Wren 160 failures
#78
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Ok, Idiot #4 here. I also own a Wren 160, one of the first. I have seen and been present at 3 of the 160 that destroyed themselves here in South Africa. I could not wait for the 160 to be released as I had a Wren 54 kit build and Super Sport. Both brilliant turbines and had no hesitation in placing the order with Sarah for the 160. To our dismay, these 160's were falling apart. Unfortunately the failure caused a total loss of a Skymaster Hawk on takeoff. The first upgrade to to replace the compressor with another cast one and change of ECU. These compressor too came apart. We could then choose to send them back for a machined compressor at our own cost - grrrrrrrrrrrr! The last two to destroy themselves had machined compressors.
I never sent mine back for a third compressor because I thought it was not fair for me to have to pay for a design fault. Mine is still running at reduced RPM(max 120K) and I have been lucky until now that it is still in one piece. Fortunately the airframe that it is in doesnt require 16kg.
So Wren turned a fanatic supporter into a disgruntled end user! Pity really as the Super Sport and XL 200's were awesome turbines.
I never sent mine back for a third compressor because I thought it was not fair for me to have to pay for a design fault. Mine is still running at reduced RPM(max 120K) and I have been lucky until now that it is still in one piece. Fortunately the airframe that it is in doesnt require 16kg.
So Wren turned a fanatic supporter into a disgruntled end user! Pity really as the Super Sport and XL 200's were awesome turbines.
Last edited by jgracco; 03-07-2014 at 12:09 PM.
#79
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#80
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I got the engine back from wren. It was repaired at half the cost of the original quote. Wren gave a new 12 month warranty on the engine, so any mods is out of the question. I am installing it into the F15, and will be flying it a lot hopefully. We will see what will happen! Leonie claims that none of the upgraded engines with the machined compressors have failed, although we have seen some on here. I think that everyone that has had a failure, especially those with upgraded compressors, should contact wren and let them know. I would urge the owners of such engines too contact wren and speak to Mike Murphy, give them a chance too repair and extend the warranties, then post on here the result of your inquiries. On this forum then, we can have a record of what happens to these engines.
#81
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Hi,
I own a Wren 160 turbine which recently had a compressor failure and shedding its blades.
After learning that I was not the only one that had this failure and there is a probability to fail again if it is repaired, I am looking for a new turbine in the 140N class.
Did anyone own or had any experience of the following turbines:
Merlin from Jet-Munt: M140XBL
Jetcraft 130+
Regards
I own a Wren 160 turbine which recently had a compressor failure and shedding its blades.
After learning that I was not the only one that had this failure and there is a probability to fail again if it is repaired, I am looking for a new turbine in the 140N class.
Did anyone own or had any experience of the following turbines:
Merlin from Jet-Munt: M140XBL
Jetcraft 130+
Regards
#82
Vince,
It was stated here that Wren were going to look into the matter but there does not seem to have been any feedback on this up to now. I hope someone will have some fresh news on this.
It was stated here that Wren were going to look into the matter but there does not seem to have been any feedback on this up to now. I hope someone will have some fresh news on this.
#84
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I got the engine back from wren. It was repaired at half the cost of the original quote. Wren gave a new 12 month warranty on the engine, so any mods is out of the question. I am installing it into the F15, and will be flying it a lot hopefully. We will see what will happen! Leonie claims that none of the upgraded engines with the machined compressors have failed, although we have seen some on here. I think that everyone that has had a failure, especially those with upgraded compressors, should contact wren and let them know. I would urge the owners of such engines too contact wren and speak to Mike Murphy, give them a chance too repair and extend the warranties, then post on here the result of your inquiries. On this forum then, we can have a record of what happens to these engines.
Wow, all this, what could reasonably be called a, tirade, and you are still going to use that engine?
Hmmm....
#85
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#87
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Thanks got a kero start at a very good price that's still new in the box, has the upgraded compressor wheel and putting into a Jet legend l-39 so just wanted to see if anything had been done .. now to go fly then
#89
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You need to remember that rpm is dictated by the diameter of the turbine disc, not the thrust. There is an optimum speed for the turbine blades to run at, so for any given diameter there is an optimum rpm, hence the physically smaller engines run at higher rpm than the physically larger engines. The Wren 160 is the same physical size as many 120s, and since rpm is related to diameter it would expect to operate at similar rpm to those 120s.
#91
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How sure are we of that memory of a verbal report of 130k? The current 180 which is the 160 pumped up a bit, is max power at 120k. I can have a check of the spec of my original 160 tonight.
#93
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You need to remember that rpm is dictated by the diameter of the turbine disc, not the thrust. There is an optimum speed for the turbine blades to run at, so for any given diameter there is an optimum rpm, hence the physically smaller engines run at higher rpm than the physically larger engines. The Wren 160 is the same physical size as many 120s, and since rpm is related to diameter it would expect to operate at similar rpm to those 120s.
You probably not have noticed that the Merlin 200 produces 20 KG thrust from the same size 110mm dia case that the old 160 but it is produced at less rpm. The quoted max rpm is 115,00 rpm, quite an achievement. Also the Kingtech 210 is the same case size (112mm dia) and produces 21 Kg thrust at 120,000 rpm. The Wren 180 is quoted as thrust 18.75Kg at 120,000 rpm. The most limiting factor on RPM is the strength of the aluminium compressor not the turbine wheel.
There are other powerful engines out there. There are 2 Frank turbines one of 22KG thrust and one of 25 KG thrust both are case size 112mm and run at 123,000 rpm. The Evojets 220 is 22 KG thrust from a case size 112mm dia and runs at 123,000 RPM. There is an IQhammer 220 with similar specification.
I find it astonishing that our small engines have developed so much, with much of it being very recently with the use of 5 axis cnc compressors and cramming larger compressors, turbine wheels and NGVs into the same case and still getting good combustion. After all we started off with the KJ 66 producing 8-9 KG thrust using the same physical size.
#94
Harry I had sent my 2 new (unused) turbines for checkup as one was 2009 version. The older version had its compressor replaced with a latest version but the newer one was left untouched as it had the latest compressor. When they returned back from factory I was told not to run them in excess of 130k otherwise they were good to go. Err .... Needless to say these adjustment had to be self funded despite these were two brand new n.i.b. turbines. In my heart of hearts I know that no further developments will be effected despite previous claims here. Pity.