Open track day and parts runner build

[Advancedynamix]

The 1.5 was here in the protege. Non vvt.

That is the z5. It has a different head than the zm/zl. I also think the crank may be different and I know it has the 2 piece oil pan. Still not a bad engine to swap, and it's more adaptable than the ZL/ZM if using stock festiva management because it has provisions for a distributor. The injectors are the same style as the 90 up festiva as well.

Another thing worth noting about the z engines is that they have a tighter cam pitch, so the engine mount will be easier to adapt than the b series engines. The mounting points on the block are a little different iirc, but the Z series mount is pretty easy to adapt to a festiva mount.

[David88]

Very interesting discussion guys. I had been seeing that car on craigslist. I thought it looked like it had good potential. Looks like its got a bright future. Glad you saved it.

[blake4591]

I'm pretty sure your right that the z series have a better rod ratio than the b series from Mazda. The problem is that when most people go to upgrade the z engines they just go the the b6 parts bag for internals. If some of the mounting holes are different, I wonder if the xr2 intermediate shaft would bolt to the z series. I know that they used intermediate shafts but I'm sort of curious about the bolt pattern now. I'm going to go through my power-train options and make a list tomorrow to keep everything organized.

David,
Yes the car will have a better home now. It's in OK shape, its got plenty of dents and dings, and needs a complete cleaning of everything but it should come out nice.

[Advancedynamix]

I will check the IM shaft compatibility the next time I'm at my storage lot. I hadn't even thought to check that.

[blake4591]

I have been thinking about what my engine options are for this build and wanted to sort of outline everything for everyone, as well as myself, to reference.


1. Use the BP that’s in the blue car and put a b3 back in it. This was my original plan but requires two engine swaps and a little wiring on the blue car to switch it back to a b3. This is the lowest cost since I have the bp and b3 already. It does however require finding a 90 to 93 festiva to pull the engine half of the wiring harness out of and then setting that up as a standalone for the BP. This of course does require some cutting to get the BP in the silver festiva happily and an intermediate shaft mounting bracket to make everything work.

2. Use a b6 (NA capri motors are about $200, turbo motors are going to be more and be harder to find). These obviously are going to have the best fitment and won’t need any special pieces to mount the intermediate shaft. The N/A motor is probably the only option that could possibly use the 89 auto ECU and engine harness, but I’m missing enough of the engine side parts (sensors, throttle body, distributor, etc.) to make this a pain. I also think that while everything is out of the car I should set it up has a standalone engine harness so if I ever want to go to an aftermarket ECU it’ll be a lot easier. I’m considering the B6T since if I’m going to buy an engine I might as well go with as much power as I can buy. It’ll probably be the most expensive and the most rewarding when done. This will need a harness made and a bunch of other things. I’ve done a turbo motor swap before so I know what I would be signing up for and really wasn’t planning this much work and investment for this project.

3. Use a ZM since it's the evolution of the b6. I looked at the ECU and engine wiring for these engines and think I could get it up and running with a factory ECU and modified harness without too much trouble. The big question here is what is the potential of these motors and what are all the little differences with a b6 that are going to cause problems with the swap. Like, Charlie said the head has a lot of improvement over the b6 but it looks like to make power most people go to a turbo with b6 rods and pistons. With forced induction I think either motor could easily make the power I want so it’s not completely necessary to go down an unproven path but there is some cool factor to saying I did it.


Any of these engine options are going to have a G series trans and the XR2 axles. I’ll have to sort out want trans exactly to try to complaint the motor choice has much as possible with the ratios.

[Advancedynamix]

If you decide on a b6t then don't bother with the b6t. The ex. Manifold is problematic, the turbo is outdated and the super low compression is unnecessary. An automatic Capri engine with manual miata/Capri exhaust cam and a fabbed exhaust manifold with a better turbo would save you time and money in the long run. The b6t management just dumps tons of fuel to keep the engine safe, but it's hard on turbos, oil and rings.

[william]

Are the auto capris higher compression?
I knew they had a different exhaust cam but thought that was it.

[blake4591]

Well I primed most of the interior panels last. One can of x2 primer is enough to do everything except for one of the rear seat side panels. I also did the first two passes over the seats and got most of the stains off them. I'm going to go over them once more with cleaner and once with just water to try to pull the most of the cleaning chemicals out this weekend. I still haven't decided if I want to sell them or just put them in my 93. I also took a very close look at everything that came with the care and realized I actually have a decent amount of the 89 fuel injection stuff. The guy I bought the car from was actually right that the intake was for an 89 and has all of the correct parts bolted to it. The biggest problem is I don't have the distributor. A quick check on rockauto revealed that they are quite expensive. So, I'm still leaning toward pulling all the 89 only stuff out of the car just to not have to deal with it any more.

Charlie, I think your right about the b6t, it's not really worth the time if you don't already have the parts. Some checking revealed only high mile engines for high prices. I thought it might be worth it to get the turbo parts (rods, injectors, etc.) that are going to drive up the cost of adding a turbo on later but I'm thinking there isn't enough usable stuff to justify the extra cost (there's really no money to be saved). The manifold and turbo leaves a lot to be desired and limits you to only that setup or something custom, so very little to be saved there. I'm not super familiar with all internal differences other than the rods and compression, but I don't think the turbo rods would be necessary since the people have had good luck making power on the N/A rods, so again very little to be saved. I believe and to william's point, that the N/A capri motors are very similar except for the cams and some sensors, and the auto miata engine is also closely related to these. If this is the case I can pick these up in running condition very cheaply. This does still leave the question of the ZM which is about the same cost of the b6d. I also think it might be easier to get running with a stand alone harness since I have all the wiring diagrams for it and 2000 proteges are more common to getting the starter harness out of. If you can confirm the fitment of the intermediate shaft I'll probably per sue the ZM engine, if it's a no go on the fit I'll probably pick up a B6 for ease of getting everything put together.

[Advancedynamix]

Are the auto capris higher compression?
I knew they had a different exhaust cam but thought that was it.

The miata and Capri automatic b6 engines had lower compression. 9:1 as compared to 9.4:1. They make a better turbo engine than the b6t and these pistons are a known upgrade in the b6t community. The automatic exhaust cam is considered by some GTX enthusiasts to be an upgrade, but It's not helpful on our little lightweight cars because it kills the top end of the tq curve and makes the engine more prone to detonation under high boost pressures. The turbo cam and the manual trans cam are practically identical. They all use the same intake cam.

Blake,
Only the pre 89 B6t came with the heavy rods. The Capri XR2 rods are identical to all the other DOHC rods (bp included). There is no need for the thicker rods, in fact they are a detriment, due to the rod weights effect on harmonic imbalance.

The NA Capri only differs from the b6t in it's pistons, it's rear main seal plate, it's oil pan (the steel oil pan uses a studded seal plate like the Festiva one) and the turbo exhaust manifold. Oh, and the turbo sticker on the intake manifold.

The miata has lighter valves and different intake valve springs. The miata has a different oil pan that can't really be used for fwd and the oil pump has a removable plug where the dipstick goes on a fwd layout. The intake manifold, valve cover and coolant flanges are all different and not really usable on FWD. The head, block, crank and most of the little bits and pieces inside are all the same or similar.

[blake4591]

Charlie,

Thanks for posting that info. I found the B6 engine thread only minutes after posting that. I don't know how I never noticed that thread before but it covers all the little stuff between engines that I wasn't confident about; there's some good info over there. I'm still very interested in the ZM motor. I found one picture of a ZL block that looks like the intermediate shaft and block are extremely similar to XR2 shaft and b6 block. I would think that since Mazda didn't change most of the machining of the block there would be little reason to invest money in moving the intermediate shaft mounting holes but I've seen odder things done by OEMs. I'm also a little concerned about the total width of the motor. The intake looks a lot bigger than the b series to the point that I'm concerned with how close it will be to the firewall. I don't know if this is just the side effect of the narrower head throwing the proportions off or if its actual size difference. I'm going to try to get to a junkyard in the near future to get some rough measurements for comparison.

[Advancedynamix]

Next weekend I can probably drag my ZL-de out and get some pictures and measurements. I recommend moving the drivetrain 2" forward from stock centerline. This drastically improves every handling dynamic of the car except wet weather traction in the rear (easily fixed by using narrow, deep tread tires on back in the rain).
The ZL-de has a different manifold than the ZM-de. It's a welded tubular runner and cast dual plane plenum. A very nice piece. The ZM-de is a long runner with a very low volume plenum. This engine would be awesome with itb's from a cbr929, which would work well with your microsquirt. Bhearts is working on a weld flange to make this possible. I sent him an ITB set.

[blake4591]

Well I worked on the car a little this weekend. Saturday I finished the cleaning the front seats, I still have to go over the rear seat a little more before I'm completely happy with it. I also finished painting most of the interior panels. I wanted to know how well the Rustoleum 2X works on plastic so I tried scrapping some of the paint off one panel with my nail to see if I would have any problems with the paint flaking off. That paint was completely bonded to the panels and the granite grey matches the grey festiva interior almost exactly so if any one wants to clean up their interior that is a great cheap option. I then spent all day Sunday painting and cleaning my house so nothing else got done on the car. I did get some of the garage cleaned out so hopefully I'll be able to get the car in there by this weekend.

Charlie,
If I go with the Z series motor, I would just use a complete ZM-de motor since they are cheaply and readily available. I'll be moving the motor forward since I'll be going with a G series trans. I'll probably just use the spacers with the festiva mount to make the motor mount as simple as possible. I figure that if one mount is simple I can put more time into making the other two mounts for the trans. For what it's worth I've read in a couple of places that the ZM intake is an upgrade over the Zl intake. I don't need to make up my mind on the motor choice for another two maybe three weeks, so if you can confirm the fitment of the motor mount and intermediate shaft that would help immensely.

[Advancedynamix]

I havn't forgotten about this. Just been too busy to clean the shed out enough to actually get to the engine. lol.

Also, a correction needs to be made: THE AUTOMATIC B6 DOHC INTAKE CAM IS ALSO DIFFERENT FROM THE TURBO OR MANUAL TRANS CAM. I learned that last weekend when I took a second look at a set. Sorry for the bad info.

[blake4591]

I'm guessing by now everyone is probably thinking I forgot about this. Haha

I'm still collecting parts to put the silver car together. I picked up Rio knuckles last weekend along with carpet and a clutch pedal assembly. I'm still thinking about exactly what motor I'm going to use but the money for the motor got spent on keeping other cars on the road. I'm saving up again but it'll by a little while before I have enough again.

[Advancedynamix]

Well, that gives me time to get to that Z engine and give you an answer to your question.