Thorp Air Command - T18.net

I was enjoying the cowl cheeks made on an English Wheel, when I noticed a comment about horizontal induction and HA6 carburator / fuel injection.
I've been noticing some of these parts on fleabay, likely cast offs from engines converted to an RV, where they won't fit.
I'm shopping for an S-18, and reading as much as I can about all Thorp T/S-18 variants. The smooth bottom cowl really sets these apart from 'the others'.
I'm finishing my RV-8, and these open bottom cowls (on RVs) are getting a lot of attention in their forum as a source of drag right now.
Larry Vetterman has made a teardrop shaped body that fits under the fuse and attaches to the back of the lower cowl exit...think of the back of a wheel pant.
Anyway, my point is that the Thorp simply does not have this problem, due to the cooling exits being on the sides. Those T/S-18 with horizontal induction have a totally smooth lower cowl with the exception of the exhaust tips.
Can anyone shed some light on the rear facing horizontal induction sump, maybe post some pics?
Pictures of the induction, airbox & intake assemblies would be very helpful.
Show us what you have, really, it's not like bragging or anything...think of it as sharing.

Ill post one when I get home. Im on a trip for work righ now... My sump had a block off plate where I could pick front or rear to mount the carb. I had to put it on the front do to the engine mount cross tubes.

On another note this thing sounds like a beast with the 4 pipe system from Aircraft Custom Exhaust!


Chris >:D

Here is a sample. The airfilter box is off a Dodge.

Bob MO

Ok, so I just want to make sure I understand this photo correctly. You are picking up carb intake air from off the top of the cylinders? And running it thou an automotive filter.
So, no carb heat?
No air intakes on the bottom of the cowl at all?

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http://www.dixiefriedfabrication.com/

Correct, but I took these pics in 06. I don't know enough about HA6's. If you need carb heat, I'm sure Bill had it.

Bob MO

Bob;
That looks great,
The prop looks like it's sticking out of the end of a needle. Even smoother than a twin comanche nacele.

We still have carb heat ... picked up the same way as on a standard updraft carb. The only difference is that the carb is horizontal.

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Lee Walton
Houston, TX
N51863,N118LW
KEFD

Add mine to the list of carbuerated engines with internal induction. I like the looks of a smooth cowl but already had an MA4 updraft carb, so I built a thin, aft-facing airbox. Induction air comes from above the cylinder baffle and an air filter, as others have done. A damper on the box pulls carb heat off the tailpipe nearby. I did have to add a small blister on the bottom cowl. It was my first attempt working in fiberglass, but I got some good suggestions and it came out good. It doesn't stick out more than a couple inches and I think it blends in well. The invisible paint could make it even better.

Les Krumel, Albuquerque

These pictures are of Bill Beswick's T18 and had a injected engine, hence no carb heat.
Same as Bob Highley's. I run a HA6 carb and fashioned a filter box copy from a twin Commache. I built a carb heat box and pull heat from the exhaust.

That picture was taken when Bill had the HA6 carb. I asked him where he found the air filter box. The date on the pic was 2006.

Bob MO

I ended up copying Bob and Bills air box, the big difference was that my version of the ha-6 would not allow me to mount the box horizontally, in addition I was going for more breathing room in the engine compartment so I ended up with a horizontally inducted motor that still picked up its induction air from the lower cowl via a Naca scoop. In retrospect I like the aft baffle pick up more mainly because i hated to cut a hole in the cowl but it works and still gives the airplane the "clean cowl" look.

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Lee Walton
Houston, TX
N51863,N118LW
KEFD

If I remember correctly, Bill B used a bottom mount sump. He made a 90 degree adapter that mounted to the sump and the HA6 mounted horizontally to the adapter. That would have given him some additional room. Sorry, I did not get a pic.

Bob MO

That's the 90 deg setup I mentioned in the other thread. That's Steve Hawleys design and yes it's outlined in the newsletters.

_________________
Lee Walton
Houston, TX
N51863,N118LW
KEFD

BTW that's NL 56 if anyone is interested.

_________________
Lee Walton
Houston, TX
N51863,N118LW
KEFD