I have made some discoveries, by contacting some extremely well experienced, sources in the world of historic motor racing.
The genuine Lotus 15s in period used the Midget Diff in a special housing. This was exactly the same differential arrangement from the Lotus 14, (Elite Sportscar) These get broken all the time with original 180 hp 2.2 litre Climax engines. The limitations of the original design reduce the strength of the genuine things to about 100bhp for reliability.
A lot of work has been done in recent years to make these stronger and now, many original racers are using specially constructed diffs with racing Ford "English" axle differential unit, components specially modified to fit in.
The general consensus of opinion amongst the experts, is that the "Ford Atlas" differential is the only thing that will really withstand the higher power outputs.
My idea to use an MGB GT axle has been met with general approval. The axles, although quite heavy, are plentiful and modestly priced.
It appears that this is the axle of choice used by the very best replications of the AC Cobra type cars.
The axles are reportedly reliable up to 400 ft lbs of torque with NO-one reporting any actual failures.
There are a number of even stronger axles available in the family, those being the MGC, and the BGT V8.
I have had the chance to talk to Mike Brotherwood who has been a contact for a little while. I'm currently building a "Toolroom Quality" very early 7 with a Ford Precrossflow, (54 BHP) engine and Mike has been a point of call for a couple of hard to find things.
The topic of the of the "Dizzy Addicott" Lotus 15 body and in fact, the "Replica" Lotus 15 chassis he has in stock, has come up!
Where I am a little cautious about jumping in and buying the chassis is this. The price is substantial and likely to be in need of almost 50% re-engineering for the V8 installation. I have built one off scratch built racing car chassis in the past and have the capability if absolutely necessary, to make the whole thing from a drawing.
The attractive part of the Westfield car is the "Short cut" with having the chassis and body together as a finished item.
I guess, I start working quietly on accumulating the running gear first and see how it fits together.
The Rover V8 has been problematic over the long haul. Depending on the bore size/year of production, it suffers from loose cylinder liners (requiring a remanufactured block, or a new block, with updated liners), valve gear problems... All sorts of stuff. Not many engines are completely reliable, but...
Are you thinking of putting 400,000 miles on such a machine? I have a W11 with around 60,000 miles on it, and it has taken three decades to do this, even using the car on a near daily basis. Race car miles are considerably less. And then there is the cost and reliability of the Spridget engine that I have been using for the last 10 years. It's perfectly reliable. No problems.
My last American road/racer was my Mustang, which had a T5 gearbox. This gearbox has a very short life span, lasting in most cases, around 20K miles before the 1-2 shift gets crunchy, even if you baby the thing. Then, there is the notoriously weak 3rd gear, and the probability that the 5th gear synchro will also be weak. Oh, and 1st is way too low, especially for a light car.
These things can be fixed, with a "World Class" gears, using a longer 1st and shorter 3rd, with improved synchros. Properly built, this should give about 60K miles of life, even if tracked.
But... You will have to find a way to fit it into the tunnel, and still have room for your feet.
As an aside... Morgan installed the Rover V8 into the +8, moving the compact Moss gearbox back a foot or so on an extension to keep the tunnel from being too large to accommodate pedals and driver's feet. When they switched to the Rover 4 speed and 5 speed, they needed to widen the frame and cockpit for it.
I can see how a Lotus 15 with a V8 would be something that might interest any enthusiast. This was done in the US back in the day, and the car didn't work... But it looked scary. 'Probably was, mostly to the driver.
You can get more power from a small 4 cylinder engine. Yes, it may cost more (or not... An SVT ZTec puts out about 230 HP with just webers, and no other mods). The gearbox can be the more common Type 9, and will fit the Westfield T9 chassis. The engine fits on XFlow mounts, so it will fit within the Westy chassis. You will need a bubble, and the Spridget axle will work fine with a set of good axles, double bearings and a TranX/3J LSD.
Oh, and it will burn about half the fuel, which is important, since the Westy chassis has few places for fuel.
The chassis will be more easily sorted, as there is not too much additional weight to deal with.
Yes, there will be more ground clearance as well. Remember, a dry sump for a Rover V8 will probably cost around £1000, plus the tank (and where would you put THAT??
I really appreciate what you want to do. Best course is to look at the Seight, then figure out how to put the W11 body on it. This takes care of your suspension, engine, gearbox accomodations, brakes, fuel location.
Hi, sorry for brief reply , am on hols and limited web access. V8 westf Eleven was done in the late 80s by a bloke called Reg something using Leyland touring car engine mangement, enough hp to rip a rear axle trailing link clean out of the chassis type! All written up in Kit Car magazine or Kitscars and Specials at the time....
In fact IIRC the rolling chassis sold a couple of years back
Cheers all Tim
PS lovely Eleven rep at Classics on the Common on weds...
Further googling has revealed the chap with the V8 westy was Reg Woodcock who is quite well known in TR racing circles, so shouldn’t be too hard to track down. What is proving hard is to find any pics on the web of the westy concerned...!
