Anyone have or used IDF carbs on manifold ?

Mike Stewart

Mike Stewart

True Classic
I want to go either , IDF because they are cheaper alternative to DCOE or DCNF , other option was to go bike carbs and just make my own manifold to suit, they are certainly affordable.

Just want to put this out there if anyone has a suitable manifold , I'm not prepared to pay new manifold prices or carb prices , I be interested even if they need a service or overhaul though.

There will be plenty sitting in boxes in the shed or garage just waiting to be put on a n engine ,


MINE :)
 
IDFs float bowls are oriented the wrong way, which may cause starvation on turns. They're also quite large compared to a dcnf and lack some of the precision tuning you can get on a dcnf.
 
I had dual 40 IDFs on my 128 (recently sold that manifold) and they worked just fine even though in theory they should not be used in a transverse arrangement. I like the picture in one of the FAZA bibles of a pair of 48 IDFs on an 1100 engined 128 in a European race car. As Brad notes, the are physically larger than the DCNFs and I don't know if they fit under the hood of an X. IDFs are my comfort zone and I can always get them to work but have always had problems tuning DCNFs....more a problem with me than the carbs I suspect.
 
Thanks for feedback, I knew there were reasons for the different carbs, its always better to ask.

DCNF manifolds are quite pricey, then carbs too. Dcoe same but will I have clearance issues there ?

leaning more towards bike carbs due to cost purely which is a shame really, any thoughts anyone ???
 
Brand new IDFs are about $340 each, DCNFs about $399, so I'm not seeing the cost being a factor here. DCOE you'd have to open up the rear trunk to let them have room for an air box. I wouldn't install a motorcycle carburetor, the fabrication of every single part to make them link up and work isn't worth the time, and they'll never perform as well as a DCNF. IDFs are brutish carburetors, DCNFs are like a compact little work of art.
 
Brad, I like your style input....a pair of IDFs on my spiders with some silly velocity stacks and people ooh and ahh.....a pair of DCNFs on an X or 128 and people might not even notice those petite things.

As to price for any of these, a pair of new Weber carbs are going to be a significant expense as they are probably not cheap to make. I have never bought new dual Weber carbs, too expensive for me, I always buy used ones for half the price.....and then spend a week repairing bodges from the previous owner.
 
praticly impossible to find an intake manifold for 2 idf on x19 shim gonna be need so
idf carb + intake + shim$$$$$$$$$$$$
Byke carb with a good tunning have a better curv on dyno then any other weber carb just see it on web (try to find the link)
yzf 600cc 36mm rejetting to 1.85 WOW a lot better the weber dcoe dcnf and idf
I think Guy Croft write somethink about racing with byke carb
 
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So why did you bother to ask about Webers if you want to install motorcycle carbs? Have some respect for people's time.
 
I am currently running 40 IDF's on a 1500. The carbs are originaly from a 124 BC coupe. I am not sure about the manifold manufacturer, it came with the car. Clearance is tight but any air filters 55 mm tall fits. Setting up the carbies wasn't too hard the original jetting was close and I only had to change a couple of things.

I know manifolds for IDF can be found here. http://www.fiatorque.com.au/ go to products then third down is twin webber kits.


Apologies for the photo it is the best I have at hand.

IMG_20160909_131952.jpg


Edit: I broke the picture link, trying to fix it.
 
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Its good to see a few different people with different opinions , that's probably why I'm having a dilemma as to which direction to go in, Firstly Brad has stated a fact regarding IDF's which I take on board , they are over here certainly cheaper than DCOE where I have looked anyhow, I would never be buying new , cannot afford to so I'm with you on that one also Carl that's what ive been scanning for. Jack I have been told of a few set ups with the bike carbs that work really well as you say after a proper tuning session or dyno, carbs are cheap , manifold a pain but DIYable .
Dishy have you encountered any problems the likes of what Brad has spoken about ? Owing to float bowl orientation or is this with a spirited drive or race this only happens ? So Brad a few gentlemen here including yourself with varying views , ive not made my decision yet , why am I wasting peoples time ?
 
Hello Mike,
I have not had problems with starvation. I have done Motorkhana(autotest) on dirt with these carbies and there was no starvation problems. Mind you I was concentrating really hard on which way to go and not so much on how the engine was running at the time. I am about to try a Motorkhana on the asphalt this weekend so that will be a better test. During regular driving I have not had any problems.

There is a slight problem with my setup at the moment though. When you stand on the throttle at low revs there is a slight delay before the carbs catch up then your off. This wasn't noticeable with the original #55 idle jets but with the current #50 idle jets it is noticeable. I changed because the fuel mix at cruise was 11:1. This is the thing I am noticing with the duel carbies. You could spend forever tuning, adjusting and slowly improving how they run. But I think I am going to draw a line and say they are not perfect but they are a lot better then the original DATRA.

Dishy
 
Hey Dishy , well that certainly sounds like they are get thrashed about without any noticeable problems , I think there is always a trade off if you like , it either costs you in your pocket, low end performance , erratic idle or the suchlike when you change things like a carb or a cam or even air filter , but you are 100% right, am certainly not after perfection this is for a fun daily driver not a serious resto, I'm a single dad cant just go buy a new manifold and new carbs I wish .

Is that Motorkhana the same as the gymkhana ? If so I watched an incredible Smart car recently fitted with a Hyabussa engine , what a tool!
Thanks Dishy

Sorry meant to say it looks a good setup btw , do you run with filters ?
 
More than one type of carb can be tuned to "work".

But the common wisdom for X1/9 engines is that if you want to run dual carbs, DCNF is the way to go.
Reason 1: There are a ton of people who have gone before you and can advise on how to set them up.
Reason 2: For most other options there is a much smaller data base to tap into.
Reason 3: While you think you might be saving a few bucks up front, you will soon blow that saving on a collection of jets, emulsion tubes, venturis and sundry other bits and pieces. (I have a draw full of bits!)

And consider this, bike carbs are designed to work on small capacity, high revving engines.....

Cheers,

Rob

p.s. I think Motorkhana (in Australia) = Gymkhana (in the UK) = Autocross (in the US)
 
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Mike Stewart said:
Its good to see a few different people with different opinions , that's probably why I'm having a dilemma as to which direction to go in, Firstly Brad has stated a fact regarding IDF's which I take on board , they are over here certainly cheaper than DCOE where I have looked anyhow, I would never be buying new , cannot afford to so I'm with you on that one also Carl that's what ive been scanning for. Jack I have been told of a few set ups with the bike carbs that work really well as you say after a proper tuning session or dyno, carbs are cheap , manifold a pain but DIYable .
Dishy have you encountered any problems the likes of what Brad has spoken about ? Owing to float bowl orientation or is this with a spirited drive or race this only happens ? So Brad a few gentlemen here including yourself with varying views , ive not made my decision yet , why am I wasting peoples time ?
Click to expand...

I couldn't decipher your post where you referred to everything in some kind of Velocity-channel slang, I assumed you meant you were going to use "byke" carbs because apparently they produce more power than a Weber. Given the amount of time people take to reply to posts I figured you were wasting everyone's time. Forgive me for not understanding whatever language you were using.

My final point on the topic: how much is your time worth? If you want to drive the car then get twin DCNFs or a single 34DATR and drive around. If you want to tinker get something else. The "something else" route will involve a lot of your time in fabrication and not driving, which for some is fine.The proven solution is twin DCNFs.
 
Hello Mike,
Yes I do run these http://www.weberperformance.com.au/product_info.php?cPath=36_83_191&products_id=624 air filters. The only reason they are off in the photo is I was trying to show someone the size of the carbs compared to the size of the engine. When I first bolted them up I had a bit of an oh crap what have I done moment.

Also I changed the camshaft at the same time I changed the carbies. I doubt the engine would need enough air to justify twin carbies on the stock camshaft.

Dishy
 
Hi Brad , must just be a cultural difference or something but the only reason I'm on here is that I respect others experience on what they have been doing for years ! Being a workshop foreman for over 25 years ive never stopped learning or asking questions , your a fool not to . If I take a while to respond to any posts/alerts please remember the timezone difference currently as I write it is now 0520 I don't have a clue what time it is where you are !

Dishy thanks good point made about the standard cam , I do have other spare engines that can be modified whilst being able to drive whats in car currently , never driven it so don't know what its like anyhow. Is there a visible way of telling a standard cam from say a fast road cam ?

I met a guy at weekend whos had x's for years , currently has 5, his ways, thoughts of modifying , style are different and diverse not all I agree with but who am I to judge and I wouldn't. He will immediately chuck out the O.E engine saying its useless , powerless and not worth the tuning !

Whos correct because I don't know , my last old car had similar reputation for being underpowered but I didn't swap it out but improved as much as possible in stages when I could afford to, it was a blast to drive . Having a plan is important especially with carbs choice dictating a manifold also, so confusing .
DCNF seems like ultimate choice if you don't have an FI lying around, IDF also work and even in competition , bike carbs also work as ive seen plenty of footage.
Biggest problem I know I have is that ive never owned a 1/9 , never driven a 1/9, so cant predict what it needs for me to be happy with re; performance so keeping it standard until its roadworthy is an option , cam , carb and ignition such can be done with engine still installed.

I reckon you should ship your car to Scotland Brad , let me have a cruise about then drive a standard car, then decide what I want out of mine.
That's only way I will know lol:)
 
Sorry Dishy just noticed your post on the Motorkhana that looks great fun, are there power restrictions , tyres , rollcage . Does it have to be roadgoing to compete ?
Not sure I could put mine through that but its so cool to see the old school competing .

Thanks for that.
 
I'll try to get the rules right but I have only done a couple of events . So if someone knows better hopefully they will correct me.
- tyres must be road legal no cut or rally tyres.
- power no limits. classes are based on car size.
- no rollcage required. unless car is special built.
- car doesn't have to be registered, but does have to pass scrutiny.

most of the cars I have been competing against in my class are original minis.
 
bradartigue said:
I couldn't decipher your post where you referred to everything in some kind of Velocity-channel slang, I assumed you meant you were going to use "byke" carbs because apparently they produce more power than a Weber. Given the amount of time people take to reply to posts I figured you were wasting everyone's time. Forgive me for not understanding whatever language you were using.

My final point on the topic: how much is your time worth? If you want to drive the car then get twin DCNFs or a single 34DATR and drive around. If you want to tinker get something else. The "something else" route will involve a lot of your time in fabrication and not driving, which for some is fine.The proven solution is twin DCNFs.
Click to expand...

I think you read someone else's post as being Mike's!
 
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