Big Sam returns to the track!

I'm afraid I only supplied the more mundane parts for the engine, so not privy to its internal specification...
Dyno bhp from last week was being quoted at 269 at the fly. Torque (I think) was 215 ft lb.
They are using the dog leg box which I believe is the one that was bought with the car and the differential ratio is quoted as 3.5:1. Apart from new seals, I have no reason to believe that this is anything other than the original.
The car is restored to Blue Circle 1974 livery with reproductions of the original sign-writing and decals.
 
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The engine builder used to work with Dave Hills at IES in the Super Touring BTCC days so wiothout a doubt the motor will be right, shame they went to Lawrance originaly, I would have loved to have built the engine for that one, As a matter of interest my time in my old modsports Z in 1998 was almost identical in 6 laps of qualifying, the event was cancelled due to weather so no race time.
 
Thanks for the info guys, much appreciated.

I suppose it will get quicker and it's not fair to judge but if Alex Buncombe was up to fourth in 1.23 then Charles Barter in his car would have been pretty close to him!!!

Ok, so then down to 1.19 which is more like it. I'm sure there is more to come and I look forward to seeing it. Mike the Gp C's will be at Spa later in the month, can't wait.
 
Thanks for the extra info Mr. F and Dave J.

I'm still interested to hear any clues that might help satisfy my curiosity. Wasn't a lot wrong with the engine that was in it when they bought it ( it was pretty quick at Goodwood when Mark Hales tested it for the Octane article, and he was using a red line about 1500 rpm short of peak without realising it ), so the only reason I can think of for changing it might be extra capacity - hence the curiosity......

pmac, can you divulge any details of this 'kit' of parts? A peep into the engine bay would easily confirm block casting type and head casting type ( unless they have been erased ), so shirley can't be too much of a secret, can it?
 
Around two months ago, I had a phone call from the aforementioned Michael from JD Classics about a different Cam for Big Sam & put them on to DJ for more relevant advice on Racing spec stuff, but the reason given for changing it was that the 'Guest Drivers' thought that it was too 'peaky', and couldn't drive it even down the Pit Lane.....

A travesty, really - if it were my car, I would just have changed the Drivers !
 
Hi, im the guy who built the engine for Big Sam at Jds, I cant take all credit for it as i was under the eye of "engine builder used to work with Dave Hill at IES in the Super Touring BTCC days".

The engine when we recieved it had 3 bent valves and a low compression ratio, standard 69mm crankshaft, Farndon rods. The outcome was high rev, low torque and power engine (220hp/165lbs/ft). And after talkin to a few guys in the Datsun know was suspected to be a try out spec and something new in its time.

We have since replaced these parts with a decent crank and rods, revised cam timing, valve gear and compression ratio.
The engine that we have built was a compromise due to lack of time and various parts, we believe there is room for improvement from its current spec.

Thanks to MJP and all those who helped
 

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ali86 said:
The engine when we recieved it had 3 bent valves and a low compression ratio, standard 69mm crankshaft, Farndon rods. The outcome was high rev, low torque and power engine (220hp/165lbs/ft).
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Thanks for coming on to give more information. Much appreciated. However, I can't help thinking that a few things aren't adding up.

You quote power and torque figures for the engine "when we received it" ( 220hp/165lbs/ft ), but you also mention that it "had 3 bent valves". I'm wondering how accurate the figures can be if you dynoed the engine with three bent valves...?

I'm also wondering when the valves got bent? As far as I'm aware ( and I'm not saying that I know all the movements of the car between the Octane magazine track test at Goodwood and the Bonhams auction at Silverstone ) Mark Hales drove it at Goodwood for Octane - part of the publicity process leading up to the Bonhams auction - and it wasn't exactly what I'd call slow. The engine also appeared to be pretty much on song ( I was there ), and Mark Hales wasn't exactly bouncing it off the red line on the tach. In fact, he was being very conservative with his maximum RPM.

If Hales was the last to drive the car before the Bonhams auction, then when did the valves get bent? Did you take the engine out and put it on the dyno before anybody from JD Classics tested the engine in the car? I'm just guessing of course, but I presume somebody actually drove the car before it was decided that it needed an engine rebuild or in fact a different engine altogether? A post a little further back up this thread would seem to confirm that.....

My point is that I don't think the short-stroke ( L20A crank = 69.7mm stroke ) Tim Riley-built engine that was in the car when it was sold was the dud that it is being made out to be. It was built to a particular theme for a particular type of use, and with a particular budget in mind. It seemed to impress Tony Dron, Win Percy and Mark Hales when they drove the car with that engine anyway.

ali86 said:
We have since replaced these parts with a decent crank and rods, revised cam timing, valve gear and compression ratio.
The engine that we have built was a compromise due to lack of time and various parts, we believe there is room for improvement from its current spec.
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More specifically, I believe you have used a later engine block with a bigger bore, a different - aftermarket? - crank with a much longer stroke, as well as rods & pistons for a much bigger swept volume, but you have used the modified L20A 'E30' cylinder head that was on the car when it was bought - yes? I'm sure you can get more power and more 'driveability' out of your new engine than the Tim Riley-built engine, but yours has a much bigger capacity and a longer stroke crank for more torque - so it's not really all that surprising. You've changed the diff ratio to suit as well, yes?
 
Is the aim to wring the most out of it or keep it in 'period' character ?

That may depend upon final use as a track Z'll need upwards of 300 to help it be competitive in historic racing.
 
Sorry if the facts offend you, we thought you would like to know a little of what we know.

"My point is that I don't think the short-stroke ( L20A crank = 69.7mm stroke ) Tim Riley-built engine that was in the car when it was sold was the dud that it is being made out to be." Unfortunately it was.

If all was well then it would of been left as we got it.

It doesnt matter what you think you know,
Its what you know you know;).

Thanks
 
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Lovely jubbley - a few european circuits ?......he asked hopefully, keen always to see more Zs on the tracks gleaming in the light of their rarity and under-estimation..........

I have video footage of the car at Goodwood at which it was presented the black plaque on the 'dashboard'.
 
Should be racing at Portomao at the end of the year, If its any good it will also race at Spa.
Thanks
 
Bloody 'ell - you travel !

Spa...? Which race....the 6hrs ? I can garantee you some faithful spectators if you do.
 
ali86 said:
Sorry if the facts offend you, we thought you would like to know what we know.
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Facts don't offend me. Nor does the truth, although it has hurt me from time to time ( ouch ).

Seeing as you appear to have avoided answering any of my questions, but have started talking about "the truth", here are some STRAIGHT questions, if you feel like answering them with some straight FACTS:

Were the valves already bent when you bought the car? And...

Were the valves already bent when you took the engine out and put it on the dyno?

Did you know the valves were bent when you put the engine on the dyno?

What's the point of quoting power and torque figures for an engine that has three bent valves? ( OK - you don't have to answer that one.... :cheers: ).

Did J.D. Classics know the spec of the Tim Riley-built engine when they bought the car?

What are the dyno figures for ( your ) engine build as it raced at Donington?



It doesnt matter what you think you know,
Its what you know you know;)
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And that works both ways, doesn't it? ;)

Can't help thinking there's quite a lot of "not built here" syndrome going on with all this. Business is business, after all.....
 
ali86, please keep the info coming as most of us love the stories about this car and are glad to see it back on the track.
 
Throttleton said:
ali86, please keep the PR coming as most of us love the stories about this car and are glad to see it back on the track.
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There, fixed that for you ;) :)



Sean Dezart said:
Spa...? Which race....the 6hrs ? I can garantee you some faithful spectators if you do.
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What class ( and what particular race ) at the Spa 6hrs meeting are you expecting to see it in, Sean? ( serious question )
 
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