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Engine basics => Engine set up tips => Topic started by: Paul Taylor on October 24, 2007, 01:48:21 PM

Title: LA .46 vs FP 40
Post by: Paul Taylor on October 24, 2007, 01:48:21 PM

So if you had a choice between the two?

More power with the ?
Better fuel efficient with the ?

Will the FP use the same fuel at the LA?  10/22

Thanks
Paul H^^

Title: Re: LA .46 vs FP 40
Post by: john e. holliday on October 25, 2007, 08:50:57 AM

Read my post on the LA 46.  DOC Holliday

Title: Re: LA .46 vs FP 40
Post by: Bill Little on October 25, 2007, 04:43:32 PM

Quote from: john e. holliday on October 25, 2007, 08:50:57 AM

Read my post on the LA 46.  DOC Holliday

C'mon, Doc!  I just did a search on LA 46 and did not see an article by you.  Then I went all the way to page 8 in this section and could not find anything by you on a LA 46.  Where is it?

Title: Re: LA .46 vs FP 40
Post by: Bill Little on October 25, 2007, 05:02:56 PM

Hi Paul,

I wish I could help you out on this one.........

I have never run a *Stock* OS 40FP.  I have personally looged a BUNCH of flights in years past on a Byron Barked reworked 40FP in both profiles and built up fuselage planes.  Runs as good as the day I got it from him (used at that!).  Strong, great break and it is an iron piston verson.  I have another one with exactly the same mods.  Exactly the same run!  As good a 4-2 break as anyone could ask for.

I have a LA 46 still in the box, haven't finished a plane for it.  Everyone of those I have seen have been running in a wet 2.  Seem to have a good bit of power.  I plan on using it on one of two profiles I will be building.

Best thing is to try them both! And see which one works best for you.
Bill <><

Title: Re: LA .46 vs FP 40
Post by: Greg Hart on October 25, 2007, 10:47:02 PM

LA all the way. No contest

Title: Re: LA .46 vs FP 40
Post by: Dennis Vander Kuur on October 26, 2007, 03:11:43 PM

Paul,

I own and have flown several LA.40, FP.40, and LA.46 engines over the past 6 years so maybe my experience will help answer your questions.

Based on my experience with "STOCK" motors, I think the LA.46 has a little more grunt to turn larger propellers than the LA/FP.40. However the LA/FP.40 motors are no slouches. I've flown a kit-built Brodak Pathfinder (55 inch wingspan, 620 sq in area) in competition for 4 years with an LA.40 and this included some contests with winds blowing to 30 mph. I run most of my LA engines in a "wet 2 cycle". The LA motors NORMALLY come without boost ports, unlike the FP.40, and if a breaking 4-2-4 run is what you're after then you'll probably have better luck with the LA motor.

I've personally found that MY FP/LA.40 and LA.46 engines consume about the same amount of fuel. Several factors can cause a significant difference in the amount of fuel any of these engines will use to complete the pattern. IN MY EXPERIENCE, using a smaller inside diameter venturi, running in a 2 stroke mode vs a 4-2-4 mode, using a higher pitch or diameter propeller, running a fuel with a lower oil content, using a more restrictive muffler, or using shorter flying lines will all reduce the amount of fuel you need to fly a complete pattern. The experience of others may vary.

They all run fine on a 10/22 fuel (i.e. 10 percent nitro, 22 percent oil preferrably 50/50 synthetic-castor). The one exception is the older style FP.40 that has an iron/steel piston/liner. How do you know if your FP.40 is the old or new style? Look at the attached picture. The iron/steel engine will live longer with more oil (i.e. 25 percent oil and preferrably mostly castor). The LA engines and newer FP engines are of ABN (i.e. aluminum/brass/nickel) construction and run fine on less oil.

Hope this answers your questions. Keep your lines tight.
DennisV

Title: Re: LA .46 vs FP 40
Post by: Crist Rigotti on October 26, 2007, 09:34:10 PM

I can atest to what Dennis says about his 40LA powered Pathfinder.  He whipped more than several times with that combo.   H^^

Title: Re: LA .46 vs FP 40
Post by: Ward Van Duzer on November 03, 2007, 02:56:32 PM

Don't be overly sure that your early model FP is an iron piston/steel sleeve. I know I'v had mine redone by Randy (maybe twice already) and with ABN parts! My guess is most of those old ones out there have also been rebuilt...

Just a thought.  H^^


W.

Title: Re: LA .46 vs FP 40
Post by: Dennis Vander Kuur on November 03, 2007, 08:16:32 PM

Ward,
I have 5 of the old style O.S. .40FP engines. Every one is iron/steel. However, you are correct. If you need to rebuild these engines the original iron/steel replacement parts are pretty much "unobtainium". In contrast, O.S. .40FP ABN piston/liner sets are still available from TOWER HOBBIES. The sure fire way to tell if the piston/liner is iron/steel is to put a magnet up to the liner. If it sticks (i.e. the liner is magnetic) then it is the iron/steel version.
DennisV

Title: Re: LA .46 vs FP 40
Post by: john e. holliday on November 04, 2007, 07:21:26 PM

Quote from: Bill Little on October 25, 2007, 04:43:32 PM

C'mon, Doc!  I just did a search on LA 46 and did not see an article by you.  Then I went all the way to page 8 in this section and could not find anything by you on a LA 46.  Where is it?

Bill I missed this as I don't check on what the experts say too often.  It was on the Jim Oliver post on the three different engines.  Have fun,  DOC Holliday