Converting an IO-360-C1C to forward facing induction

A forum to discuss the installation and maintenance of the O-320, O-360, & O-540 engines and their variants.
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tmbg
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Posts: 613
Joined: Wed Feb 07, 2007 11:05 am
Location: Atlanta, GA (4A7)

Converting an IO-360-C1C to forward facing induction

Post by tmbg »

so I bought this C1C last summer. The C1C is an angle valve 200hp engine that was on the Arrow among others, and it's setup for aft-facing induction. I bought the engine knowing that this would need to be done, and last night I got off my duff and got it done :)

I did the machine work on my Bridgeport clone 9x42 mill.

First thing I did was bolt a 246 block to the table and indicate it in parallel to X travel

Image

Next, I set the sump on another 246 block placed under the existing aft servo mount pad and clamped it down. This way, the aft servo pad is parallel to the table. This way, since the surface that I cut will be parallel to the table surface, this ensures that the new servo mount surface will be parallel to the table. Also, I made sure that the sump flange (where it bolts to the case) was flat on the rear block that I previously bolted down. This insures that the new servo pad is also square to the case flange.

Image

Image


Then, I surfaced the pad with a 3/4" endmill

Image

Finally, I drilled and tapped the stud holes, and bored the induction hole. To bore the hole, I started by drilling it in steps up to an inch, then I used a boring head to enlarge it about 0.300" at a time. I got a nasty surprise when I noticed that my boring head would only cut about 2.5" maxed out, but I discovered that I can turn the boring bar horizontally and cut much much bigger holes. The induction hole is 3.5".


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I ended up cutting the pad a little higher than I wanted to, which is why it looks like I had to cut high up into the wall of the sump, and also why you can see a ridge at the bottom of the bored hole. The casting was irregular, and there wasn't enough meat on the bottom left corner. When I originally laid it out, I wasn't happy with the edge distance that I would have on that stud, so I decided to cut it up higher to make sure I'd have the edge distance. I'm going to need to take a burr to the inside of the bored hole and smooth that sharp edge for good airflow characteristics.
Ian
RV-7 SB, chugging toward final assembly
IO-360-C1C 200hp obtained.
Hartzell BA prop received.
James Cowl ordered.
N773WW reserved!

Spike
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Post by Spike »

Nifty work. Thanx for the pix. I am curious, do they use the same casting for both rear and forward directions? If not how did you get comfy that that casting would hold up to the stress of having the intake/carb hanging off of that side?

John
http://www.rivetbangers.com - Now integrating web and mail!
Current Build: 2 years into a beautiful little girl

tmbg
Class C
Posts: 613
Joined: Wed Feb 07, 2007 11:05 am
Location: Atlanta, GA (4A7)

Post by tmbg »

I'm pretty sure that it's the same casting, because they have the same pad with bosses for the studs cast into the front as they did on the rear. The holes are drilled and tapped into 1.5" deep 5/8" diameter bosses cast into the inside, and there's a forcing cone cast into the interior as well as a sniffle valve hole drilled and tapped but with a plug, same on the front as there is on the rear.
Ian
RV-7 SB, chugging toward final assembly
IO-360-C1C 200hp obtained.
Hartzell BA prop received.
James Cowl ordered.
N773WW reserved!

Spike
Chief Rivet Banger
Posts: 4013
Joined: Thu Oct 14, 2004 8:40 pm
Location: Baltimore, MD
Contact:

Post by Spike »

Suweeet. Sounds to me like you are money :thumbsup:

Spike
http://www.rivetbangers.com - Now integrating web and mail!
Current Build: 2 years into a beautiful little girl

tmbg
Class C
Posts: 613
Joined: Wed Feb 07, 2007 11:05 am
Location: Atlanta, GA (4A7)

Post by tmbg »

It was worth a shot, because worst case I was going to have to replace the sump anyway. This way, I don't have to buy a $2200 cold air sump.

The downside is, I believe none of the standard vetterman exhaust kits will work, but I've been told that I can call vetterman directly and have one made that will work.
Ian
RV-7 SB, chugging toward final assembly
IO-360-C1C 200hp obtained.
Hartzell BA prop received.
James Cowl ordered.
N773WW reserved!

tmbg
Class C
Posts: 613
Joined: Wed Feb 07, 2007 11:05 am
Location: Atlanta, GA (4A7)

Post by tmbg »

I still have to fabricate a block off plate for the rear pad.
Ian
RV-7 SB, chugging toward final assembly
IO-360-C1C 200hp obtained.
Hartzell BA prop received.
James Cowl ordered.
N773WW reserved!

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