

whilst 13b RESI i think is an "M"

not to mention the obvious injector holes in the primary plate
and the 6 p inlet ,,
and the FC revision with extra inlet manifold bolt

bonobo

Very interesting! I was looking for an engine to rebuild (i've never done one before) and this came up for sale, is it something I should steer clear of? Is it worth any money?

j9fd3s

iTrader: (3)

if it was a 12A i'd say it was an 80 california, but its a 13B so its probably not a factory assembly.

the creme colored pulleys we see in the US on the SA's, 79-80, although the fan drive on this engine is different. thermostat neck is also the 74-80 aluminum one

irons look like 80 California parts. the 1980 CA engines had the EGR on top like an FC. the clutch inspection cover is the correct 2 bolt one, tall oil filter pedestal. other tip offs would be the number of tension bolts, a screw in heater hose fitting.

the rotor housings are Thermal Reactor ones, and also look to be correct for 76-80.

in the US we didn't get a 13B with EGR, so its either built from parts, or its another market. mazda stopped importing the 13B to the US in 1979, but they still had it elsewhere

the oil pan on the engine might be another tip off, the rx4/5/repu had different pans than the rx7

bumpstart

OP is a pommie !
(oops, limey )
so am expecting to see a shitty port NO plate in a R5 grey nitrided series 13b


however,, if its a mix match rebuild,, clues come in the engine number on the front plate
-- originally 13b plates will have a letter code before the number
( so far-- D,W,H for pre 1980 and C for FC 6p, E for FC turbo )
and 12a plates will have a large numeral instead preceding all the little numbers



its looking like an early 13b,, internally it will be much like most 12a's
it will not be able to be made fit into any 2nd gen rx7
and it cannot share many parts aside maybe rotatiing gear with any FC or FD engine due to changes in water groove positions

it is however a good purchase if cheap enough,, want to learn,, and possibly have an older 1st gen rx7 or old school car

old housings like this are hard to find in good condition
however pulling down random engines is hit and miss,, many worn out housings and much corrosion to be found before you trip a good set

so weight that up against maybe instead restoring an FC engine which is lots easier to chase parts for ,, with much evolutionary improvements
and can be universally retrofit for whatever purpose/car

j9fd3s

iTrader: (3)

oh i didn't see that! europe didn't get a converter until 89, so that motor could be 76-85....

bonobo

Thanks for all the info guys, doesn't look like something I want to get into for a first rebuild then, anyway it's sold now, someone got a potential bargain for £60. I'll keep looking for a later 13b from an fc.

Jeff20B

iTrader: (13)

NO intermediate plate. Look at the casting.

coslevel

I thought 13b's were bigger. Are you sure thats what it is?

barkz

iTrader: (1)

^ good resurection....