[Berlinabrisbane]

I am doing an engine rebuild on my 1972 Berlina and need to replace the flexible carb mounts. The car is fitted with 4 individual mounts as per standard.

I have noticed that a double centre mount is available and was apparently used on the later transaxle cars.

Is there any advice or opinions on what is better - 4 single mounts or a duplicated centre mount with single mounts at either end?

If the double centre mount is better, would this fit on by 1972 vintage motor?

For the curious, I have owned the car for since 1977, and it has done 133,000 miles. I will provide an update at some stage on how I go getting it all back together.

Thanks for your help.

 

[alfaroad]

hi, and welcome to alfabb! well, it is ok to have 4 "mono" type mounts, however your car might had the double mount originally. I didnt see any manual for a berlina with 4 mounts, too. Double mounts werent only for the alfetta range and actually only the earlier alfettas used the same mounts like the 105 cars. Be carefully if finally buy a double type from the alfetta range, later used different patters. The correct double central mount will give your carbs a better synchronization than the 4 types, in any case.BTW, if you need any nos part for your Berlina you can ask me , have plenty as am maniac with these sedans...

 

[alfaroad]

I was reffering for a 2000 berlina, if your car is a 1750 maybe had 4 mono type mounts, since a RHD 105 as seen plenty in the past , used to have many parts mainly from earlier 105s, originally.

 

[Alfajay]

My understanding is that:
- The double center mount is "better" in that it helps to control vibration. It would help damp a vibration mode where the two carbs move in opposite directions (front down / back up, etc.)
- I believe that the double mount will fit your Berlina. I have them on my 105's.

 

[101/105guy]

One note on the double mount...
Got one for a set of DCOE 32s for my Super. I mocked up the assembly to set the butterflys before mounting on the car.
Found the double mount to be about 1 mm thicker than the single mounts ! Caused the carbs to sit crooked when checked with a straght edge.

 

[alfaroad]

Oh, thats a serious note, indeed. I taken that all these mounts had the same height...is it possible this difference came out from different suppliers? I know that all 2L engines originally had both single and double mounts at least in europe,so originally these must be of the same height.

 

[Bertonemorten]

I have had the same experience with different heights, so I prefer 4 separate carburettor mounts.

 

[101/105guy]

Single or double, it's good to check that all of the mounts are the same thickness.
Possible mine are from different suppliers.

 

[Gordon Raymond]

For what it's worth. The OEM application was four rubber insulators / isolators. As I restore Webers for BB customers, that center link can get pretty tired. The double center reduces wear on the connecting link, as well as engine vibration transmitted to the Webers with 4 individual mounts.
Yes the current production insulators / isolators are NOT the quality of the old Perelli individual units, but those are NLA as far as I know. So, yes the double center unit is preferred for functional use if perfect restoration is not an issue. And yes, they may differ in length. Sometimes this is not critical, as the difference is minor. Other times I have pulled the studs and lapped the steel plates to get them closer. Note that many of the new gaskets that fit between the insulators /isolators are THICK, particularly when compared to the thin, paper style gaskets we had when Perelli was the builder. The thicker gaskets will allow mix and match with the thin old style paper to even things out. DO NOT start stacking gaskets. You may get air leakage and burned through gaskets just with the thick ones used with the unaltered stamped (NOT flat) plated in the insulators /isolators.
Here is my solution. I buy from a dealer I know, and ask them to take a caliper to the double and singles checking for those close to the same length. On arrival, I measure, and lap all steel plates to get the FLAT, then reasonably close in length. I may mix and match thin and thick gaskets sealed on both faces with Permetex Ultra-Grey to the manifold (flat) and rubbers. Then I measure again. By now I'm close enough so the gaskets can be all the new ones, AGAIN Permetexed to the rubber and Weber.
NO air leaks, little or no in-out stress, and perfect linkage balance for a very long time is the result. Not a lot of effort for excellent reliability gains.
From my experience.

 

[GTVMk1]

I dumped the rubber mounts and went for the machined aluminium replacements from Alfaholics. Great quality and look awesome, and never need replacing.

 

[gtv27]

I have the solid mounts on the race-car - they are good but the o-rings wear out - you need to check them regularly for cracks. Does transmit more vibration to the carbs, which could be an issue for smooth running on a road car.

Single mounts are fine, so long as you use the centre bracket and the bush is in good condition.