|
choices
I am going to buy my first diesel. These are all new in box. Which would you buy and why. I have years of glow experience, but never ran a desiel. The choices are: CS .15, Elfin .15, MVVS .09, PAW 2.49, PAW 1.49, I am leaning toward both of the PAWS simply because I have heard of the brand, but the Elfin name sounds interesting. All are new in box and priced from $60.00-$40.00 each. I have bought engines from this person before and found him to be honest and trustworthy. He is a retired Hobby Shop owner with a large collection of engines he is selling off.
Thanks, Oscar |
RE: choices
ORIGINAL: SBOT I am going to buy my first diesel. These are all new in box. Which would you buy and why. I have years of glow experience, but never ran a desiel. The choices are: CS .15, Elfin .15, MVVS .09, PAW 2.49, PAW 1.49, I am leaning toward both of the PAWS simply because I have heard of the brand, but the Elfin name sounds interesting. All are new in box and priced from $60.00-$40.00 each. I have bought engines from this person before and found him to be honest and trustworthy. He is a retired Hobby Shop owner with a large collection of engines he is selling off. Thanks, Oscar Oscar, it would be an easy choice for me! I'd leave the CS alone, very variable quality. The original Elfin was a quality engine, sixty years ago! Again modern replica's are of variable quality ranging from very good to unrunable. The MVVS 09 is a good beginners engine but a little weak on power. Which leaves the PAWs. Good strong runners, they can take a lot of punishment and spares are available still direct from the factory. Not much ambiguity there for me! Ray |
RE: choices
Thank you for the information. So you would buy the PAW. The Elfin is an original.
Oscar |
RE: choices
SBOT get the PAW if funds enought get the Modela MVVS 09 also a very good diesel works fine in small planes mine has lots of air time
no issues put pick up both if you can martin If you do not want the modela 09 PM me and I will take it quite sure Fiery would also |
RE: choices
I would recommend the PAW engines too, very reliable and should you damage anything you can easily get new parts for them.
|
RE: choices
PAW would and is my choice. I have around six new and used sizes. Their factory service is responsive and fast. Last year I bought a used PAW that had the four cylinder head screws over torqued. It felt good so I didn’t pull it apart like I usually do before running. It ran a few times before the head popped off. A quick email to PAW had the screws and gaskets to me in double quick time. Great service for their fine line of motors. MVVS also makes a fine, easy handling, engine as well.
|
RE: choices
PAW
|
RE: choices
I learned diesel with an MVVS 1.5 (.09). If it has a throttle and muffler they are hard to find. I remember it tuned well even with an Enya carb fitted and a homemade exhaust. I sold it when I was done with it. A few years back, I picked up another with an original carb and muffler. Bench running it did bring back memories. It has it's own character.
Either the PAW or MVVS. Spares available for the PAW is a definite plus. Greg |
RE: choices
SOBT It appears you are going to go for the PAW,( as the classic) after cutting your teeth on the this one I would consider a modern engine conversion. if you
have some glows, check the Davis site for heads, if you are lucky you may have one of them and only need the head, this covers both worlds of diesel classic and modern regards martin |
RE: choices
The PAW it is. Thanks to everyone for the help. After the purchase I will be back for help on starting and break-in.
AMB give me a minute to drink some coffee, I work the midnight shift, and I will PM you with some info. Thanks again, Oscar |
RE: choices
Moot point now. Just talked to him he has sold everything but the CS.15 and the ELFIN .15 At the prices he was asking I knew they wouldn't last.
Thank you everyone, Oscar |
RE: choices
SBOT you can call Eric Clutton here in USA for PAW no web site 931-455-2256 for PAW here in USA (Tenn) cheaper shipping domestic
Davis heads [email protected] (site) phone 615-625- 3778 (Tenn) if you have a glow that he has a head for Both can give you a lot of info over the phone and of course great printed instruction sheets from both wiith engines and heads and of course diesel fuel from both too bad you missed on the PAW martin Post note if Elfin are reproductions and CS is from China would not chance buying one with their spotty qualility issues Clutton does test run the engines and sets them up |
RE: choices
I reiterate what's already been said. The MVVS (or Modela-depending on packaging) 09 has a good throttle and muffler-probably-in my opinion-better than either of the PAW equivalents. That being said-the Modelas I believe are out of production, so spares and support will be a dwindling resource-which is sufficient justification for going the PAW route. In the case of the Elfin, you would need to establish whether it is: a) an original
b) a Burford replica c) a Dunham replica d) an Argos replica e) a Puma replica f) a CS replica As you can see its been a much replicated engine! All but the CS replicas are excellent, with the Burford and the Argo being the highest quality. The Dunham and the Puma-which I have, are also good, but not quite so nicely executed-ie cosmetically they are not quite as nice as the former two. These comments assume you are referring to the radial mount earlier Elfin 249, if you are talking about the beam mount Elfin 249, AFAIK the CS is the only replica-and CS have a well deserved reputation for being variable in quality-and with variable metallurgy. That being said-there ARE good CS replicas-but you take pot luck! If the Elfin turns out to be an original, well you are in a grey zone-nothing wrong with the originals-they were fairly rough by modern production standards-but generally ran well-better in fact than most of their contemporaries-but how much use has the engine in question had? If a lot you might well be facing additionaL refurbishment cost-such as a rebore, to get a good runner ChrisM 'ffkiwi' |
RE: choices
ORIGINAL: SBOT Moot point now. Just talked to him he has sold everything but the CS.15 and the ELFIN .15 At the prices he was asking I knew they wouldn't last. Thank you everyone, Oscar George |
RE: choices
With the reproductions listed above, again the quality issues are with CS the rest are fine, this is an issue with other CS made engines'also not a good track record martin
|
RE: choices
These are orginal engines. This man has been collecting engines for over 60 years. However, I am not sure what an original CS would be. I was looking at these engines instead of modern engines because they are NIB and priced at $40-$60 each. Anyway for $40 I went ahead and bought one of the CS .15, and an Elfin .15 for $60
That you everyone for all the information and help. Oscar |
RE: choices
Good luck with them SBOT.
Before running either of them take the back plate off and rinse them out with kero. It's not unheard of for CS's to have a little swarf left inside. The Elfin? just do it on suspicion. Regards G |
RE: choices
Not a fan of the PAW engines (blasphemy on this site). Go for the MVVS. It is everything a nice little diesel should be. Easy to start. Certainly as powerful as the PAW .09 if not more so and throttles very well for a diesel.
That being said, no one ever indicates whether they need a throttled diesel or not when they ask for info! This is crucial as some perfectly good non throttled diesels perform quite poorly when throttled. For example, The Engel Rebel .09 is a superb non throttled engine but is awful with a throttle. Same for the Cipolla .09. The MK .17 with an O.S. throtttle is amazing and the best of all in my experience. All depends on your application. Max;) |
RE: choices
I don't think anyone has anything bad to say about the MVVS, but they are not made anymore and there are no spare parts available, so for a first dabble in diesel it would be better with something else.
The PAW engines throttle well but the carb is a little crude with the fixed airbleed. The Enya 09 carb (from the glow engine and available as a spare part) is direct drop in though on the PAW 09 and then you get an adjustable airbleed and they run much better around idle. |
RE: choices
Although the PAW engines are fine and OK, I sorta like other engines though. The MVVS or MP-Jet series are some other good examples of model diesel engines.
If you can get them, the Mills types of engines are nice, although some clones might be questionable as to whether they work or not. Converting some glow engines to diesel is a valid choice too. You can go to Davis DieselDevelop0ment's website and peruse the engine list to see if you have something on the list already you can convert. The Cox .049 converted to diesel might be a good warm up engine to get started with too. I have a couple of CS Engine's Elfin .09 engines and neither one works. Not even a pop out of them. I would avoid them as a first engine to try.. |
RE: choices
EARLWB your advise is " on the money" for the newcomers on the site, check out his posts, he is making up a new drone 29 from a set of castings he got from Davis. he knows what he is doing and talking about.
A machinist I am not, but having many Davis conversion heads 049 to 90 simple, never any issues, Yes I have PAWs great classic engines I have not had carb issues, remachining CS engines??, yes its been done, but why go there?? my MVVS and UK irvines again no issues Well in conclusion ,use what works without issues its all here post after post martin Post note I am referring to " everyday use sport engines. the specialty competition engines are an other ball game |
RE: choices
Has it been a year already. Wow; how time flies. Anyway I want to thank you all again for the advice, as I said earlier I bought the CS-15, and the Elfin-15. The Elfin is an orginal Elfin, not a reproductiuon. It runs great, starts easy, just a joy to tinker with. The CS, however, as everyone warned me; is another story. I spent hours flipping it by hand and I could only get short runs out of it. I didn't want to put on electric starter to it for fear of bending the rod. But, I finally reasoned that there is little practicle difference between an engine that will not run and an engine that will not run with a bent rod. So after a brief touch with the starter it fired right up and seems to run quite well.
Now to the reason for this post. How do I tune these engines. I have figured out how to start them. At least what seems to work. I open the NV till flipping the prop easily draws fuel to the engine, and back off the compression. Start flipping till the engine pops; then another tweak on,the "Tommy Bar?" is that what it's called? more compression, and the engine usually starts up. Using this method the Elfin starts easily, and the CS is getting better, but I don't think the CS will have a very long usefull life; as the piston leaks badly. But it does run, and pretty good. Now how do I tune the NV and compression for best preformance; and by best preformance I don't mean max RPM; just good, reasonable output. I'll probably build something like an old time 2 channel or maybe FF to put them in. Many thanks, Oscar |
RE: choices
Tuning takes some practice to learn, and you have to listen to the engine and hear how it runs. A leaner needle setting can handle (or needs) a higher compression setting. So if the engine is too lean or under compressed it misses every now and then, while if it is to rich and overcompressed it is down on revs and sounds labored.
|
RE: choices
The PAW would be my first choice as a beginner and the MVVS second as a beginner. Those engines are fairly well made and would give one a good first experience and success running a model diesel engine. The Elfin engines had many bad examples made that don't work and the CS can be similar where you have a strong risk of getting a defective engine.
|
RE: choices
SBOT you can get a fox 15 USA made, fox is one of the best from Davis with the original glow head and his diesel head the fox is a nice set up on the carb it is mounted on a flat
plate and c/l and r/c carbs quickly change out 2 screws, if you have a clunker you can trade it in to Fox and just get the Davis head for it The Fox is of course made in the USA one the best out there martin of course in the classics the PAW good choice both PAW and Fox are factory run MVVS is a great engine however as pointed out supply of engines and parts limited I do have them the 09,15,40 AND A 60 ALL DIESELS NO ISSUES in the wee ones MPJET 061 is back Davis Owen in Australia and I Care RC Quebec has them -fantastic engines When you time go back in time on the posts you see all the engines, results, good and bad, fuels, props for each one, pix and videos quite informative |
RE: choices
If that's an original Elfin .15 I'd grab it for old time FF or as a collectible.
The PAW and MVVS are both quality engines and I like both. |
RE: choices
Getting back to your question Oscar...;). Youll probably find a few different opinions on diesel tuning, but there are some good general principles. You should be looking to run the minimum compression necessary to get an adequately smooth run. As far as the needle goes, I find a peaked setting (any leaner and it will misfire), and then back it off a few hundred rpm to give it a bit of fat for unwinding in the air, manoeuvring,etc.
Something worth mentioning is that a traditional contrapiston shouldn't be treated as something to be constantly wound up and down and messed with unnecessarily. If you do this it will wear and become loose. Obviously it's meant to be adjusted or it wouldn't be there, but try to keep it to a minimum once you've found a good running setting. (Steve Rothwell, who knows a bit about model diesels, has engines on which he hasn't adjusted the compression setting for years). When starting, I usually open the needle a turn or so, but try to leave the compression where it was. With a choke or two and maybe a judicious prime to the side of the piston, the engine should start. Some engines may need to have the comp adjusted to get them going (particularly if a muffler stops you priming the exhaust), but even then it shouldn't be more than a quarter of a turn or so. Once running, the engine may be misfiring, but as long as it keeps running, I leave it alone for a bit rather than making a lunge for the tommy bar. Remember it hasn't warmed up yet, and the misfire will likely reduce as the engine heats up. If you gradually wind the needle in, you'll hear the engine speed up even though it might be misfiring. If it stops speeding up and just misfires worse, then you're a bit too lean. With a bit of running and a leaner mixture, the engine will have warmed up and may well no longer be misfiring. If so, great. Otherwise, you can increase the comp just enough to get rid of the misfire, and maybe readjust the needle if necessary. Remember that the engine will need a minute or so to warm up, so there's no need to rush. So in summary, I'd recommend: just enough compression, mixture a bit rich of peak, and don't mess with the comp too much. I'm sure there are those who are much more knowledgeable than I am who will have more to add, but hopefully this will be of some help. Steve |
RE: choices
I always blow air through the NVA with a piece of fuel line to get an initial setting on a new engine. I close the needle then open slowly while blowing in the line. Once the air starts to get though, give it another half turn or so and you should be pretty close.
Blow through one that you're already set and you should get an idea of how much air. |
RE: choices
ORIGINAL: steve111 Getting back to your question Oscar...;). Youll probably find a few different opinions on diesel tuning, but there are some good general principles. You should be looking to run the minimum compression necessary to get an adequately smooth run. As far as the needle goes, I find a peaked setting (any leaner and it will misfire), and then back it off a few hundred rpm to give it a bit of fat for unwinding in the air, manoeuvring,etc. Something worth mentioning is that a traditional contrapiston shouldn't be treated as something to be constantly wound up and down and messed with unnecessarily. If you do this it will wear and become loose. Obviously it's meant to be adjusted or it wouldn't be there, but try to keep it to a minimum once you've found a good running setting. (Steve Rothwell, who knows a bit about model diesels, has engines on which he hasn't adjusted the compression setting for years). When starting, I usually open the needle a turn or so, but try to leave the compression where it was. With a choke or two and maybe a judicious prime to the side of the piston, the engine should start. Some engines may need to have the comp adjusted to get them going (particularly if a muffler stops you priming the exhaust), but even then it shouldn't be more than a quarter of a turn or so. Once running, the engine may be misfiring, but as long as it keeps running, I leave it alone for a bit rather than making a lunge for the tommy bar. Remember it hasn't warmed up yet, and the misfire will likely reduce as the engine heats up. If you gradually wind the needle in, you'll hear the engine speed up even though it might be misfiring. If it stops speeding up and just misfires worse, then you're a bit too lean. With a bit of running and a leaner mixture, the engine will have warmed up and may well no longer be misfiring. If so, great. Otherwise, you can increase the comp just enough to get rid of the misfire, and maybe readjust the needle if necessary. Remember that the engine will need a minute or so to warm up, so there's no need to rush. So in summary, I'd recommend: just enough compression, mixture a bit rich of peak, and don't mess with the comp too much. I'm sure there are those who are much more knowledgeable than I am who will have more to add, but hopefully this will be of some help. Steve I went and moved the comp screw on my R250 and still haven't got it back to where Steve had it. <br type="_moz" /> |
RE: choices
Steve,
Thank you, That is just the info I was looking for. One question though. How do I tell the difference between an under compressed run and a overly rich run. Oscar |
RE: choices
Undercompressed will misfire. Too rich will put out a lot of oil and, if you turn the needle in the engine will speed up. If you are using a commercial fuel, your exhaust will be between clear and honey colored when all is well. Some say clear indicates a little rich.
|
RE: choices
SBOT There is an other factor here also, its harder to get a handle on this on the smaller engines .10 and down the larger ones say 40 are easier to set up Lets assume you have over primed and rich needle the engine more fuel than needed this takes up volume in the cylinder and raises the compression now its over compressed as soon as this burns off you could be in an under compressed state engine missing, lower rpms, a quick turn in on compression ( not much) maybe 1/4 -to half turn will correct this then you adjust then needle you then can do the balance for a prefect run condition yiu may need a tweek on compression and needle the needle is only going to be a half turn or so, then you get that nice hum as pointed out harsh heavy sound over compressed , missing under compressed or lean you have to find the balance between the two. and if you change props bigger less compression smaller more a tach is nice but you can hear it when set right or wrong martin Forgot if you change fuel formulas the Ether/Kero % ratios effect the above rule of the thumb more ether less compression needed less ether more compression if you lose ether from your fuel the engine will be very hard start or not at all require excess compression which an be harmful to engine, tough on crank and rod and run hot |
RE: choices
ORIGINAL: SBOT Steve, Thank you, That is just the info I was looking for. One question though. How do I tell the difference between an under compressed run and a overly rich run. Oscar What Jim said. Unlike glows, diesels won't generally 4-stroke when rich, if that's what you're getting at. A better question might be, "How do I tell the the difference between an under compressed run and an overly lean run?" Both will cause misfiring. I guess I'd say that being too lean will cause a harsher misfire, whereas undercompressed is more of a crackle. If in doubt, open the needle a bit and see what happens. Don't worry, you'll work it out pretty quickly with a bit of experience. Something to watch for with your CS is that the compression is prone to unwinding when running, due to the fit of the contra and the design of the comp screw. You might need to make a locking lever out of some aluminium. The CS NVAs are also a bit suspect, and some of them don't meter properly. |
RE: choices
I bought a couple of MVVS 1.5 diesels on fleabay. I like what I got BUT, both had casting flaws in the cases. one had a pin hole in the bottom of the case and the other near the intake. I cleaned them up with laquer thinner and brake cleaner, then pressure fit some JB Weld through the pinhole(s). result, 2 perfectly good engines. run like a top. nice plain bearing sport engine, with mufflers, no ear piercing scream.
The PAW engines I have, all have excellent cases-perfect. conclusion: check the mvvs engine cases very carefully before buying. I could not see any of this in the pictures on fleabay. |
| All times are GMT -8. The time now is 03:52 PM. |
Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.