Which fast road engine for a sevenesque kit car on a budget?

[Chris71]

Hi,

I'm looking at getting an affordable kit car for road use and possibly the occasional club sprint or autotest. My budget limits me to something like a Sylva Leader or Dutton Phaeton.

The question is, which engine to go for?

I'm looking for a completed car, so trying to gauge which is the powerplant to go for. Baring in mind we're talking about a car costing a maximum of about ‚£3000 and probably using 80s components, I would expect the options to be something like,

1) Fiat Twin Cam - this is my favoured choice, powerful enough for a lightweight live axle car, yet also reasonably light. I gather there are various incarnations, which are larger just stroked versions of the same design(?) I'm told a fairly standard 2 litre TC on twin carbs will produce abouit 140hp.

2) Ford x-flow - probably account for most of the cars on sale. I'm told the limit for road use is about 135hp, after which they start having drivability problems?

3) Ford Pinto - I'm told these are very tunable, but quite heavy? From what I hear 150hp (about as much as most people seem to think the chassis' can take in standard form) is reasonable attainable.

4) Ford Zetec - would have to be a recent transplant and is probably optimistic in my price range, but might be an option. If I remember correclty, the 1.8 produces about 130hp in standard form, which should be fine without any modifications.

5) Rover V8 - possibly too heavy for the types of car in question? 160hp from a standard 3.5 should be enough for predominantly road use and [at the risk of being childish...] it has the noise!

As you can probably gather, outright performance is only one factor - it must also be reasonably tractable and strong enough for regular use without constant rebuilds, realistic for a car costing as much as many club racers will spend on an engine build (no cosworths or BDAs I'm afraid...) and preferably have a bit of character. The aim is around 130-150hp.

I'd like to hear any comments about the suggestions above and also any other possibilities, but also find out a bit more about them - prinicpally suitability for the purpose. Are they too heavy? too delicate? will they have a wide enough torque band for regular road use at that sort of level of tune?

Many thanks,

Chris.

[Julian]

You missed the zetec out of your list of options in the poll!

In my opinion the Zetec and the Fiat twin-cam sit about level in terms of preference provided you aren't interested in more than superficial tuning.

If you want to go beyond that then the Zetec falls behind, it isn't that it is a bad engine but it has more foibles while the Fiat twin-cam has a wealth of tuning history to fall back on.

Alternatives to look at? Honda VTEC, Rover K-series, Toyota VVT-i and Ford/Mazda Duratec. All four offer a much lower weight than previous generations of engine coupled with scope for tuning. They have been designed right from the start to be used in motorsport rather than the works teams adapting a "mundane" road-car engine. The Fiat twin-cam is likewise designed right from the start for motorsport but being of a generation behind it is heavier and bulkier by comparison.

The downside on all of these alternative engines is potential cost of implementing them in your car. None of them have been engineered to work inline so a sump conversion will be needed at the very least.

If you wanted a V8 I would suggest you look at the newer generation of Jaguar V8. Tuning is a problem thanks to the bottom end of the engine being pretty much untouchable without sending it back to Jaguar to get everything torqued up correctly (there is a way around this but it is a closely guarded secret). It is light and compact when compared to the Rover V8, it sounds gorgeous and produces rather more power. Ignoring the Nikosil liner issue it is a fantastic engine. The Jaguar engine is also engineered for RWD and given the relatively low price of a donor engine compared to one of the smaller 4 cylinder engines mentioned above it might be worthy of consideration.

[Guy Croft]

Despite its huge advantage in out-of-the-box torque and power against any other 8V 2 liter (or any other cubic cap below that) the thing that mitigates against the entire Fiat TC range in those types of cars - I'm sorry to say - is the depth of the crankcase and sump below the engine mounts, even with an ultimate low-profile GC sump fitted the sump drain plug sits 6.25" below the engine mount centreline. You'll be knocking the sump all the time.

GC

[Chris71]

Thanks gents.

That is indeed a rather tall engine. Despite this I know it was the favoured engine for the Sylva Leader which is said to handle even better than the later Strikers and Furys, so presumably the overall effect on the C of G isn't too dramatic. That or perhaps they're all predominantly used for track use and only have an inch of ground clearance!

Julian - some good suggestions, but I'd be lucky to find a car of that price and era with a zetec in (it would have to be a more recent transplant) and I don't really have the facilities to do it myself. Things like the Jaguar V8 and duratec are very unlikely to have been fitted to a rather crude lightweight car with a total value of about ‚£2.5k

Going back to the twin cam - just how superior is it to the crossflow? Is it worth going for a lower powered (or significantly more highly tuned) kent rather than the twin cam on the grounds of size and weight?

[andy97]

What about the 2 litre Alfa Twin Spark as another alternative?

[Chris71]

What about the 2 litre Alfa Twin Spark as another alternative?

I expect the lack of a conventional RWD gearbox (due to transaxle or FWD setups) makes these rather rare. I agree it is a lovely engine though, will keep my eyes open.

[Julian]

Going back to the twin cam - just how superior is it to the crossflow? Is it worth going for a lower powered (or significantly more highly tuned) kent rather than the twin cam on the grounds of size and weight?

In most cars I would say that the Fiat twin cam is definitely worth the penalty but you are talking about fitting it into a car that is very sensitive to overall weight and weight distribution.

If previous builders have an installation solution for the twin cam and regard it as the preferred solution then it should be a no brainer. If not then looking for a cheapish xflow might be the order of the day. The smaller capacity engines are still in production (now labelled as Duratec).

[sumplug]

Fiat/Lancia Twin cam my favourite, but the logical engine is the Vauxhall 16v Red Top or XE engine. Very tunable too.

Andy.

[Chris71]

The Vauxhall 16v seems to be rather rare as well. Dunno if this is down to economics, or simply the fact the chassis can only handle about 150hp in standard form.

Can anyone give me an idea of power output for various states of tune on the x-flow and how likely you are to encounter problems at that level? I only want about 140hp or so, so hopefully not talking about full race tune on either?

The twin cam does seem to be a popular choice in the earlier sylvas (it seemed to be Jeremy Philip's engine of choice I think I'm right in saying the prototype Leader, Striker and Fury all had one) and I've never heard anything but praise for the handling. That said - is it purely CofG you're talking about or is there much of an outright weight penalty? I know the crossflow is far more plentiful as a lump and I suspect the same goes for tuning bits and spares.

[sumplug]

Forgot to add, some time back, there was a Striker with the BMW 1800/2000 slant four engine from a 2002ti. Plenty of these slant fours in scrap yards fitted to 316 and 318 for example. Nice and compact with good gearbox.
To get the X flow to make 140 bhp, will need plenty of money throwing at it.
318is produced 140bhp from its 1800 engine. This M40 engine is an excellent unit.

Andy.

[menno]

Hi Chris,

I run a narrowbodied 1991 westfield on a live axle with a tuned Fiat twin-cam. It has a modified sump. Not sure how this sump compares to one of Guys units, but looking at the picture it seems very similar.

Guy is correct about the ground clearance between sump and ground. Its only 6-8 inches. For the driving i do and the roads i use this seems to be fine.

In my opinion, using this type of engine in this type of car is a great choice. Its different to the usual engine choices and there is a huge tuning potential. I have a friend who claims to get over 185 bhp from their twin-cam.

I'll post some pictures soon, but currently my westfield is under a foot and a half of water.

Menno

[dp]

Hi Chris,

To come at this from a slightly different angle, if you pick up a cheap crossflow and run with it for a while, you can be saving up for a Zetec which would be a straight swap to the gearbox later on (ignoring suspension settings for different weight). You get on the road quicker and for less money then instead of tuning for more power bit by bit, save for the newer engine. I think Zetec's can be had for around ‚£1600 new.

On the other hand, you could get going cheaply on the crossflow and swap out the engine/ gearbox combo later to whatever engine took your fancy if you felt the need.

thank you,

Darren

[andy97]

What about the 2 litre Alfa Twin Spark as another alternative?

I expect the lack of a conventional RWD gearbox (due to transaxle or FWD setups) makes these rather rare. I agree it is a lovely engine though, will keep my eyes open.

It can be done. "Alfaholics" fit the Twin Spark to their 105 series GTVs - Give them a call.

[Guy Croft]

You may have noticed I am being a bit circumspect about advising on this post. i have written what has been put forward and well done all for making this an interesting thread.

You must all now consider this:

1. Never buy a 'built-up' engine unless is fresh built with papers from a reputable source - or a factory overhaul, excepting in the case where you physically see (and experience) the engine running/driving. An engine is an amalgam of many bits and it is impossible to assess the value/fit-for-duty of what you buy by any other means.
2. The overall budget for the whole car is ‚£3000, that was stated from the outset.

If a 'second-hand' engine is bought without consideration of the above the rebuild and check/tune/dress to fit costs will more often than not take half the budget - or more - even if the overhaul is mainly executed by the owner himself. In the worst case the engine will be unuseable scrap, and don't think I'm overstating, I give this advice all the time.

Thoughts along these lines will help the owner, speculation as to what might be good choice if given double the budget - or more will not.

I myself would not attempt a project on that budget, but that is neither here-nor-there, so I am not personally going to offer a recommendation, except to say by far the easiest engine to 'do up' and also the most compact is the Ford kent 1600 Crossflow - if you can get your hands on one and find a good RWD gearbox. Not as easy as it sounds, believe me. No it is not the most torquey or powerful unit around but it will do the job well enough.

GC

[Kev Rooney]

As you are looking for the best choice of engine ready installed in the car, much as I love a high revving four cylinder , I have built several Rover V8's and even a standard unit will give the most power for your money and weighs the same as a Pinto 2000 ( which is only marginally heavier than a Kent unit ) as it features an aluminium block ,heads , timing cover and water pump. Tuning parts are considerably dearer than an equivalent American V8 but the lack of weight is a huge advantage.