hey guys, I just found out about these forums through a friend, and so far so good, especially as its a US based forum.

now onto the question, I am led to believe that you guys tend to run holleys on your rotors?
alot of guys down here in Australia love their webers, but I'm looking to be different, as well as fast.

do the holley carbs work well with rotors? and what are peoples preferences, holley or weber?

what manifolds are best for holleys?

I am mainly interested in holley info, as I know everyones thoughts about wevers in aust.

also any comparisons anyone can make?
thanks

 

Go a IDA weber style throttle body and EFI it, holleys suck, we had one on a stock 327 chev and it couldnt say in tune on that, i would never put one on a rotor, i pulled the fuel bowls off the holley and fitted a TPS and am using it as a throttle body!

 

Hollys are Great and easy to tune. Parts are cheap and can be purchased anywhere.

Webers are Fantastic and can be infinitely fine tuned but parts are VERY EXPENSIVE and not many distributors.

If it were mine I would go with webers. The reason - I have more parts in my weber kit than most supply houses. Got them for free too. Also - the port configuration on the rotary is better suited for Webers.

 

Rota, you did'nt just base that statement off of the other 2nd gen carb thread, did you? Honestly I don't think hardley anyone is using a holley on thier rotary motor. Esp. not 2nd gens. I'm the only person that I've heard of using one on a 2nd gen. When I bought my RB kit they did'nt have the 6 port maniflod out yet, I had to build a 4 port. As far as 1st gens, I think everyone prefers Webbers. There just hard to get. Also for the street, I believe that Webbers are hard to start when cold. Holleys, no prob. Squirt,squirt, turn the key. Braap,braap,braap.

 

hey guys, no it wasnt the second gen thread that got me onto it, I been wondering for a while now.

actually I hadbnt heard of anyone using carbs at all on 2nd gens until I got on these forums, everyone down here has access to cheap aftermarket management systems, and usually go for turbo power.

anyway, I am playing with the idea of using a holley, as if I can find a manifold, I can probably setup a holley for about half the price of a weber, and have absolutely no problems finding one either. like someone said, easy to find a V8 person that knows how to tune them.

yeah injection would be the way to go, but Im not cashed up enough for that, and I'm doing a 1970 1300 as my project, so I want to keep it all old technology so it doesnt look out of place.

 

holleys are just real easy to get down here and everyone already pretty much understands how to turn them. i personally think there the best for rotory

 

Holley manifolds can be had from racingbeat.com

Weber carbs and manifolds can be had from mazdaracing.com

 

I'm not sure if those Webbers from Mazdatrix are IDAs. I think those are sidedrafts. Not the same and a different HP than the IDA downdraft.

 

Detriuch, that is the exact reason I am looking into a holley for my car, my cousin bought a brand new 465 holley for his commodore (australian midsized car) and he paid around $500 I think he was telling me, brand new in the box, but the going price for a 48mm IDA weber seems to be around $1000 second hand, as I believe they are not made any more.

as for manifolds, I am aware they are available from racing beat, but I have to investigate whether it will be cheaper to buy one from there or to have on fabricated locally.

oh and also, what sized holley would be suitable for a large bridgeported 12A?

 

$1000 for an IDA? I paid $600 for mine here in Brissy but they normally go for about $700-800.

IMO, the IDA is the only way to go. No other carb offers the same level of tunability and ease of adjustment. Plus, they just seem to work damn well on rotors.

As a point of interest, Weber's actually putting the IDA back into production. The new ones should be available by the end of the year and expect the price to be around 2000 bucks. Might drop the price of used ones a bit as well.

 

that sounds good, if they start making them again, used ones are sure to drop in price, as long as the new ones are to the same standard

we can only wait

 

Weber all the way for me. Try this company for any parts you may need.

www.piercemanifolds.com

 

Ok, well here are the differences..


Most Holleys are too big for a 12a or 13B, a 600CFM holley would be a good size for a bridgeport 12a and 650CFM for a 13B Bridgeport


As for webber sizeing (They are alot more tunable so can vary more)

I would say a 48IDA for a Street port to a bridgeport

and 51IDA for a P-Port..



Now about drivability.. The webber is ALL top end pretty much, you can not floor a webber or it will bog, untill you get to ~3K rpms..


And for the holley, they can be punched from ANY rpm, but on turns they like to bog, because of the floats.. But you can buy racing floats to minimize that..



Hope that helped a little..


-Zach

 

Got a mikuni, but think I'd go the Weber route I didn't get the Mikuni with the car. Well, it does do the job, though.

 

I heard the new webers are go to run between 600-700 US. So thats about what they go for now, but the old ones mabe will go down some as mentioned. Oh ya i run a weber IDA and i love it. If you just want to go out and drive down the highway and save some money then get the holley, But if your going to be making lots of turns on the backs roads then get the weber. Youll have problems with float bowls and stuff on the holley when making turns, even if you get the ones that move the float bowls to the side.

CJG

 

the holley idea is mainly because I am thinking of running a car for mainly 1/4 mile work, with a decent shot of nitrous, I am just thinking the holley would be better than the stocker, and a weber not worth the extra.

 

I run the holley setup that RB carries. I had a Mikuni once but the holley is better on gas and they're about the same at WOT. RB's setup for stock engine is 465cfm, which I use, and works really well. I'm not quite sure what the size is for the street port but I think it's 500cfm or 550cfm, either way, a friend had it on his street ported 13b many years ago and that thing would screeeeem, and is what got me into rotarys.

 

550cfm, was for a 13B streetport, but good luck finding that carb.. I looked it up years ago, and it came on like the edsel or something.. haha

 

Do RB perform any mods to these Holley's or just slap em on out of the box?

 

They are very modified.. but nothing someone else with experiance in holleys couldn't do..


Might require drilling the air bleeds.. stuff like that.. I am not sure of all the mods they do.. and don't know everything about holleys..



-Zach

 

Ha! Better be some crazy mods to that carb for what I paid for it. Better be stuff they put on the space shuttle. Or I could just believe that.
Only thing I can see is the choke is taken off. There's some blue silicone closing one of the ports on top/side of the carb, and I've been told because I called them and asked. The "race" float boal mod is installed, to eliminate the cornering/rich problem. But I saw on a thread about this same issue that it does'nt cure the problem completely.

 

Rota, you might find the 4 barrel to be a snug fit in a 1300. I had a Nikki on my 1300 wagon and it was a ***** of a thing to work on, however if a 4 barrel is your preferred option look around for the "Stuber" modified ones from Melbourne.... apparently they are very good power-wise. Also they should be better to drive for cruising as the webers are pretty much just idle and acceleration (ie no cruise circuit). Plus the induction noise from a weber on a big ported engine really gets annoying on a regular driver. I drove my 13b BP with 48ida weber (42mm chokes) today for the first time in a few months and it was a pig to run around through school zones and stuff - it only wanted to accelerate! EFI would be nice, but I agree, too expensive. You should be able to find a weber, manifold and filter for $600-700. Don't forget to be careful about the port match on the inlet.... best idea is to get the inlet manifold done at the same time as the engine.
You might have fun making the weber fit under the bonnet.... I'm using sock filters which rub on my "street" bonnet (so I might get a Pajero scoop for the spare bonnet).
48 ida is plenty big, even for a bp or pp 12a. I spoke to a guy with a 10pp last week, he is sleeving his 48ida DOWN to about 45mm to maintain air velocity... and the 10a isn't that small. I will likely stick with my 48 for torque ( I also use carb spacers for added mid range) as we don't have a dragstrip here.

 

I never have much difficulty starting my side-draft in the cold, my roommate on the other hand cant figure out how to start it even when it is warm out. My method, turn key to on, let fuel pump go a few seconds, pump pedal 3-4 times, crank giving no throtte. Works nearly every time and usually starts in about 5 seconds. Worst case scenario keep a plastic bag in the car to slip over the filter and "choke" it, worked great on the occasion I needed it in Colorado.

I guess my point is not to let cold weather starting effect your decision of which carb to choose.

 

They also put a different flaot bowl on. center pivoting fulcrom or something. Its supposes to help the bad cornering ability.
?
CJG

 

Oh one more thing. Racingbeat sells the flaot bowls so you can do it your self. Its called their "racing float bowl"
CJG