vw diesel into a mazda rx7

[bigblue]

I don't know what my rpm is at 70mph in my b4 since it's not my primary driver and it's got a canadian speedometer. My best guess is 1900rpm but that could be off.

 

[12MPGHWY]

my A3 is between 2200-2300 at 70.

the mazda rear end is 3.9 the mazda 5th gear is .71 1st gear is 3.475

 

[lews930]

My mazda turns 2700 at 70 mph so I should be good to go if i use the mazda box

thanks
lewis

 

[Pat Dolan]

Lewis:

You've got e-mail

Pat

 

[lews930]

thsnks pat. Going got machinist today. Perfect timing I might add. We'll see what he has to say

lewis

 

[lews930]

Ok, the machinist tells me no problem. the catch is $65/hr and 15-20 hours. That was a little more than I had planned but doesnt kill the project. If I could only get the drawings for the rear of the VW engine and the clutch assembly that would save some $$$.

BTW, how does the clutch get actuated on these VW motors?

thanks

lewis

 

[bigblue]

I sent you a PM

 

[Frankendiesel]

BTW, how does the clutch get actuated on these VW motors?

Hydraulic clutch - master/slave configuration. Pretty standard. You should be able to adapt it to your car (if it has a hydraulic clutch master) by simply hooking them together with the right line. If you have a hydraulic/hose shop in town, they should be able to build you a line with the right connections on either end.

Good luck!

Travis

 

[lews930]

Thanks frank. I knew it was hydraulic, I meant the acutual working end. I see the fly wheel comes off first then the pressure plate(BTW, how do you remove the pressure plate?)

My Mazda has the pressure plate outside of the fly wheel with the t/o bearing visible. any body got a pic of a clutch assmbley?

And yes the mazda has a hydraulic clutch as well. I am planning to use the mazda tranny to make thing simple and also use the mazda fly wheel.

thanks

lewis

 

[Pat Dolan]

Lewis:

We need to give you a bit of a primer on the different versions of VW stuff:

The older transverse engines used a pressure plate bolted to the flywheel, but the newer cars all use a conventional flywheel on crank with ordinary pressure plate (clutch cover) bolted to that.

The TDI cars used a "DMF", or dual mass flywheel that is both heavy and expensive, but the standard upgrade for performance guys is to use a G60 (that was the G-lader supercharged 1.8 gasser used in the 4 cyl Corrado and some early Passats). All inline 4 banger VWs (not sure about the 1.8T and 2.0 FSI) up at least until 2000 use the same crank bolt pattern. So, if you find a 4 cyl VW or Audi car you are on the way.

Before getting too far down the road, you REALLY need to score the drawings for the VW side. Remember that you need to accomodate a starter on the engine side (to match the flywheel as well) AND squeeze that into the Mazda bellhousing (the starter nose will stick out). BTW: If you want to low-buck the flywheel/clutch (and maybe starter) look for a Passat, Fox (either Audi OR VW) or Dasher with a 4 cyl. They will have the bits you need.

You should now be starting to see why an adapter from Kennedy is a bargain. Even at 65 an hour (a very low price for machine work in these parts) it can add up over a grand before you get anywhere near a running assembly if they have to start generating numbers from engines and trannies.

Pat

 

[lews930]

ThanksPat, now we're getting some where. I plan to have the Mazda fly wheel adapted tothe VW crank so I will be able to use the Mazda starter.
Kennedy doesnt offer a adapter plate to fit the VW water cooled motors.
BIGBLUE on this site sent me a cad drawing of the engine. forwarded it to the machinist to look over.
Now to remove the pressure plate? I looked at it real quick while my 4 year old was biggin me to pick black berries, had to go!

thanks
lewis

 

[12MPGHWY]

you need an aftermarket mazda flywheel, and will need to make an adapter plate, Stock mazda flywheels use a gland nut.

ALL aftermarket rotary flywheels look like standard flywheels and bolt to the counterweight used by a rotary with an automatic.

The gland nut stock flywheel has the counterwieght built in.

 

[lews930]

Thanks 12mpg. I didnt take that into account. That's the kind of help I'm looking for. I did some test fitting of the supra intercooler last night on my bare chassis and it looks like it was made for the car. I will neeed to run the pipes through the area where the a/c lines run through but should work just fine.

 

[Pat Dolan]

Lewis:

You aren't that badly off in the flywheel department.

MANY of us here (my turn hasn't come yet) have converted their TDI DMFs to G60, so there is a mess of DMFs out there that nobody wants. You need one to cut the center out for your new flywheel. You need an old Mazda recip unit (i.e., no counterweighting - or you can just machine the bits on an old rotary to clear off the excess counterweight material) and bore the Mazda unit to the same diameter as you cut the center out of the VW one. The bit that is critical is to measure the depth of the clutch surface, remembering to add you adapter thickness, to locate the distance from the VW crank flange to the Mazda clutch surface. Do this BEFORE cutting anything up, since the two may not match, and you may end up needing an intermediary piece to connect the two. Press everything together and weld the seams CAREFULLY (to keep things round, little opposing stitches to start with - then burn them together) and then you pretty much have to re-finish the flywheel and re-balance.

BTW: Could you ask BIGBLUE to share the CAD drawing? It may be the most valuable bit of VW tech stuff in the world of swapping (engine, not wife).

 

[12MPGHWY]

I just did the clutch on my TDI (98) standard flywheel.

I am very sure that the OD of the flywheel is significantly smaller than the OD of the mazda flywheel. This is just going by eyballs, check this one out for yourself it may work.

One very important point,

Mazda turbo and NA cars use different flywheel clutch combo's with a different spline on the input shaft.

You will be hard pressed to find an NA clutch (actually I think it would be impossible without making something custom) that will handle anything close to 300ft pounds of trq.

a NA 13B even modified to the max can make at most 300HP and about 175 tq.

A turbo aftermarket clutch would be no problem.

I am pretty sure you also can't use an NA disc in a turbo flywheel/Pressure plate, the NA and turbo discs are different sizes. But this option would be something to investigate/call racing beat or mazdatrix about.

 

[bigblue]

Lewis:
BTW: Could you ask BIGBLUE to share the CAD drawing? It may be the most valuable bit of VW tech stuff in the world of swapping (engine, not wife).

I just found it on a website a while back where somebody swapped a TDi engine into a vanogan so I saved it. I remember somebody else mentioning that website on this forum so I'm surprised nobody else chimed in before me. For a limited time I'll host it.

http://henry.binrock.net/1997_passat_tdi/tdi_engine_cad_drawing_small.pdf

 

[lews930]

Sorry BigBlue. I should have asked before I shot my mouth off. Hope I didnt create a monster.

 

[RoundHouse]

Will a toyota pickup 5 speed fit under the tunnel?

 

[lews930]

It will fit but the shifter location is wrong and I'm not sure it can be coerced into being moved 8".

Anyone know the hp rating of the VW starter motor? I'm not so sure the Mazda unit will work. at least not for very long. Or is that an issue?

Pat, would it be logical to redrill the Mazda fly wheel to fit the VW crank? I suppose I could use a dmf fly wheel hub as a spacer if needed. BTW, anyone not needing their old fly wheel I could use it

thanks

lewis

 

[12MPGHWY]

The Mazda turbo starter motor is supposed to be better than the NA version.

Although I don't think its a huge issue, I have use the mazda starter to get the car up my driveway before with no ill effects

 

[lews930]

After reviewing the drawings the machinist tells me he can do the adapter for $350. He could not quote the cost for adapting the Mazda fly wheel to the VW crank.

I'm not sure what to do about the pilot bearing that will be missing. The Mazda's bearing sits in the end of the eccntric shaft. Soother than a really thick spacer between the crank and fly wheel I dont know what to do.

Any deas?

I'm suppose to take the VW and the tranny to the machinist again on Monday for measurements to adapt the fly wheel to crank

lewis

 

[bigblue]

I'm not sure what to do about the pilot bearing that will be missing. The Mazda's bearing sits in the end of the eccntric shaft. Soother than a really thick spacer between the crank and fly wheel I dont know what to do.

Could you mean the mazda's bearing sits in the end of a concentric shaft? That's generally how they go together but I suppose a wankle shaft may have been machined with an eccentric bearing blind hole in the end. Either way if you bring your machinist the enigine and transmission he should be able to figure out what to do. 12mpghwy probably knows them much better than I do.
Can you put up pictures?

 

[lews930]

Nope it's the ecccentric shaft. And the bearing is installed in it.I will need to take the rotary the Vdub and the tranny to the machinist. Thisis where a rabbit p'up would be nice

I did a test fit today(sorry cant upload pics, I dont know why). the only issue I see now is the p/s pump wont clear the steering rack. can I run the motor without p/s and if so how is tension applied to the water pump pulley?. That is the big hurdle now but should be able to over come it

Big blue, in regards to the clutch/fly wheel is it possible that the early 1.9 TD had a backwards arrangement? The fly wheel is removed firt then the presuure plate. I'll send pics to anyone that will provide me with threir email address

lewis

 

[12MPGHWY]

Smaller belt and run without PS would seem like the way to go. Not sure how the belt would be adjusted though as the belt is adjusted by moving the PS pump. If you could find a perfect sized belt then it would probably work without an adjustment.

If you do this there is a mazda manual rack, that has a lower ratio. I have that one in mine and I like it much better than PS.

Than manual rack was available as an option on all 86-88's

 

[je]

I drove mine for a while with the PS fuse pulled. Steering was hard at low speeds, but it was a lot more fun. It should be easier to do with the PS fluid ports at the rack bridged, not pushing against that pump.

Like above there's a manual rack available if you look around. Not sure how easy it is to find any more.

 

[12MPGHWY]

Its easy to find the manual rack, allmost all base model cars from 86 to 88 have it, which seems to be the mazority of FC that where sold it was also optional on all the other cars. My uncle had an 87 T2 with a manual rack, Have also seen a few verts with it.

They come up on Rx7 club freqently for under 100 dollars. I remember when I went to the junk yard to get one a few years ago there where about 5 to choose from out of maybe 8 rx7's between the 3 pull it yourseld yards in san diego

I drove mine for a while with the PS fuse pulled. Steering was hard at low speeds, but it was a lot more fun. It should be easier to do with the PS fluid ports at the rack bridged, not pushing against that pump.

Like above there's a manual rack available if you look around. Not sure how easy it is to find any more.

 

[lews930]

the type of steering rack is not the problem. And yes I'm aware that there is a manual rack available. I parted several 7's in the past 2-3 years. Good money BTW. The location of the rack is the problem.

After the machinist visit today I'm going to bring my bare chassis to the front of work shop so that I have concrete to lay on. That way I can jack it up to get better visual on things.

lewis

 

[12MPGHWY]

I wasn't talking about a clearance issue, I just had a bad experience with a PS rack minus the lines and seal (depowered the proper way). The worm gear on the rack stripped leaving me with stuck steering on a tight right turn, and the rack was properly adjusted, the fact is that a PS rack isn't designed to take steering forces through the worm gear, all the steering forces with PS are put into the seal and the "shaft?" directly by the hydralic fluid.

I had to use the ebrake to bring the front end around, and Had I been going any faster I would have been in a head on crash.

Although the manual rack is actually smaller, I initially had a clearence issue on my car with the 13B-REW where the oil pan was, there was 2mm of clearance because I made my engine mounts a little low... No issue with the manual rack.

 

[Rub87]

I must also say you should drop the NA rx7 tranny.. these ones are totall crap, even with the sucky NA engine 150hp or something like that, and half the torque of the diesel they go bad pretty soon..

Use a TII, they will take Alot more and have better ratios..

 

[Frankendiesel]

On the note of PS options...has anyone looked into adapting an electric PS pump from, say, a Saturn Vue? I believe GM even turns it off at highway speed = more efficiency. Haven't priced one yet though. You can remote mount the little turkey pert'near anywhere you want (trunk?) just need a custom hose set to adapt up to the Mazda rack.

Travis