O/T Compression ratio and supercharging, also efi pumps

[Rudi Machilek]

I used to run an E-sports 850.  850's were notorious for burning the center main and #3 rod.  That and a lack of an oil filter (OK the centrifugal inside the crank pulley did sort-of work) made for one weak bottom end.  There was an external oiling mod that took oil from the head and flowed through a hose to a fitting and hole drilled trough the side of the block into the oil galley above the center main.  Someone with Abarth experience might be able to tell you the exact point.  
The heads will likely need to be o-ringed.  Running 11.5:1 we blew head gaskets regularly.  We modified one head to accept 4 Mikuni carbs.  With 14 cm or so stacks and tuned exhaust, it ran quite nicely.  Adding injectors to the Mikunis would be great.  You could also add injectors into the log manifold directly above the intakes.  The original head with the center mounted Weber did not flow well (or evenly) at all.  The #4 cylinder ran extremely lean.  With injectors mounted directly to the head, I am nor sure how you could even that out.  
Oil provides a great deal of cooling in that engine.  Abarth had a mode for an external oil filter and oil cooling.  A must for HO operation.  The 843cc engines had a finned cast aluminum oil pan that cooled better than the later stamped steel pan.  

Enough rambling, good luck with your project.  

Rudi Machilek
90 Camaro TBI
93 T-bird TPI
86 Suburban, project conversion to TBI


Original Message

Dave, its a Fiat 903cc, 4cyl, bore/stroke=65.6mmx69mm, 5 port alloy head, max
power rpm=8000.  did some measurements last night.  Chamber volume=21cc, deck
height=0.889mm, headgasket=66.7mmx1.6mm (uncompressed).  In this configuration I
can only bring compression back to around 8.8:1 (9.5:1 std), and I guess with a
compressed head gasket this will be closer to 8.9:1.  As I'm not ready to get
into any machine work I'll take the chance and see how it goes at this
compression, if I have to water inject it as well so be it.  I just need to get
the car running well enough for me to start on the fuel injection side of
things.  Although this will be a dedicated race car it would be nice to just run
on 96 leaded, but if I have to mix Toluene in it and bring it up I can do that,
or i can just run avgas (which according to CAMS is 106 octane in OZ).

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