NA Miata Duratec/MZR Conversion

[zchris]

Well I am contemplating this conversion and would be interested in comments. I think I talked to Gordon or Will about this. There are so many race parts available for the Duratec/MZR, I gotta see if its do-able. You can buy a new CNC ported head from Ford for under $900. And the engines easily go to over 2.5 liters. I have heard the argument to just turbo a 1.8 engine. But I am not a Forced Induction guy. And I could not find any good info on miata.net. Thanks
Chris Howard

[Grippy]

Hey Chris,

I contemplated the same question last year. The problem is everything is on the opposite side of the motor. You would need a custom PPF and motor mounts just to start. Plus it is taller than the BP motor so a new hood would be needed.
I decided to just get the whole chassis upgrade along with the motor. NC's are coming down in price, plus you get the bigger brakes, multi link rear, aluminum control arms etc. etc.

I would be interested in info on that head!

Gordon

[zchris]

Gordon, just go to ebay and type in "Duratec head" and you'll find it. I think Cosworth is having Ford Motorsports build them as they have the same flow increase claims. Heck, Cosworth has Carrillo make there rods. And I can tell you Cosworth is not what it once was when it comes to quality. I got a set of pistons for the vq35 engine. There 11:1 Cosworth and the piston dome is massive thick. Have not put them on a scale yet but I'm guessing they are 50 grams heavier than either the Wiseco or CP pistons I have. I am not impressed.
Chris

[Grippy]

Very interesting head, the only difference I could see was that the Cosworth uses oversize valves.

[zchris]

Yes but is there a $3200(cosworth)- $900(Ford Motorsports)= $2300 diff in valves. Cosworth is just way out of line in much of there pricing. Come on Gordon, buy a Ford head so I can come over and see if I like it.
Chris

[timmmy]

The LS6 drops in there quite nicely, and plenty of tuning parts for those too







(I am evil Haydn, I am evil Haydn)

[Grippy]

I agree, $2300 can buy a lot of HUGE valves, or a good part of the rest of a motor. I think CW is a bit out of touch. I am surprized I had not heard of that Ford head. One of the ebay sellers is Taska Ford in RI. I bet you could go there and take a look at one. I would love to look at one side by side with the Miata head to see if it looks like it will work.
Now what about cams?

[zchris]

Well according to interchange guides the Mazda Tribute and the Ford Escape have directly interchangeable engines in the 2.3. I believe they are the same engine other than maybe sensors. So the head I would imagine is the exact same. As for cams, Cosworth has a nice set for under $600 that should net 280hp with 14:1 pistons and a IR intake. The intake should be easy enough to make. As to the question above about just do a v8, been there, done that. Do not want to unbalance the car that much. I was so happy with my FP Miata turning a 59.2 at Limerock last year, I do not want to mess with a chassis that works. I like light cars that are easy on tires. I do not understand the lure of big HP in 3k lb cars.You kill tires and brakes fast. Different strokes you know.
Chris

[breakaway500]

Weight IS the enemy.

[timmmy]

FYI the LS6 crate motor with factor FW & clutch is allegedly 420lbs (All Aluminum) .....not that heavy really. Anyone know how much the Miata motor weighs ? I have read they are about 385 lbs, so for 400NA HP from the LS6 you are giving up about 35lbs...... not so much really for 3x HP

[breakaway500]

According to Flyin-Miata, who do a lot of these conversions, the LS swap,with the 6 speed GM trans and CTS diff and axles etc etc adds about 230lbs to the overall weight of a Miata. They also say it actually gets the car closer to a 50/50 weight distribution. I'll bet they are a blast to drive! Timmmy,will you be bringing that white one to COM?

[timmmy]

According to Flyin-Miata, who do a lot of these conversions, the LS swap,with the 6 speed GM trans and CTS diff and axles etc etc adds about 230lbs to the overall weight of a Miata. They also say it actually gets the car closer to a 50/50 weight distribution. I'll bet they are a blast to drive! Timmmy,will you be bringing that white one to COM?

Yeah those numbers sound about bang on to my thoughts too, once you factor in the trans, race rad etc.

I wish I was bringing the white one, its not mine And its not local either, built by someone I only know online. Seems like a killer conversion to me.

Once I get the Audi finished up and dialed in my green Miata will likely get a turbo, then maybe a turbo VR6 later in life.

[paultg]

I have a friend working on swapping a mid-90's Ford Taurus SHO Yamaha V6 into my old 1992 Miata.

3.0 liter DOHC V6
Horsepower: 220 hp @ 6200 RPM
Torque: 200 lb-ft @ 4800 RPM

I believe the motor is all aluminum, so his thought is it doesn't way much more than the stock 4cly. I don't think he has weighed it yet though, working on modifying an NB sub-frame now. I know the SHOs can be found pretty cheap. He bought the car for $300 ish, is going to sell the transmission to make up the cost, and junked the rest of the car (not in very good shape).

Paul G.

[timmmy]

The Mazda 6 V6 is a popular swap too.

My 2001 NB bone stock is great, I always think if it had another 30-40WHP it would be about perfect. I am thinking a Rotrex might be the go.

[breakaway500]

The "new" Jackson racing has developed a Rotrex kit for the NB.Reasonably priced too,with engine management.I am waiting for them to finish the Rotrex kit for the NA,which should be out shortly.