A35 preparation and racing on TV next week

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Canon MOWOG
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Re: A35 preparation and racing on TV next week

Post by Canon MOWOG »

They had used the same engine all through the season and testing, but the problem only showed up during first qualifying.
Several people had engine issues, and all appeared to be the same end result but possibly via different routes.
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Big Daddy
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Re: A35 preparation and racing on TV next week

Post by Big Daddy »

Canon MOWOG wrote:Several people had engine issues, and all appeared to be the same end result but possibly via different routes.
Melted pistons :?:
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Canon MOWOG
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Re: A35 preparation and racing on TV next week

Post by Canon MOWOG »

Always no3.
Theo Paphitis burnt one at Combe so well that I could see the piston rings.

Those of us that spent the time sorting the inlet and exhaust manifolds out so that they seal properly (about 5 hours), ran the engines in as advised by CMES on a safe setting, and then took the car to the rolling road for final fettling don't appear to have had any problems compared to the slap-it-together-and-go-racing attitude.
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Re: A35 preparation and racing on TV next week

Post by Big Daddy »

Do you know the nominal geometric compression ratio of CMES Academy engines :?: Which fuel do they recommend :?:
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Re: A35 preparation and racing on TV next week

Post by Canon MOWOG »

Somewhere in the region of 12.5-13:1 static compression.
105 leaded racing fuel is recommended, and having seen the size of the valves, I suspect the unleaded inserts may have been removed. I've certainly not had any detonation or pinking.

At the first big test at Goodwood in March, a whole bunch of people were cheaping out and running 98 octane unleaded - Optimax is NOT racing fuel and their engines protested somewhat...
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Re: A35 preparation and racing on TV next week

Post by Big Daddy »

Canon MOWOG wrote:Somewhere in the region of 12.5-13:1 static compression. 105 leaded racing fuel is recommended...
That's high CR and way beyond anything I've run on racing A-series up to 120 hp. Also 105 unleaded race fuel cannot be cheap. Wonder why Academy have gone in that direction :?:

Red Rocket has geometric CR of 10.0:1 and we enjoy the economy of undoctored V-Power petrol (99 RON). I really do not like pushing the detonation margins too far... :thumbs:
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Re: A35 preparation and racing on TV next week

Post by gazza82 »

So the claim this is a cheap way to start is even more challenging ...

Not cheap to build OR run ...
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Re: A35 preparation and racing on TV next week

Post by Big Daddy »

Suspect these Academy racers spend rather more than we do on Sierra XR8 with over 500 hp, including initial build costs... :whistle:
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Re: A35 preparation and racing on TV next week

Post by Hurtzberg »

If you want a well organised, level playing field , the caterham academy looks great.
Andrew

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Re: A35 preparation and racing on TV next week

Post by Big Daddy »

Hurtzberg wrote:If you want a well organised, level playing field , the caterham academy looks great.
:iagree: Great option if you want to start racing at sensible cost... :thumbs:

http://www.botbnews.com/2015/07/caterha ... r-in-2016/
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Re: A35 preparation and racing on TV next week

Post by Canon MOWOG »

Short duration cam, combined with big valves in a standard head and a high CR should be a recipe for peak power at low rpm and long engine life.
Okay, so the fuel isn't cheap, but running expensive fuel is cheaper overall than paying £25,000 for a competitive engine that need rebuilding twice a year...

No, historic racing isn't cheap, but this is certainly a budget way of going about it.
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Re: A35 preparation and racing on TV next week

Post by Big Daddy »

Canon MOWOG wrote:Short duration cam, combined with big valves in a standard head and a high CR should be a recipe for peak power at low rpm and long engine life.
Short duration cam increases dynamic compression ratio pushing engine closer to detonation and dreaded pre-ignition, big valves reduce land area between inlet and exhaust where invariably cracks appear writing off the head, and from my experience CR over 11.5:1 on an A-series results in head gasket problems.

If the engine survives those factors, lower engine speed will improve longevity. But I ran my Midget race engine to 7500 rpm at every gear change and it lasted several season without problems, and only needed rebuilding because it had worn and lost a few hp. Rated between 90 and 95 hp, it ran on regular pump fuel and was very reliable and cheap.

Interesting how Academy approach similar goals in a very different way - hmmm... :whistle:

Canon MOWOG wrote:paying £25,000 for a competitive engine that need rebuilding twice a year...
£25k is presumably for a Swiftune 140hp A-series - Wow :shock:
Going to an American V8 race engine was definitely the right economic choice... :thumbs:
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Re: A35 preparation and racing on TV next week

Post by gazza82 »

Big Daddy wrote:If the engine survives those factors, lower engine speed will improve longevity. But I ran my Midget race engine to 7500 rpm at every gear change and it lasted several season without problems, and only needed rebuilding because it had worn and lost a few hp. Rated between 90 and 95 hp, it ran on regular pump fuel and was very reliable and cheap.
Is that the one in my garage? Engine No 1?? :whistle:
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Re: A35 preparation and racing on TV next week

Post by Big Daddy »

gazza82 wrote:Is that the one in my garage? Engine No 1?? :whistle:
Yes... :mrgreen:

No 2 was a lower spec engine assembled from random parts which was only raced once when No1 dropped an exhaust valve, because it tightened in the guide. Problem occurred soon after initial engine build. Replacement head from Richard Longman proved excellent... :thumbs:
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Re: A35 preparation and racing on TV next week

Post by Countryboy »

I spoke to Daryl Davis of motobuild recently. He said that they regret going down the A+ engine route as they are not as robust as originally thought . He feels Spridget engines would be more reliable
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