ALFAGTV6.COM

[Jim K]

Hi guys,
I've been working on my 3.2 project on and off for some time now, as the 3liter 24v will go into a friend's 75 when the new lump is ready. Since its a separate project I started this thread. Yesterday I got done with all block machining work, crank balancing, clearance setting, align-boring. I stayed at the machine shop all day to see everything through and help the guys out with whatever. I was especially interested in finishing the balancing job with the sensitivity knob set at 'max' -not usually done... Two pulleys were balanced, will decide later which to use.
The block comes from a 164 which broke a rod, bent 8 valves... No head damage though. Lots of preliminary work was done at home like rod/piston balancing, cleaning, crank tapping, valve spring matching etc.
What is going into it:
3.2 crank ( )
CPS pistons
Maxspeeding rods
Lightened flywheel
75 Motronic pulley
Threaded crank oil plugs
IH crank scraper
Flowed/ported heads 11.5:1cr
Ferrea std size valves
JK 10.3 cams
JK 24v headers
Optimised oil pump
Long intake w/large plenum/short 75 intake+plenum (choice later)
Emerald K6 ecu/164Q4 (both will be used/mapped)
Details will be posted as we go. Here are a few pics.
Jim K.

[Duk]

Nice!
But when are you going to fix those overly large 24V ports???

[Jim K]

Yes they are huge on the 3/3.2. There's a thought to find some 2.5liter heads and measure those, but nobody has a set laying around here. I will not epoxy or otherwise weld the ports to increase velocity for fear of little lumps detaching... I have however thought of the possibility of fitting suitably formed 1-pce alloy 'tongues' in the ports, held securely in place with bolts from outside and finally refinished/reshaped in place. Lot of work though... Small consolation, if nothing else, the heads are the same for 3/3.2 engines so they should behave a bit better with the little extra capacity.
Jim K.

[maxiboy]

Been so looking forward to this thread

[75evo]

Is align boring necessary? I need to ask my machinist how much it would cost.

[Jim K]

Call it peace of mind one way and a necessary step for clearance setting in another. If you want to be cheap, just measure ID of main bearing seats (no bearing shells) with caps properly torqued and if perfectly round, no align-boring needed But then, mine were round too... so, take your pick. Without align-boring, how else are you going to set main bearing clearance? Chances are factory clearance is <0.04mm and 0.06mm is a good value for performance engines seeing track use.
Jim K.

[MALDI]

Jim, would you explain the measurement of the connecting rod in the picture where the scale says 151.5 g. What is being determined? Thanks.

[Jim K]

The scale was zeroed with the little fixture on it, so it now measures only the weight of the rod small end. This weight, added to the piston weight gives us the 'reciprocating' weight to use in the formula to determine the balancing bobweights. The rod then is weighed the other way to determine rotating weight.
Jim K.

[MALDI]

Thanks!

[Duk]

Yes they are huge on the 3/3.2. There's a thought to find some 2.5liter heads and measure those, but nobody has a set laying around here. I will not epoxy or otherwise weld the ports to increase velocity for fear of little lumps detaching... I have however thought of the possibility of fitting suitably formed 1-pce alloy 'tongues' in the ports, held securely in place with bolts from outside and finally refinished/reshaped in place. Lot of work though... Small consolation, if nothing else, the heads are the same for 3/3.2 engines so they should behave a bit better with the little extra capacity.
Jim K.

Silly question time...............................

Can the later model chain driven oil pump be fitted to the older auxiliary drive engine block?
Same said for the drive sprocket. Can it be fitted to the older type crank?

[Jim K]

I think the block mounting surface is different, but I'll have a more detailed look tomorrow for you as we have a 166 24v on the stand. The lower pump body is also supported somehow by one of the bearing caps.
As cranks go, the old 164 one would have to be machined considerably to make room for the sprocket. The front journal where the timing cover oil seal rides is replaced by the sprocket front step.
Why would you want to change from the old pump? They have proven adequate for any job.
If you want any specific pics of the two blocks/cranks/pumps, let me know as I'm building my 3.2 (164 origin) at home and we have the 166 in the Alfa garage.
Jim K.

[kevin]

You can't change to chain pump .

[Duk]

The reason I asked is that getting a 2.5 litre 24 valve is easy enough. But they are, as far as I can tell, the later engines. So building a 24 valve engine (obviously need new 3 litre 24 valve pistons) with 2.5 litre heads is out of the question because of the oil pump.

[Jim K]

I was under the impression that early 2.5liter engines (which chassis?) appeared with the old pump but I don't have any info on them. If not, then 2.5 heads can't be used on old pump blocks. It would be nice to just have that alternative open.
Jim K.

[Giuliettaevo2]

Earliest 156 2.5 24v i've seen was from 1997 i believe and that one had a chain driven pump.