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Index > Engine/Drivetrain > Thread: A few Q's about my REPU (repu newb)
Thread: A few Q's about my REPU (repu newb)
RW-7


1st Gear
Posts: 16
posted April 11, 2009 09:46 PM

A few Q's about my REPU (repu newb)

Wondering what the bolt pattern is for the wheels, How many years Mazda made them, and waht the trans and final drive ratios are in an automatic.
Thanks in advance... :)

       
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RW-7


1st Gear
Posts: 16
posted April 12, 2009 09:56 PM

Well Got the Carby and intake off today to do a carb rebuild and some minor modifications. Went smooth. A little different from the RX-7 carbys I'm used to, but close enough. Also did a compression test and it read 116 psi front and 104 psi rear. Seems to be some good numbers, although I have mostly worked with 6 port 13B's.

Are these good numbers?

       
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RW-7


1st Gear
Posts: 16
posted April 12, 2009 10:00 PM

Oh and I looked in the glovebox and found an owners manual. 4.3 gears in the auto I beleive and 4.6 in the manual. Wow cool chit! Also 74-77 with 4 more inches in the cab in 77. Ya, Ya I've been doin my research!!! :)

       
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Klaus45


Redlining
On two wheels
Posts: 218
posted April 13, 2009 03:13 PM
Edited By: Klaus45 on 13 Apr 2009 15:20

Greetings, and welcome!

So.. what year is your REPU, RW?

Book lists the rearend ration for an auto trans. model as 4.375 in 1974, and 4.111 in 1975; trans. ratio's listed as 3.683(1st), 2.263(2nd), 1.397(3rd), and 1.000 (4th), for all,'74-76... with the '76 5-speed adding a 0.862 top gear.

Does your truck still have the correct, early 4-port 13B ?




       
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RW-7


1st Gear
Posts: 16
posted April 13, 2009 08:29 PM

Thanks Klaus! Yes it has the original engine! 4 port 13B and a hitachi carb. Are those good compression numbers for a 4 port 13B? 74. phoenix blue. I had it runnin a bit today. Bad gas. Maybe some coolant and oil blow by. I will presurize the coolant system soon to see if it has a leak. I found an owners manual in my glovebox, and that answered most of my questions.
Hey do you know what the bolt pattern is for the wheels? and offset?
Thanks again, BTW where are you located? I am in Albany, OR and looking for a tailgate.. Maybe a few other parts.. I talked to BLWFLY he is close and I have known him for a while but he dosn't have any parts for sale..
Thanks again!

       
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Klaus45


Redlining
On two wheels
Posts: 218
posted April 14, 2009 10:37 AM
Edited By: Klaus45 on 14 Apr 2009 10:42

Nice!

quote:
Thanks Klaus! Yes it has the original engine! 4 port 13B and a hitachi carb. Are those good compression numbers for a 4 port 13B? 74. phoenix blue. I had it runnin a bit today. Bad gas. Maybe some coolant and oil blow by. I will presurize the coolant system soon to see if it has a leak. I found an owners manual in my glovebox, and that answered most of my questions.
Hey do you know what the bolt pattern is for the wheels? and offset?
Thanks again, BTW where are you located? I am in Albany, OR and looking for a tailgate.. Maybe a few other parts.. I talked to BLWFLY he is close and I have known him for a while but he dosn't have any parts for sale..
Thanks again!


Compression is a tricky thing on an old rotary... and, of course, it would be preferable if you had close to identical readings for both rotors. But, a rotary can run pretty well, even with fairly low compression... although it might be harder to start. What you're really looking for, more than anything, is even increases in compression for each of the three sides of each rotor, on the way to your max. compression reading...
That said, it would typically be the rear rotor that I'd expect to have an issue, if your engine has been overheated -- and if you have good reason to suspect/evidence of 'coolant blow by'... that's probably what the deal is... in which case, your rotor housings are probably shot, as they get crushed between the steel side plates during the expansion of overheating.

Before assuming that, though: Any white (coolant)smoke out the tailpipe? A certain amount of oil 'blow by' (making it past worn oil control rings) is normal for an old rotary; fresh oil & filter, and fresh fuel treated with a bottle of Techron concentrate (not the Techron-branded injector cleaner) may help condition those old oil seals, and somewhat reduce oil consumption, for a time.

Sounds like you might need to go through (rebuild) your carb., and maybe replace your fuel filter, (and possibly clean out your tank and fuel line, as well)...

My memory may not be accurate, but I believe that our 6-bolt pattern is 4.25" on center... I can tell you that certain Toyota and Mitsubishi wheels will fit... as well as the old Courier ones. Offset, and stoick vs. just how much you can squeeze under the front fenders, especially if you're looking to lower, or autocross, etc., is a whole 'nother bunch of variables. You can squeeze much wider wheels and tires under the back, and run a different offset than you'll need on the front... or, you can run something like a 205/50/15 tire on all four corners, with a fairly standard/common offset rim.., There's several threads about such on this Forum, just do a search for 'Offset', and/or, read Brad's threads on wheels, tires, and suspension. ;)

I'm in Eugene, not too far from you. I have an entire early '74 spare bed, among other REPU's and parts... Not any separate tailgates that are anything to write home about, condition-wise... but the one that goes with the spare (grren) bed is pretty good... and it's the rare 'single stiffener' early one, at that.

You, me, and Chris ought to get together sometime... and you guys might want to bring your parts lists, and some $$$...

       
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