jayroc

Okay, I have finally gotten around to posting up some pics of the manifolds my friends and I want to start fabbing and selling. The pics are on my website here:
http://home.mindspring.com/~wilkinsj...20pics/single/
They are IDF/DRLA downdraft manifolds for the 12a. For those who don't know the IDF is weber and DRLA is dell'orto. They share the same bolt pattern.
FYI, the IDA and IDF bolt pattern is different.
Basically, the IDF is the streetable version of the IDA. Not that the IDA isn't streetable, but the IDF has a choke and also has a better progressive circuit. This translates into easier starts and better progression through the RPM range, especially when you floor it. It does come at the cost of a few CFM, but it's negligable from what I've read about their differences.
Porsche and VW has used these carbs for years and they are plentiful. There is an Italian fellow on ebay whose ID is alfa1750. He sells a lot of dell'orto carbs at very reasonable price. As of right now, he has a buy it now auction for two 40 DRLAs for $180. Two good used rebuilt ready to bolt on carbs.
We have developed a prototype dual carb DRLA setup, and are finalizing the single carb setup. The pics on my website show the late single carb prototype, but we got some small tuning work to do still.
We are looking to sell the singles for around $125-150. I'm not sure on the duals, but it looks like they will be around $225. No other company I know of sells IDF/DRLA style manifolds, so I believe we got a unique product for a very good price.
Let me know what you guys think.

jayroc

Ah, a couple more things. I know the car in the pics is dirty as hell, but it's my dirt track race car, so it gets to be the guinea pig.
Also, some notes about the construction.
It is all aluminum piping and flanges. The tops have threads to bolt the carbs to. Naturally, it's all tig welded together and very lightweight.
The outside welds on the engine flange are mostly for support. You might notice they don't go all the way around. It doesn't leak however, because the inside is buttwelded then ground flush and port matched to the engine. You can kind of see this from the pics...
Any other questions, shoot me a PM.
I'll get some pics of the dual intake manifold Monday or Tuesday, and hopefully some quick video of it running with the carb to demonstrate throttle response and whatnot.

Barwick

Dude no offense, but those look ugly as all crap. At least could have used a piece of aluminum to stiffen the two runners together instead of globbing a bunch of welds in there. But really in the long run all that matters is performance, but I think if you're selling them, it'd be much better to clean 'em up a whole lot first.

wwilliam54

they arent pretty, butf if they work ill look into it

jayroc

Well, they're not quite symmetric, I know. Cutting the perfect length and angle pipes and being able to weld them the first time is not easy. This is aluminum afterall. Please keep in mind, too, the pics are of the later prototypes and we're still working out the process as these are all hand made.
I don't think a support for the runners is necessary. It seems pretty solid as it is. The later model intakes will have a single piece carb flange, so this will add support as well.
Personally, I think they look good. I suppose that being involved in the creation process, I am a bit biased, though..
Any welded intake isn't going to look as good as a cast one, unless it's damn perfect. Casting is pretty much the standard, so people compare anything new to that. Naturally, ours isn't going to look as good as a cast one, but, I think it will be a solid product at an affordable price.

wwilliam54

for 125$ it can be be one giant weld bead as long as it flows well
id be happy with a mani that looks like that

I noticed you smoothed the inside of the runners

jorx81@aol.com

iTrader: (6)

The "globbing" isn't for reinforcement, it's so that there's plenty of meat inside the manifold to port out so there is a nice sharp edge dividing the runners.

We're not ricers, I don't care what anything looks like under my hood, the satisfaction of knowing that I built it myself and that it works makes me happy.

Joe

solobarixl7

i think it looks alright...but i too am a big do it yourself kind of person, especially when it involves welding, and i know how hard welding aluminum is ( for me anyways)..whatever works..thats a thumb up from me

Directfreak

iTrader: (2)

I understand the concept of doing everything yourlself and all. Is it any better than a Cast unit? If not, why Re-Invent the wheel? For example, I had to have my intake made because I have a wierd engine (Cosmo RE), and the ports and mounting points are different from a standard 13B, 13BT, and 13BREW engine.



From Rotaryshack

It seems like saying that you're gonna build a new tire and better tire, and then you have to copy a current one, and it's not better than the Goodyear's you could have bought for a fraction of the price you paid in materials, and time in R&D

I could be wrong, but at this point, I just don't see an advantage to the ones you posted.

jorx81@aol.com

iTrader: (6)

I couldn't disagree more, but to each his own.

We have already made a much better manifold, I'll get pics up tomarrow, we'll probably list it on e-bay as well tomarrow to fund the making of more. It has a one peice carb flange.

The material cost is pennies compared to cast manifold we could purchase, but does anyone make a manifold for weber idf's and downdraft dells? None that I am aware of.

Rotary shack is outrageous.
We could make a sheetmetal intake like rotary shack sells starting at $2000.00 for under $20.00. (so can they, any application) I'm sure rotary shack has good products not to mention many more years of expirience.

The point is that it's affordable. Lower cost than using
an IDA.

Downdraft delloroto 36's and 40's are dime a dozen and arguably better carbs than webers.
48's cost a bit more but not too much more than weber 48's.

You can get two 36's for 129 all day long, and two is plenty for any engine port.

There will be lots more cool stuff coming soon.
We've only just begun.

wwilliam54

would one be great for a street port?

jayroc

As my cohort stated, rotaryshack does not offer an IDF manifold and neither does anyone else I've seen or heard of. As I said earlier, IDA and IDF are different.
So far as casting vs ours. Our advantages are lower cost, lightweight, but arguably sacrificing some looks.
The finished product will look nicer than the prototype pics, but the goal is inexpensive functionality, which we have already achieved.

Also, in answer to your question, yes one would work okay, but you may want to go with two smaller carbs instead of one big one.

rotarygod

iTrader: (1)

I do applaud custom efforts that people go through. I fabricate much of my own stuff as well. I will agree though with some others in that those welds are anything but pretty. I know that function over form is the goal but my custom aluminum T-II manifold has absolutely perfect welds that are much smaller and cleaner. Aluminum is a hard metal to learn how to weld good. Any weld joint can be cleaned up with a little grinding especially aluminum since it is so soft. 10 minutes with a die grinder and the right bit would make those look just fine. When aluminum welds are done right they look like small overlapping coins and are a work of art. If the performance is there then your price is good. They just need a little help in the looks department. A heat shield would be nice as well considering the exhaust pipes below and how easily aluminum heats up. It is a good effort never the less and I am curious as to your performance numbers. Please don't take me as hostile, I know how hard it is to weld aluminum.

Rutnick

I'm down in madisonville and I have to say you have peaked my interest some. The one thing I noticed on the prototype is the uneven lengths and was concerned about tuning of dual carbs and flow. I just may be talking out of my butt though. I believe the best way to sell these is get some dyno runs with your setup vs stock and then vs another manufacturer and and their carb setups.

Honestly, the thought of using my car as a baseline for a dyno and then modding it with your setup does sound interesting. I have to say that I am still leaning toward a modded nikki through carl but I am interested.

You can PM me.

DriveFast7

iTrader: (1)

I commend your work and thank you for sharing with us here.

I think if you can target a niche you might be able to sell them. Niches I see:

1. Inexpensive alternative to IDA/DCOE which you've already pointed out.

2. If you can put together a bolt on plug and play dual carbed IDF/DRLA downdraft with dynotested performance gains then you'll have something sharp.

People still ask for the old Rotary Engineering dual 36 DCD setup. Are the DCD's still available? If so you can recreate that setup and have a nice progressive carb setup that has good low end with gas mileage and can still scream in the upper rpm range.

Oh, and it'll need to be pretty and have good tech support too.

As a side note I was reading on a guy's website how he had an IDF carb on his rotary and it wasn't making the power he wanted it to. He ditched it and installed an IDA; got better power right off the bat. IDA's are really good at dumping fuel.

!!!Best of luck!!!

jorx81@aol.com

iTrader: (6)

Disregard the pics of the manifold jay posted, I'm not sure why he even posted them. It was the first one we made, the ports are rough and don't match, the runners are way uneven, on top of being dirty as hell.

jayroc

I posted 'em so you and Beau would get to work makin manifolds.

zenjoe

I have an IDF/DRLA manifold on my 12a right now. I have an adapter to change the bolt/flange pattern to an IDA style. The manifold looks identical to the cast manifold pictured above, although the ports going to the intermediate plate are siamesed.

I will Trade anyone a 12a IDA manifold for my 12a IDF/DRLA manifold.

PM me if you wants to trade!

bigmac119

If you have a 6 port idf manifold I'll buy it

Andre The Giant

iTrader: (21)

Well this thread is only 11 years old so maybe he still has one :-P

DivinDriver

iTrader: (15)

If he's still, like, alive... he hasn't posted in over three years.

Cookboy

iTrader: (10)

Craigslist Norfolk Va auto parts has one (6port) listed for sale.