Grafting FC RX-7 subframes.

[MrGable82]

I've searched the threads and can't find anything on this. I've heard of a guy who grafted Miata subframes into his 520, but haven't seen anything about an RX-7. The only reason I'm doing this is because I'm building on a budget and I happen to have an '86 RX-7 with no drivetrain and a trashed body and interior that was given to me for free. I'm no stranger to fab work and am confident that I can make it work but I was just wondering if anyone had already tried and what to look out for. Final product will be a '67 Datsun 520 with '86 RX-7 subframes and a KA24DE (maybe turbo) with a 5 speed. Any help would be appreciated. Please don't make any other suggestions on engine and trans, these are what I've decided on. Thanks guys.

[MrGable82]

Follow-up question:

Anyone happen to know which KA I need to source? I know the oil pans are different between the 240s and the trucks. Thanks guys.

[Charlie69]

Easist to install the engine would be the truck, it has rear sump and the 240sx has front sump I believe.

Edited February 24, 2021 by Charlie69

[MrGable82]

Does that still apply since I'm using RX-7 subframes?

[Charlie69]

I would source the Wankel drive train.  Trying to fit a KA drive train to the RX7 sub-chassis might prove to be more work than you want to do.

 

Here is the link to Bob's MX520.

https://ratsun.net/topic/23159-the-mx520/

 

 

[Lockleaf]

You will need to combine some research.  You need to look to see if anyone has installed a KA in the gen RX7 you have.  That will tell you a great deal about the engine install that you need to know.  None of us are RX7 experts at all, so an RX7 forum may be a better starting place for all your questions.  I don't believe I have seen RX7 subframes installed in any datsun.  Most I have seen is an RX7 solid axle swapped in to some datsuns.

For what its worth, I bought a Miata for $100.  It was missing almost the complete shell, but suspension, brakes, etc was all complete minus steering rack.  Its not the only one that cheap  I have seen.  You might be better off to sell off what you can from the RX and buy a miata.  Then you can follow much of Bob3s build.  And I wouldn't be surprised if there have been some KA swaps in Miatas that would give you good info on the engine to subframe fitment side of things.

[MrGable82]

You've given me a lot to think about. I'll post in the build thread when I make a decision and get started. Still making space in the garage 🤷‍♂️. Thanks guys.