Perusing I noticed some IDF40’s used. Looking for some feedback on the Chinese knockoffs. I purchased a six pack of these to replace the originals instead of rebuilding them. Was about to swap them when I noticed that the fuel mix running from the main jets to the Venturi throats had holes instead of a solid wall! So, what I’d like to know is if anyone has these knockoffs with similar defects? To me, these openings are going to suck in more air and possibly create piston burning tops? I compared the real carbs and could see the fakes don’t have enough casting metal to keep from breaking through the wall! Apologies if my topic is off base for discussion Max
As much as I like British cars personally, this is the wrong forum for your question. Traditional American Hot Rods only.
Drop in a small block ford and use a bunch of real webers? I have one 32/36 off a Pinto I bought for my truck but haven't put on yet, so I can't say from personal experience. From what I saw my brother go through, the webers were a bit too sensitive/temperamental, needing adjustments when the weather changed.
The 32/36 is simpler and less cantankerous than the IDF: numerous sizes of jets for mains and idles. Also they have nice electrical or water choke to help cold start. Idfs only option is manual cable. Invested too much into the V12 to abort now. Your brother would have better luck (if multiple carbs) to hook in oxygen sensors and fuel air gage. Tweaking 6 of these by sound and smell is futile without! You know if his are idf and knockoffs?
I would stay away from the Chinese carbs. I had two installed on an off topic VW and they are a nightmare to tune. I wasted more time screwing with them than three sets of Webers. I did not build engine, they came with the whole package.
At risk of taking this thread even further off topic, rather than use some new carbs that it would be difficult to have any confidence in from your experience so far with a basic casting fault, I would rebuild the genuine Webers you already have. Rebuilding/servicing these carbs is a bit time consuming, but not in any way a complicated job. The 4 IDFs on my OT racecar in this photo came from two scrapped Alfa Romeos. Once I had rebuilt them and got them re-jetted on the dyno they have been completely trouble free. The key thing I found was that the lead plugs on the drillings need to be pulled out, no amount of time in the ultrasonic bath seemed to clear the dirt/corrosion in the drillings. The couple of Holleys I have rebuilt were the same. As Holley seem to use steel plugs at the end of the drillings I tapped threads into the carb casting and made some screw slotted brass plugs. You can see them in the photo of the 4 barrel I have on my pickup truck.
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