232 Engine

[Samuel]

I am curious about 232's engine. Was it a slow case? Rebuilt after last years hiccup?

[ChrisMX105]

Re: 232 Engine

Yes to both

[comancheflyer]

Re: 232 Engine

I am curious about 232's engine. Was it a slow case? Rebuilt after last years hiccup?

sorry if this is a stupid question but whats a slow case?

[JayReno]

Re: 232 Engine

sorry if this is a stupid question but whats a slow case?

The slow nose case has more gear reduction than a standard case.
It Turns prop slower RPM than standard at same engine RPM.

[ChrisMX105]

Re: 232 Engine

I can't remember the exact ratio's

Purpose of a slow turn nosecase is to allow higher engine RPM/Power without causing the prop tips to go supersonic and lose efficiency.
Standard nosecase this is about 2950 RPM on a 3350.
Slow Turn is around 3200 depending on weather.

[Samuel]

Re: 232 Engine

The slow nose case has more gear reduction than a standard case.
It Turns prop slower RPM than standard at same engine RPM.

And there are a limited number of slow cases left? Something like a dozen?

[Race5]

Re: 232 Engine

And there are a limited number of slow cases left? Something like a dozen?

Probably less than that. I think Rod has three, Luftansa has four they are using for their Super Connie restoration, and one that the Riff Raff team had. I am not sure where it is now.

[ChrisMX105]

Re: 232 Engine

I believe Rod has the one from Riff-raff but I may be mistaken.

[Samuel]

Re: 232 Engine

Did he get one for the American Spirit air racer project? What is the dash number of the slow case engine?

[ChrisMX105]

Re: 232 Engine

Did he get one for the American Spirit air racer project? What is the dash number of the slow case engine?

Last I heard American Spirit was on Hiatus.
I believe that the Slow-Turn nose will mate with most late model power sections. Not sure on what they originally came off of.

[Race5]

Re: 232 Engine

Last I heard American Spirit was on Hiatus.
I believe that the Slow-Turn nose will mate with most late model power sections. Not sure on what they originally came off of.

If I remember correctly the 3350-93B was the one with the slow nose.

[wingman]

Re: 232 Engine

They were only used in the Lockheed 1649A Super Connie. Lyle first used one (from the Aircraft Cylinder guys, I think) in the very early 1970s. This was little known (outside the team) for a long time, and was a big factor in the Bear's dominance in the 1970s and 1980s...

It does little good with a stockish motor -- but really makes a difference with a properly built Race engine.

Neal

[ChrisMX105]

Re: 232 Engine

They were only used in the Lockheed 1649A Super Connie. Lyle first used one (from the Aircraft Cylinder guys, I think) in the very early 1970s. This was little known (outside the team) for a long time, and was a big factor in the Bear's dominance in the 1970s and 1980s...

It does little good with a stockish motor -- but really makes a difference with a properly built Race engine.

Neal

Did just fine in 2009 strapped to the FIFI engine(= Finished on Sunday 3 mph race average over current qual speed

[stuntflyr]

Re: 232 Engine

The '80's Alameda gold dyno engines were stock -26's with the EA-2 nosecase. They are very competitive with that set-up, especially at lower elevations like Bakersfield. The Fifi engine was very similar. The slow nose case allows higher rpm, and hence BMEP, turning the propeller at it's best efficiency rpm.
Chris...

[RichH]

Re: 232 Engine

If I remember correctly the 3350-93B was the one with the slow nose.

The dash-numbered engines were a military designation. The only slow nose variant (.355:1 reduction gearing) was a civil designation... specifically the 988TC18EA-2. In the case of 232's engine (the original configuration of which was to be used on Dave Cornell's "American Spirit" project) the EA-2 nose case was grafted onto a military designated R3350-93 with mechanical fuel injection. The turbo-compounding bits were removed but the TC intermediate section was retained (the "Bear" variants leave this out and install a spacer) with blanking plates where the turbines would have been. Attached is a photo of the engine in question, removed from 232 for possible scavenging of parts for use on the Bear one year: