12a Sand Rail project
 

Thought I would post up a few pics of my Rotary-rail build.

Here it is a few months back. It's an '81 Berrien shortback. Around 1000lbs fully loaded, street registered. Originally, this car had early-beetle swing axle suspension and single-port 1600cc VW motor making around 30hp.

http://bfhracing.org/duck/newrail.jpg

This winter I've been converting the suspension from swing-axle to IRS. It took a long time, but now that it is complete I'm concentrating on building the motor.

http://bfhracing.org/duck/railsusp1sm.jpg

http://bfhracing.org/duck/railsusp3sm.jpg

I purchased a 12a motor along with the Kennedy adapter for about $700. I'm doing a junkyard rebuild and port with the help of Chris Ludwig of Ludwig motorsports. Here's what the engine looked like a few weeks ago.

http://bfhracing.org/duck/12aapart1.jpg

When I first did a compression test, some really nasty sludge came out of the oil cooler. It was definitely water/oil mix, and so fearing the worst Ludwig and I disassembled the motor.

This was a bad sign. Oil pickup tube is covered in what look like chunks of bearing, and there's a very obvious hole in the screen.

http://www.bfhracing.org/duck/12aapart2.jpg

Here in the oil pan, you can see the chunks of crap that were all over the inside of the motor.

http://www.bfhracing.org/duck/12aapart3.jpg

Baby-poop colored oil all over everything usually indicates disaster.

http://www.bfhracing.org/duck/12aapart4.jpg

This sludge had the consistency of watery-mud, but there wasn't really any grit to it.

http://www.bfhracing.org/duck/12aapart5.jpg

After fearing the worst, everything looks to have survived pretty well. The bearings, stationary gears, rotors and e-shaft are still useable.

http://www.bfhracing.org/duck/12aapart6.jpg

The housings are in good shape as well. This is probably the best possible outcome I could have hoped for. Since this is a junkyard-dog rebuild, I'm going to reuse the hard seals.

http://www.bfhracing.org/duck/12aapart7.jpg

http://www.bfhracing.org/duck/12awork1.jpg

http://www.bfhracing.org/duck/12awork2.jpg

http://www.bfhracing.org/duck/12awork3.jpg

http://www.bfhracing.org/duck/12awork4.jpg

http://www.bfhracing.org/duck/12awork5.jpg

http://www.bfhracing.org/duck/12awork6.jpg

http://www.bfhracing.org/duck/12awork7.jpg

http://bfhracing.org/duck/12aport.jpg

http://www.bfhracing.org/duck/dellorto.jpg

http://bfhracing.org/duck/12aparts.jpg

It's coming along nicely.

WOW!!! That thing looks like its gona be a hoot!!!

You're doing well. Keep the progress updates coming!!

looked like it had a bad water seal. progress looks great. let us know how it runs.

http://www.bfhracing.org/duck/12aready.jpg

Everything is ready to go and I'm very excited. Final assembly sometime this week.

Here's hoping I can make DGRR.

Plan on moving some weight up front. I had a Berrien rail years ago that I hung a VW GTI engine on. It had about 150hp and would launch the front wheels at with little effort from a stop.

Buy a turn brake if you don't already have one.

Turning brake works great.

I've done my best to keep track of the weight. The 1600cc weighed 220lbs fully loaded. The 12a short block with the stock water-pump and bee-hive weighed 217. I'm using a late model water-pump housing. The manifold and carb weigh about 8lbs. My goal is to keep the motor under 260lbs.

I'm looking at buying wheelie bars or at least a skid plate.

You sir are my hero.

But I'd flip the ring and pinion and turn the trans around. Mid-engine Rotary dune buggy FTW.

Probably not enough room though.

Nice project!
//Magnus

Nice project, lookin good. Does anyone know what center iron is pictured on the above engine with the tall ports and the rectangle egr port below them? I have the exact Iron on my 12a and when I go to Racing beat or Mazdatrix to get an intake gasket they have no idea what plate it is. All the intake gaskets they have are for small port with the exhaust port below or tall port with no egr port below. They said it might be from a Japan spec engine? Can anyone comfirm?

Good question. I ordered the late-model gasket set. I haven't checked to see if it would fit.

Uhg. That is a Y intermediate plate. They came in 12As from '81-'85. Very I mean VERY common. For Mazdatrix to confuse you like that...

The gasket must cover the ACV port below the intake ports. If not, you'll have a very audible exhaust leak. So avoid the '76-'80 gaskets which, while they have tall middle ports, lack coverage over the ACV area. Only get '74-'75 or '81-'85 intake manifold gaskets. And if you're like Ducktape, whose weber manifold I assume has tall runners in the middle, all you need to do is spend a little time with an exacto knife or similar to trim a small amount of gasket above and below the holes. Or if your manifold has short runners like stock or some RB Holley manifolds, leave the gasket alone as there is no need to enlarge it.

I've found it extremely easy to trace the tall runner shape on a short runner gasket by having access to both styles. I don't recommend buying both, but if you have access to both, it makes it easy. Otherwise line the gasket up on the manifold, taking care to keep it aligned, and carefully trim the excess gasket material.

Well, I would love for you to show me a gasket that hasn't been cut at all that matches that plate- tall ports with the ACV port below them. Racing beat is right next to my house and they pulled every gasket possible for the 12a and none of them work. I had to use the gasket with the small ports and ACV and had to cut the gasket out to match the tall ports. With Mazdatrix it was the same story so I don't know what you mean by very very common. :Wconfused

The gasket you seek doesn't exist. Racing Beat and Mazdatrix are correct. That's why I posted an explanaition for how a person can create such a gasket and described two ways ie the gasket trace method and the match it to a manifold method.

Like I said, the Y plate is very very common. What did you think I was talking about? The gasket? That's not what I said at all. lol

Looks like you wound up doing what I described above after all. Glad it worked out in the end.

No, I was wondering if the y plate was so common then how come they don't make a gasket for it? Are you telling me Mazda made these engines and hand cut every f-ing gasket for these plates? Sorry, if I sound pissed it's just I think it's stupid that they dont' make a gasket for this engine. It makes no sense. It's not a big deal to cut the other one out but it took awhile to ask around and go thru the hassle of finding out they didn't make a gasket for this plate.:wallbash: :wallbash:

They do make a gasket for this engine. '81-'85 as mentioned. There is no need to cut it when used with a stock manifold.

Sorry for mucking up your thread, ducktape.

Alright, I guess we aren't on the same page. Since you don't understand what I'm talking about as clearly stated above, I'll make it real easy. Show me an intake gasket that has the tall ports and the ACV port, uncut.

I guess I could take a picture of some gaskets.

I hope this isn't confusing.
https://www.rx7club.com/forum/attach...1&d=1233290333

^Alright, now were talking. Ok, the first gasket on the left is the 81-85 12a, but it only has the small ports and the ACV. So my big question is why would they make an iron with tall ports and an ACV and not offer a gasket? If you just bolt on that gasket without cutting them to match the tall ports then you just created a huge restriction and loss of power. So that is why I and Racing Beat could only think that they may be a Japanese or Euro spec engine? I don't know but it makes no sense to me. When they built these 12a's with the tall ports what gaskets did they come with?

Update: Brought the motor home from Ludwig's
 

http://ludwigmotorsports.com/ducksfbt/P1010009.JPG

http://ludwigmotorsports.com/ducksfbt/p1010012.jpg

http://ludwigmotorsports.com/ducksfbt/P1010014.JPG

http://ludwigmotorsports.com/ducksfbt/p1010016.jpg

http://ludwigmotorsports.com/ducksfbt/p1010017.jpg

http://www.bfhracing.org/duck/12adone1.jpg

http://www.bfhracing.org/duck/12adone2.jpg

http://www.bfhracing.org/duck/12astacked.jpg

In this state of dress the motor weighs 225lbs (dry). I expect in running condition with fluids it'll weigh in the neighborhood of 250-260lbs.

/The VW type I motor this engine is replacing weighed 220lbs

Yeah, Zenjoe says a rotary weighs 40 pounds more than a VW. Great progress!