Cabrio engine choice

[kieran78]

New Cabrio owner here. Just picked up a rolling shell Cabrio with a view to modifying it to a hybrid sportster ("Cabrio ST"?).
A 4cyl 1800 zetec and mt75 was in there originally but I'm thinking of ST170 (will certainly fit) or perhaps going mad and looking at a Jag 3.0L v6 AJ30 to Getrag 221 box. Both options appear to be about the same cost but I am not sure the V6 will fit: schematics for the lump indicate it SHOULD fit (tight) and may require a ST220 inlet manifold to reduce the height.....any experience or advice on all of the above...or should I just stick with the well trodden path of ST170 and MT75 or Mazda RX8 box?

Thanks.
K

[jon_cox]

Re: Cabrio engine choice

Have you considered the BMW route?
Lots of Sportsters and a few Cabrio's have the straight six engine fitted.
Loads of info on here about the process. Would cost less than the Jag option for sure and we know it fits....

It is all down to personal choice and financial / personal circumstance. For some, money is not the obstacle but time, usually due to family or career pressures, so long complicated engine upgrades very quickly become eBay listings.
For others, money is the obstacle so they become very protracted projects and the dream of driving down a country road with the wind in your hair becomes very distant.
Then there is the issue of talent or ability. What looks quite easy on a kit car blog or forum when attempted by someone who has lots of it (and the equipment) does not necessarily translate.....

What ever engine you choose, try and strike a happy balance so you can get your new toy out on the road and being enjoyed by all.
If it were me, I would go MX5 mk2.5 1.8 engine with the 5 speed box (6 speed is pointless in such a light weight car as you will never use first gear). This has been used as the engine swap of choice for all sorts, kit cars, classic car (Spitfires, MGB's, MGA's, Midgets), Resto Mods etc... so there is a wealth of info on the internet and a huge supply network. Oh.. and it is CHEAP.
Has even been done to a Roadster...
New engine i.JPG
New engine iii.JPG
New engine vi.JPG

[dogoncrazy]

Re: Cabrio engine choice

Having had a Cabrio with the straight six BMW I wouldn't bother again. Great engine but tight fit in a Cabrio and first gear on the box is useless whatever diff you fit. Chopping the anti roll bar to get the engine in the chassis has also thrown up a few issues.
If I had another I would look for one with a zetec, more than enough power as you're unlikely to want to go over 80MPH, and more than proved itself with one member who has toured Europe extensively with such a powerplant.
Or how about an Alfa twin cam [which I have in a Roadster] ,Spanking engine, enough power and classic good looks. It's what the Cabrio should have had!!!

[chris_cussen]

Re: Cabrio engine choice

After destroying my DOHC engine I went the Zetec route. The way I did it wasn't cheap as I bought a complete engine (already adapeted for RWD) and ECU from Omex. On top of that the major expenses were Exhaust Manifold (from Burton Power) £175, bespoke stainless exhaust including CAT £500, loads of silicone host to connect up the plumbing £100, and HP fuel pump £100.

The engine cam with a low profile sump so it cleared the anti roll bar and bush in rear of the crank.

I documented the whole project here https://www.marlinownersclub.com/for...an-engine-swap

[kieran78]

Re: Cabrio engine choice

Thank you for the help and advice. As an impetuous youngster (41 is still young, right) I bought a road worthy 1998 S-Type 3L V6 with manual box. I am massively out of my depth and can't even see my comfort zone with a telescope but I'm going to give it a shot and document the build.

If I crash and burn (not literally) then I can sell the lot and get my £500 (plus extras) back for a much more sensible ST170 option.....

Follow the blog (just set up) here:

Https://cabriosportster.weebly.com

[copperleaves11]

Re: Cabrio engine choice

From my own experience of changing engine types (Rover V8 - Bmw M20) ,the anti-roll bar on a Sportster is unnecessary,except maybe for track days.If you have the choice of sump design, go for the one with the lowest part at the front. With the low point at the rear of the engine it ends up approx midway down the car, perfect for sleeping policemen. Best of luck.

[dogoncrazy]

Re: Cabrio engine choice

Unfortunately with the Cabrio you have to retain some form of location for the TCA either with the original anti roll bar or with a compression strut arrangement. [This again posed some problems in the course of time as the stresses imposed on the chassis rail caused cracking in that area.]
You can do it with the Sportster as they employed double wishbones thereby negating any additional support.
Pity that the Cabrio wasn't later given the sportster set-up as it also made setting camber/caster easier.

[kieran78]

Re: Cabrio engine choice

TCA? I'm not up on abbreviations just yet.

[wiggiesworld]

Re: Cabrio engine choice

TCA? I'm not up on abbreviations just yet.

Its rather apt that TCA also stands for Three Character Acronyms! I suppose it could be Train Collectors Association? Also short for for trichloroacetic acid; tricyclic antidepressant. Given the way my car behaves at times I can see me going that route........

[copperleaves11]

Re: Cabrio engine choice

Kieran, Please ignore my comments, Dogon is quite right, the Cabrio set-up does'nt give you the flexibility re. roll-bar and sump that the Sportster has. There is also less room in the Cabrio engine bay.

[dcunn]

Re: Cabrio engine choice

Track Control Arm

[kieran78]

Re: Cabrio engine choice

Tight for room isn't the half of it! Now I know what a TCA is and I'll make sure I leave it alone...regarding clearance of the anti-roll bar, fortunately the Ford ST220 sump is a straight swap with the lower part 180 degrees rotated from the Jag sump, so gives several cm of additional clearance. ST220 top inlet manifold is also lower profile than the jag one, so shouldn't upset the bonnet line. My main concerns are the plumbing (hoses) space required, electrical dark arts, and the steering column.
And my own stupidity.

[ggrum]

Re: Cabrio engine choice

Agree with Dogon re the choice of engine. If I had to replace the 8V Ford twin cam EFi engine in my Cabrio the 2 litre Alfa DOHC would be my first choice. Classic design, carbs, simple plumbing, simple electrics and adequate power but easily tunable to c.150bhp if required.

[milliemarlin]

Re: Cabrio engine choice

My car began life with a Ford Pinto. When that went wrong I changed it to a 2L Ford Zetec. I am pleased with the Zetec. It’s a fairly modern engine with more than enough power for my use.

It was a lot more work changing from a Pinto to a Zetec than I expected. You will underestimate the complexity by at least a factor of 10. The big question you have to ask is why you are doing it. If you are looking for a long term technical project then changing the engine will certainly provide that. If you are looking to make an excellent car that’s fun to drive a new Zetec will get you on the road enjoying the drive quicker.

In short; replacing the Zetec is the sensible choice but owning a kit car is not about sensible choices.
Paul

PS: I would urge you to check the mounting of your Anti Roll Bar as part of your refurbishment, as mentioned by dogoncrazy. It is unlikely you will have the problem but it only takes a moment to check. You can read about it here:

https://www.marlinownersclub.com/forum/showthread.php?7895-Safety-Alert-Ford-Sierra-Compression-strut-problems/page3&highlight=compression

PPS: One issue with all engines is routing the steering extension shafts. The shaft will foul the standard Zetec plastic intake and an alternative arrangement must be found.V6s are particularly tricky as the V angle puts the exhaust piping in direct line with the steering shaft.

[kieran78]

Re: Cabrio engine choice

My car began life with a Ford Pinto. When that went wrong I changed it to a 2L Ford Zetec. I am pleased with the Zetec. It’s a fairly modern engine with more than enough power for my use.

It was a lot more work changing from a Pinto to a Zetec than I expected. You will underestimate the complexity by at least a factor of 10. The big question you have to ask is why you are doing it. If you are looking for a long term technical project then changing the engine will certainly provide that. If you are looking to make an excellent car that’s fun to drive a new Zetec will get you on the road enjoying the drive quicker.

In short; replacing the Zetec is the sensible choice but owning a kit car is not about sensible choices.
Paul

PS: I would urge you to check the mounting of your Anti Roll Bar as part of your refurbishment, as mentioned by dogoncrazy. It is unlikely you will have the problem but it only takes a moment to check. You can read about it here:

https://www.marlinownersclub.com/forum/showthread.php?7895-Safety-Alert-Ford-Sierra-Compression-strut-problems/page3&highlight=compression

PPS: One issue with all engines is routing the steering extension shafts. The shaft will foul the standard Zetec plastic intake and an alternative arrangement must be found.V6s are particularly tricky as the V angle puts the exhaust piping in direct line with the steering shaft.

Thanks Paul. I may end up on the zetec route if the v6 is overly complex or not even fit, but for me it's about a shining lump of jaguar engine in the bay and the sound...rather unusually for me it's not about speed or power.

Great pointers from everyone here, thank you all.