Re: the Navarro Six, more revealed

[Tom Jennings <tomj@xxxxxxx>]

Thanks a ton Frank for finding this photo, as I'm pretty sure I
now know what this engine I have is.


On Fri, 22 Jul 2005 farna@xxxxxxx wrote:

> After some research, I found a photo of the first Indy car in an AMC ad for 1967:
> http://www.amccf.com/mainokset/67Rambler_Six_at_Indy_ad_MT_sept67.jpg




I've been studying the pictures of the intact #2 motor that sold
at auction as the "Indy motor" (I'll call it the twin-turbo from
now on) and the parts I have and I now believe -- pending hard
facts -- that I have either this first motor or a copy of it or a
"developmental" version, etc.


First -- the manifold. In this picture

http://wps.com/AMC/Navarro-turbo-motor/images/man3.jpg

the rectangular flange in the middle of the manifold is an exact
match for an AirResearch T04 turbine. Precisely.  Plus I have a
bunch of exhaust gaskets that fit it.

It makes perfect plumbing sense -- the flange is attached directly
to exh #3 and #4, there's two stubs to plumb in #1 & #2 on the
left and #5 & #6 on the right, so it's a cast stainless exhaust
collector hugging the block, and only two custom "Y" pipes needed
for the entire exhaust-side plumbing. Sweet!

It leaves the compressor inlet in exactly the right place for that
1967 car -- pointing forward (driver's left shoulder), with the
turbo exh outlet pointing straight back as in the Rambler Indy ad.
I'll later mock this up for a photo.

Note also that on the manifold that there is a circular outlet
(with two "D"-shaped ports) pointing straight up -- it's got to be
for a popoff valve, but the Rambler Indy ad photo shows an
assembly awfully similar to the one on the #2 motor below the
turbo, so I don't know what that means. Maybe there's a "J" pipe
that points it towards the ground instead of poking up through the
fiberglas (and behind the driver's head!)

The one gotcha in this hypothesis is that the manifold has drilled
and threaded bosses for the fuel injection. I'm going out on a
limb a bit, but the twin-turbo motor uses the same (probably quite
expensive) manifold. It's certain that somewhere between the first
motor and the twin-turbo the decision was made to go FI. The
smallest possible change would be to add bosses to the casting.

It does seem certain to me though that this manifold was designed
to support one T04 turbo, and was later adapted for twin-turbo
use. Sure makes assembling this engine a hell of a lot easier!
Plus it might fit in a car in single-turbo mode.



In the photos of the twin-turbo motor,

http://wps.com/AMC/Navarro-Indy-motor/images/indy12.jpg

there is a popoff on that top double-D outlet, and something
bolted to the rectantular turbo flange, but what that is I can't
tell from the photo.  It looks like some rectangular thing with a
second popoff?

[Someone suggested that the left-three cylinders exhaust fed
one turbo, and the others fed the second turbo; this clearly
is not the case. It's plumbed as I state above, and you can
see it in this photo

http://wps.com/AMC/Navarro-Indy-motor/images/indy12.jpg

so it seems really likely that the second turbo is in series with
the first, both intake and exhaust. It might explain why going to
two turbos plus fuel-injection only netted 100 hp over the single
turbo and carburetor.]


I also have a straight section of exhaust pipe precisely the right
diameter for the smaller two turbos I have (more on that below).
It's clearly seen exhaust-pipe duty, cumbustion products inside
and typical bluing outside. However, the turbo-flange end has been
lopped off with a pipe cutter. This pipe could be the first car's
exhuast, and the working end lopped off for reuse, or it could
have been a dyno test pipe, or of course any old engine project
with the same size pipe. Who knows.




I have three turbos; I thought they were the same but they are
not.  Two are TE06's (by all indications, including box markings,
but I'll research numbers later) 1.54 A/R and 1.89 A/R (or
possibly .89 A/R). These two are identical except for different
size housings. The third is about 20% smaller over all, probably
same manufacturer. One of the boxes was marked "T04" then X'ed
out, so maybe it's a T04. It has a much smaller housing, so it
probably produces boost at lower exhaust volumes.

Last, and circumstantial, on the twin-turbo motor a lot of the
incidental parts (water pump blockoff, thermostat blockoff) are
very nicely machined and/or cast, and on my motor clearly
fabricated from ordinary flat stock by hand. The oil pan on mine
is a heavily modified stock pan; on the twin-turbo it's cast
aluminum with fins. I'll do side-by-side photos of these, but they
point to incremental developmental changes, since the parts look
otherwise the same.


Oh yeah, the number on the twin-turbo block are different than my
block, unfortunately the first digits are obscured by a hose. I
haven't looked at the other photos to see if I can discern the
missing digits, but what is readable is:

	??70721



I'm going to write this whole thing up as a coherent story,
hopefully with interviews.