Engine swap

Sep 13, 2004 9 Replies

Hey all, just got to thinking 'bout puting some decent power in a Miata. Like a 7+ litre, oops sorry 427 cid side oiler, in the little beastie, but I need to know the rough dimensions of the engine bay (mainly the depth from hood-line down to the bottom of the control arms) and the width of the rear axle inside of rotor to rotor.



Any help is welcome.



If I go thru with this I WILL post weekly updates on progress.



TIA


Not while retaining the front suspension--there's not nearly enough width between the spring towers. The largest that will fit without extensive butchery is a Ford 302, a fairly common conversion. There are even kits to smooth over the bumpy parts of the swap. IIRC, there's a mailing list or forum where 5-liter Miata owners hang out.

Mmm, the 427 isn't THAT much wider than the 302. 'Sides butchering the insides of shock towers to gain another inch or so isn't a problem (have welder, will cook. You may be thinking of the 429/460 which is MUCH wider than the 302. The beauty of the 427 is several-fold:

1) It doesn't take much effort to get an extremly reliable 425 Hp@ 6000 and 480ft/lb@3700. 2) You can spin the big motor to 10 grand on a regular basis and not have it self destruct (The chev 427 tends to go south VERY quickly when pushed past 7000). 3) Nostalgia/novelty value, When was the last time you saw a 427 in a car? 4) Remember the Shelby Cobra? ... Nuff said.

A Miata doing 'bout 150+Mph in 3rd with a gear to go and 60Mph in a tad less than 4 seconds. Sound enticing?

Just some VERY random musings ......

Problem is the Miata's track and wheelbase are shorter than the Cobra's. -- There are plenty of other options to persue to get nearly the same power, without chopping the car and damaging its integrity. (Much less the suspension/weight-distribution nightmares...)

- L

'97 STO, "Chouki"

// Change TEJAS to TX to reply via eMail //

This has been done during the 60's (with some input from Shelby)- a little beastie called the Sunbeam Tiger, combining a Sunbeam Alpine with a Ford 302 (eventually killed when Chrysler became the parent of Sunbeam/Rootes Group). Lots of comments about rear wheelspin, and nasty handling characteristics in the damp. What I've read about the Monster Miatas is better, but I still think you'd be better off keeping the Miata and buying a used 302 Mustang for straight-line thrills.

Joe Silver '99 (Stock)

Check out:

formatting link
They will put a Ford V8 into your Miata or supply a DIY kit.

Randy

Ok, I visited the above site. YAWN !! all small block conversions, but I left an email question anyway. My thoughts are a pre-smog (65-68) ,8V 427 that is TOTALLY stock. Stock as in y'all could buy one in a crate from your local Ford parts counter.

BTW the HP/Torque specs I mentioned are the ' published ' figures. The 425 HP is more like 475-500 and the 480 FT/LBS are closer to 520 .

Twitchy handling in the wet is not a problem, same with excess wheel-spin. Butchering the inside of the car not a concern,keeping the exterior basically the same is. Think anyone would notice the streetable 40 series rubber or wheel tubs in the back ? Weight distribution not much prob, fuel cell underneath and in trunk plus a

9 inch rear end isn't exactly light either. I figure about 60/40 balance at worst.

I understand and respect that you're more interested in the uniqueness of a 427 than in actually going as fast as possible in a straight line (forget about handling). I'd guess you'll be breaking new ground, building what's essentially a Miata funny car.

Aside from the 302 Ford, all the other V8 conversions I know of are Rover (think 215 Olds aluminum) from the UK, and an outfit in Oz that uses a 4-liter Lexus engine. I doubt either of those will keep up with an FM turbo on a stock Miata engine. Given the traction limitations, I wonder if a 427 would be any faster than, say, a good 351 with a Lysholm blower. Still, I realize that isn't the point. It ain't Fred Lorenzen's

427.

Suppose you cover both the tires and the road with contact glue and let it dry. Then take off. That would be very fast.

Leon

Well, it would be OVER very fast. If you used PerfectGlue(tm), all you'd get would be a wheelie and an upside-down Miata with a severely-deranged rear suspension.

I just love these thought experiments, Leon.

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required