fiat x19 manifold 128 idf weber drla dellorto new

I wonder if it would be possible/feasible to have a bolt on flange to change the manifold from the 128 to X1/9 angle?
 
I wonder if it would be possible/feasible to have a bolt on flange to change the manifold from the 128 to X1/9 angle?

That would require two types of adaptor flange... it would be simpler to mill the raw manifold with the correct included angle to begin with...

I was thinking it looked like an IDA to IDF style adaptor... or perhaps originally for a flexible mount a bit like you find on Alfa twin DCOEs...and on the 130TC Ritmo.

SteveC
 
Steve, when I saw it I thought it was to reverse the carb to face opposite...perhaps for linkage/cable attachment. But I don't understand why they would have made it the other way around in the first place. I believe I saw in another post this is actually a 128 manifold so it might be for angle correction but I doubt that. Maybe you are correct, it changes the bolt spacing for carb types.
 
i do them like this because dont put plates between. is ready to put at your car. job perfect without problems. i have and other with not adaptor but want plates. is perfect manifold.
 
I understand that to mean these adapters are in the place of the usual "insulators"...to make up the difference in height. Although if this is correct, I'm not clear why they reverse the carb in the process, as opposed to just making them as direct aluminum spacers? Just curious Jim, thanks.
 
I'm curious about the bolt on adaptor flange? what's the purpose of casting the manifold that way?

While I can't exactly understand the sellers reply, looking at the photo, it seems that the removable upper adapter flange piece(s) might be manufactured in different variations to suit different carbs (perhaps one for IDF, one for DCNF, one for DCD, etc.), then simply bolted onto the lower "universal" (base) manifold?
 
I think what he means by plates are rubber/steel (vibration) isolators, not phenolic (thermal) insulators.. a bit like this (which is actually for a DCOF but you can get very similar things for DCOE etc)

s-l1600.jpg

one manifold with dcnf / IDF uses... well that would be hard because of the bore centre differences between those two types of carbs....from memory the IDF is about 90mm between bore centres and the DCNF is about 50mm.

SteveC
 
rubber/steel (vibration) isolators, not phenolic (thermal) insulators
Either way, the fact that it also reverses the mounting position of the carb (the base mount bolt locations on the carb side face opposite those of the manifold side) seems to indicate it is indeed for multi-fitment of various carbs: IDA, IDF, etc with different bolt patterns. Otherwise it would seem much easier to just make that section a "straight through" design rather than having two sets of mounting bolts. Interesting.

I have wondered how effective it might be to have a mount similar to the one Steve C shows (in the photo above), but also acts as an adapter to fit the DCNF to the Fiat manifold. For example maybe something like the aluminum one the eBay guy makes to mount the DCNF onto the DGV manifolds:
http://www.ebay.com/itm/351761422985?ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649
 
DGV and DMTR are different bolt patterns, but something like this could easily be made to go from dmtr to dcnf patterns, but the carb orientation is still all wrong for the float bowl and for easy linkage pickup, as well as for trying to even up flow across all four cylinders. There are several Weber factory recommendations for fitment of carbs, one being that throttle shaft axis should be parallel to the crank axis for even flow distribution, another that the float bowl should be oriented to the 'front (''i'e' direction of travel) and another that the float fulcrum axis also be towards the front of the vehicle and parallel to the wheels rolling axis, you'd be going against all three of these 'recommendations for best performance' by using a dcnf in the position an adaptor like this would place it.

Bonding rubber to steel to make a good vibration isolator is also quite involved...

SteveC
 
Steve, I think this is what you were saying but it finally hit me.

If the manifold was originally designed to be used with the old-style 'vulcanized rubber' vibration isolators, then the mounting bolt locations (on the manifold) would have been "reversed" intentionally due to the design of those vibration isolators.
There isolators had a rubber cushion sandwiched between two metal plates. The plates were off-set (rotated) from one another to allow separate bolts to be used on each plate, without the bolts interfering with one another. One pair of bolts mounted one plate to the manifold and a second pair mounted the other plate to the carb. This allowed the two plates to move independently, with the rubber acting as a shock absorber. However the rotated positioning of the plates also required the carb to be mounted in a reverse orientation from the manifold.

I have not seen that style of isolator in a long time (I think due to the use of alternative materials like urethane?), and I don't recall ever seeing them for IDA/IDF's...only for DCOE's (I could not even find a picture of any of them). But that certainly does not mean they don't exist.

Therefore when this style of insulators are replaced with "solid" pieces (as in this thread), they also need to be "reversed" in order to retain the original positioning of the carb relative to the manifold (as it was designed).
 
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