Mr. Davis, I stand appropriately corrected. I went back and reread your diesel page and you in fact don’t recommend operating diesels without a muffler, I just got that impression.

I don’t think my comments were particular negative. It was not my intent to present a comprehensive survey of diesel vs glow, I just related my personal experience. If there were substantial gains to be had by using diesels, I wanted to fine out. As I stated, there are indeed some advantages, but not without drawbacks. Even though my PAW is not representative of the latest technology, it was recommended as a “user friendly”, easy to operate engine. I believe I now have finally reached the point where I will reinstall it in an airplane and try again.

Your comments regarding modern diesels apply equally well to modern glow engine technology. The modern glow engine is a small marvel compared to the early ones that I cut my teeth on. This doesn't change the fact that there are two rather than one adjustment to make on diesels, and the cost difference is real.

I believe my conclusions are still valid. Diesels offer some performance advantage, but are more complex to operate, and are much more expensive than glow. New, made for diesel engines are more expensive than a comparable glow engine and modification of a glow engine with a diesel head can add 50 to 100% to the cost of the powerplant. If one enjoys tinkering with engines, and is willing to pay for the privilege, diesels will fill the bill nicely. However most modelers have already made the choice. Glow engines are powerful, simple, dependable, cheap, and allow them to concentrate on flying.

Running a Diesel is no more complicated than the first time we all ran a glow engine, driving a four speed stick seems intimidating at first but is second nature after about ten minutes. When using Davis conversions the compression adjustment rarely needs re-adjusted after the initial setup unless there is a drastic change in the ambien temp. or you change props. If someone doesn't like using Diesels, then don't, it's as simple as that.

The originator of this post asked for information based on actual experience. That is what I tried to provide, both good and bad. Is it your position as moderator that "diesels are wonderful" opinions are the only ones welcome?

Lou, I was a happy Diesel user long before I was a Moderator. I've been buyin stuff from Mr. Davis for 12 or 13 years.

Once one gets familiar with a diesel's operation, it like everything else in the hobby becomes second nature and you dont really think about it. I have had a glow engine with a three needle carb (OS 61 SXWC heli engine) that I ran for two years in one of my helis, I found adjusting three needles no more trouble than two or one

It all comes down to an individual preferance. I like running engines, ALL engines, and diesels to me are worth the "trouble" for me. For someone else, maybe not.

But I still like to let someone try something first and then make the descision, rather than just base it on someone elses opinion.

I dont like certain things in the hobby, so I dont participate (gliders for instance). But I at least had two, gave them a try and now I can say that I made the descision, not my buddy who told me they are "boring". (that s but one example, please dont take it persoanlly if you indeed like gliders).

My point is, TRY one and then, only then, make your decisions. And if you decided that diesels are too much trouble, no benefit, a pain in the *** or just too expensive, well, thats perfectly allright! We do live in countries here with free choice.

AJC

buy a PAW from eric clutton best source off information and help you will ever find from experiance i found longer flight times quiter operation only down side is messy exhaust they don,t care about back pressure use tubing to rout exhaust to where it is least noticed. my experiance thejc

hbbsy, I think you misunderstood my question. Based on you previous post, I asked in effect, if you, as moderator, considered this forum a place for the honest and open exchange of information, or a commercial advertisement for Davis Diesel. I believe I have my answer.

Lou, I also have three PAWs and an Irvine Diesel and am experimenting with a thing called the Gadget from Louis Furco.

Ok guys will add my 2 cents I have messed with these (conversions) long enough that it
is second nature some times I do crank in the comp screw a half turn to start then back off
in 30 seconds some of the engines can be left alone as you know from my posts I have the
traditional PAWs we are not going through the differences that has already been addressed.
As far as expense yes the heads are 50 or 60$ the bigger ones more I think the fact that
these are limited production products with limited sales potential to a very few,not bad
(and nicely made) The fact remains davis believes in his product and the fact they are
still here after 25+ years says something if he wanted to be rich he would be better off
making widgets or something.Some of the golf nuts will drop $1000 on a club I rest my
case. An other point very very few of us have the talents of AJ and a few others that
cannot only make a head but a complete engine (AJ states he can make a head in 3 hours
I bet its a little longer which is neither here or there) I have no such ability and am quite
glad davis in cranking them out RJL makes only 2 heads (I think) When my irvine 40 diesel
dropped its piston Bob came to the rescue and made a head (have 2)
So what every your reason for running diesels the fact is you can with the selection
out there traditional or conversions you can The big bucks in this industry is in making glow
engines these folks could care less about diesels no $$ for them

Ok have got to get my 2 cents in much has been said about glow/vs diesel fuel economy etc
so no point in repeating I have diesels both the classics paw, mvvs, davis conversions snd
glow (probably more than a sane person needs ) I fly and also like messing with them
One point that is overlooked is yes the diesel owners are a small minority. the major
engine makers do not make them because of sales $$$ profit is the driving force and
they will not enter the market for a few. So that leaves Davis with a lot of choices,
RJL with 2 and few very talented guys like AJ and a couple of others who cannot only
make a head but a whole engine I do not have such talents and skill so we have the
major diesel head maker (davis) making these for the "fringe market" for the last 25+
years Davis is not getting rich making heads he runs the show himself, no big office
staff etc so making a product that works well for very limited demand and charging
$50 or $60 is not a bad deal yes some are less $20 for a cox the big stuff up to $90
Some folks think nothing about dropping $800 for a custom golf club or more so at
least for me the price of the engine plus the head is worth it, most of the 4 strokes
are 175 and up, its what you want.

Limited (very) production: If you have not seen this go Google pull up Luhrs the guy that
makes minature engines. you engine buffs will like this.

Ok must be CRS or inaptness with the computer thought that one of these was posted on the 1/2 A site at any rate MERRY CHRISTMAS TO ALL. I have hauled the planes in the corner of the living room out to set up the christmas tree (no joke)

LouW,

I think your pros and cons are generally on target. Diesel does not have to be as stinky if you can keep the raw fuel off your hands. My Davis converted Mecoa .46 runs great in all respects. Mr. Davis can be gruff and his prices (and shipping) are high but he does know a lot about model airplane engines and will help you. Diesel is different! Look at the attached stink reducing pics. Ignore comments about PAWs being 50s tech they are fine for the appropriate application.

Oily in Germantown

Francis

Francis very nice plane great installation Will take pix of my blue max with the PAW
40 and post it also my little tiger moth with the paw 06 when done my 54" cub OS10
stays [retty clean too

Please all readers, aknowlege "FREEDOM".
That's where it's at. Thank "....." that be we have the FREEDOM to exchange ideas in this way.
I began the arial leg of this wonderful sport in So.Cal. where I could launch a plane staight-up, a glider, mind you, and fly it in any manner I prefferred, including 3-D,(inasmuch as there was no 3-D at the time!) untill the batteries were dead, nearly 40 years ago.
Only tail-slides-"Falliin' outta the sky",'vertical-rolls' "HOLY-****!!" and speed, "Whoo-Hoo!!! YEAH!!!" had been invented at that time. What-a friggin'-blast!!
In short, Thank you Brothers,and Sisters, for commenting on this, our passion, in such a way as to include all aspects of this hobby, it's all "Home" to me.
sincerely,
3D-orBUST

DieselDan,

At the beginning of this thread which started in June, you mentioned Norvel diesel conversions. If you've had a chance to run these, can you comment on how well the head worked? How was throttling? Idle? steady all day? Could you get clean transition after prolonged idling? Starting ease or not? Top and bottom numbers, what prop, fuel formula?

Andy on one of my threads was alittle decathalon with a norvel 061 davis conversion
(which ran well I think around 12000 with a 7x3 or 4 the plane was lost on its
first flight in deep brush and never recovered I think idle was around 4100
it transitioned well it was a master airscrew black plastic prop I understand
the tornados are quicker davis 1/2 A fuel and head. I have just finished
running in the second 061 on glow and will "head it" will jot down the numbers
will also pick up a couple of tornado props if they go to7" Will check idle transition
to full also I do not recall any problems with this in the first one

That's great Dan,

I think that Norvels, properly done up as diesels would make a lot of converts. Starting is always the bugaboo but I've found that an electric starter, applied with care, works really well and takes some of the hassle out of diesel operation. Please do keep us posted and yes, I suspect that black Tornados in the 7 X 4 size will surprise you.

Andy right on the electric starter I use the little norvel up thru the OS10 and a regular
one above those I have had no problems I turn them all by hand first to insure no
hydro-locks my PAWs however hand start with no problem

what is the website for the diesel heads. I have, well, am hopefully going to get an Irvine. 53 engine. What would the head cost me?? I have heard that is you put the diesel head on a .40 engine, then the power would be as that of a .60. I don't know if that is true, just saw it in Model Aviation. I could imagine what the power would jump up to from the Irvine .53........THANKS ALOT!!!!!!!! MERRY CHRISTMAS!!!!!!

Mike I have 3 irvine 53s converted to diesel heads from davis diesels irvine 53s
from just engines go to google search for Just engines when you get there
cataloge pick Davis diesel and connect the irvines are good deal from je also
aLSO ON THE DAVIS SITE MY REVIEW IRVINE 53 MARTIN BENDER

50% power increase depends how you look at it that is not across the board per se
on diesel they will turn increased diameter and pitch which is more thrust and your
fuel economy will be much better up to twice the time on same size tank, 11x7 and
12x6 are what I run which are wood zingers with a fairly wide blade the apc comp
props will run at least 500rpm faster

mike got off the track a little I think the heads are $60 (53 irv) from davis I run a bunch of them from .10 thru 61s and well pleased with all if you read all the posts you
can pick up lots pros and cons for me the pros win

if only i could get a davis head for my NT-16(in a CEN MT2 btw) i acually like the smell o burnt diesel

Gasoline is much less powerful than either Diesel or glow; the order is Diesel (1),Glow (2), Gasoline(3): You forgot to factor in the appropriate mixture ratios with air. In other words, just how much fuel is ingested at each cycle? Also, a lot of the glow fuel is dumped out of the exhaust still burning and doesn't help to move the prop. Not so with the Diesel.

More complication, yes; that hasn't done too much harm to the complicated, 'way overweight 4-stroke engine sales, now has it?

Lot of your other statements are similarly tainted; won't go into it now.