RX 7 Engine in a 124

[donnsx]

Hi,
I'm new at posting here, but thought I would give it a try.
I hope I won't get slagged too much for doing what I'm doing. I am a long time Spider fan and have owned 4 , 124's prior to doing this swap for my son and this is his car. I'm from Canada and when my son turned 16 he decided he wanted to buy a Spider. We flew down to LA and bought 2 Spiders and drove them back to Montreal. Both my sons now have 1 each.
Well the 16 year old drove his for about 2 years and the engine started to get pretty tired. He also wanted more horses and we started looking around for speed equipment and rebuilding the engine. About that time, a friend of a friend, got in an accident with his RX7, getting broadsided at an intersection.
Well the wheels started turning and the tape measure came out. We bought the car for $500 and started our journey.
We decided to change the engine AND trans as a unit.
There were a few issues to contend with,
1. The RX7 engine sits lower in the car and a new crossmember needed to be made to let the engine rest lower. That was done with a piece of 4 inch channel iron, re-enforced at the bends and bolted into the stock mounting bolts.
2. The trans fit well but some cutting of the tunnel was needed to accomodate the clutch slave cylinder. The Fiat trans mount was easily modified to keep the trans where it needed to be.
3. The shift leaver was further back than the Fiat shifter and we needed to modify the shifter to fit in the stock position. That was quite easy, actually and the shifter sits right where the Fiat did.
4. The lower engine and the rotary's exhaust exit interfered with the steering linkage on the right side. We moved the right steering unit down and to the rear slightly to clear but in subsequent driving we have encountered some bump steer. The geometry is not quite right and we are thinking of moving the left side the same amount to solve that.
5. We took a measurement of what length we thought the driveshaft should be and then took the Fiat and RX7 shafts down to the local shop and they fixed us up with a drive shaft that works very nicely. Changing the trans turned out to be a great idea because the 1 thing I never liked about the Fiat unit was the VERY short 1st gear. Problem solved.
At this point, we had a mounted engine and trans connected to the rear wheels. That turned out to be the easy part.
The engine we have is a 1986 13B fuel injected computerized marvel. It runs sooo smooth and revs sooo fast, it makes the 124 very fast, but I'm getting ahead of myself.
Most of the problems have been electrical, getting rid of Fiat wires that are now useless and separating useless Mazda wires from the engine harness. Fiat doesn't have the market cornered on bad wiring diagrams, let me tell you.
The car has been on the road for 2 years and we still haven't gotten all the snags fixed. It is presently in the garage where we are going from front to back in the wiring system to solve those problems.
I think I'll pause here to see how you guys react to our heresy.
Don

[lanciahf]

No heresy. here, I love engine swaps. Any pictures?

Maybe you can convert to a rack & pinion setup to solve the steering problems.

[joelbert2k]

As has been said in the past -- "no pictures, it didn't happen"

Can't wait to see them, sounds cool

Joel

[racydave]

There is no Dad, you guys are all kids!

[So Cal Mark]

I'd like to see those pics also

[azygoustoyou]

The more the pic's, the more happier we are!

[bonezrx8]

Well sir u have my dream engine in your car...
If u wernt too far in tho the wap i would of told you to put a carb on it to make it easer to wire.
A friend and I keep talking about puting a 12A in to his but the funds arenot there
Looking forward to pics too.

Bone

[donnsx]

Okay, I've got some pictures, now I need to know how to post them.
Can someone help?
Please excuse the wires every where, as I said, we are doing a MAJOR rewire.
Also, I didn't mention it before, this whole swap was done in a manner that the car looks completely stock from the outside, except for the shifter.
To answer another lister, if I knew then, what I know now, I would have gone with a carb engine. In my view, the swap would have been a piece of cake.
Let me know how to post pictures.
Don

[lanciahf]

If you email them to me I can post them for you.

stradle124@yahoo.com

[mbouse]

alright you guys, where are your manners?

Don, welcome to the site. thanks for such a lengthy and informative introduction. i am sure that you and your boys have loads of fun together in the garage. i cannot wait to begin that experience with my grandson, but it is at least another 7-8 years before he's ready to sling me the wrenches. i envy you in that.

now... WHERE ARE THE PICTURES???

[donnsx]

Thanks Mike,
As far as my sons are concerned, they are too busy to be much help. They come to Dad for that reason. The grandkids could be different but they are also 7-8 years away from being much help.
Cars have been my hobby since the early 60's. My garage is where I spend as much time as I can. I find these types of projects to be very stimulating. I do all the work that I can, including body work and paint, engine rebuild, and sewing new upholstery. I just finished restoring a 1970 AMX that I've owned since new. After the Fiat is done, I will be doing a 1970 Nova that I inherited from my mother. Right now, I have a spare Lexus V8 that just might end up in the that one.
I got an earlier email from Ralph, who is a lister and I sent him the pictures of the Fiat to post.
I hope they appear in the next while.
Thank you guys for all your interest.
Don

[lanciahf]

[donnsx]

Thanks to Ralph for posting the pictures.
As you can see, the engine is a tight fit. There are quite a few sensors, coils, relays, smog equipment and so on that need to be mounted around the engine compartment. I am on an RX7 forum that will tell me what absolutely needs to be there. My sense is that the air pump for the smog system on this California car doesn't need to be there in Canada, where we don't have emission testing. That doesn't mean that I won't keep it, just that space for an air cleaner is at a premium and it would make that aspect easier to solve.
The engine comes with an engine oil cooler and that is mounted behind the grill opening below the bumper. Two, easy to construct, brackets put that out front but below the rad opening.
Did I say that the RX7 engine runs HOT? So far the Fiat rad has handled the heat but you better ensure that the cooling fan is operating correctly.
The upper rad hose had to be moved to the passenger side and to simplify things, I mounted the Fiat temp sensor to the engine water outlet. This gave me an accurate temp indication on the Fiat guage in the dash. I also mounted the Fiat oil pressure sensor on the engine so it would work with the guage. I have put the guts of the RX7 tach inside the Fiat guage but at the time, I haven't been successful in getting it to work correctly.
One thing I've found is that the RX7 engine flows a lot of air and a bigger exhaust system needs to be added. I'm considering 2 1/2 pipe, dual exhaust but I'll have more on that later.
Once again, thanks Ralph, for posting the pictures.
Don

[digitech]

You certainly have your work cut out for you. I would like to see the Miata engine/tranny swap someone was mentioning before as I think in the looks dept., it would be a bit more Fiat-like. However, I applaud your efforts and keep us posted as you get it sorted out.

[donnsx]

I warned you that the pictures are full of wires. Things are progressing and if I had it to do over I would have taken the Fiat engine out and then taken out the Fiat wires I didn't need any more.
I would have installed the rotary and started it up and gotten rid of the wires from the Mazda harness that were unecessary.
So, we live and learn.
I will be sure to add a couple of pictures when the car and installation are complete.
Thank to all for their comments.
Don