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Re: Dual Carb setups


baja
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the factory dual carb setup was used on a different EA81/71 than what we got. They had reversed valve heads so that the middle two valves were the intake valves and the outer two were the exhaust. It also had a different cam to accomplish this. Power was somewhere in the 105 range or more depending on tune. It was designed more for high rpm breathing than the standard EA81.

 

As for the carbs...just bolting on a set of dual carbs will get the wow factor at a show but if your looking for more seat of the pants fun and reliability id just slap a weber on and call it a day. without the heads and cam the intake is not really worth the trouble.

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  • 3 weeks later...

Beg to differ there a number of people in Australia have used the factory dual carb manifold on the standard EA81 engines and they report it will run up a long freeway Hill at 90 MPH with no trouble,no standard EA81 will do that.

I am also fortunate to have a complete factory Dual carb engine including air cleaner and ancilliaries,yes the port layout is far superior with the inlet valves in the centre and exhausts outside with a divider all the way in the exhaust ports so they are not siamesed.

While the inlets are siamesed it is not really a major issue for performance with the firing order they use,they made either 108HP or 120HP in stock trim depending on model and well over 140Hp in Rally guise with weber IDA style carbs adapted.

Pretty damm good for a pushrod 1800,the Turbo EA81 didn't make as much power,from memory somewhere around just under 96HP for them.

 

If you can source a factory dual carb setup they are worth fitting on a normal EA engine,but should need some jetting changes as the cam and breathing is not as good especially for the top end where the dual carb factory engine makes power beyond 8500RPM.

 

The gyroplane guys have been running dual carb setups sucessfully for decades on normal EA engines so it does work even if they are using variations of motorcycle CV type carbs for their applications they must be reliable for aircraft use even in experimental types and they crave power and run at a constant RPM between 4500~5000 so it is a harder life in Aircraft than in a Car.

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woah... are these engines common internationally or just a race only thing? we didn't get them in the u.s. right? is it just the heads/cam that were different with the longblock or was there work done on the bottom end?

 

sounds like an awesome little motor. know of anywhere with more info on these?

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woah... are these engines common internationally or just a race only thing? we didn't get them in the u.s. right? is it just the heads/cam that were different with the longblock or was there work done on the bottom end?

 

sounds like an awesome little motor. know of anywhere with more info on these?

 

http://www.indysworld.com/80s/fun/projectrudy/sheet5a.jpg

 

http://www.indysworld.com/80s/fun/projectrudy/srx1.jpg

 

 

http://www.indysworld.com/80s/fun/projectrudy/spengine.jpg

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