emilio700

iTrader: (3)

Subframe in. This is being done early so we can drop the mock up engine in for header and exhaust building at Hytech. 11.75 BBK with our directional rotors BTW. Undecided on radiator. Either have Andrew build us a 1.5" double pass or modify a Koyo Hyper-V

curly

iTrader: (25)

You 'taint going to need that oil cooler spacer. Unless it's roughly in the same location on a K and roughly the same size.

KMiata

One thought on the radiator - we initially modified ours to move the upper inlet to the driver side. However, now that we are playing with some different intake setups, its turning out to be in the way a bit.

So we are going back to a stock style radiator so we can use some hard lines and couplers to duck the hose under the throttle body. It will look a bit like Andy's car. Maybe not the final setup, I'm trying to test as many things since this is such a new setup and I want to stay a few steps ahead.

I'm also very interested to see what you come up with using the RRC manifold. Obviously we thought about cutting and flipping the plenum to point the TB the right direction. However, we're also working on some other potential off-the-shelf solutions for customers.

Madjak

Why not do the whole half width Honda radiator option? So the radiator sits on the RHS with an air intake damn on the left which could duct right up into the TB. Given it's a Honda motor it would make good sense I think.

When I was looking at the k-swap I liked the RWD Magnus IM for the K-series. On a Miata it would pop out right at the front of the engine just like BP only flipped. It's probably worth the extra $ for a solution that just works. (and looks / performs good)

Batou

iTrader: (2)

Sub'd. This is definitely going to be good.

emilio700

iTrader: (3)

To both of the suggestions in your post: Because it's not a drag racer. I expect it to stay cool making 290bhp on 110*days. Runners on Magnus are way too short to make power at the correct rpm range for the cams I'm using. Beside, the RRC will work. I'm not after absolute max peak power or I would have built a K24 without Vtec and ran it on E85.

Madjak

Yeah my plan was for a K20 rather than K24... I think there is a natural fit with a race prepped miata and a high reving 2L N/A Honda screamer. I'm very interested in how it all comes together!

emilio700

iTrader: (3)

Mock up engine installed for exhaust and intake manifold fab. Snug fit. It's as far down and back as one could get given the oil pump location and transmission constraints. Head isn't a K20A2 head but it's close enough for what we're doing.

Madjak

Emilio, could you please take a photo of the RHS of the engine where the engine mount / steering rack sits? Maybe through the front radiator space so there is a bit of persepective. I've been trying to figure out if the Kmiata custom pan and engine mount will fit with a RHD steering rack and where the collision points would be.

It's will all be very tight on that side for anyone with a RHD MX5 especially given the exhaust has to squish past there too.

Edit: Oh I see you have the radiator in the car... perhaps from underneath?

AndyHollis

KMiata "Early adopter" checking in here.

Looking forward to seeing what John can do with the 2-liter. Tell me more about "custom RRC", please.


I used to think this way, too. My first K-swap in the CRX was a JDM K20A.

After I blew that up learning about K-series oiling difficiencies, I went to a K24, mostly because they were stupid cheap compared to a low-miles, running JDM K20A. $1200-1400 for a low-miles K24A2 that had lived its life behind an automatic trans in a luxo sedan. Later, I did mild builds on them (similar to what you are doing) that netted 300hp, but with table-top flat torque curves.

The basic difference between the two motors, when similarly built, is 800rpm. Everything happens 800rpm sooner with the 2.4. But...even if you shift the torque curves over by that 800, there is still more mid-range with the 2.4. Even geared to compensate for that rpm-difference, the 2.4 will have more grunt coming off the turns.

I post this not to belittle your thoughts, Emilio, but to give others things to think about as they consider this same swap. We all butter our bread differently.

Samakhan

Awesome!

I just placed an order for a Kmiata swap kit yesterday.I am using a low mileage k20a2 that I scored for $800. I plan on leaving it stock and bolting a Rotrex c38-71 supercharger on it from kraftwerks. Looking at around 300-350whp for around 10k.

Looking at your picture of where the steering rack and oil pan sit, I'm a little worried now that I might not have enough room for the blower and alternator to sit 😳

vehicular

iTrader: (3)

This is somewhat off topic here, but do you guys not have issues with big front bars on stock sway bar mounts?

Mobius

iTrader: (2)

Racing beat bracing blocks make stock nb swaybar mounts strong enough.

Edit. This is an na, of course, I assume similar. But I could be wrong.

emilio700

iTrader: (3)

I would suggest working with David directly to investigate RHD compatibility

My guess is no one reading my build thread will be inspired to build a K20 as soon as they shop for one or see how much easy power folks are getting with K24’s.

I just can’t get my head around the stroke length, rod ratio and high piston speeds of the K24, regardless of the power it makes. It’s more an emotional than rational decision. Wanting to get away from the BP’s 1.56:1 rod ratio , the K20’s 1.62 fills the bill. The K24’s 1.54:1 ratio is the wrong direction. Also, the 20mm taller engine and greater weight didn’t appeal to me. As it is, the swap kit move the engine forward quite a bit relative to the BP. Some of the cost savings of a K24 are obviated by the need to upgrade the oil pump and source the K20’s 50° VTC gear. If it were a race car, it would get a K24, plain and simple. It isn’t a race car though, just a fun street toy, HPDE and ride-along mobile. I’m happy with the power it will make, rpm it will spin at with impunity and how it will sound.

Meanwhile, I’m looking at this gauge set from revlimiter, but with 8800rpm redline and marked to 10k. Speedo marked to 160mph



No. We always use the brace blocks. Never found any other issues with tabs on control arms or pivot mount brackets tearing.

SchmoozerJoe

iTrader: (2)

Beat to the reply...

Jaynen

Can't wait to see the K swap. What did you guys decide to do with the motor you were already running in Deviate?

Emilio on the cost/power option in a 1.6 car is the rotrex still the cheapest reliable power adder option? How easy is it to get more out of than the CARB setup?

emilio700

iTrader: (3)

That motor gets a new Wiseco 84.0mm, 10.5:1 bottom end and goes into the OGK. Rotrex questions in our Rotrex thread

Jaynen

Thanks Emilio l will check out the other thread.

AndyHollis

Tell us more about "custom RRC", please.

Flipped plenum or custom plenum?

CNC'd runners?

emilio700

iTrader: (3)

Sorry, damn changes in forum settings time out after just a few minutes. I have taken to drafting on a word doc for anything past 150 words. Drafted a detailed reply and lost it..

RRC being used because John says it’s the best match for my build. F20 has smaller ID and shorter runners more optimized for it’s rod ratio, cam timing etc. The RRC will make more power. Rough plan is to hack the RRC in the middle of the runners, flip the plenum. John also adds a special contoured spacer to the TB to improve #1 filling. I’ll post pics once we have it mocked up.