Hello all,
I just recently acquired a completely rebuilt and custom 13b. I got in in a trade and the guy said he acquired it from his uncle that just had passed away and had no idea what kind of motor it was. He said it was recently rebuilt and his uncle was about to throw it in his gtu. There is grease coming out the ports so i know it was rebuilt and it is spotless no sign of exhaust or any kind of wear at all. I have little knowledge in these motors and would just like to know a little more about it. I got it for cheap and was thinking of selling it. Any help would be much appreciated. Thanks h[IMG][/IMG]elp

 

Also is there anyway i could test it? what tests should i do and how? again i appreciate any replies or advice. Oh and by the way i know you guys will probably give me crap for having it outside, but i only put it out there for a moment right outside the door of my garage because of low light! thanks

 

show the exhaust side of it,and the front.
I'll pm an expert and see if he can pop in!

 

repu maybe?

 

I have little old-school rotary knowledge, I mostly deal with 86+. It's obviously got 70's rotor housings. Beyond that, without seeing the ports, I have no idea.

 

I'll post more pics tomorrow. Thanks for your guys help i appreciate it alot. I can also tell it has a brand new oil chain and the flywheel is aluminum and i'm guessing thats expensive by itself!

 

Its an NA type, came off FC, RX3.....

 

looks to me like its an rx4 13b engine .. those are 74/75 housings .. it has a 12at or 13b GSL-SE water pump fitted
( has a coolant sender and a nipple that used to be a wax cam coolant return )

the housings have water grooves.. these must be used with pre 86 plates
the rear plate also lacks the nipple out top that would normally supply wax cam and BACv ,, which also yell as a 74-85 carby engine plate

the middle plate will lack holes for an engine mount under the sump.. which rules out fitment into an FC and thus must be mounted from timing cover, oldschool style


dizzy is s2 rx7 .. .. flywheel is 9.0inch 225 mm s3 and s4/5 NA rx7 type

 

74/75 REPU/RX4, both are very similar.

there is some slight difference in the exhaust port, the '74 had slightly smaller ports than the '75. '76 and up had the newer(and still current) style mazda logo on the housings.

 

The flywheel looks like a racing beat, with the removable friction surface, those go for over $350 last I checked, even without the counterweight!

I may now know what it is, but I know what it isn't, and I know that nothing there is from an FC. Way to spread misinformation.

 

no parts off that are from anything past 1985. if it has the proper endplates then there will be a "3B" cast on the front iron under the water pump, meaning it is a complete 74/75 block. the apex seals would also be 3mm cast iron but that is rather difficult to tell without ripping it apart.

i'm a little unsure on the plates but they do look like FB plates due to the Y in the heater line, none of the REPU/RX4 blocks i tore apart had that Y on the rear iron heater outlet, someone with more knowledge on FB irons may know if those are Y plates or R5. IIRC the Y was for the mid range year FB "beehive" oil cooler so it appears to not be a totally original early block. the 3B plates had a hex under the heater outlet to thread the fitting into the block and i don't see that here. 3B plates also had a bolt in the top of the rear iron where the later models had a coolant port to feed the thermowax and cold start assist systems(ie all 13B irons had that port tapped and either plugged or ported, 12A engines just had the casting filled in that spot).

 

I was thinking of just putting it up on ebay or something for 1500+shipping COD. I dont know though i would hate to sell it for that cheap when i could get more you know

 

i doubt you will get much more for even good condition old school stuff, those guys are cheap!

the flywheel is a big chunk of the value though so you might get $2k if you're lucky, without knowing what was replaced and the condition of the internals it's going to be a tough sell.

 

Hey guys here are the side pictures of the ports you guys were wanting. the one is one of the ports up close

 

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looks like an R or R5 middle plate ( later rx4 , oz or US spec primary ) and exhaust ports have had the insert removed and used to feature the banjo bolt up through sump air injection nozzles

look from bottom of engine and check if these banjo bolts that reach into the exhaust runner have been blanked over
this is usually done during engine porting and thumbs nose at the old use of the air pump // however potential owners in some states my require this system to be functional

the exhaust ports look like they may be modified .. or maybe matched up as some of these housings have different exhaust ports suit different states/ markets

 

No telling, if it came from Japan.

 

which it didnt... as they dont receive the R or R5 tall runner middle plate and usually get the N0

 

iirc, the 3B REPU center iron wasn't far off from the R5 tall runner centers so i wouldn't use the center iron as an indicator. but they probably are all R5 irons, if the R5 had the beehive cooler(honestly i don't know, i VERY rarely ever get any first gen work).

exhaust appears to be ported, although not all that much. pressed in early port sleeves were removed.

 

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Im still confused guys on what this is can someone just sum it up and tell me what it is please? Is it a performance special kind of motor or just a normal 13b with a fancy flywheel? I'm Pretty sure i got a good deal on it but it just sucks because the person i got it from didnt know much about it and the stuff he did tell me i forgot and i cant even get a hold of him now because he was just a guy on craigslist. Anyways i thank you guys all for your help very much.

 

late model regulator. talk about another mish mash parts engine. who knows what's inside..

we can only tell you what it appears to be from the shell. the rotor housings are old school REPU/4 housings. the irons are likely R5 from an FB, exhaust port sleeves removed, regulator is FB/FC/FD can't tell you if it is turbo or non since they are indistinguishable. rotors? can't tell you. you can tell us if the compression pockets are machined or cast and rough looking, even then we can only guess what the compression ratio is, since you can only tell by measuring the pocket depths. the flywheel counterweight should tell you what series the rotors are from, if it is correct.