PROJECT, DCOE + MANIFOLD ( PhydeauX )

[1988starter]

Still looking good keep us updated and try to get a dyno run or a track run.

[AccordSi]

The webers look great...How do you like the sound? Awesome, huh? I admire the way you took your time and got your project up and running.
What size are the carbs, anyway?...40 0r 45?

accordSi

[PhydeauX]

The sound great, they are 40s, I wanted to keep more of my midrange.

andy

[A20A1]

Hmm... i'll keep and eye out for the #3's down here... the 40 webers are pretty common.

[Site]

Hey Phydeaux, what size are you main venturis? Mine are 30 mm (the used DCOEs came with them). That will supposedly give me the strongest performance from the DCOE 40s at around 4300 rpm, since our engines are 1950 cc, based on what I've read.

[PhydeauX]

My primaries are 32mm and the aux are 4.5. I lost my book mark of a site that had a good chart of engine displacement/veturi size/rpm range so if you have a link to where you read that can you post it. The site I had also had jetting recomendations. Imho 30mm is too small, even the 32s are too small for the engine to really breathe. I think 34-36 would be a good choice for a performance a20 engine (some 45s with 38mm ventruies would probalby be best for max power, but may make it a bit of a pain to drive around town). I'll eventually get around to getting some, but the ventruies are $22 a piece. You problaby should be thinking about a cam soon to to take full advantage of the carbs, but even with the stock cam you want a target rpm of some where around 5000. The 30s will give you a bit more grunt in the midrange, but it at a sacrifice of top end.

andy

[edit]
I found the link http://members.aol.com/dvandrews/webers.htm
[/edit]

[Site]

Thanks for the info! I already had that link That's where I got the info on the 30 mm primary vents. Someday I may save up for 36s, but until then I can hopefully tune the carbs so the 30s give me a great ride.

[1989 DX R]

So I'm buying a set of DCOE 40's and I'm wondering who *glances at Site and Phydeaux* would know how to piece a manifold for these babies together.

I want to go the "stock manifold >>> matched to the DCOE ports" option...where would be the best place to get a DCOE manifold/mounts?

[PhydeauX]

I went the route of buying some pre fabed flanges from Pierce Manifolds, then formed the runners out of some aluminum tube, and mated them to an accord flange. Site got his hands on an existing manifold and had it mated to the accord flange. The flanges and tube is going to run you about $100 and its a bit of work. If you can get your hands on a manifold for cheaper then modifying it may be the way to go. If you have the cash you can always drop the flange and carbs off at a fabrication shop, tell them how long you want the runners to be, aprox 3" total is good for a stock motor useing stock 2" weber stacks, and have it tilt down 10°-15°. Closer to 10° is better.

andy

[1989 DX R]

Ok, I'll make some phone calls, and see what people think it would be.

[shepherd79]

i think site knows a company that can make manifold for you.

[1989 DX R]

Ok, so I'm getting my paws on the carbs, and then a stock Honda manifold and the aluminum flanges online. The carbs are rebuilt already, so that takes care of that. What else should I need?

[PhydeauX]

You'll need some material for the runners and somone to do the welding. www.onlinemetals.com will have what you need for the metal. I recomend 1/8" wall tube. If you're useing the flanges from pierce then you'll need 2" tube. The flanges are sized for 45mm carbs, but its just fine to use them with 40s. I'd recomend tig welding and take it to a reputable shop. The last thing you want is for one of the welds to be bad and it to crack.

A few other things while I'm on it. You're going to need some linkages, air horns, filters, and possibly jets. If you can afford it the PM3714 linkage kit from pierce (its like $90) is one of the best linkages you can get. Its not that hard to throw one together if you'd rather go that way. There are two diferent setups of air intakes for weber carbs. One with air horns and one with out. Which ones you have depends on the style of av (auxiliary venturi) the carbs are fitted with. The weber air horns slide around the the av. If you have carbs that arnt fitted with air horns and you want them them you can either buy weber air horns and some av's that will allow you to mount them (air horns and av's cost $20 a piece), or you can get some mikuni air horns. Or you can just not use the air horns. The air horns increase the air flow of the carbs by 10% or something near that (don't quote me I can't remember). What you decide on the air horns will effect what you can use for air cleaners. If you don't use air horns or if you use very short ones (less then 2/3 the height of the air filter) you can use the k&n style air filters. If you use the air horns then what I feel is the best thing is the foam socks. Similar to what they use on street bikes. They just clamp onto the airhorns, easy to install and remove.

andy

[seancornelis]

Wouldn't it just be much easier to use a dual carb manifold from the 2nd generation Prelude engine which already fits the A20 and modify that to accept DCOEs?

[PhydeauX]

Because it doesn't fit the a20.

andy

[AccordSi]

PhydeauX....I got to say, I respect your knowledge of the DCOEs...you really did your work.