Looking for info on RAM engines
 

Hi Guys,

I know RAM, at one time, was king of the hill... and then died. But, it amazes me that there is no history, or real info out there, about them. OK... I know Carlos can service them... and still produces his version of the "1000". I also know that Modellbau had their versions of the 500 and 750. And finally, I know Bob Price can service the ECU.


So... does anyone know what the "X" versions were? I knew there was a 500x, but I have just recently stumbled across a few comments about a 1000x. Was this a mechanical upgrade, or just something in the software?

Second... does anyone have a digital copy of the newest RAM manual? I have a paper version of rev.2, but I'd like it in my computer for reference. (I found rev1, and the modellbau manuals)

Thanks

I do not recall exactly, but it's either the autostart version of each model or the updated bullet starter (from a flat spinner nut to a conical spinner nut)

I know i also have a copy of the manual, just don't recall where, yet I did forward it to several RCU mermbers, any may chime here and forward you a copy

Main difference in the "X" models was the removal of the problematic (and stupidly expensive )coreless starter and the change from a flat faced compressor nut to an industry standard acorn nut and updated ECU software. In my worthless opinion that flat faced compressor nut was hugely responsible for RAMs demise. The O ring on the Bendix could just not get a good bite on the nut which led to a myriad of starting problems. Low RPM slipping starter, led to flaming starts, failed starts etc. Also the A version ECU hit the starter motor with a full 7.2 volts and huge amp surge which led to starter motors burning out after just a few starts. This was fixed with the "C" software that had a "soft" start for the starter. By the time Rei fixed the starter issue it was too late. Huge service backlogs from the above and bad word of mouth.
That being said I have had about 4 500s and one 750 and they were all great engines after the fixes. The 1000s on the other hand had an issue of blowing up at the wrong time. RAM was a pioneer and they paid the price that pioneers often do. Scotty

Thanks for the info guys.

I guess the reason I don't see the "X" moniker more often, was that it was all the newer versions.

GSR: Since the 750 and 1000 were basically the same engine... would the 1000 be more reliable if it's turned down to the 750 spec? Or was there other internal changes?

Tony,
I believe that RAM also offered + engines, mostly for the 750, where it was "kicked up" to 22 lbs of thrust instead of the basic 17 lbs.
I had a basic 750 uprated to a + by Carlos along with an ECU upgrade by Bob Price. The unit's balance and EGT behavior allowed this upgrade. Depending on how each turbine performed in the test cell would determine their rating, either a 750, 750+ or 1000.
I understand that this criteria was also in effect for the RAM 500. Life expectancy was the final determinant with these upgrades.
I'm still operating a 750+ and a FTE-500 serviced by Bob and Carlos-both running well.

Art ARRO

I am still flying a 1000X on my Kingcat, it has over a 1000 flights on it and it’s still going. But it was updated by Carlos so that it has all the good stuff in it (Wren NGV and turbine wheel, and Carlos’ combustor).

FWIW, my take on the demise of RAM. The real culprit was the vendor they were getting turbine wheels from. The vendor was supposed to do a full inspection on every wheel (X-ray and spin test), but it would seem this was not happening. The 1000’s just kept breaking turbine wheels. During this problem RAM received an order of 100 wheels and they did the inspection. Around half showed voids when X-rayed and quite a few more failed in a spin test. So out of that 100 something like 30 where usable. This meant a lot of engines where breaking that where built before they started doing inspections, and their reputation went down hill. After a while they started getting the wheels from Wren and the breakage problem went away, but it was just too late. If you know what to look for you can look down the tail pipe and tell which wheel is in the engine. If it has a Wren wheel the engine might be a good one, although if it still has the original combustor it will probably need to be changed, and Carlos makes a real good long life one.

Steven

Thanks for that.....

S_Ellzey: The reason I was asking about all of this was:

1) I did just buy a RAM 1000 from a member here, and it looks great. It's smooth... all the parts work, and it has a brand new ECU. (This was a great change, as my last used engine was cr@p !!) When I get a chance, I will get the S/N off the engine, and contact Carlos to see if he has a history on it.

But, reason #2 is... I have a buddy who has been buying parts to get into flying turbines... and I bet he has a dozen ram engines, in all different stages. (A couple OK, and a bunch of parts) So... I figure I can learn what I can, and help him get up and running.



SO.... does the Wren wheel have Wren makings on it? (What would I be looking for?)

Tony you are pretty correct in your thoughts about the 7501000. They would assemble them and if they ran very well they were 1000s if not they tuned them as 750s S

Hey Tony I have a PDF version if that will help, [ATTACH]1931507[/IMG]

I also have an excel file you maybe interested in;)

You are looking for the word "Wren"

Exactly, but word of caution on the older RAM's (like year 2000 or so) - These had the manual start box and the ECU used case pressure to control the speed, not true RPM sensing like current turbines. Some people would take a 750 and use a 1000 ECU causing their own self destruction. There were even a couple scam artists trying to sell a used "1000" that was really a 750 with a 1000 ECU.

750 max CP of 1600 Mbar = 21.3 lbs of thrust (approx 120k RPM)
1000 max CP of 1900 Mbar = 28 lbs thrust

Sorry if I went off topic on older RAM info - just nice to remember times when people had to actually know what they were doing - not like today where the ECU does it all and people have no clue when something goes wrong & how to troubleshoot.

Rich: I have the Modellbau manual... but I'll PM an email to send the XL file.

GSR: OK. I didn't see a wren marking on the wheel. (I put a bore scope in the center cone) So I guess I didn't get lucky on that one.

sc0tt: I pulled the front cover today, and it has a "1K" serial number, Also... there isn't a port for the air line... so I'll assume this one was an RPM controlled engine. No prob getting off topic. It was actually helpful. Since my buddy has a box of parts, and I know he has a couple of the pressure ECU's... it will help keep that part straight.

If it is an RPM engine with a Hall sensor it will have the sensor board mounted with a servo style lead coming from it. Else it is a pressure controlled ECU. S

Yes... there is a hall sensor board under the cover.

Anybody knows if WREN can actually supply any similar turbine wheels?

Wren list a 55mm wheel that would be suitable for the Ram 500 and Dieter Albisser (jetmax.ch) makes a number of wheels including 66mm size which is the same size as the Ram 750 and 1000. Any wheel you buy will be better bought as a casting unbored and then bored out and ground on the outside to fit your engine. If you buy it machined you need to be very careful that it will be a tight fit on the shaft and fit the NGV with the right clearance. Inconel 713 is a very tough material but it can be bored on a Boxford/Myford lathe run slowly with the correct drills using oil and using a sharp carbide boring tool to finish to size. You will need to make a jig to hold the wheel nicely central and which holds the wheel on the flange that the blades sit on.


John

I am not sure that the back side of the wheel is marked, it might be the front side. The way I was shown to tell the difference is to look at the point where the trailing edge of the blade meets the wheel and see if there is a lump there. I don't remember if the lump was good news or bad, I'll take a look tonight and get back with you. Along time ago I posted pictures of this, but it's been so long ago I don't even remember if it was on RCU.

Steven

Interesting. I always wondered what happened. I think I still have a yellow Ram T-shirt somewhere..

Still have their yellow RAM T-Shirt but I seem to have outgrown its size! heheheheh

I found an old thread from 2003, and it said that the "Bumps" were the wheels that were questionable. The S/N on my engine is 1K158, and the printed manual is from 2002. So, I guess I can assume it's a later engine. And, hopefully, it's when they decided to start x-ray'ing.


Last question.... when did they go out of biz? (year?)

If you look at the picture (provided I can figure out how to post it) you see a suspect wheel. The bumps where the trailing edge of the blade meets the wheel is the give away that can be seen looking up the tail pipe. If that area is smooth you probably have a good wheel.

Thanks for the pic. I can see what you are saying. It's almost like a weld bead at the junction.

BUT.... I just put a bore scope down the center cone, and my blades transition smooth !!!

Ignore this post.... It seems I need to reply to subscribe now days.

I have a few RAMs and they still run fine.

I have converted most of them to the Xicoy ecu and makes them even better.

Clay