mx5cartalk.com

Hi Guys,

Around a month ago now I got a phone call from cookie, he'd spotted this clean MX5 at a local car club (Seven of Clubs - All Jap Day). So jumped in my car and drove down there

Car was pretty clean, has massive amounts of overspray which is unfortunate, but the car looks really good for its age. No obvious dings, new soft top and drove well. Around a week later I was the proud owner of a stock MX5.

The car is a 1991 Australian delivered MX5 with 235k on the clock, original engine, even came with racing rims . Plan is to swap a engine build I completed for another car into the mx5 with a few extra additions. Details regarding engine build below.

Old Car - RIP :

In 2013 I started the ambitious project of getting decent naturally aspirated power figures out of a FS-DE engine. Most people I'm sure have heard the adage that, there's no replacement for displacement. Which is an old saying that really comes from a time before we had dynamic heads with VVL and VVT.

The reality is that the only replacement for displacement is either the addition of boost or revs. In stock form the FS-DE represents a stroker FP (1.8 litre engine), which makes a good naturally aspirated contender. In order to make the two litre FS engine mazda took a FP increased the stroke and altered the deck height of the block.

In effect creating a 1.8 with a stroker crank. Problem is that in combination with the short rods, the rod ratio was abysmal. In conjunction with weak stock rods, the engine wouldn't survive at rpms required to make good power. The engine quite literally would fall apart around the 7400rpm mark due to the forces at that rpm.

To resolve these issues, some ambitious work was required. As a result I purchased 3SGTE rods and pistons that someone else had already purchased, but never had the funding to continue his build. The added benefit (which i don't believe was fully realised) was the benefit of being a bit over 3mm longer then the stock rods. Hence the custom pistons with the wrist pin offset, however I don't believe the original owner had the rods measured so much as used on hand figures to buy pistons. Or there was a slight mistake with the order, as the end result was this:


Quite flush no? Final figures worked out at around 12.46:1 IIRC so 1.46 higher then the calculated 11:1.

Other then snapping a head bolt due to being provided the wrong bolts (the box had the right number, just the bolts inside weren't):


Me in the background, researching for alternates to heli coils. Unfortunately none was found, so the engine had to go back to the machine shop to have new threads added. While there they fitted and torqued the head down for me. Just prior to the head bolt incident:



Head Bolt:


Picture of the fittings and Peterson Pressure Release Valve used in conjunction with my customised oil pump:


Common issue with FS/FP is that sustained high rpm, is fraught with oil cavitation and aerating due to the internal pressure release valve. So had my pump modified to remove the internal pressure release, also had the pump coated to decrease the tolerances and thus generate better pressure

I have more pics etc but heres the final mod list:
Custom Weisco ~12:1 Pistons with 21mm wristpin.
3SGTE Rods
3SGTE Oversized Bearings
Modified Crank to Suit Bearings (i.e. tighter tolerances all round) + Achieve thicker bearings.
Modified Head - 5 Angle Valve Job, Blending, Ported and Knife-Edged Intake Ports, Ported and Knife-Edged Exhaust Ports.
Twiggy Cams
Adaptronic e440D
DocB Racing Oil Pump
Peterson Pressure Release Valve
Modified MBSP for Oil Return
Oil Filter Relocation Kit:
- Works Engineering Oil Adapters
- Aeroflow AN10 Fittings All Round
- Aeroflow Black Tubing
Focus Adjustable Cam Gears
Jay Racing Thermal Spacers
MSP Oil Cooler
Stant Low Temperature Thermostat
Fidanza Flywheel - 7.5lb
Custom NPC 760kg Clutch

Please say you are planning four throttle bodies and high compression bp for the mx5!?

Pics of the car?

This is the engine going into the MX5. I don't know much about the F series engines but they should be fairly easy to fit in? Should be a good read!

What sort of power are you aiming for?

Always was interested to see if the 2.0 from the SP20 was a contender for and MX5, but never knew if it was in anyway similar to the BP.


Are there any other Mazda blocks that were similar to the FS? or was it a bit of an orphan? (not just a tiny FE is it?)

3gress wrote:Please say you are planning four throttle bodies and high compression bp for the mx5!?

Pics of the car?

Ahh. No, swapping my build FS into the MX5.

madjak wrote:This is the engine going into the MX5. I don't know much about the F series engines but they should be fairly easy to fit in? Should be a good read!

What sort of power are you aiming for?

The engine should make around 180whp with the lighter wheels on the MX5. Hoping with a better intake manifold then I had + better tune that I might eek out around 188-192whp. More on a hub dyno

An easier fit then a FE, but not as straight forward as I'd hoped.

hks_kansei wrote:Always was interested to see if the 2.0 from the SP20 was a contender for and MX5, but never knew if it was in anyway similar to the BP.


Are there any other Mazda blocks that were similar to the FS? or was it a bit of an orphan? (not just a tiny FE is it?)

Ahhh its a bit of a frankenstein engine. Its like FE and BP love child, FS has similiar features to the FE in some regards, but has the same bore as a BP

Similiar head design etc. Though the flow rates for a FS head seem to be a little higher then a NA8 head, somewhere between a NA8 and a mild worked BP-4W. It has it's downsides, mainly in aftermarket support.

Very few people have persued a NA FS engine, as they came turboed in the states so people tend to turbo them. Further they dont rev very well stock, so most people right them off. Stock they come with a log style manifold which chokes them something chronic.

So everything NA related is kinda of untroden territory, frustrating, but rewarding

Week into ownership and the old CD player had to go, it was an old item from the early 2000's. So quick trip to the local autobahn and I walked away with a new Pioneer unit. Sounds much better, only issue is I ran out of time to replace the speakers with the Pioneer items that I had pulled out of my old blue car.

I had also purchased a radio surround from omgpham, that comes with 3 holes for gauges in preparation for the rebuilt engine. It was quite tight, and unfortunately the only photo I have:


Some double sided tape will hopefully fix the issue. I'll have to take some more photos of the install, as I said I was working against the clock to get it all done. As It's winter and the sun goes down super quick, stupid winder. Had more troubles running the cables down the sides of the car then I thought I would, which delayed me.

Other then the tightness pictured, super happy with the product. Can't wait to install gauges and finish off the look

Did however find and document the following items:


The trunk release switch. Which doesn't work, think it may have something to do with this:


No need to worry about shorts or soldering :/

And also:


That ball action. Pretty sure there is meant to be two gaskets/seals between the gearbox shifter and the cabin. So going to need to buy some new ones.

Had the help of two good friends to remove the engine, with their help we were able to remove the engine and transmission in an hour! Solid work.




Racing mags, check out the chrome. This is actually the only picture of the car I have too :S:


Unfortunately one piece exhaust and header bolts that refused to budge meant the exhaust had to be chopped. Luckily one of my friends had brought his work truck so, busted out the portable grinder:


And its out:


Looks like the main seal is a little leaky. Looks to be a long nose too:


Just need to sort out the transmission, because the car is using an engine that never came with the vehicle the miata bell housing won't bolt up. Further, differing clutches might require different throw out bearings. So more research ahead!

I know castlemaine rod shop down here in vic used to make a heap of box adapter plates. Maybe give them a call and see if they can help (I doubt they'll have an FS to BP adapter on the shelf....)

You might be lucky though, since according to wikipedia the F2 was used in the B series ute, which was RWD (not sure if the bellhousing pattern was similar to the MX though... MX boxes are the same pattern as the 929 if I recall?)

If you're SUPER lucky it might even line up with the MX5 box


I'd be shocked if the FS used a strange unique pattern, wiki seems to suggest it's almost a weird child of the FE and BP, so i'd expect it to have the bolt pattern for at least one or the other.

Found this:
http://fordlaser.com/forum/viewtopic.php?t=83813

might have some info.



Although I imagine by the time you read this you've already stuck the engine and box next to each other and checked if they line up.

Indeed hks. One more post and the thread is up to date

So ended up buying a E2200 box from the gold coast. Was searching for one that was cheap enough that it didn't break the bank and that meant i didn't feel bad throwing away the back half of the box.

Randomly was searching one day and found one on the gold coast. Was good, didn't pay too much for it either, with the help of my house mate we separated the box and bolted it up to the race engine:


The wing bolts and two top bolts bolted up, the rest didn't. So off to the fabricator it went to have two more holes grafted on the bottom half and two wholes drilled. End result plenty of box attached to block

Some shots:
Comes pretty close to fouling on the water neck!


Was able to get away with using stock FS clutch and Flywheel, B2200 throw out bearing, b2200 slave and clutch fork:


Shot down the box showing how well everything lines up:


Just hope that the output shaft penetrates far enough into the clutch and that I have good clutch engagement etc.

Looks like a pretty good fit.
I didn't even think of the vans to look for boxes!


Hopefully the van boxes ratios are close to what you need as well. Last time I drove one the ratios felt similar to the MX5, maybe a bit shorter in 1st and 2nd.
Hard to really say though since no doubt the diff ratio is well beyond what the MX5 has.

I think the idea is that this bell housing will bolt up to the MX5 rear gearbox housing. So gearset and tailshaft will be MX5 with the B2200 bell housing on a Mazda F engine.

Awesome read - subscribed

hks_kansei wrote:Looks like a pretty good fit.
I didn't even think of the vans to look for boxes!


Hopefully the van boxes ratios are close to what you need as well. Last time I drove one the ratios felt similar to the MX5, maybe a bit shorter in 1st and 2nd.
Hard to really say though since no doubt the diff ratio is well beyond what the MX5 has.

The van boxes ratios are similar, but not exactly the same.

The problem with the van box is that they use remote shifter as opposed to a gear stick. Further they also don't have the ppf frame meaning that its more then just swapping the bell housing to get the box to work. The gear sets would need to be placed onto the miata shafts realistically.

Also the miata yoke doesn't fit the van box. So unfortunately more to it then I even thought, I was under the impression that other then some bearing redesigns and alterations to gear sets the gearboxes hadn't really changed at all. Seems this isn't the case (bad pun I know )

madjak wrote:I think the idea is that this bell housing will bolt up to the MX5 rear gearbox housing. So gearset and tailshaft will be MX5 with the B2200 bell housing on a Mazda F engine.

Yeah. Apart from liking the ratios a bit more and the bearings being better in the miata box. The above also proved to be hurdles that I would have needed to overcome as well

speed wrote:Awesome read - subscribed

Thank you

It's nice to know people find the concept interesting.