Valve Problem

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Mike Stewart

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135 to 140 are reliable, normal speeds for KR's at 8000. You didn'yt mention power settings or what engines the various models are designed for . . . just curious. I think, from what I recall in talking to Mr. Thatcher, that he designed the 4 around the VW.

RPM is the all critical component. Without knowing that, speed means little. WhenI got my KR with the 52x 52 I did a two way run and got 167 MPH and I think there was even some more RPM left in the engine. That was at about 2500 ft. Unless people enjoy rebuilding their engines every year like the dune buggy guys do, our air cooled engines will become unreliable and eventally fail at some point - usually case leak or rear seal leak - unless the engine is run firmly but gently and great consideration for keeping oil cool. Revmaster makes a really nice oil cooler that would help a lot in running tha engine faster than, for instance, I do. Or Steve did. Or Hoover did. With one of those nice coolers and good baffling (tins) I think a person could run a Type 1 at 34 WOT. Not me though. Prop tip drag alone would keep me down around 0.8. On a good day when the moon is in the correct position my RPM will creep up from 3100 to something short of 3200. I let it go where it's smoothest and up high, at those RPM's it settles into a turbine-like smoothness. I have a prop balancer so that helps.

Mike
 

Pops

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VW's Type 1 has a sweet spot at around 3K rpm. On my 1835 cc engine it will turn a Culver 60"x26" prop at WOT at 3200 rpm and I cruise at 2650/2700 rpm. Zero heating problems. Everything balanced and very smooth.
 

Marc W

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The Thatchers are all designed for VW's. The CX4 prototype has a 1700 cc VW. The CX5 is designed for the Revmaster 2300. The prototype CX5 now has 1000 hours on it. The upcoming CX7 also uses the Revmaster.

My CX4 has a 2180 originally built by Scott Casler. Prop is a Sensenich 60 x 44. WOT @ 8000 MSL gives 135-140 MPH TAS @ 3050-3100 RPM. 2600 RPM gives 100 MPH IAS + or - 5 MPH depending on temperature.
 

Mike Stewart

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Thanks for the refresher Marc. I'm so out to lunch that I've had it in my head that the CX-4 was a two-place, even though was actually present at S&F when Mr. Thatcher was presenting his new (single-place!) metal airplane. :mad:

Clearly I've gotten the 4 confused with the 5? I better do some Googling before I embarrass myself any further.

Just watched the video of the CX-7. They are all such "perfect" looking planes.

His recommendation of Revmaster's R-2300 is bound to sell some engines and support that good company that's been around so long. Despite their great reputation, I would still want to take that brand new R-2300 apart and put it back together. That's the only real way one knows for sure what we've got. Nobody is going to be half as careful in assembling an engine as the person who is going to fly behind it. Plus . . . I'd bet a dollar to a donut that no matter who put the engine together at the factory, there will be some (hopefully very minor) descrepencies. That's what was good about Great Plains - they sold the engine as a kit (as well as completed engines I think). I think Revmaster will sell the engines as kits if requested. In any case, they surely can be taken apart and put back together. Doing this allows one to open up the intake areas somewhat and improve breathing. Also perhaps do some improvements for cooling. If there is a choice between magnesium or aluminum on the cases I would choose the latter. A little heavier but less prone to cracking and heat distortion. I'm sure there are some Revmaster fundis out there who have learned some little improvements that can be made once the engine is opened up.

Hopefully the R-2300 doesn't come with hydraulic valve lifters. They work fine on cars I suppose but cause a lot of wear on start-ups since it takes a while to get them pumped up. Steve taught me that. In any case, easy enough to change them out for solids.
 

Marc W

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I think the R-2300 comes with solid lifters. I also think they already have larger ports. Probably not much to gain there. They are supposed to have more durable cylinder heads with harder seats. They claim more fin area too but I don't know where it is. I don't know what the case is made of.
 

Mike Stewart

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This picture was taken by an unhappy R-2300 customer.

A good example of why (IMHO) it's important to take the engine apart and put it back together, no matter who it comes from. Much better to find something like this early on than somewhere over mountains or at night . . . or both.


R-2300.jpg
 

Mike Stewart

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Probably did not like the margins for the studs. “Bore it out all the way” is all the way with that one.
Considering more precise drilling might correct this particular problem, just how close to the edge is it safe to get with those heads? Since that picture was taken they easily have had time to cast new ones with more meat on them but in case they haven't, can stud holes be that close and still survive over time? I guess the answer to that would be to talk to some R-2300 operators.

Joe has an engine even bigger. Significantly bigger. It is built to have the mass to sustain the increase in power and heat, although this 2300 turning at 3000 is not a heat generator. The edges on those stud holes look bothersome, but some improvement or modification surely has been done by now. R-3000 owners will have had time to accumulate an operational profile.

The bigger engine that Joe has though . . . he doesn't advertise it and was waiting for development funds to go any further with it. That too was about five years ago. That bigger engine is really something. Wish I could remember more about it . . . I only recall how neat it was. I don't think he had brochures & things for it or I'd remember more . . . it looked like a finished engine to me but there are development costs that aren't visible. Maybe it's on his website?

**************************

I don't see anything about a larger engine on his website. Focus is on the R-2300. One can only do so much in one lifetime yet he's done a bunch of stuff. The 2100D has a stellar reputation. I'll be interested to see how well these newer engines are liked in the actual operating community. That Contact Magazine article was an excellent introduction. If it has turned out that the R-3000 is perfect or has just very minor flaws that can easily be modified/strengthened/improved in ways that don't require major modifications, for the money the R-3000 with an EFS-2 would certainly be at the top of my list of good engines to consider. A former KR builder (2 KR-2's in his builder's log) is building gorgeous little plane out of metal called a Panther and putting a UL Power engine in it. Expensive as hell and parts, if ever required, are going to take some planning and some moola since it's not a cheap engine and it's made in Austria or somewhere close. As to whether its a good engine or not time will tell but quality seems excellent in a Teutonic sense. It's another with roots in the Type I. although heritage gets hazy by the time one adds all the sensors and systems and accessories. I'm guessing this engine with shipping is going to cost almost three times what the R-3000 will cost and as for using one another engine from that part of the world, Rotax's, price would also be quite an issue plus . . . . After having had some exposure to engines on an Air-Cam I developed a slight aversion to them and not just because installing or deleting weight was such a tedious process but just because I got the idea, accuate or not, that AD's are an issue with these engines and that they are generally maintenance demanding motors. Plus they have that "dependable" re-drive that's proven itself over all these years but still . . . they waste energy just by their very nature in in changing the direction of power a good 90° and too just from the extra friction in desiging and mainmtaining all thjat complexity. But what do I know? Nada. I know they work well. No bad mouthing on my part regarding Rotax. I do think they are pretty expensive and I'm pretty sure I'd rather have a real engine like the R-3000. I still like things measured in inches and miles and plus it just seems familiar. My first car was a 1964 Beetle.

***********************

Well I found the engine I was thinking of. It's called an R-3000. Picture attached. That front bearing looks amazing eh? I later have found a comprehensive write-up on the R-3000 in Contact Magazine.

Re the picture below . . . I once had care of a Franklin 0-235 which had a plate sitting on top of the crankshaft area much as this R-3000 appears to have. What a supurb idea to be able to get to the crank/bearings/oil-ports, etc. without having to crack the entire case requiring replacement of seals and whatever else . . . not to mention the mess. Franklins should have never gone out of business. People would have a lot sess trouble with their Continentls and Lycomings if they hadn't.

The Franklin, imho and within the short exposure I had with it, seemed to be a suburb engine! And smooth! It has some sort of built-in crank balancer that smooths out the pulses and makes the engine an absolute pleasure to fly. I had mine dynamic balanced since I have the toys to do it, but even with the attention I'd given it to static and dynamic balancing, the engines have a reputation for innate smoothness. Except when it comes to finding parts, I've never heard anyone say anything negative about the Franklins. I sure thought mine was excellent even though I barely got to know it. Beautiful engine.
 

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TFF

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The only thing a Franklin doesn’t have going for it is weight. They are heavier than the other two brands. They outsold the others until the Tucker auto company bought it and went bankrupt the next year. Then the Franklin drift started.

I bet the R3000 has a big stroke crank which required the new case. Not going to bore anymore. The compression leak had to have started because the gasket can’t hold without a support wall all around to act as a backing and heat sink. All that was CNCed but they did not want to scrap the part. They had to of known it was short. Someone had to say keep using it. There is the balance of going max effort, if it’s not perfect, it’s going to have problems as there is no margin left.
 

Mike Stewart

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The only thing a Franklin doesn’t have going for it is weight. They are heavier than the other two brands. They outsold the others until the Tucker auto company bought it and went bankrupt the next year. Then the Franklin drift started.

I bet the R3000 has a big stroke crank which required the new case. Not going to bore anymore. The compression leak had to have started because the gasket can’t hold without a support wall all around to act as a backing and heat sink. All that was CNCed but they did not want to scrap the part. They had to of known it was short. Someone had to say keep using it. There is the balance of going max effort, if it’s not perfect, it’s going to have problems as there is no margin left.
Yeah . . . we do like our margins . . . but I like mine a little thicker than what's in the picture.

If I'd inherited that engine and not just bought it new from Joe, I'm thinking I would have filled in those stud drillings with some industrial quantity JB Weld, let it cure really well and (from what I'm reading) maybe stuck it in the freezer while it was cooling off and then carefully, so very carefully, redrilled my stud holes. Maybe even gone to small diameter studs and drilled more of them - eight or six instead of the four normal/stock ones. Don't know if that's even possible but hey, American ingenuity at work.

I'm in love currently with the R-3000.
 

Pops

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Would love to see the R-3000 come on the market. Been waiting for a long time.
 

Mike Stewart

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> "I don't know what the case is made of."

It says in that Contact article I read last night on the R-3000 that it can be had in both aluminum and magnesium. There's enough options and choices that putting one of these together would be fun. There's room enough in the ordering process that one can build almost exactly what one wants . . . so it seems.

Revmaster is actually what has become a custom shop. They build, in many cases, their own high-quality parts and I doubt would not let a buyer hang around the shop for a day or two and just watch the engines being put together. Could even be filmed (maybe?)

I think the R-3200 winds up with extras and mods to be a $10K engine. Goodness Gracious though . . . ten grand for a new engine with this lineage? Seems like a marvelous bargain in a world where it osts 35K to overhaul a 520/530/550.

******************

Can't recall just how extensive is the number of compatible parts that can be had at your low cost Chevy dealer (Brown Field junkyards and the ones in El Paso and Brownsville are the best, I think) But who wants to put used parts in their aircraft engine? That's what RIMCO does. Any of us can do a better job then them . . .

The idea in using easily compatible parts is so they can be easily and cheaply found. n the ase of the R-3000 it looks like we'll divide out time between VW custom part producers and Chevy dealers.

I haven't checked prices for a new piston for an R-3000 but I imagine its reasonable since it comes from a low-end Chevy which, I suspect will not be hard to find in the next ten years.

I'm just dreaming here . . . thinking of new engines. I've got a 2180 with an Ellison that could not suit me better.
 
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Vigilant1

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I figure it'll cost ten grand before all is said and done but my goodness gracious . . . ten grand for a new engine with this lineage? Seems like a marvelous bargain.
It would be, but I don't know if that would be the price. In any case, don't hold your breath. This engine has been in existence for almost a decade, it still isn't available (Joe did have one in a racing car, maybe he sold some for that application). I don't think it is ever going to be available.
Revmasters are great engines. I have only 2 qualms:
1) It appears that they don't care if they ever sell any of them. Their advertising/marketing is awful. Just a spiffed up and current web site would do wonders.
2) Revmasters have a lot of proprietary parts (their front bearing, their alternator scheme, etc). That's their strength, but also a weakness. All the aero VWs have this issue to some degree, but it is most acute with Revmaster.
 

Hot Wings

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can stud holes be that close and still survive over time?
Yes. I've seen lots of bored heads (some I did myself) with stud holes exposed due to core shift during the original machining. Most survive as well as a head with well centered stud hole drillings.

However, the head leak in that picture is a classic example of a head leak due to improper loss of clamping pressure on the lower head studs. The leak probably would have probably occured even with a stock head and 85.5mm bore pistons.
 

Mike Stewart

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It would be, but I don't know if that would be the price. In any case, don't hold your breath. This engine has been in existence for almost a decade, it still isn't available (Joe did have one in a racing car, maybe he sold some for that application). I don't think it is ever going to be available.
Revmasters are great engines. I have only 2 qualms:
1) It appears that they don't care if they ever sell any of them. Their advertising/marketing is awful. Just a spiffed up and current web site would do wonders.
2) Revmasters have a lot of proprietary parts (their front bearing, their alternator scheme, etc). That's their strength, but also a weakness. All the aero VWs have this issue to some degree, but it is most acute with Revmaster.
The only two front bearings I'd trust is Revmaster or Great Plains. The rest have made do with bearings which haven't really proven themselves.

I was just on their website last night and it seems their section on the R-3200 was complete and full of technical info . . . just what you'd want in looking.

What was lacking was info on the D-3000 but I don't think Joe is pushing that engine for aviation use. He started out with cars and he's still at it. That's why if one goes through the Revmaster engine catalog one can order a D-3000 in parts then take them home to put them together. That's really the best way to get to know you're engine in my opinion.

Theur propropriety parts are indeed an issue. If what they've come up with works better than the original, they only choice is to improve. Used to be only a few things were propriatary but with this D-3000 looks like the whole front engine is their own design - but incorporates oil pumps that work more efficiently and perhaps some other things too. It's probably just bearings that eventually need replacing those are replacable parts in any application. Or maybe the whole front end cracks from heat and if it can't be welded for some reason, I guess a new front end would cost something but one would need to examine these prices. I haven't done so.

I'm so happy with my Great Plains 2180 that this will probably be my last aircraft engine.
 

Vigilant1

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The only two front bearings I'd trust is Revmaster or Great Plains. The rest have made do with bearings which haven't really proven themselves.
Yes, the Force One prop hub and bearing sold by Great Plains, along with the crankshafts they sell, are top notch. For those who don't want to build an engine themselves, Scott Casler ("Hummel") uses the Force One bearing/prop hub in the stroked engines he sells, he has a very good reputation and his prices are reasonable (IMO).

For smaller VW engines with the stock stroke, I'd be comfortable with the stock pulley end bearing and a shrink fit prop hub--they have proved themselves in service on 1835/1915cc engines. But, a flywheel drive setup, with the beefier bearing on that end, does give a bit more margin.
 
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Vigilant1

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I was just on their website last night and it seems their section on the R-3200 was complete and full of technical info . . . just what you'd want in looking.
The info for the R-2300 >looks< complete, but:
- It was "posted by admin on Nov 11, 2012." This is the main page for their primary aviation product and it hasn't been updated in any way in over 7 years? Is that $9,400 price still right?
- How much HP does the engine make? At what RPM? The information is inconsistent:
Text: "maintains the earlier R-2200’s engine’s top horsepower (82) at 2950rpm continuous. (Takeoff power is rated at 85, at 3350rpm.) "
Specs below the text: " HP Rating 85 @ 3200 Continuous HP: 80 @ 3000 "
There's one photo of this engine, and no measured drawings (significant, because a "standard" VW engine mount (for a Great Plains engine, etc) needs to be modified to take a Revmaster). Pat Panzerra did a great write-up in Contact magazine (nice content, annoying proprietary reader software here: Special Issue 104 5 ), but Revmaster doesn't even have an easy-to-find live link to it on their web page.

What's on the Revmaster Aviation "News" page? Nothing but the same 7 year old info on the R-2300.

I think Revmaster makes great VW based engines, but their emphasis does not appear to be on communicating with the public about them.
 

Mike Stewart

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The info for the R-2300 >looks< complete, but:
- It was "posted by admin on Nov 11, 2012." This is the main page for their primary aviation product and it hasn't been updated in any way in over 7 years? Is that $9,400 price still right?
- How much HP does the engine make? At what RPM? The information is inconsistent:
Text: "maintains the earlier R-2200’s engine’s top horsepower (82) at 2950rpm continuous. (Takeoff power is rated at 85, at 3350rpm.) "
Specs below the text: " HP Rating 85 @ 3200 Continuous HP: 80 @ 3000 "
There's one photo of this engine, and no measured drawings (significant, because a "standard" VW engine mount (for a Great Plains engine, etc) needs to be modified to take a Revmaster). Pat Panzerra did a great write-up in Contact magazine (nice content, annoying proprietary reader software here: Special Issue 104 5 ), but Revmaster doesn't even have an easy-to-find live link to it on their web page.

What's on the Revmaster Aviation "News" page? Nothing but the same 7 year old info on the R-2300.

I think Revmaster makes great VW based engines, but their emphasis does not appear to be on communicating with the public about them.
I don't understand it either. Joe and Roberta are getting up there and without energy coming from below (same thing happened with Great Plains - Steve's son had zero interest in aviation).

I don't know what's going on. Next time I land in Hesperia I'll stop over and see what's going on with their shop.
 
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