TheSamba.com :: View topic - Weber 36 / 40 IDFs

Thu Jul 02, 2009 4:07 pm

James & Marv,

Thanks for your help guys in investigating this for me. =D> My venturi are the same style as James (full circle both main venturi and the full circle upper "bar" section), so i think i should be fine.

James, whats your starting vents / jetting combo for your friends 1600?

Im building a mild either 1600 or 1776, with some mildly ported heads, and an engle 100 and am thininig the following (at sea level),

28 vents
50 idles
125 mains
180 air
F11 emulsions

Sound about right you think?

Thu Jul 02, 2009 5:40 pm

I am starting out here...I am at 1500 feet.
I don't know about your F11's...maybe harney will chime in.

28 vents
50 idles
115 mains
200 air
F7 emulsions

Fri Jul 03, 2009 12:04 am

vgajames wrote: For stuborn aux vents i have had good luck with a real skinny long screw driver handle that i open the butterflys and stick the handle end up against the bottom of the vent and tap it loose with a hammer on the screw drivers tip.Hav'nt broke one yet, ya have to be careful and is beter then useing pliers... :wink:
I got my freinds 36'd done and we hope for cooler weather next week end to put them on his 1600 thats got CB 044 specials (40x35.5) and Engle 110. Thing it will do better then the K-duds.
You can see on the carb on left i put a fuel inlet going the other way and blocked off the other hole where the pressed in inlet was.
Also neither carb had return springs so left got a CB missing link and right got a stock spring.

yeah, for aux vents i usually end up using the rubber coated pliers handles, it's the main venturi that won't budge at the mo :(

I'm thinking of casting an ice cube to slip down into the vent and other equally daft ideas at the minute :lol:

Mon Jul 06, 2009 2:14 pm

OK, so it's taken me a few days due to technical difficulties but here are some numbers in an the art form of mobile phone photography

pardon the quality, but it's a crap phone ;)

36 idf

throttle opening size

body diameter

main venturi outside diameter

Main venturi Depth

Aux venturi diameter

Aux venturi depth

Overall layout

later model 40 IDF with cross bar aux vent

main throttle opening

carb body diameter

Cross bar aux vent

Overall layout. Can't get the feckn main vent out yet. It's being awkward

Early model 40 IDF with high speed enrichment circuit.

These puppies have certainly seen better days and it's proving really difficult to get the pump jets shifted. :(

throttle opening

Auxilliary vent outside diameter. This is a full circle aux vent, not a cross bar as seen in my other 40's

Overall layout

A particularly grubby set of DRLA 36's that need a good shoeing to sort them out, but disassembled enough for a comparison

throttle opening

Auxilliary vent outside diameter

Overall layout. Note the big ass lump of metal in the top of the frame. this is the ALFA air intake plenum which i've always thought would be a good start for a blow through turbo system ;)

Fri Jul 17, 2009 6:22 pm

Thought i would update my 36 IDF info.We ran into problems with the straight manifolds.So had to get some CB offset manifolds and offset
CB AC base's so finnally got around to installing them today.
I set the carbs up for his 1600, It has a Engle 110,CB 044 special heads
40x35.5 and bugpack 1 3/8 header.So went with 28mm vents, 200 air, 115 mains,50 idles.Set the butterflys to .004, Mix screws out 1 1/8 from bottom.turned on fuel pump and she fired on first hit of starter.let it warm up at fast RPM about 2600 for a few minutes.let it idle and purred like kitten at about 720 RPM. So we sync'd the carbs and adjusted the mixtures which were almost spot on as is and idled up to 850.Test drove like a dream and even has some weber bark to it.Cruise down freeway about 85 and likes it fine.Good take off and no flat spot accelerates great.My freind is very happy now from his flat spot kadrons he had on there.First 36 IDF's ive ever messed with and really like them.

Sun Jul 19, 2009 5:15 am

I just picked up a set of these myself and they have the enrichments still on them, did you remove them off the red bug for a reason? are they needed? how are they on warmup?

Mon Jul 20, 2009 8:51 am

Ampdub wrote: I just picked up a set of these myself and they have the enrichments still on them, did you remove them off the red bug for a reason? are they needed? how are they on warmup?
No those were alraedy gone when we got them.I don''t think you will find anybody on this forum that would agree that you need them.
So, Not needed on ACVW. :wink:
Oh warm up.As usual, liitle rough on first start up, but fast idle a few minutes to get some heat in heads and your go to go, thats after ya tuned jetted etc.

Mon Jul 20, 2009 1:26 pm

F-11 emulsion tubes are the usual tubes on dual 40/44 IDF. F-7's are used mainly for single carb application. According to Mharney's article he also used the F-11's on his 36 IDFs.