Recycled Flyer

I have just read an engine comparison by Brian Winch between the Saito 56, Stalker 60 and a PAW 51. But I have never heard of a PAW 51 before, so could this be the 49 and a typo inflating the capacity or was there indeed such a beast? Thanks.

AMB

40, 49,60 as far as I know in the 40 and up sizes thats what Carlson lists in his site and PAW UK

steve111

Interesting read, was it?

AMB

is possible PAW may have done a test engine just open bore a little bit on the 49 and made a little larger piston, do not see any point in a production version martin

greggles47

It's more likely that BW got the name wrong.

What fine publication was the review in Chris?

Recycled Flyer

Hi Greg,
The publications were ACLN but since I only have print outs of the pertinent pages I don’t know which issues that they were extracted from.
Anyway there was that comparison test and an earlier article showing a control line Freebird at K.M.F.C. again with a PAW 51(?) and from memory Winch stated something like ‘the 51 was an attempt to take the vibes out of the 49.’
But I have seen zero since on the fabled 51 and perhaps Martin is right, it may have been a prototype only.

Steve,
It was an interesting read as I have never seen anything remotely like directly comparing a 2/2 and 4/2 two stroke glow engine, a two stroke diesel and a fourstroke glow in the control line stunt arena, and all in the same model.And it even forced Mr Winch into picking the best one and that is not something he ever does in tests.

Thanks guys.

AMB

IF they did go from a 49 to 51 prototype my guess would be a slightly lengthened rod would not require increasing bore , just the stroke the contra would just go up a very small distance the clearance might be there to allow this just my wild guess martin
same liner might need a slight change in porting??

greggles47

Martin, the easy way would be to increase the bore by whatever no. of thou. Changing the stroke could also require a bit of work on the porting to keep the timing the same.

Unfortunately the PAW site doesn't give us any bore/stroke dimensions, so we can't estimate the changes required to shift from 49 to 51

Greg

AMB

Greg Have agree on that one, might need a slight head revision also too for liner fit martin



whoops wrong screw on cylinder outside of liner same size the contra just a few thou increase in diameter to match piston diameter
forgot cylinder with compression screw on top clamps down the liner

Recycled Flyer

Just found it Greg, issue 41 of alcn!

Recycled Flyer

And a mention of a PAW 51 page 11, issue 40.

And there was an Aeromdeller article on it too, (must dig that one out though.)

AM issue #738 Ibelieve.

steve111

Thanks for the references, Chris - as you say, it was worth a read. (You mentioned Brian Winch as the author, but the article says Derek Pickard - are they one and the same?) It'd be interesting to know what became of the .51 - Dave Owen can probably shed some light on it.

I understand PAW are still looking at doing a flat-twin .38, which might be a bit of fun and hopefully not shake as much as some of their other big'uns.

Recycled Flyer

The author, Iwill put that down to Alzhiemers mate!

But anyway, by all means ask Dave.

AMB

STEVE Flat twin 38 PAW sounds interesting and tempting if they knock it out very very usable size martin

Recycled Flyer

Excerpt from the AM article –

“Besides this efficient 40, the company also makes two other big diesels – a 49 and a 60 with the former having now been upgraded to a 51. The main difference between the old 49 and this new 51 is not only the small amount of extra cubes from the longer stroke, but the fact that the extra swept capacity has come about the use of a stronger crank which incorporates more counter – weighting that helps offset vibration.”

So it seems that the stroke WAS lengthened and a 0.265” venture was used with a 4mm spraybar and a 12 X 5.75 three blade prop.

PWF63

Where did you get this information from Chris?

Recycled Flyer

As above Fred, Australian Control Line News issue 41 has a full comparison going on, issue 40 page 11 has a mention in the competition placings and (gleaned from Chris Murphy) Aeromodeller #738 has a full test on the PAW 51 in an enlarged Freebird design.

But that is all Ihave ever seen about a PAW 51 and like you have never seen it advertised or used in any way outside of Derek Pickard.

My best guess is that the 49, weighing in at more than the 60, has languising sales and so PAW blended the two together in a different way to come up with a better mouse trap.

Recycled Flyer

In fact you canbuy the Aeromodeller mag in question right now -

http://www.ebay.co.uk/itm/AEROMODELL...-/160994374120

greggles47

That's pretty old Chris, as is issue 41 of ACLN.

One would think it would give the manufacturer ample time to shout about it. Do you think?

It makes me think the 51 is not readily available - maybe not even for sale at any price.

G

qazimoto

My Feedback: (1)

Mmm, I thought that Eifflaender finished his st*nt career using a ST 46.


Don't think it was a diesel either.

PWF63

Here's the Photo out of ACLN No 41 showing the 3 engines on test.
The so called PAW 51 in centre shows no resemblence of a out of box PAW.
Looks to have a Enya NVA. The Muffler doen't look like PAW original either.
Could just be a bored out 49 or just plain BS.

Fredo

p.s.
wouldn't allow upload so here's URL to photo on Flicker


PAW 51 | Flickr - Photo Sharing!

ffkiwi

I wouldn't get wrapped around the axles over this PAW 51 business-modelling history is littered with examples of promising engine prototypes or pre-production models that didn't make it into production-for all sorts of reasons-poor performance, too heavy, too expensive to produce, design required additional tooling, production machinery already fully allocated, no time available, not enough manpower, rule changes, market changes, change of company ownership and focus-the list goes on!
Remember-that despite their prodigious output of engine models, PAW are still a small family firm with a very small workforce-they may have simply decided that the market for a 51 simply wasn't there, and it wasn't worth producing them as a catalogue item.

ChrisM
'ffkiwi'

Recycled Flyer

Hi Fred,
           The aeromodeller review says that this engine has a custom venturi and an Enya needle valve going through where the RC carby grub screw would normally be - but to me the muffler looks exactly the same as my PAW 40 one.

Anyway, just emailed PAW about the existence of any 51 around the time of 1997 and they said the engine size was a 49 sleeved down from a 60, too heavy, not powerful enough and thus proved unpopular.

So there you have it.

Thanks.

PWF63

Thanks Chris.

Recycled Flyer

What, and bypass all the controversy and tension with the truth?

But seriously, it really sounds like the review was a bit ficticious doesn't it?.