Rolling Road session

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Roger King
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Rolling Road session

Post by Roger King »

I have finally got around to running the Cobra on Peter Baldwin's rolling road. Peter's 76 now but still winning races and championships, and will be sharing an FIA Mini at the Silverstone and Donington Historic meetings again later this year. I've known him 40 years now, from when he set up my Lotus 907-engined Jensen Healey in the late seventies, so I kind of trust him now...

Anyway, trying to take my mind off possible engine catastrophes we managed some full power runs at 5500 rpm which on a basically unsilenced car in a confined space is not the nicest way to spend a sunny morning. Figures produced were 293bhp at 5150, which I'm pretty pleased with especially for a very standard car. A few interesting points:
The stock Autolite Ford 4-barrel performs incredibly well, producing all the mixture the engine was asking for. It seems anything else would produce a very marginal increase in power delivery at a massive cost in efficiency and engine wear, so it seems Ford got it right (as you might expect from a massive manufacturer). These early Autolites share their jet fittings with Holleys, and it's running 55F in the primaries and 68F secondaries.
The distributor is a stock '65 hipo Autolite with no vacuum advance (I have the correct '63 dizzy, but it has a terrible design of mechanical advance which is very unreliable (hence the '65 redesign) so sits in a box for special occasions. Never thought of one yet). Despite what the tuning books advise, it was very clear that for full power the engine was very sensitive to timing and would only take 29° total advance at 5150 rpm, after which power began to drop off. Bizarrely, this gives idle timing of 6°BTDC @ 800 rpm, which is a lot lower than the books say. But this figure gave excellent CO and HC figures all the way up the range, so is right for this engine. The distributor has been plotted by Martin at 'Distributor Doctor' and is absolutely spot on the Ford curve reproduced in Bob Mannel's 'Small Block Ford' so I'm happy with all this.
This engine has a lot working against it: stock cast-iron Hipo heads, albeit machined for larger valves, 10:1 CR instead of the original 11 or 11.5:1 to enable it to run comfortably on modern Super-Unleaded, the stock Ford air filter with the chrome lid (which Peter reckons is costing 20-25 bhp) and, probably worst of all, the four cast-iron exhaust manifolds rather than aftermarket headers. So all in all, I'm very happy with 293bhp - and given the handling of a stock chassis, leafsprings and all, I really don't feel the need for any more!
Marsh
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Re: Rolling Road session

Post by Marsh »

That's great to read Roger - if he got your Jensen-Healey running well, then he clearly knows his stuff.

293 bhp is more than enough in an car as diminutive as a Cobra.

Where is he based? I might need his services in the not too distant future. If he's also good with classic Mini's, he can do my Cooper S...

Lee
427 'side oiler' in 1965 Street trim
Paul Blore
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Re: Rolling Road session

Post by Paul Blore »

Cooper S?

Did we know you had a Cooper S? :shock:
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Roger King
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Re: Rolling Road session

Post by Roger King »

He's at Wilsher's Garage in Wimpole, near Cambridge.

This is how good he is in Minis:

http://www.brdc.co.uk/Peter-Baldwin

...and his history goes back another twenty years before that. This year he's doing Silverstone, Donington and Spa, and a few others.

If you're taking him something with US parts you'll need a jet kit and anything else that might need changing - he stocks a lot for SUs and Webers but not the US stuff. And if it's a Holley you'll need all the stuff to catch fuel due to the stupid design which means you have to empty both float chambers all over the hot engine to change jets.
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Roger King
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Re: Rolling Road session

Post by Roger King »

We obviously need a 289 Register Cooper S race. What spec is yours? Mine's crawling with Swiftune bits and fully adjustable suspension - nothing like a bit of toe-out at the rear to give you four-wheel-steering.
Marsh
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Re: Rolling Road session

Post by Marsh »

Paul Blore wrote:Cooper S?

Did we know you had a Cooper S? :shock:
I seem not to have mentioned that :lol:

It's a 1971 'S - 68000 miles from new and a nice history. It's pretty standard, apart from a set of Minilites.

The paint isn't original - it's currently finished in a non standard shade of Almond Green with an OE roof, which Roger will rightly tell you isn't correct for a Mk 3, as they were all monotone from the factory. The son of the first owner claims that it was always painted like that and that the owner got the supplying dealer in Exeter to deliver it that way, but I'm 'yet to be convinced'.

It's rather lovely as it is and I won't change it.

Anyway, never mind that; there's a Cobra on the way!

L
427 'side oiler' in 1965 Street trim
Colin Newbold
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Re: Rolling Road session

Post by Colin Newbold »

Take it back to 289 BHP Roger, it'll save fuel, be easier to remember and much more poetic :D

My reg number '290' works a bit like that... sort of a slightly faster 289.

My current engine is pushing out 200, but its surprisingly capable at that.

Looking forward to the Road trip in May which is far enough to stretch its legs.

P.S. First race of the season this weekend, at Snetterton on Sunday. Allan Horsfall's coming and I still have one free e-ticket if anyone's at a loose end :wink:

Colin
"How you see yourself is all very well, but it's how others see you that will determine the results you get as a leader!"
Paul Blore
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Re: Rolling Road session

Post by Paul Blore »

Is that in the MG or the Fiesta Colin?
CobStang
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Re: Rolling Road session

Post by CobStang »

Good result Roger
I drove my K code the other day, I had forgotten what a wall of torque the thing has. I will check my timing now as Martin did my distributor, I note your maximum advance figure with interest.
I see Peter has the kit to cope with SU carbs, I will need his services when I re engine the Rover.

Cheers

Mark
Early B.R.A. Warmed 3.9 Rover, 5 sp, 3.07 rear, Fully adjustable front suspension with AVO coilovers, 4 link rear suspension AVO coilovers and Panhard bar, Big 2 pot front calipers, rear discs, servo'd, adjustable front / rear bias, scruffy paint job !
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Roger King
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Re: Rolling Road session

Post by Roger King »

Mark, as you know timing will vary greatly with individual engine spec. I have a number of internal (non-visible) changes - forged pistons (which hipos never had) with a different relief pattern, bigger valves, modern flow patterns in the heads and runners, Compcams modern 'nostalgia' 271HP solid lifter cam which has a similar LSA but much more aggressive ramps, 1.6 roller rockers etc. so you'd really need a dynamic testing session to make any meaningful comparisons. There's a lot of lightening gone on, too - 3.5lbs off the crank alone. Apart from the cam and pistons, It's all standard parts, but with a fair bit of internal modification. It was very interesting to see what went on when we took the distributor past 29° total - very surprising, all my other 289s/302s have just built power on increasing advance until the pinking comes in. Didn't get anywhere near that with this motor for max power. And with these exhausts and the stock pancake air filter I was, frankly, expecting around 50-60 bhp less.
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