L

lancef53

Well Known Member
This info has to be on here somewhere, but I can't find it. Where do I find the information on RPM restrictions, specifically for a IO 360 A1A engine with a Hartzell CS? How about with a fixed pitch?

Thanks for the info, Lance
 
Type Certificate Data Sheets (TCDS)

Type Certificate Data Sheets (TCDS) list engine/prop combinations (and restrictions). TCDS information is available from the FAA at
http://www.airweb.faa.gov.

Click on the TCDS link in the lower right, then do a "Current Model (TC Holder)" search for the engine...look up "L" then navigate down the list to Lycoming...then find your engine model. Operating restrictions are shown for each engine.

You can also look up TCDS for the prop...look up "H" then navigate to Hartzell, then look up the model number, etc. Operating restrictions will be listed in the table for the prop/engine combination.

Good hunting,
 
Last edited:
thanks!

Thanks for the info, so according to the info on the Hartzell pages, with the propellor vans sells, (C2YR-1BF/F74972 or F7497)continous operation above 24" manifold pressure between 2350 and 2550 is prohibited, correct?

Thanks --does anyone have any experience with this? Is it a big problem to work around? Thanks for the help--Lance

Another question, is it possible to find out RPM restrictions for a wood experimental fixed pitch prop? Do you just have to check with the manufacturer?
 
Last edited:
Wood props

lancef53 said:
.....
Another question, is it possible to find out RPM restrictions for a wood experimental fixed pitch prop? Do you just have to check with the manufacturer?
Click to expand...

Check with the prop maker, but I believe the flexing/damping properties of wood prevent resonances at specific frequencies (RPMs) so they should have no RPM restrictions....

Has anyone got a wooden prop with an RPM restriction?

gil A
 
Fixed Pitch

Lance,
Lots of data out there (and I'm sorting through it myself as I begin to research engine and prop combinations for my 8).

Sensenich has a table with various FP prop recommendations for RVs at: http://www2.sensenich.com/direct/vans.htm

FWIW, I flew an RV8 with a composite Catto FP (O-360, 180hp, two-blade Catto) last Sept and it was very smooth. Other threads here have also been positive regarding Catto props but the Catto website doesn't have a lot of technical info so you'd need to contact them for specifics.. www.cattoprops.com

With regard to your question about CS rpm restrictions: The restrictions typically state "no continuous operation" with a certain power setting (like the example in your post). As a generality, you use the prop and throttle settings as needed for takeoff and initial climb, then pick a combination that avoids the restriction during cruise climb and cruise. Manifold pressure changes with altitude, so whether or not the restriction is a serious consideration for a given flight depends on how high you're flying...Yes, it's one more thing to think about, but if you're flying the same plane on a routine basis it's not a big deal.

As I looked at the TCDS for the prop you listed (same as sold by Van's) I'm sure there's a good reason, but can someone explain why there's a difference between the O-360-A1A and the IO-360-AIA regarding CS prop restrictions? Are there internal differences between these two engines that would affect harmonics? Maybe an A&P or prop expert can comment?

Thanks,
Mike
 
Transporter said:
Type Certificate Data Sheets (TCDS) list engine/prop combinations (and restrictions). TCDS information is available from the FAA at http://www.airweb.faa.gov.
Click to expand...

One note for everyone trying to look TCDSs or similar... Firefox has some problems showing page correctly (or the page has been done incorrecly). So like if there is more to show, Firefox doesn't show "Show more..." for me at least even it does so with IE.
 
Lycoming SB or SI or SL

If you are talking to official red line yes the type spec.

If you are talking about how much you can exceed that, its a service letter, bulletin or instruction. I recall its about 5% over before Lyc gets draconian and recommend tear down. So we are talking 2,825 rpm. This is by my memory so by all means check the Lyc publication. They have a whole matrix diagram an it varies with some engines but the 5% is what I recall.
 
Transporter said:
As I looked at the TCDS for the prop you listed (same as sold by Van's) I'm sure there's a good reason, but can someone explain why there's a difference between the O-360-A1A and the IO-360-AIA regarding CS prop restrictions? Are there internal differences between these two engines that would affect harmonics? Maybe an A&P or prop expert can comment?
Click to expand...
These are two quite different engines - 180 hp vs 200 hp, parallel valve vs angle valve, different pistons, possibly different cranks and rods. Given the substantial differences between the two engines, and the different power vs rpm curves, there is no reason to expect them to have the same prop restrictions.
 
Lycoming Tech

Kevin,
Thanks for the response.

I'm researching engine (and prop) options for my 8 and would like to know the tech details.

Differences between engine models are expected...but it looks like Lycoming has been working on some kind of Guiness record for model variations!

Can you recommend a source for tech info on Lycomings that shows what components are in a given model?

Mike
 
Transporter said:
Kevin,
Thanks for the response.

I'm researching engine (and prop) options for my 8 and would like to know the tech details.

Differences between engine models are expected...but it looks like Lycoming has been working on some kind of Guiness record for model variations!

Can you recommend a source for tech info on Lycomings that shows what components are in a given model?
Click to expand...
The only source I know of is the Lycoming Illustrated Parts Catalogs.
 
You must log in or register to reply here.