View Full Version : 1.8 motor swap what clutch/flywheel should I buy

03-26-2013, 02:56 PM
In process of getting things to do a 1.8 swap on my 1993 Miata. The vehicle I am getting motor from is a 1994 Miata. I know that I can use my 1.6 clutch and flywheel but I do not know the condition of mine I minds well go ahead and replace clutch while it is out. That leads me to this question. Should I buy a 1.6 clutch and flywheel or should I get a 1.8 clutch and flywheel. Please help me by explaining why 1 or the other. Because either way I am purchasing a new clutch and new flywheel. By the way I am using my 1.6 tranny.

03-26-2013, 03:10 PM
1.6 items will be lighter, that will help the 1.8 rev a little easier.

03-26-2013, 03:18 PM
So the benefit is lighter for quicker rev. Does it also mean easier to burn up clutch ? I'm 6'2 and sometimes I forget to take foot completely off the clutch. Its not all the time but sometimes I do and I don't want a burnt up clutch in less than a year

03-26-2013, 03:46 PM
If the current clutch and flywheel is good, I'd leave them in, after all, they're free.

03-26-2013, 04:10 PM
Car has 207,000 miles on it and it is unknown as to how many of those miles are on the clutch. And I will not have time to wait to order clutch after motor swap begins

kung fu jesus
03-26-2013, 08:25 PM
James, I would err on the side of caution. Bear with me here.

With the new motor, I would suggest doing the seals, water pump, timing belt. It would be a perfect time to do the rear main seal. This is, of course, easier if you can work on the motor on a stand or a bench and the motor is well supported.

It would be good to have a clutch ready. As you mentioned, the current one in your car is in unknown condition. Taking it apart and discovering it will need replacing sooner rather than later is pretty discouraging.

The F1 clutch I bought from Goodwin was very similar to an Exedy clutch and was very nice.

There are two roads here: either your new engine comes with a flywheel or it doesn't. If it does, remove it, have it turned at any shop that turns rotors and drums. Maybe $5-10. You can also look into having a bit of the inertia ring shaved off, usually about 3-5 pounds. This will cost more to have done, maybe $80-100? The stock flywheel is around 18-20 pounds, if I remember correctly.

If your new engine DOESN'T have a flywheel, you can either R&R the one on the car now, hoping it isn't beat or heat spotted, most aren't, OR have another waiting in the wings. OEM or aftermarket, it doesn't matter. The 1.6 flyweel and clutch is lighter than the 1.8 because it is smaller (200mm friction ring), the 1.8 is 225mm. The 1.6 can hold the power of a 1.8 just fine, and many autocrossers or enthusiasts will use a 1.6 FW and clutch to save the weight in their 1.8 cars (NAs and NBs).

The lighter flywheel, regardless of size, allows means less rotating mass, so the engine spins more freely/faster while in neutral. It doesn't mean the car will idle higher, the computer will adjust for this. Is makes for quicker rev-matching and a bit better response. It also remove some of the inertia of the stock flywheel, so the RPMs drop off quicker when it is in neutral/clutch pushed in. It doesn't wear the clutch out faster. It *can* add a little more gear lash noise, particularly while decelerating in gear. The aluminum aftermarket FWs are more prone and noticable to this than chromoloy ones, in my experience.

Which ever flywheel you choose, you must use the matching clutch. You cannot put a 1.8 clutch on a 1.6 flywheel and vice versa.

03-26-2013, 08:39 PM
Yes I understand I need all new seals and I will be purchasing everything on that list tony made. I was just curious about the whole clutch/flywheel being 1.6 or 1.8 and what to even use. I think I am gonna go with the f1 stage 1 clutch. I'm just not knowing if I want to purchase a lightweight flywheel or get the f1 OEM spec flywheel. Either way not gonna buy something old used or resurfaced just new.

03-26-2013, 08:42 PM
On a side note I flipped an 82 inch TV tonight with stand. 200.00 profit= more money for swap

Demon I Am
03-27-2013, 10:14 AM
[duplicate post]

Demon I Am
03-27-2013, 10:16 AM
James come by and drive mine. I have the 1.6 with the f1.
That's the easiest/cheapest way to know if you'll like it.

Also, you may want to try removing your dead pedal. it took me a few days to get used to it, but now I am completely comfortable with it, and it lets my leg stretch out a bit more

03-27-2013, 10:37 AM
Sure OK I guess I could drive your Miata lol. At the next meet I will give it a shot. And until then I can hold off on ordering that.tony I need you to either come over to my house one day so we can get on my laptop and start ordering stuff or I need to come to you