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Old Jun 27, 2015, 01:52 AM
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Hervey Bay, Queensland, Australia
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Frog 3.49

The good old FROG.

One of the most innovative british diesels from towards the end of the hey-day for diesel power.

Look at the features. Drum valve induction, single ball race, and loop scavenging together with the option of an R/C throttle. All more or less unheard of in a 'consumer spec.' diesel engine at the time.

FROG in house designer George Fletcher must have been given considerable leeway with the design. Finishing it off, the fine casting showed what quality the brits could really do.

However, despite its impressive specification, the package just did not quite deliver. Somewhat overweight, it only revved up to a few hundred more RPM's than its stablemate the FROG 250 modified. The entry onto the scene of the decidedly high performance Rivers Silver Arrow 3.5 cc probably put the nail in the coffin, and it was left to languish powering boats and early R/C aircraft, never selling in the sort of quantities FROG had hoped for.

Still, it ran steadily and had no real design flaws. A fine piece of engineering available to the diesel masses at a very good price. I am glad to have the example shown in my stable.
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Old Jun 27, 2015, 02:39 AM
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Mt Evelyn, Melbourne, OZ
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It may not rev harder than a 2.49 on an 8x6 but put a 10x6 on it and its a different story. Mine really pulls hard, and the idle on the simple RC barrel is very reliable and steady.

Not as powerful as my Silver Arrow and not as refined as my Ollie Major but I still really like my Frog 3.49!
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Old Jun 27, 2015, 07:58 AM
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Bill Mohrbacher, MECA Fox Guy
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Beaver Falls, PA
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AMEE Volume II

Those interested in North American engines are no doubt familiar with Tim Dannels's American Model Engine Encyclopedia. It is the most definitive reference on the market. But it stopped at 1975. Tim had been threatening to run it out to current (2015) for some time and has been working on it for years. With Ron Chernich's passing, Tim accelerated his work on AMEE and has it completed.
It contains new material, corrected material, and is in color. It is an addition to, not a replacement of the original AMEE.

From Tim:

"Volume 2 of the very popular American Model Engine Encyclopedia will soon be ready for circulation.

Advance orders are now being taken. Estimated delivery will be no later than the first of September, but you can get on the list now.

The Advance Order price is $60.00 and will be shipped post paid until September 1. After that appropriate postage will be applied. This is for U.S. buyers. Canadian and “rest of world” orders will get a reduction in their postage, but an additional amount will be required. Write for details with your country.

This edition will contain much new and updated information on many of the lines featured in the first edition, but it is not a repeat of that Volume 1. Some lines will not be illustrated again while others with show the entire line from start to finish. Most of these will have new material included.

And speaking of illustrations, all picture pages will be printed in full color, just like our popular Cox Model Engine Handbook.

$60.00 US to the Model Museum (Tim Dannels) – 28795 County Road 331 – Buena Vista, CO 81211 – PayPal to <ameebooks@gmail.com> "
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Old Jul 01, 2015, 03:24 AM
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Mornington Vic
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Re Frogs

Quote:
Originally Posted by kakariki View Post
Hi All
I'm after some clarification of my Frog bicycle spokes. After reading Adrian Duncans review http://modelenginenews.org/ad/bs_frog.html all mine seem very different so I'm not sure if there were more variations or mine have been modified over time. There is no mention of a 180 glow in his report, I have measured the bore and stroke on these to confirm the size. (I know the needles are in the wrong way).
No.1 - 100 Mk.l - Has thick mounting flange and 2 peice threaded NVA. Ser.# 18.4.80
No.2 - 100 Mk.l - Thin flange, normal NVA, and a different head. Ser.# 5845
No.3 - 100 Mk.ll - Thin flange, normal NVA, no cylinder lock down nuts. Ser.# 13.583
No.4 - 160 Mk.ll - Thin flange, normal NVA, no cylinder lock down nuts. Ser.# 1.204
No.5 - 180 Mk.ll - Thick flange, normal NVA, has cylinder lock down nuts. Ser.# 8.259
No.6 - 180 Mk.ll - Same as No.5 but 2 peice NVA. Ser.# 3.193
No.7 - 180 Mk.ll - Glow Thick flange, normal NVA, no cylinder lock down nuts. Ser.# RG 4.739
No.8 - 180 Mk.ll - Glow Same as No.7 but 2 piece NVA Ser.# RG 4.096

Thanks for your comments.
Barry
I hoping to get more feedback on this if anyone knows. Pics in #9223
Thanks Barry
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Old Jul 01, 2015, 04:10 AM
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Sticks, Tissue & old Diesels
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France, Centre, Amboise
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Hi Barry,
I don't know much about Frog engines, but I think that the Frog 180 and the 160 are virtually identical, except that the diesel version is called 180 and the glow is called 160. Therefore, logically, a 180 glow shouldn't exist...
Apart from that, be very wary of stuff you read on the Web which, after all, is only someone's opinion, just like earlier paper magazine content (with the exception of PGFC's engine tests, which must remain sacred...).
The greatest and perhaps the only Frog engine (as opposed to kits) expert that I know is a gentleman (in the broadest sense...) called Richard Dalby. I think Richard is very occasionally present on this forum as "Frog 50".
Rather than waffling around, and people's opinions, etc. if you really need Frog expertise, you should contact Richard.
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Old Jul 01, 2015, 08:39 AM
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Canada, ON, Hamilton
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Frog 3.5

This was my first R/C diesel and used for my first flight.
It flew a Good Knight with an old radio using relays.
I also had a water cooled version in a PT boat.

I found that the head bolts were a very different thread (to me, unfamiliar), BS? or BA? rather than 4x40's.

The marine version once lost a head bolt while running and the water shot up out of the hole, but the Frog kept on running.
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Last edited by JohnAV8R; Jul 01, 2015 at 12:13 PM.
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Old Jul 01, 2015, 10:58 AM
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I'd rather be flying.....
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United States, IA, Story City
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John -

Good knight - is that a walt musciano design ? the plan looks like his style......

i'm building enthusiasm to run my FROG 3.49 aircraft version thanks to all the FROG comments

Best Regards,

Jeff
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Old Jul 01, 2015, 12:15 PM
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Yes, Good knight - a Walt Musciano design.
Just added the cover page to the above post.
It's an old scan and the magazine is presently buried down below.
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Old Jul 01, 2015, 04:02 PM
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Quote:
Originally Posted by brokenenglish View Post
Hi Barry,
I don't know much about Frog engines, but I think that the Frog 180 and the 160 are virtually identical, except that the diesel version is called 180 and the glow is called 160. Therefore, logically, a 180 glow shouldn't exist...
Apart from that, be very wary of stuff you read on the Web which, after all, is only someone's opinion, just like earlier paper magazine content (with the exception of PGFC's engine tests, which must remain sacred...).
The greatest and perhaps the only Frog engine (as opposed to kits) expert that I know is a gentleman (in the broadest sense...) called Richard Dalby. I think Richard is very occasionally present on this forum as "Frog 50".
Rather than waffling around, and people's opinions, etc. if you really need Frog expertise, you should contact Richard.
Thanks for that, I'll track him down.
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Old Yesterday, 09:39 PM
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ED vs Frog

Both of these are from about the same era.
Both are 3.5 cc and have a rear intake.
Rather than look at published "specs" does anyone have experience to suggest if they are of equal power, or does one have a slight edge?
I never tried each of them in the same plane.
The Ed in a U/C stunt model was quickly replaced by a red head McCoy .35 which was almost twice the size and power.
The Frog 3.5 was initially in my Good Knight, but was replaced with a Johnson .36 having considerably more power.

The ED had the NVA from my ETA.
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Last edited by JohnAV8R; Yesterday at 09:49 PM.
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