manifold machining

[mike mager]

Peter Gargano is planning an AlfaSud EFI conversion:
(complete quotation below)

>. . . because then I can add a fancy manifold, perhaps going through a few 
>iterations . . .

<Beavis_And_Butthead>Fancy manifolds are cool!</Beavis_And_Butthead>

>My only concern was that, as injector is close to the inlet valve, and in 
>the head itself, that the O-ring or injector may get too hot in this 
>position (it's a cross flow head - exhaust manifold is on other side from 
>injector).

(Is the AlfaSud 1500 liquid cooled?)
I'd be happy to use a high-temperature O-ring right outta the catalog;  they 
are used in Diesel engines, and in certain spots in certain automatic 
transmissions, and mebbe Jeep 2.5 injectors;  check Diesel repair shops and 
bearing supply houses, if you can't find a catalog anywhere else.

Hot injectors, I'll just leave to the appropriate experts (but they do try 
to hold up as the factory installs them).

>Any thought about machining directly into the head? (I checked clearances, 
>even sawed an old head in half to check that there's enough metal below, 
>nowhere near the coolant!)

Thoughts? - Always!  (Well, I _claim_ that I'ma thinking . . . )

First, _every_ head is machined, iron, aluminum/magnesium, other(?), so it 
can definitely be cut!  You seem confident, and the plan seems reasonable, 
but none of us have seen it.

You've got at least one development/practice head, right?  Spot-face with a 
larger endmill as a first step before the bores;  drillbits are generally 
inferior to endmills for the bores, BTW (use a center drill first, if you do 
drill);  if the bore size is odd, you can get a tool-sharpening shop to 
resize a generic endmill to just the right size  (right, and be sure to 
_know_ just the right size!).

IMHO, as they say:
Oh, yeah, don't even think about trying your first one on a drill press - 
save that for later;  no doubt somebody has done it with a hand drill!

You've heard it before:  (I read a shop book, once)
"Measure twice, cut once"
"clamp your workpiece securely"
"don't force it, let the tool do the work"

Sounds like a fun project!

Mike (_Bad_ carburettor!)


>From: Peter Gargano <peter at ntserver.techedge.com.au>
>Reply-To: gmecm at diy-efi.org
>To: gmecm at diy-efi.org
>Subject: Re: manifold machining
>Date: Sun, 09 Apr 2000 12:22:13 +1000
>
>Dave Williams wrote:
>
> >  When you find those injectors that can spray through a 90 degree turn
> > and around a curving path to the valve let me know....
>
>I have two options for mounting injectors on an AlfaSud 1500 (flat 4).
>
>  1. About 5-6 inches away from inlet valve, using existing (carby) inlet
>     manifold. Has a 90 degree turn (injectors vertical, valve stems
>     horizontal)
>
>  2. Directly onto back of the inlet valve, but the injector hole is
>     then machined into the (alloy) head itself. I don't see a need
>     for a bung for this position.
>
>Option 2. seems to be the best, because then I can add a fancy
>manifold, perhaps going through a few iterations, without worrying
>about re-doing the injector mounts. My only concern was that, as
>injector is close to the inlet valve, and in the head itself, that the
>O-ring or injector may get too hot in this position (it's a cross flow
>head - exhaust manifold is on other side from injector).
>
>Any thought about machining directly into the head? (I checked clearances,
>even sawed an old head in half to check that there's enough metal below,
>nowhere near the coolant!)
>
>Peter.

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