Does anyone know the center to center distance on the mainshaft and counter shaft? Also looking for front case inside dimensions I.E. side to side and depth.
This is part of my kooky search for a transmission solution for my Datsun; looking to see if it is possible front case from Datsun and slide it over Miata gearset and bolt it to rear half (I said it was kooky)
Tom
I'll get a measurement from my open rx7 box this morning.
Same internals as the miata...
Much appreciated, I'm pretty much whizzing up a rope trying to get around spending 3k for a box with decent ratios that won't break.
Tom
ohh, you said wont break. These things are not known to survive well behind 180 hp and 150 lb/ft of torque in a racing situation.
BTW, I have the box and bellhousing at work with me. Just need to get the dimensions...
Tom1200 wrote: Does anyone know the center to center distance on the mainshaft and counter shaft? Also looking for front case inside dimensions I.E. side to side and depth. This is part of my kooky search for a transmission solution for my Datsun; looking to see if it is possible front case from Datsun and slide it over Miata gearset and bolt it to rear half (I said it was kooky) Tom
Yes........ The Nissan bell would be an SR20 bolt pattern
ohhh, newer Miata.
I have the old type without a replaceable bell...
still need dimensions?
Mazda trans haven't had a separate bellhousing since the r-type, found in early rwd cars and the later turbo RX-7. According to an old RX-7 race prep manual, the older separate bellhousing trans has a center-to-center distance of 73.5mm; the new trans without separate bellhousing has a CtC distance of 68.5mm. Exchanging gearsets made by different companies is very likely not feasible. Changing the entire trans would be more cost effective.
OK I should have been clearer:
This is for my Datsun 1200, AZ6 will not fit in the trans tunnel.
I am talking about Miata 5 speed, this is equal to Datsun Mid-Close trans.
Then Mazda trans and Datsun 210 5 speed use the same input shaft bearings. The thought (however damaged) is slide the Mazda bell-case off and slide the Datsun bell-case on. There is a whole lot more to it than that.
I have an ultra close 56 series box in the car but after a while these shred 3rd.
Current bolt in options are T-50 bellhousing adapter for Datsun A-series from Dellow $700 and Cusco close ratio kit $1800 (if you can find one) or $3000 from Houseman. Still requires custom drive shaft.
Use 1200 Auto bellhousing to make an adapter for a trans with a true bell housing. Ford rocket boxes have $1000 gear kits or use XR4Ti 5 speed.
Find somebody in the world who would modify a cluster gear for my 60 series box (these have crazz wide ratio)
Modding a bell housing is way more technical then people realize
Finally wvumtnbkr please let me know the dimensions on that 5 speed.
sorry. I will get those today. still have the housing with me here at work.
Thanks
If the trans you want to use won't fit the tunnel, there might be the option of modifying the tunnel or swapping to a different tunnel that has plenty of room. Here's a link to my RX-7 build (RX-7 build link) which has had the center part of the tunnel cut out and re-installed, which isn't much different than cutting out the old tunnel and replacing it with a larger tunnel. The RX-7 is a great tunnel donor, as it's usually much larger than the tunnel that most piston engine cars come with. It's so big that plenty of RX-7's get T56 6 spds installed without any tunnel mods at all. Just throwing it out there as a possible option that you might not have thought of.
Also on that page (about halfway down that same page) is a bellhousing fabrication project that might interest you. It's basically shows the steps i took to make a bellhousing to adapt one maker's engine to another maker's transmission. Here's the link again, TNTRC.com
Very nice but the problem with what you've done is you have actual fabrication skills. I have an excellent fabricator but need to,get an up tigon with the fewest modifications. I currently have a Datsunauto bell housing that can be used as part of the adapter but as you know it's still a good bit of work.
Has any headway been made with this project?
I know this thread is 7 years old but I wanted to update it as I think it may help anyone searching the net:
So I never ended up doing this for several reasons;
The Miata trans is several inches longer and the shift lever would be in an awkward position.
It would require modifying and or using a custom clutch disc (part of the intent was to have off the shelf parts vs hard to find NISMO stuff)
The input shaft of the Miata trans would need to be turned down or the crankshaft drilled to accommodate the pilot bushing.
At the end of the date it was going to be easier to simply change the final drive ratio so that most tracks would only require the use of 3rd and 4th gear.
Does a T5 fit in the tunnel?
http://datsun1200.com/modules/mediawiki/index.php?title=T5
Shifter goes wherever you want, with those.
matthewmcl said:Does a T5 fit in the tunnel?
http://datsun1200.com/modules/mediawiki/index.php?title=T5
Shifter goes wherever you want, with those.
It's to big. In the intervening years I picked up an auto trans tunnel......that will open up some options.
Regardless it still comes down to what will bolt to the motor.
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