Super Tigre G90 or S90K as diesel?
03-02-2016, 09:58 PM
#1
Super Tigre G90 or S90K as diesel?
I have both, but only one Davis head. I read somewhere that the G90 is a slightly lower performing, or at least a slower revving engine than the S90K, but don't remember the source. Does anybody have any experience with these, or an idea which would be a better candidate for dieselizing? Thanks!
Jeff
Jeff
03-03-2016, 04:18 AM
#2
They're probably about the same on performance if you read through the tachometer forum. The nice thing about the S90 was that it had a removable front housing that allowed clockwise rotation. The two engines share the same cylinder head and liner, but have different cranks, conrods, pistons, and rings. If you have both, try both as a diesel. You may find a stronger engine between the two, you may not. I have an S90K myself and it's a great running engine. If I had a diesel head for it, I'd try it.
03-03-2016, 09:56 AM
#3
My Feedback: (90)
[QUOTE=RDJeff;12184643]I have both, but only one Davis head. I read somewhere that the G90 is a slightly lower performing, or at least a slower revving engine than the S90K, but don't remember the source. Does anybody have any experience with these, or an idea which would be a better candidate for dieselizing? Thanks!
Jeff,
I ran a ST90 both versions quite extensively. It is probably the sweetest running engine to dieselize in the ST line. easy running neither of them, are even as a glow, a high rev engine. But they are good at supplying torque in large amounts. So use either of them with complete confidence. One thing to remember is to break your engine in as a glow, it will set the ring better and the heat cycles are advantageous to the performance of the engine. Running as a diesel will really take too much time and fuel to get it bedded well.
Another thing is that I have a nice used Davis 90 head that can be had reasonably if your interested. Let me know via a pm. Thanks.
Dennis
Jeff,
I ran a ST90 both versions quite extensively. It is probably the sweetest running engine to dieselize in the ST line. easy running neither of them, are even as a glow, a high rev engine. But they are good at supplying torque in large amounts. So use either of them with complete confidence. One thing to remember is to break your engine in as a glow, it will set the ring better and the heat cycles are advantageous to the performance of the engine. Running as a diesel will really take too much time and fuel to get it bedded well.
Another thing is that I have a nice used Davis 90 head that can be had reasonably if your interested. Let me know via a pm. Thanks.
Dennis
03-03-2016, 10:10 AM
#4
PM sent!
[QUOTE=dennis;12184832]
[QUOTE=dennis;12184832]
I have both, but only one Davis head. I read somewhere that the G90 is a slightly lower performing, or at least a slower revving engine than the S90K, but don't remember the source. Does anybody have any experience with these, or an idea which would be a better candidate for dieselizing? Thanks!
Jeff,
I ran a ST90 both versions quite extensively. It is probably the sweetest running engine to dieselize in the ST line. easy running neither of them, are even as a glow, a high rev engine. But they are good at supplying torque in large amounts. So use either of them with complete confidence. One thing to remember is to break your engine in as a glow, it will set the ring better and the heat cycles are advantageous to the performance of the engine. Running as a diesel will really take too much time and fuel to get it bedded well.
Another thing is that I have a nice used Davis 90 head that can be had reasonably if your interested. Let me know via a pm. Thanks.
Dennis
Jeff,
I ran a ST90 both versions quite extensively. It is probably the sweetest running engine to dieselize in the ST line. easy running neither of them, are even as a glow, a high rev engine. But they are good at supplying torque in large amounts. So use either of them with complete confidence. One thing to remember is to break your engine in as a glow, it will set the ring better and the heat cycles are advantageous to the performance of the engine. Running as a diesel will really take too much time and fuel to get it bedded well.
Another thing is that I have a nice used Davis 90 head that can be had reasonably if your interested. Let me know via a pm. Thanks.
Dennis
03-03-2016, 10:13 AM
#5
Thanks for the tips guys. I have a few test flights with the S90K as a diesel, and it flew the Senior Telemaster quite well, but the test was to see if it would suit a 1/4 scale Cub. The Cub has been gaining weight with scale gear and 8" tundra tires, etc., so I went to a Super Tigre G2300 instead. Now if I could just find a diesel head for that one...
03-04-2016, 11:17 AM
#10
My Feedback: (90)
Thanks for the tips guys. I have a few test flights with the S90K as a diesel, and it flew the Senior Telemaster quite well, but the test was to see if it would suit a 1/4 scale Cub. The Cub has been gaining weight with scale gear and 8" tundra tires, etc., so I went to a Super Tigre G2300 instead. Now if I could just find a diesel head for that one...
This is probably your lucky day as I have a brand new 2300 head. It is not in the package and there are no instructions but it is new never run. Send me a PM if interested for price and shipping. Can not sell on these forums.
Dennis
dennis
03-04-2016, 11:54 AM
#11
My Feedback: (90)
You can certainly run an 18/6 on a 90, even 60's can run one also but it may not be optimum for the aircraft. Certainly never on a Kaos 90. Ground clearance alone would preclude it. I'd run a 15/8 on it with enough authority to carry it through the aerobatic regimen. I ran a K&B sportster 65 on an Air Flair Sundancer for years with a 16/7 ( a reworked prop). It was an incredibly good running engine and was not underpropped for the model.
Interesting, when the OS 90 and ST 90 engines first cane out the recommended prop was a 14/6. Even the K&B 100 recommended the same prop.
Fifteen inch props were recommended for the ST2300 but dieselized an 18 inch is fine. I ran a 90 inch 11 pound Road runner with a dieselized Tartan 1.3 for years on an 18/6 with more than satisfactory results, for more thrust I used an 18/8.
Guess what I implying as you all know there is no one recommended prop for any engine or any model. Try a few different props and see which one is really the best for that particular model. Props are the most important item in the engine package don't assume that the 'expert' is right all of the time. You just might surprise yourself. Also keep your eyes open for 3 blade props they are excellent at harnessing the diesel engines power.
dennis
03-04-2016, 12:40 PM
#12
Yeah, I was thinking 15x8 or 15x10, or maybe a 16x8 for the Kaos. It has the ground clearance to run up to a 17" prop.
The 2300 will need to turn a 21" prop to be scale, which is probably doable.
I'm also planning on using a 20x8 3 blade prop with an ST3250 on a Dynaflite Decathlon that should weigh about 17 pounds.
The 2300 will need to turn a 21" prop to be scale, which is probably doable.
I'm also planning on using a 20x8 3 blade prop with an ST3250 on a Dynaflite Decathlon that should weigh about 17 pounds.
