Hello All,
 If I remember correctly, Larry Renger was one of the first people to say that the AP Wasp had good 1/2A potential. So I bought one and gave it a try. It seemed OK, so I just ran it in as per the rather weird instructions. Put it in a plane and flew it, I used somewhat larger props and didn't run it at maximum bhp revs. I was very pleased with the Wasp and knowing how a good engine will be discontinued as soon as you discover it is good, I purchased half a dozen more. I decided to have a closer look and found the crankshaft fits to be all over the place. One was so bad, I sent it back for a replacement. I then dismantled the engines and checked the other critical areas. The good news was that all the piston / liner sets were beautifully made and were excellent fits. However the rest of the components were a severe disappointment. About the  sort of fits and finishes that I would expect to see on current CS manufacture. You may like to toy with what the initials CS stand for perhaps.
  Reading the more recent threads on the Wasp, I see Larry has got through four crankcases (was that the reason I sent you four cases Larry?) Kenneth Cook also managed to wear out a loose fitted main bearing bush and he also had other issues with the engine. I do know that Ken does use extremely high revs in his 1/2A combat applications, so maybe that is the cause of the problems.
  Up to now, my first Wasp has had a fairly gentle life and has only put in a couple of hours running. The crank does feel more sloppy than I would like. I am just about to put a second Wasp into operation and I am beginning to feel that these engines may not be all that good after all! Which is a great pity as I stocked up with them! Maybe should have spent more and got a couple of Norvels?
  What have been peoples experience with the Wasp? Am I just expecting too much from what is a very cheap engine?

Regards,

Andrew. 

Hello Larry,
Thanks for the reply. I suspect you have more control line hours than most, using AP Wasps. Seems that everyone so far has had problems with crank / bearing bushes. These seem to be either pure lousy choice of components on assembly or the bush material is not good when it comes to wear. I know that Ken punished his AP Wasp at very high rpm for 1/2A combat, Have you been running at high rpm too? My first Wasp has been pampered and the main bearing is beginning to show slackness. Your APvel sounds a good way around the bearing problem, but is a rather extreme and expensive solution! Should we not do better by warning people off the AP Wasp and going for Norvel? From recent posts, it sounds as if a bunch of people are looking at a C/L venturi conversion for the Wasp. I think my advice would be to steer clear of the Wasp and buy Norvel. The Norvel fits and finishes are just so much better than those of the Wasp. Seems a shame to say this, especially as I have 7 of the Wasps!

Regards,

Andrew.

Thanks for those observations Ray, I am beginning to think that you are correct. Oh well I can always build a few more trainers! At least I have one grandson that is interested and another baby on the way! So trainers are the order of the day.

Thanks,

Andrew.

               Andrew, I wouldn't give up on the engine. For my needs, it just didn't do it for me. I'm willing to accept that but I tried very hard to make it work. Remember, that was the only 1/2A engine available for a while. Norvel's were out of the price range due to demand and no supply. I haven't used mine for stunt like Larry has. My hats off to Larry for making it a viable power plant. I have really thought about doing what Larry just suggested and that's to cross breed it with the Norvel. I did like the piston sleeve fit. I believe you noticed the same in the fits of yours. I feel that if you keep things in the designated rpm range you may just love this little engine. Give it a try and let us know your findings. Ken

Ken,
You can flog a dead horse all you want but it's still dead. I never bought one . I guess that I've been trained to immediately ignore a knock off. In this case it seems that I saved a few dollars. Did you get my offer of some wing cores?
dennis

Disclaimer! I do not have, nor have seen the latest NV engines. My comments are based on the old Norvels.

If I were buying an engine right now, it would be the NV. First, it is now almost the only game in town, as the AP seems to be discontinued. Second, it comes with a CL venturi, so is cheaper than an AP combined with the cost of a now unavailable aftermarket venturi. It is properly equipped right out of the box.

With the Galbreath head, the Mk 1 Brodak is an alternative worth looking at, they run with near TD power and Medallion fuel draw, a great combination. The caveat is that I have little experience with them on a long term life basis. The NV is probably cheaper and likely more reliably proper fits than this combo too.

I still have a couple of NIB APs, and you may be sure the cranks will be well polished before they ever run.  Chuck a cut-off bolt into your drill, mount the crank, and run it at low speed. 2000 grit paper with oil followed by Simichrome on a paper towel will provide a mirror finish. I published this recently in the Cox newsletter with photos.

OK, so where do ya find Norvel .061's these days? now that I just bought 2 NIB AP Wasp's

In answer to James, most of the APs are fine engines that perform well. Even with stunt use they are driven hard. I figure that I have over 100 runs on the ones that have worn out. That's 8,000,000 revolutions or more.

And I believe that going with more oil will prolong the life farther.  I suspect that added oil only degrades fuel consumption, not performance. And may improve performance by reducing friction and carrying away more heat.

Hello James,
Alex is the chap that does the Norvel engines in the US. Last time I looked he had some of the old C/L engines in stock. Don't get me wrong, the AP Wasp isn't a total disaster and I have been reasonably impressed with it in stunt use. It just doesn't last too long. I have several left so I will make use of them in the end. Just buyer beware , if it sounds very cheap there is usually a good reason!
Don't be downhearted about the fact there isn't a readily available venture for them. The use of a Cox TD venturi and the Texas Timers Kirncraft NVA assemblies, leaves only a simple threaded bush to make and you are away.

Andrew.

If I were buying an engine right now, it would be the NV. First, it is now almost the only game in town, as the AP seems to be discontinued.

Another one worth considering is the MP Jet 061BB.  I'm sure they're considerably more expensive and also a litttle heavier than an AP or NV, but against that, they're beautifully made, ballraced, and likely to last a long time.  What I also like about them is that you don't need to spin a toothpick at 25000 rpm, or use a lot of nitro. With an APC 7x3 and 5-10% nitro, I'm seeing around 17000 rpm from the 061 glow (and have clocked the 061 diesel at 17600 with the same prop), which to my way of thinking is a lot of good useable performance for 1/2A stunt.

Steve 

Hey Larry, maybe it needs a different temp. range glow plug???...No clue about diesels though.   BTW, Has anyone tried the Big Mig/ NV .074 for stunt? Sounds good in theory huh?---TIA,  James

Hi All,
So has anyone tried a Big Mig/ NV .074 in 1/2A or "so called" 1cc sized stunt ships?  What'd ya think about it?

Later,
      James

                    James, I used the Big Mig .074 on the Brodak Pathfinder. It flew the plane well but it was waaay fast. Props are just somewhat difficult to find with that engine as it's a size that's in between. I played around with a few props, but I also was using the r/c version. I personally disliked it. It was extremely difficult to start as I had the carb wired wide open. The instructions suggested only to crack it slightly open on startup. I later found the .061 control line venturi  fits the .074. I haven't tried the engine, but I bolted the venturi on and it's awaiting another try. I switched the .074 to a .061 on the Pathfinder and I don't even use the engines full power potential as I don't need it. Ken

Ken,

Using the Norvel 074 is overkill as it pulls most models that use an OS10 with no apparent effort. These were a hot set up in upgrading the House of Balsa 1/2A warbird models a few years ago. If you adapt to a Nelson head or turbo head there are significant gains to be had. I really wish that 1/2A was classed the same as Great Britain. It just makes a whole lot of sense to me.