Transmission Swap

[Mattk]

For what is worth, I’m doing a KA-T swap, if I had to do it all over again I would go Miata engine or electric. KA’s are becoming more difficult to find in good condition, where as Miata engines are plentiful, cheap and have a ton of aftermarket nick nacks available. As for electric, prices are coming down and more is becoming available, and you can put batteries under the car in between the frame and slam the center of gravity down low. Range is not going to be great but it will be fun!

Just my hay penny.

[mschel]

Is there a particular miata engine/transmission year range that works best in your opinion?

I have a used leaf motor I ended up with and I saw a bolt in adapter for around 1k. The batteries cost/weight per mile and also getting good tested ones still a challenge along with a custom BMS. I am doing an electric conversion on an old 60s cub cadet tractor with Ford Energi battery modules and a golf cart motor so getting familiar with building the packs with bus bars and custom adapters for motor to transaxle. Its only 48v vs 300v+ for a car but a start.

For what is worth, I’m doing a KA-T swap, if I had to do it all over again I would go Miata engine or electric. KA’s are becoming more difficult to find in good condition, where as Miata engines are plentiful, cheap and have a ton of aftermarket nick nacks available. As for electric, prices are coming down and more is becoming available, and you can put batteries under the car in between the frame and slam the center of gravity down low. Range is not going to be great but it will be fun!

Just my hay penny.

[mschel]

To revisit earlier in thread, I am looking around fb marketplace and not really much in the way of 60s/70s datsun motors other than the 240/260/280 motors that are local.

I did see a later 80s 300zx VG30e and transmission locally that says it needs crank work at 110k but otherwise ok.. The low mileage does make me nervous already needing crank turned.

I think I saw one of those swapped but would need to do a lot of research on it. No idea on fitting the matching transmission in the tunnel without major reworking.

I am also investigating finding just an ok running stock motor/trans for a roadster to get it going again while doing a bigger custom build.

[jamesw]

From what I have learned the easiest swap is to the KA24 - but they can be tough to find.

The next easiest would be the SR20 because there is good support for the swap.

Finally - the original engine is fantastic. Fun to tune, sounds incredible, plenty of power, and there are lots of other intangible benefits.

Finally finally there is another Nissan transmission that will work with the roadster motors - it's an 80's diesel pickup motor. Someone on here will remember the model.

Cheers
James

[Daryl Smith]

Irrelephant

[mschel]

Thanks for the info with more options. If I could find a cheap original motor/trans might consider putting that in to get on road while I continue research on all these options.

From what I have learned the easiest swap is to the KA24 - but they can be tough to find.

The next easiest would be the SR20 because there is good support for the swap.

Finally - the original engine is fantastic. Fun to tune, sounds incredible, plenty of power, and there are lots of other intangible benefits.

Finally finally there is another Nissan transmission that will work with the roadster motors - it's an 80's diesel pickup motor. Someone on here will remember the model.

Cheers
James

[mschel]

After more thought, a high rpm motor would be fun. Watching some random youtube videos with 10k-13k rpm 150-200hp kawasaki, honda, and suzuki sport bike motors in light cars has some gears turning. Reverse, oil pan clearance, and weird mounting would be the problem of course.

https://www.youtube.com/watch?v=IU98_D2sE1U was one example.

Will add your suggestions to my list of research options.

thanks.

The Miata would probably be the easiest modern swap to source, and is a good engine. Up to 2.3L (Ford? version), and lots of parts between the Mazda and Ford variations.
After that the Honda K24 would be the next engine, it is considered the "small block chevy" equivalent for 4 cyl. Tons of them around for reasonable
cost, and lots of go fast goodies for it (did I hear 9,000 rpm?).
You would have to get an adapter for a transmission, but, those are available also.
Sorry, No idea what the fit is like, but, I believe someone on here started a swap a while back.....

The stock engines are the easiest to fit, but, you have to work it over and spend a little money to really get some performance out of it. If performance is your goal, better to start with the newer engines.
I like the stock stroker pushrod engine....simple, basic, and capable of pretty decent power, but, can't compete with a dohc engine. Mine is not quite so simple and basic anymore tho....

[mschel]

Still going through all these options noted. So far the Miata and Acura/Honda K24a(2) along with the sport bike motors seem pretty common and reasonable cost in MD. Not sure how all the little things add up on those though.

Would love to find an original "running ok" motor/transmission for cheap locally as well so I can put back to stock if I ever want to.

Definitely the high rev idea sounds like my direction for a swap. I have a Gt350 top end in my 2016 Mustang GT convertible and love how it sings at upper 7k rpm range.

Eventually electric is my thought but after the batteries get better/cheaper.

[theunz]

Somebody on here was doing a sport bike swap a number of years ago, but I think they may have abandoned the project. Seems like he had it pretty well figured out though. Perhaps a search for Suzuki (I think that’s what it was) or similar will show something.

[mschel]

Interesting. Will have to search for that topic.

Somebody on here was doing a sport bike swap a number of years ago, but I think they may have abandoned the project. Seems like he had it pretty well figured out though. Perhaps a search for Suzuki (I think that’s what it was) or similar will show something.

[Alvin]

Interesting. Will have to search for that topic.

Somebody on here was doing a sport bike swap a number of years ago, but I think they may have abandoned the project. Seems like he had it pretty well figured out though. Perhaps a search for Suzuki (I think that’s what it was) or similar will show something.

AKpilot's Hayabusa-powered roadster:
https://www.youtube.com/watch?v=pX-fC4sMLac

viewtopic.php?t=21410&start=255

[mschel]

Neat video, I am starting to read the thread now. Looks like lots to read on the conversion.

One item I always see on the motorcycle car builds are the these custom or expensive "1 speed forward/reverse boxes". Is there a datsun/nissan transmission that could take an engine spinning at 10k rpm easily? I know on the muscle car side they used to faceplate and do other mods to toploaders etc for that.

I have read a lot about electric motors being coupled to regular transmissions by using basically cutting down clutch disc centers on the transmission welded to some joint or straight coupled to the other end. Would need some way to stabilize it or account for off center movement in this case. Maybe a bearing support and brackets in middle. Maybe a driveshaft coupler on motorcycle end like they do for the reverse boxes and same on the spline where the clutch would normally go.

I see a fair amount of z 4 speeds and also vg30 5 speeds for cheap within an hour of here but most of those motors are 6k rpm ish stock.

Basically are there any 10k rpm datsun/nissan motor builds out there and what would they use? I just need a 1:1 (4th probably) and a reverse so no need for fast shifting etc.

I found a Kawasaki sport bike guy and am going to pick up a cheap frame/motor/trans/everything to run it stand alone and start playing around. I don't want to make any mods to the car that can't be reversed except motor and trans mounts. Since it still has the L18 and R16 mounts I will probably just adapt the motorcycle cut frame to one or both of those as a start. For now just want to experiment with it out of the car so will not make much progress for a bit.

I also have a possible very cheap vg30 transmission in the works in case it will work.

If this project actually takes off will start a new thread.

Still considering a lot of other options but this sport bike setup is cheap enough its worth a try. I always wanted a motorcycle but (probably wisely) stuck to fast cars/trucks!

[mschel]

Just an update. Getting the kawasaki zx12r this week. Supposed to be just the frame and everything needed to run for $1300. Its EFI with supposed 178hp at crank at 10k rpm. When new of course. But from what I am reading its pretty common to build turbo versions making way more so thats on my future radar if I can make the base swap work.

I found a few places that make sprocket to driveshaft adapters. Looking at a few options for reverse.

Once I get going will post new thread.

I am going to try to make adapters that bolt in with minimal mods to the car itself.

Thanks again for all the suggestions. I have the other options as backups in case this ends up being a terrible idea

BTW, I read the other sport bike swap thread and it looks like the driveshaft to reversing box caused a terrible vibration due to angles. Considering a lot of other options for reversing.

[mschel]

Change of plans, the zx12r guy flaked out on me. Drove an hour down there and he had the thing blown apart trying to get it started. Then just disappeared after that. No replies.

Anyway, found an "ugly fairing" 05 Hayabusa for 2k. Needs a starter and hopefully will have it running. Then the teardown etc once its running so can fit to car. Will start a new thread when I have some interesting stuff to post. 175hp/102tq at high rpms of course. I got a t25 turbo manifold off ebay for cheap to see if a turbo would fit. Then I would be in the 250hp range which would be really fun!

I also have a line on a 71c transmission which I will use for forward/reverse initially at least with a coupler to motorcycle output gear adapter/driveshaft/some other coupler/tbd. Good thing is that will also work on a Z supposedly with some minor machine work if this all turns into a mess of an install. If I ever want to go ev there are adapters for it too.

Thanks again for all the ideas/input. Backup plan if this all goes wrong is Honda K, Miata, Ford swap. Trying to find a really cheap stock 1600 motor/trans as well just to have if ever want to return to stock.

Look for a thread once I have something interesting to report.

[Daryl Smith]

Irrelephant