SHO into a 912

[earlybroncoguy]

So, I rescued a sad '66 912 that was headed to the scrapyard many years ago, had big plans for it but not a lot of money or skills. It ran and drove, but had a VW engine in it and rust in the usual places. I took it completely apart and started cleaning, sandblasting, and rebuilding what I could, but got sidetracked and the project got put on the back burner. one thing led to another and 20 years went by. Fast forward to now - moved out to the country, built a shop, realized I'm not getting any younger and better get to work on the Porsche. Admitted to myself I'm not anal enough to do a real "restoration", it's just a 912, not a 911S, and I'm a hot rodder anyway, so might as well build it like I want. Didn't want to go with another VW engine, not going to pay ridiculous prices for a 912 engine, didn't want to go with an LS V8 like everyone else seems to (I've got 3 of those already in other vehicles), decided to swap in a 3.0L SHO V6. Yes, they came with god-awful Ford Tauruses wrapped around them, but the SHO V6 was designed by Yamaha and are pretty sweet little motors. Only 220hp stock, but plenty for a little lightweight bare bones 912. I've searched far and wide, and I haven't found anyone else that's done this exact swap, although I did find people that have put SHO's in just about everything else - a 914, an Austin-Healy, Ranger pickup, etc. Kennedy Engineering actually makes an adapter kit (plate, flywheel, clutch) to mate the SHO block with the Porsche 901 transaxle, but I had actually fabricated my own adapter plate out of 6061 T6 aluminum before I discovered Kennedy. The project is still underway, going slowly as I find time to work on it, but at least it's up on the lift in my shop rather than shoved back in a corner gathering (more) dust. Here's a few photos of the "progess" so far:

[BYprodriver]

Great idea! I never click on this thread but had to check this out, I remember riding in a SHO back in the day, 1992 ish.

FYI Rick Titus made a few SHO into Ford "Festiva" I think & called them Shogun's, Jay Leno bought one.

[earlybroncoguy]

It's tight. but engine lid clears intake.....barely. Oil pan is about 1 inch lower than transaxle.

[Eric at Pelican Parts]

I have to commend you for taking on a different approach and doing a very interesting swap! I'm quite interested to see how this swap goes. Please do keep us updated!

[jadewombat]

Updates? Those are great engines.

[jadewombat]

I thought the block on those was ceramic??

[earlybroncoguy]

https://en.wikipedia.org/wiki/Ford_SHO_V6_engine

[earlybroncoguy]

Had to fabricate another rear engine mount crossmember, the first one I made to clear the A/C compressor ended up too far away from the factory 912 engine mount brackets - so I decided to get rid of the A/C compressor and it's heavy cast iron bracket (saved 35 lbs) and simplify things.

I used an aftermarket tubular crossmember that's made for swapping transmissions into hot rods - it's nice and strong, and the bend in it clears the SHO oil pan perfectly. I fabricated plates to bolt to the sides of the engine block and the brackets between them and the crossmember, and used round tubing to attach the ends of the crossmember to the factory Porsche engine mounts.







I ordered a custom flywheel from Kennedy, it will bolt to the SHO crank, mate with the original Porsche starter, and allow the use of a 228mm (9") clutch disc and pressure plate. I also picked up a set of 30mm diameter rear torsion bars, which will be needed to support the added weight of the iron block V6.

I fabricated an adapter plate to bolt the SHO block to the bellhousing of the 901 transaxle out of 5/8" thick 6061 T6 aluminum. It wasn't complicated but having to clearance a "pocket" in it to clear the bolt-on breather at the rear of the SHO block was a little tricky, and I ended having to use countersunk bolts for two of the plate-to-transaxle mounting holes to clear the breather and the SHO oil pan.




Once I had the engine mount done, I bolted the engine in to the Porsche and raised the entire vehicle on my 2 post hydraulic lift to find the center of gravity - it ends up right at where the rear torsion bars are located, which is pretty far back. I had to put some weight in the trunk (battery and spare tire) to keep the car from teetering on the lift arms.

[kach22i]

Originally Posted by earlybroncoguy

https://en.wikipedia.org/wiki/Ford_SHO_V6_engine

Fascinating link, and your project is remarkable.

Love seeing that old Bronco in the background.

[earlybroncoguy]

Thanks- the Bronco is another long term project, drug it out of a field back in 2001 and have been working on it off and on since then. Stripped it down, pulled the body off the frame, had it sandblasted and powdercoated, built a 351W, dropped in a ZF 5 speed, Dana 44 front and 60 rear (full float) axles, converted them both to disk brakes, etc. It's coming along.

[kach22i]

Looks strictly off road from that stance, and a lot of fun.

[earlybroncoguy]

The flywheel arrived from KEP, they do nice work. Clutch face is machined for a 228mm (9") clutch disc and pressure plate.




The 8 holes for the crank bolts are drilled perfectly, the center bore is a nice tight fit over the lip at the rear of the SHO crank, and the ring gear for the starter just BARELY squeezes into the 901 transaxle bellhousing. They include the bolts and a roller pilot bearing.





Man, those are some big honking cylinder heads, aren't they?

[ClausGraf]

I like this swap!

[Burny]

Very cool. Subscribed!

[EuroShark]

Awesome project! Love the Yammahammer!

[Andy Somogyi]

Sweet swap indeed, following with interest


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[MrRPJ]

whats happening here??? no updates

[earlybroncoguy]

Haven't made a ton of progress lately, so many other things going on don't have as much time as I would like to spend in the shop. I did spend some time (and some money ) trying different options to fit the huge SHO intake manifold and throttle body into the 912 engine compartment.

The bolt pattern and intake ports on the intake manifold are symmetrical, which allows the intake to be installed either "forwards" or "backwards" on the engine (throttle body towards front or rear in a longitudinal installation), but unfortunately neither option will work well for my 912 - since the throttle body is at the extreme end of the intake, it would either be protruding through the firewall, into the back seat area (if installed frontwards), or several inches outside and above the engine lid (if installed backwards).

I considered using a 911 Turbo engine lid and whale tail to allow room for the intake and throttle body mounted facing the rear of the car, and even purchased an aftermarket fiberglass engine lid and whale tail, but the fit of the throttle body was still too tight, and I really want to keep the body of the 912 looking as stock as possible.

I ended up deciding to block off the original throttle body opening in the intake manifold, and instead use the opposite ends of the plenums, which are normally connected by a crossover tube. The openings in the ends of the plenums are 2" in diameter, which if combined, gives more area than the original stock 65mm opening - and, with the use of mandrel bent aluminum tubing to mount the throttle body in a different location within the engine compartment, allow the intake to fit under the stock 912 engine lid. Maybe not the most ideal situation, but doable.







I'm still in the planning stages, so the tubing is held together and in position temporarily with silicone couplings, once I know where everything will fit it will be tig-welded. To enable the use of a single throttle body, I used a 2-into-1 collector fabricated from stainless steel that's normally used in custom motorcycle exhaust systems.

I'm also working on mounting a small, lightweight, 90 amp single-wire alternator to replace the heavy stock Ford alternator. The original alternator mount was also the air conditioner compressor mounting bracket, and was a huge lump of cast iron. Doing away with that, the A/C compressor, the stock alternator, and power steering pump and bracket dropped a lot of weight off the engine and cleaned up the looks as well.

[dtakenname]

Keep going!
Very interesting.