Welcome to our resource for MG Car Information.



MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB GT V8 Factory Originals Technical - Zetec MGB

I've been off board for a long time, but I'm back now, and seriously considering putting a Ford zetec motor out of a Focus into my MGB.
Does anyone know of a good source for these motor in the US (built not salvaged)?
I'll keep the board posted as I make my decision to swap or not.
Bill Mertz

Im in the beginning stages of this swap. You can get a crate motor through Ford. Then comes the big choice...which trans? Im going to use the Ford T5 but some use the Sierra box like what the Caterham has.
Jarrod Hills

Yeah, all the Birkin sevens use the type 9, which is the sierra box. If this is the same as the XR4TI and the US spec Merkur 5sp, I'll probably go that route.
please keep me updated on the swap. I looked at crate motors, but I've seen a few of the SVT (cosworth worked) motors floating around on ebay, they make around 170 hp in stock trim. However they are an iron block so they are a little heavier.

What year MGB is the swap going into?
Bill Mertz

What is the difference between these Zetec motors and the 2.3L I4 used in all the mustangs, rangers and tbirds up till arouns 1993??? I know the old 2.3L are iron block, but so where the stock MGB motors. Some boost on the 2.3l gets over 300hp very easily..
Larry Embrey

Its a derivative of the Ford CVH motor used in the 3rd generation Escort and Ford Sierra.
The Zetec was based on a strengthened CVH, with several key improvements - the most notable being the 16 valve head and twin cams. Improvements to the bottom end included a fully counterbalanced crank, larger capacity oil pump and on the 1.8 130ps and 2.0 models, oil jet sprays to provide under-piston cooling.
The Zetec has variable valve timing, and the SVT version has variable cam timing. The motors are light and physically pretty small, which is the main reason I considered this motor. They also like to rev, which makes them fun for my driving style, and you can upload more aggressive fuel/ignition maps for more power, or to alter the powerband.
I think the 2.3 is a pinto based motor, and I considered it for awhile (it has a pretty extensive racer following) but I think in the long run the focus motor is more up my alley.
Bill Mertz

I'll be interested in your progress Bill, because I've always thought the ZETEC swap would be a good one. I've seen used SVT motors for about $800 which is cheap for $$/HP
CD Dewey

There was/is a guy named Patrick Bartle who was swapping a zetec into his chrome bumper gt. He had a website with a lot of good pictures, but it appears to be shut down now. From memory, he had an issue with the intake interfering with the passenger (RH) side inner fender. Seems he cut a hole in the inner fender, but then maybe he resolved it by rotating the engine towards the driver (LH)side. I think it would be a neat engine in an mgb, especially with some of the aftermarket parts that are available in the uk.

Sweet looking engine!
Ryan Reis

Yeah, its either a zetec or a toyota 4age 20 valve.
Tough choice, but a high reving 160-190 horse 4 banger would sure be a kick.

If you find Patrick Bartle's contact info let me know.
Bill Mertz

Lost my webpage for awhile but I found it again,
, seems like the server was changed and the links not updated. I think I should udate the page soon as things have progressed. As of now the intake is in and the waterpump/alt pulley system completed using Ford. The rad will be soon hooked up to the Zetec thermostate housing which is no longer at the back of the block. coil pack is in place and wiring is under way using the Ford harness. Yes I cut the inner fender too much and realy only a small amount of reshaping will be required. Canting the motor was a good solution. Remote oil filter is neccesary and still has to be plumbed. Oil pan is new and the pick up had to be altered. Anyways it can be done with a ZX2 motor. Looked at a Focus motor today and noticed that they changed the water pump/alt ect pulley system and mounting points tensioner is now on the intake side. John at quadsforods has the bellhousing for the focus motor only not the zx2 motor (at least he did 2 years ago) this bellhousing is good for T5 and the Tremec which is probably a better unit, however the T5 from a 4cyl Stang will take all the power. One thing sure to let you down is the stock shifter unit as it is poorly made, Steeda makes a neat shifter unit that is sure to make you smile and has a gated third.
So after all this work the MG still lets you down at the rear with the cart springs, maybe a irs is called for to make it really worthwile.... still trying to come up with the perfect solution. The jag irs is good but hard to come by, and there isn't much room back there. Also a bit of suspension dynamics needs to be known to do this safely.


Patrick Bartle

I know that zetec motor has a big following here in US. Bieng in the focus which is one of two serious US "tuner" car, the guys out there are doing lots of tweaks on them.

love to put one in my 4cyl mustang heh But it already has a hairdrying on the garage waiting for install... How do those Zetecs do with boost??

Patrick, what about re-inforcing the bulkhead and doing a 4link rear suspen?? much like a mustang does?? might be another optio ot "sport up" the rear suspension and require less blank paper engineering??
Larry Embrey

To the focus entered in world rally championship the two liters turboed engine produce 300bhp/6000rpm with a 34mm inlet restrictor, torque 406lb-ft/4000rpm.

With $$$ the zetec has made 400hp. The new Duratec I4 which is in the Focus now will do that for less money and is perhaps a better engine for tuning for big hp. I think 200hp can be achieved without changing much of the internals. The web is full of that stuff.
One idea is to follow the route of the new mustang rear axle, three bar plus a panhard rod. This would be easier to fit then a four bar and as driving shows the new stang handles quite well. I haven't ruled it out yet.

Patrick Bartle

On the rear suspenion, Alfa's used a live rear axle with coil springs, trailing arms and triangle shaped bar that mounts to the center section with a ball joint, and bolts to the car and keeps the axle laterally stable. It works great, and seems like it could be done to an MGB without too much trouble.
Bill Mertz

Good point patrick!!

Larry Embrey

Going of into the never ending suspension tangent. The Alfa set up is simple and works, Lotus used this also. However you do have the battery boxes in the way because the triangle has to mount to the bottom of the axle. Also two upper mounts around the shock mounting points need to be added for the upper trailing arms. With the three bar you could use the front spring brakets for the lower arms and make a channel section that would mount behind the battery boxes to hold the one upper arm, which is shorter. This arm is placed as close to the middle of the axle. But I think on the MG you would need to mount it to one side of the gear case. However I don't have battery boxes to worry about so I'm toying with both ideas(have for years).

Someone should really see about fitting a Duratec I4 to an MG as it already is configured for rwd and might be just the ticket. Lots of power, light(aluminum all the way), plentiful, tuneable, small etc...

Patrick Bartle

Yeah, I just stumbled onto the duratec motor the other night.
Know a good source?
Bill Mertz

What application is the Duratec used in rwd form, and what transmission backs it up?
Bill Mertz

Bill, the Duratec is found in all the Rangers from 04 on, it's a bit taller then the Focus as the sump is deeper. I think the Tremec 5 will fit but perhaps the ratios can be changed in the oem gearbox, I don't know much. The Duratec is really a Mazda undertaking mostly and I think you'll find the same motor in the mazda pick-up. You might be able to fit a truck bellhousing to a focus motor and so on. Also the Duratec is I think found in the the 5 and 6.
The internet has loads of stuff on the applications for these motors.

Patrick Bartle

I am looking at putting a 2.3 duratec into a midget, but i cant find dimensions on the engine so i dont know if it will fit under the hood. I really dont want to modify the hood.
Andrew Burrow

Guys -
FYI, my xflow '71 B has a panhard bar mounted to help the rear suspension. It does a terrific job of keeping the rear "planted", though there is still some axle hop on very rough roads.(much better than stock, though) It's also much easier to put in than an IRS. Mine was supplied by Llives racing in Corte Madera.
Martin Connolly

Do you have the contact info for Llives racing?
Bill Mertz

Does anyone know if the change to Zetec (or Duratec) has any implications regarding emissions regulations i.e. do the catalytic converters etc. have to be retained or can they be discarded (in the US or the UK)?
Dave S.

bill, do an archives search on here for steve llives, his email and contact info should come up. he also makes nice fiberglass fender flares for b's, jim
james madson

Dave S-

In the US it is controlled on a state by state basis.

LEGALLY, in California & Oregon (the two states I've lived in besides michigan), a catalyst would be required. PRACTICALLY, if the car was pre-catalyst (74 or earlier), neither Cali or Oregon run smog checks, so no, a catalyst would not prevent registration.

In California, a 75 or later car would need to be sent to a referee, who would verify that ALL emission required equipment was in place, then you would be tested to emissions limits of the engine.

Here in Michigan, at this point, the state government has resisted efforts to compell emissions testing, so PRACTICALLY, any engine in any chassis does not require a catalyst. But that may change at any point when the Federal pressure becomes to much
greg fast

I am starting to restore a 73' mgb-gt for my mom. And was looking for some advice on what type of motor to put in. I have seen a lot of different things done, rotary, I-4, I-6. But I was wondering if anyone had any info about what would be the most direct swap? The body is perfect and intrior was striped and is all in good shape in the house. But she blew the 4 banger under the hood. Has anyone tried a 4cyl from a miata. Seems like the room is right. Any advice you guys might have would be great.

Thanks, Thad
Thad H

Regarding rear suspension setups, and you probably know this, you have Frontlines 4 link and then there is the Hoyle engineering IRS setup using sierra bits.

Thad, there's a guy oin mgbexperience that has put a miata engine in a B


Look at eclectic motorworks site. Carl started putting a miata engine in an MGB, and was looking at the possibility of building a kit. IIRC it required a deeply sectioned front crossmember.

Last time I saw it it was on a low priority list, but i understand progress has been made. might want to give eclectic a call to see where he's at and what parts he may be offering
greg fast

Dave S

In the UK the rules relate to the age of the car, not the mechanical spec of it. One thing being looked at by Governement quango's now is that all seriously modified cars are required to pass an SVA test, and if this is the more comprehenisve one then it would have to meet many other requirements as well as current emissions!

Resistance to these suggestions is ongoing, but it is a subject to monitor.

Roger Parker

Easiest thing would be to supercharge the engine that you have. After that the BOP (rover) V8 engine will go in with some modifications, and then you are into the realms of some pretty serious work to get anything to fit properly.

Our Miata-powered MGB/GT is almost done. Runs and drives great. It's down to brass tacks now. Pictures on the website are out of date, but it will give you some ideas: (this one has dyno graphs)

I did some work on a Zetec installation for a customer. Its better than the Miata in some ways, worse in others. Kind of a wash in my book.

Carl Heideman

To follow-up on Greg's post, we did notch the chrome bumper crossmember and move the rack forward/down about 1" (and kept bump-steer in check). The Miata will fit a rubber-bumper crossmember with no modification.

Carl Heideman

My zetec mgb project is still in work. Engine/gearbox is in the mockup car and it now runs. I still need to clean up the wiring, work out the hydraulic throw-out bearing, fabricate the driveshaft, patch the front crossmember and work out the cold air intake/filter and of course install this in the driveable car ... a '71 roadster ... hopefully by summer.

I used an '01 focus motor with the t9 gearbox. I've had to cut a significant chunk out of the front crossmember for sump clearance, small mods to the rear crossmember, cut-off and weld new motor mounts to the subframe and cut a 6" square out of the RH firewall for clearance to the intake manifold. I'm using the stock ford ECU (for now) and I fabricated a 4-2-1 header that avoids the steering column. Front pulley is in the same place as the MG motor and the rack has not moved. There have been many small changes to the motor as well.

A big benefit of the zetec is that it is small ... roughly a 20" cube (about the same as the MG). Duratec, Nissan & Toyota are more like 24" cubes.

btw, an important fact about these motors is that they've had a passive anti-theft system since '97. The correct key must be near the small RF receiver before the ECU will allow power to the starter.


Tom Peck

This thread was discussed between 20/01/2006 and 08/03/2006

MG MGB GT V8 Factory Originals Technical index

This thread is from the archive. The Live MG MGB GT V8 Factory Originals Technical BBS is active now.