I am converting my '78 CIS / K-jetronic engine to EFI and for this I use the intake manifolds of an LH injection engine with the intake plenum / distributor. I will spare you the details of other changes I made to make this work (no big deal, I was just incredibly lucky) but now I need to buy new intake sleeves. I noticved that the intake sleeves of my '78 are a little bit different from those on the LH engine. The old ones from my 4,5L CIS engine (part # 92811015801) are slightly longer and thicker, but the same internal diameter (48 mm) than those on the LH engine (part # 92811024100). The outer diameter of the intake tubes are slightly different. The 4,5L CIS engine: 46 mm. On the LH engine: 48 mm. As a result, the sleeves on the 4,5L CIS engine seem to fit rather loose, sloppy.


Why is that? And are those sleeves interchangeable?

 

Ad , i have a engine with those replaced by ( blue) silicon hose…. if you are not purist , this seems to me a better solution . Silicon hose stretches more ( and easy ) than rubber . So it would fit even connections that are different in a few mm , sure in those big diameters.

 

Dear Belgiumbarry,
I realise the size differences I mentioned are not really relevant for my conversion because I simply have to buy the LH sleeves. It just kept me wondering why the old onse were larger while the tubing is smaller in diameter. The originals must have leaked air at some point in time. They were squeezed to fit but were actually a couple of mm too large.

 

I use this type of oil resistant reinforced industrial hose. It can be cut in pieces to desirable length. The hose come in different sizes ID from 20mm up to 90mm in 5mm steps.
Åke