Hi,
for what I can read differences between 95 and 105
(so we exclude all engines with one double-carburetor)
where about:
- carburetors
(36 nominal, with 32mm venturi inner diameter instead of 30mm for 95cv)
- not sure about different head air intake port and intake collectors just below carburetors
- camshaft with more timing and more heigh on Intake cams
(9.5 mm or 10 mm in 105cv engines depending on the year,
instead of 9.0 mm or 9.5 mm on 95cv depending on year)
(manuals says for both OUT cams are probably 8,5 mm or eventually 9.0 mm)
- sligtly different diameter of exhaust collectors?
- diffent ignition curve advance?
- wondering if the camshaft housing note you asked was referring
to differenced with previous engines with split lobe camshaft (for example 85cv)
or opposite with new sprint 1.7 I.E. hydraulic tappets (from 1987, the date of the page),
and not some differences between 95-105cv, that have the same engine bases;
PS.: if you eventually discover to have on the engine higher lift cams (see above) maybe
your 30520 engine has been mixed not only with carburetors from 105cv versions, but also heads?
Ok..some 1.5 engine codes:
95cv:
> sprint-sud >>>>> engine 301.28 (camshaft 536627)
> alfa 33 second version of 1.5 Q.O. and some early 4x4/wagon >>> engine 505.20 and 305.14 ??
105cv (nominal, some says only some versions had the rated power)
> sprint 83 QV (and some sud TI) >> 301.46 (and you found also 301.82)
> alfa 33 QV /TI >> 301.46 (used on 33 ?), 305.08 (1.5 Q.V 1984 ?), 305.88 (1.5 TI 1986?)
Not easy know small differences beetwen engine codes of same nominal power,
also articles on old review used to cite wrong engine code and specifications,
difficoult also know years of production of each code,
hope someone that has these engines can add/correct other details.
Also I'm not sure about this:
at some moment there was a version of 105cv engine with
an aggressive camshaft with 10.2mm INtake cam height
(and pistons worked with valve pockets o avoid interference?)
but a later version was with less aggressive setup and was same/more efficient;
that camshaft that was a bit to much 'wild' on a 1.5, it will be re-used instead
as a more correct one to give enouth air, with same valve diameters, on the 1.7 Q.V. 118cv,
hope someone know better about this special camshafts/versions
It seams also before 1987 (1986?) all boxer engines are "flat heads" design,
(instead pistons can vary from year to year starting from Sud to arrive to last 33)
and all (or almost all) the versions "high performance",
the ones with two separated double carbs we are talking about,
has the shrims valve adjustement system and
no more the split lobe cams used on less powered versions
(but I'm not sure, someone say me there was also a 1.5 95cv with split lobe cams??),
and already are all "big valves" version (intake 40mm instead of 38mm diameter)
maybe only some earlier 1.3 S 86cv still having 'small' 38mm intake valve;
so probably we are talking of a group of engines sharing
all same mechanical tappets, shrims system, same valves,
the type about 98-97mm long
(previous split lobe camshaft system engines have valves about 92-93mm long)
From 1988 (or from late 1986?):
there was for each model two versions on the market, also for 1.5 105cv,
the 'old' flat head engines and a new type with head dished some millimeters
(and pistons slightly different to mantein the same RC at about 9.5:1 );
This head dished design there was at first used with the 1.7 Q.V. 118cv in 1986,
also if this engine was not labelled as RON 95;
After this (in late 1986 or in 1988) some new engines was prepared
to be labeled " RON95 " version of both 1.3s 86cv and 1.5 105cv;
the new conbustion, now head half in the piston half in the head,
should have some advantages, maybe it is more fuel efficent,
or give less pollutant, or has better control of knocking;
also RON95 engines have all 'big' diameter valves
but valves are some mm shorter due to disched head chamber,
i.e. valves are about 93-94mm long
Dished head 105cv version could be (??) the 305.88 engine?
(if so, also 305.86 1.3 79cv and 305.87 1.3 S 86cv are RON 95 version)
The 1988(1986?) dished head engines already has intake air prepared to macth
the 40mm nominal diameter carburetors (but inner venturi max measure
it remains the same 32mm of your actual "36mm nominal" set-up);
not sure if some of these 95RON engines got 40mm carburetors already on
305 alfa 33 (manuals pdf say yes but have some corrections with errors
so don't know if they are correct) or only with later 307 alfa 33 from 89;
1988 new head engines are more similar to the engines that will be used
in 307 alfa 33 series 3 years 89-94, when it will be used also on 1.3 and 1.5
hydraulic tappets and applied some other minor corrections,
one important is a better and unique camshaft for all 8v engines,
it is the camshaft that was previously used on 1.7 I.E. 110cv,
but not used on the more common 1.7 I.E 105cv catalitic/Euro1 version,
this has a little quiter camshaft (about 35mm vs 37mm total cams height);
the last 33 series this camshaft ("37mm") has a quite good
9.8mm IN /9.0mm OUT cams, it is more than most previous
boxer engines (except 1987 1.7 QV and maybe one 1.5 TI)
but with a well balanced timing, we know last series run
quite well/easy, from 1.3 to 1.7, carb or I.E. ;
hydraulic tappet engines has all same 'big' valves about 92mm long
this to say that later series pistons, heads, camshaft,
are quite good also respect some previous 'performance' engine,
they lack only a kit to adapt mechanical tappets,
to give an 'old time' aspect if used on older car and more reliability
(sometimes hydraulic tappets tend to fail
for example if car is not used for a long time)
One could mix a mechanical camshaft housing with later series 3
camshafts/heads/valves/pistons (camshaft as to be years 89-91,
after 1991-92 it changed a bit the shape of the ending of the camshafts
and of the housing, with this minor change this very later camshafts
are no more compatible with previous mechanical tappet housing)
and some shrims on/under tappets or modifyng the camshaft housing
to correct 1 mm differences on valve lenght,
I read on forum some have done this mix and modification,
or used some kits (like AHM or the "Trofeo kit" used to have mechanical
tappets on alfa 33 1.3 running in the italian 33 Trofeo until some years ago:
https://www.autodromomagione.com/2018-t ... 4-gennaio/ )
Sorry for my poor english and some errors about the engine history,
I used to work mainly with later alfa 33 series 3 engines, so missing a lot of info,
I writed this also to see if someone that had/worked on previous engines
or has some "original" manual without errors can clarify
some references about different engine codes
Ps.: the page marked 1984 you posted with 30.520 and 30.182 engine codes,
from what car manual is from? Sprint? some online pdf or paper?
I never founded the 30.182 code, wondering what car was or if for not italian country
