Author Topic: A couple of questions on PA 40 UL (reply #3) (Read 1384 times)

Matt Colan · « **on:** April 14, 2009, 08:38:28 AM »

I am going to buy an engine for my Oriental Plus and it will be either a RO-Jett .40 or a PA .40 ultralite. I have a couple of questions regarding these two engines.

1) If I buy a RO-Jett, would a PA header fit onto the exhaust port of the RO-Jett
2) How long is the PA .40 ultralite, because I can't put an engine that is longer than 3 1/8 inches. The regular PA's don't fit.
3) On RO-Jett's website, would a remote needle valve be able to fit onto a PA
4) which would you recommend, a RE muffler or a pipe.
5) are there any good inexpensive props I could use

Thanks

Edit for extra question

john e. holliday · « **Reply #1 on:** April 14, 2009, 10:25:46 AM »

Solve all the head aches and stay one engine and associated parts. I fly a RO-Jet .40 REBS or is it BSRE with the little mini muffler. Very dependable engine. The PA's are very dependable engines also. Don't mix RO-Jett with PA or vice versa. DOC Holliday

Bob Reeves · « **Reply #2 on:** April 14, 2009, 12:49:54 PM »

To add to what Doc has already said, if I could afford it I would go with Randy.. One stop shop and good service.

Matt Colan · « **Reply #3 on:** April 14, 2009, 02:21:20 PM »

Well, today I searched on the forum for more info on the PA 40UL. I sent a PM to Bob Hunt, since he had both RO-Jetts and PA's in his Genesis before converting it to electric. After reading Bob's response and other info I gathered I decided to buy a PA 40UL. I'm not going to buy it yet, because I don't have enough money so I'm going to sell some of my old stuff on ebay to get the money I need.

Now I have a couple of questions on the PA 40UL

1) Is there any way possible to get a remote needle valve on it
2) This is for Randy Smith, when I buy it, does it come with a header or do I have to buy the header separately
3) Which way should I run it, RE muffler or piped
4) What is a good starting point with this engine, venturi, head gasket, etc.

Thanks

Mike Scholtes · « **Reply #4 on:** April 14, 2009, 10:38:13 PM »

Hi Matt:

I have a PA40UL on pipe in an Oriental Plus from RSM. If you already have the kit you will note the plans show a RoJett 40 on pipe. The PA fits perfectly as well. Overall length appears virtually identical to the RoJett. Use of a pipe as a speed regulator will give you the modern engine run that the model is designed to take advantage of. The designer Dee Rice recommends use of a piped engine. For what its worth a PA61 on pipe fits just as well and I intend to try that next. Be careful when ordering the header to get the right length and rise; Randy Smith can help you get the right parts. The OPlus having fuselage mounted gear needs a fairly low rise header (to clear the gear mount plate).

RandySmith · « **Reply #5 on:** April 14, 2009, 10:57:02 PM »

Now I have a couple of questions on the PA 40UL

1) Is there any way possible to get a remote needle valve on it
2) This is for Randy Smith, when I buy it, does it come with a header or do I have to buy the header separately
3) Which way should I run it, RE muffler or piped
4) What is a good starting point with this engine, venturi, head gasket, etc.

Hi Matt

I do not recomend a remote NVA on the engine, It is a long front end and the NVA is well behind the prop

All headers, header mufflers, Pipes, slide on tubes, etc are sold separate

You can run it any way that suits you, The motor runs great either way ,if it was mine I would use a pipe

Randy

Matt Colan · « **Reply #6 on:** April 15, 2009, 06:31:21 PM »

Quote from: RandySmith on April 14, 2009, 10:57:02 PM

Hi Matt

I do not recomend a remote NVA on the engine, It is a long front end and the NVA is well behind the prop

All headers, header mufflers, Pipes, slide on tubes, etc are sold separate

You can run it any way that suits you, The motor runs great either way ,if it was mine I would use a pipe

Randy

Well if it well behind the prop then that is good. I'm just cautious since I just started fiddling with the needle. I'd like to use the pipe since it does give me extra adjustments to tune the engine.

Quote from: Mike Scholtes on April 14, 2009, 10:38:13 PM

Hi Matt:

I have a PA40UL on pipe in an Oriental Plus from RSM. If you already have the kit you will note the plans show a RoJett 40 on pipe. The PA fits perfectly as well. Overall length appears virtually identical to the RoJett. Use of a pipe as a speed regulator will give you the modern engine run that the model is designed to take advantage of. The designer Dee Rice recommends use of a piped engine. For what its worth a PA61 on pipe fits just as well and I intend to try that next. Be careful when ordering the header to get the right length and rise; Randy Smith can help you get the right parts. The OPlus having fuselage mounted gear needs a fairly low rise header (to clear the gear mount plate).

I would get a 1 inch rise for the header in order for it to clear the landing gear right? I think that is what is shown on the plans. I don't have them near me since I build at my grandparents house.

A PA61 is too big, I put a regular 40 in and it was too wide, and also not a whole lot lighter than what I was originally going to put in (OPS 40).

Mike Scholtes · « **Reply #7 on:** April 15, 2009, 09:06:53 PM »

Hi Matt:

Take a look at the plans and measure the rise (amount of bend) in the header shown. There is not a lot of clearance so you need the right header. If you are going to be serious about this "stunt" thing, and it sure sounds like you are, get one of the top line engines like a PA or RoJett. They last thousands of flights and then can be rebuilt by Randy or Rich Oliver. That is years of flying for most of us. If the cost is probibitive (figure $500 for motor, header, pipe) you can get great performance out of a stock LA46-S for about $70. Many users add a front NVA from OS (Tower has them) or better still a Randy Smith NVA (which I have in the LA46 in my Vector). Just for the record the PA61 does fit the OPlus; I test fit it in mine last weekend. Mounts and overall length are the same as the PA40. Alum mounting pads need to be narrowed is all (due to wider crankcase).

Brett Buck · « **Reply #8 on:** April 16, 2009, 08:55:07 PM »

Quote from: Mike Scholtes on April 15, 2009, 09:06:53 PM

Take a look at the plans and measure the rise (amount of bend) in the header shown. There is not a lot of clearance so you need the right header.

If you need more clearance you can file/sand a wedge into the flange, just make sure you flatten it out perfectly when you are done so it seals up. I have several headers like that where I had a tight clearance. They aren't all the same! The tolerance on the "rise" at the end of the uncut header seems to be about 1/4". It's also pretty easy to "persuade" the regular Randy and Jett headers for small adjustments - just bolt it to something solid, stick a dowel of the right size in the end, and tweak it. The tubing is quite soft and the pipe doesn't need to be perfectly round.

Brett

Author Topic: A couple of questions on PA 40 UL (reply #3) (Read 1384 times)

Matt Colan

A couple of questions on PA 40 UL (reply #3)

john e. holliday

Re: A couple of questions on PA's and RO-Jett's

Bob Reeves

Re: A couple of questions on PA's and RO-Jett's

Matt Colan

Re: A couple of questions on PA 40 UL (reply #3)

Mike Scholtes

Re: A couple of questions on PA 40 UL (reply #3)

RandySmith

Re: A couple of questions on PA 40 UL (reply #3)

Matt Colan

Re: A couple of questions on PA 40 UL (reply #3)

Mike Scholtes

Re: A couple of questions on PA 40 UL (reply #3)

Brett Buck

Re: A couple of questions on PA 40 UL (reply #3)