TECHNICAL TOPICS

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No.7 - ENGINES

There has been a lot of "bar-room chat" over the last couple of years about what is the "best" engine for a Marlin trialling in Class 7 and, indeed, I raised the issue in my Review of the 2004 Trials Season. I hope no one's under any illusions that the "best" engine will turn an inexperienced or incompetent driver into a champion overnight, but I am sure that there are some situations where a "better" - whatever that means - engine might help a driver to an improved score. I won't deny that a lot of the debate has come from those of us with BMC B-Series engined cars where there's a general feeling that the cars are under-powered and over-weight compared with Marlins running alternative engines. Pete Hart may have won a 'Gold', in his B-Series engined Marlin, on the ultra-tough 2006 Exeter Trial but all that proves is that Pete is one of the best Marlin drivers around at the moment.

I always used to say that engine swops were rare and, although they're by no means an everyday occurrence, they're definitely getting more common. In the last two years I know of one car that's gone from B-Series to O-Series (Montego Efi) power, one from B-Series to Ford Kent, one from B-Series to Fiat Twin Cam, and one from Ford Kent to Ford Pinto - and that's only the ones that I know about. If the 'experts', and in these four cases the drivers are certainly 'regulars' if not 'experts', are choosing certain power plants then maybe they know something worth knowing.

The 'Definitive List'

Now that I have sufficient data in the "Definitive List" of Trials-Prepared Marlins, I think the time has come to give this debate some solid basis. I have records of nearly 80 different cars, of which just under 50 were active in 2005. For a good majority I have definitive information on the engine type, and for others one can make a reasoned guess based on the stated engine capacity. This only works so far, however, as a '1600' could be a Fiat Twin Cam or a Ford Kent, a '1700' could be a BMC O-Series or an enlarged Ford Kent, and '2000' could be a Fiat Twin Cam or a Ford Pinto. So, could I please ask everyone to visit the "Definitive List" page, open-up the PDF file, check the entry for your car, and notify me of any errors and omissions. Many thanks!

Anyway, based on these 77 cars and making a few reasonable assumptions, the engine choices break-down as follows - View Table : Column 1.

• 1800 BMC B-Series : By far the most common engine, I won't say "most popular". A large number of these are in the "infrequently-used" category - drivers who've done only one event, or haven't competed regularly in recent years - so the true proportion of B-Series engined Marlins in recent use is definitely less.
• 2000 Ford Pinto : These are the ones that I know are Ford Pinto, or can make a reasoned guess are so from the quoted capacities. A few of these are in the "infrequently-used" category.
• 1600/1800/2000 Fiat Twin Cam : These are the ones that I know are Fiat Twin Cams. There may be more, particularly 1600s, in the "others".
• 1600/1700 Ford Kent : These are the ones that I know are Ford Kents. There may be more, particularly 1600s, in the "others".
• Others : These comprise one 1275 BMC A-Series, one 1700 BMC O-Series, one 2000 BMC O-Series, three 3500 Rover V8s, a couple of Triumph-engined cars, some "1300s", and half-a-dozen "1600s" that I've no idea whether they'e Fiats or Fords.

Active 2005

Although I've records of just under 50 cars being active in 2005, nearly a dozen of these either non-started or retired from MCC events, or competed in MCC Class 0, so I've narrowed-down my definition of active for this engine comparison. The 33 cars listed below - View Table : Column 2 - either competed in one or more ACTC events, or scored points for finishing in one or more MCC events, in 2005. This list shows very similar percentages to the overall list, with a slight bias in favour of the known Fiats and Fords at the expense of the B-Series and the others. This is understandable given that a large number of the B-Series engined cars are in the infrequently-used category, and there are likely to be fewer unknown 1600s among the regularly competiting cars.

Exeter Trial 2006 - Entries

If we now look at the entry for the 2006 Exeter Trial we find that the percentages are, once again, very similar - View Table : Column 3 - with statistically insignificant changes from the list of those active in 2005. For interest, the 'Others' were one 1275 BMC A-Series, one 1700 BMC O-Series, one 2000 BMC O-Series, one 3500 Rover V8 (running in Class 0), and an unknown 1700.

Taken together these three sets of figures provide, in my opinion, a pretty good benchmark for the percentages of the different engines in the Marlins now in regular trialling use, and they certainly provide a basis on which to assess the relative performance of the various driver/engine combinations.

Exeter Trial 2006 - Results

The Exeter results are quite interesting because, conveniently, there's a natural break after the top ten drivers - the five who won Awards, a single driver with three fails, and four drivers with four fails. (There were then eleven drivers with five, six or seven fails). Of these ten, only six also appear in the Marlin League so this ensures that we've 'captured' four others. To see the results - View Table : Column 4. Read my report on the 2006 Exeter Trial.

Marlin MCC League

The Marlin MCC League captures the Top Ten drivers in the last six MCC events and, as I say above, includes four drivers who did not feature in the top ten of the 2006 Exeter. View Table : Column 5.

Marlins and their engines - The Table

Conclusions

• Fiat and Ford engined cars hold 70% of the places in both the 'Top Tens' although they represent only 40% of the cars active in 2005 and 35% of the cars entered in the Exeter Trial 2006.
• BMC B-Series engined cars, and cars with 'other' engines, hold only 30% of the places in the two Top Tens although they represent 60% of the cars active in 2005 and 65% of the cars entered in the Exeter Trial 2006.
• A significantly higher proportion of the cars known to be Ford Kent engined feature in the two Top Tens when compared with all the other engine types.
• I could make some subjective assessments, but I think I'll let the figures speak for themselves. Now go back and read what I wrote here.

This page published 18 January 2006