Schmleff
Well-Known Member
Here you go. The bump in the cowl shown in the pictures was to accommodate his starter. Its and otherwise unmodified stock cowl. He has since re-engineered it and moved the starter elsewhere.
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Chad Stenson's Rear Drive Picts
- Thread starter Schmleff
- Start date
jwalin
Well-Known Member
- Joined
- Jan 7, 2007
- Messages
- 123
great pics!! so, it will fit in a stock cowl, without the starter and ring gear as in the GPASC setup. I like it....but......
that leaves me with hand propping....which is fine....I plan to do this anyway with an X casting instead of the Diehl. But I feel it is better to drive the prop off the flywheel end than the nose.....this is just my opinion, I don't want to start a debate.
and eliminating the accessory case saves weight......which opens up the possibility of a type 4 without the added weight in the nose.....
just thinking......
that leaves me with hand propping....which is fine....I plan to do this anyway with an X casting instead of the Diehl. But I feel it is better to drive the prop off the flywheel end than the nose.....this is just my opinion, I don't want to start a debate.
and eliminating the accessory case saves weight......which opens up the possibility of a type 4 without the added weight in the nose.....
just thinking......
Schmleff
Well-Known Member
jwalin said:
Chad moved the starter, so you can have it without the bump. The x casting will be of no use to you since it bolts up to the flange, which would be removed or at that front of the motor. I can't comment on the great plains setup and the stock cowl.
jwalin
Well-Known Member
- Joined
- Jan 7, 2007
- Messages
- 123
yes, you are right!! I won't need the X casting......I meant I was planning a 1915 or 2180 with the X and no starter.....but really wanted to drive it from the flywheel end......so I was looking into it when I saw them in the new GPASC catalog.....
and, I just happen to have a 914 2.0 case and crank in my garage....would like to use it instead of building a T1......so that is where I will head.....a hand prop flywheel drive 2056 T4.....
I noticed from the pictures that he didn't change the front of the airframe to brace it at the motor mount points. as I study the way the airframe is built, it is obvious that the loads were destributed throught the airframe with the bracing....this I will have to change for piece of mind......just add a few extra tubes to carry the loads from the 'new' lower motor mount area....much to do.....I hope to have a finished airframe by the end of this year.......
and, I just happen to have a 914 2.0 case and crank in my garage....would like to use it instead of building a T1......so that is where I will head.....a hand prop flywheel drive 2056 T4.....
I noticed from the pictures that he didn't change the front of the airframe to brace it at the motor mount points. as I study the way the airframe is built, it is obvious that the loads were destributed throught the airframe with the bracing....this I will have to change for piece of mind......just add a few extra tubes to carry the loads from the 'new' lower motor mount area....much to do.....I hope to have a finished airframe by the end of this year.......
privatepilot03
The guy with the Rear Drive VW
- Joined
- Jan 11, 2007
- Messages
- 359
Now that I can finally log in (thanks Scott) I thought I'd make a quick post...
The Gen 1 rear drive as shown in my sonerai was a direct fit requiring no cowling modification other than the bump for the starter, and a very small bump (less than 1" tall) to clear the DIS-IX ignition system. The top 2 motor mount locations use the stock Sonerai motor mount locations that you'd use in an X-casting or diehl case setup. Only the lower 2 motor mount bushings were added, mainly because it was easier to add those bushing that it was to build a mount to use the stock locations.
The new Gen 2 stuff has the starter out the back of the engine like a diehl case and options for a front mounted alternator or rear mounted alternator, both belt driven.
The future Gen 3 will be a complete rear drive setup that will bolt in anywhere a diehl case will bolt in requiring no fabrication of custom motor mounts and all that.
I'll have Gen 2 conversion parts available shortly and I'll be looking for a guinea pig to help develop the Gen 3 motor mount.
My sonerai was sold in December of '05 to a guy from arizona minus the firewall forward. That firewall forward will be converted to utilize all the new Gen 2 stuff and is mounted in my new Avid Flyer Aerobatic Speedwing project.
I'll keep the group posted.
Chad
The Gen 1 rear drive as shown in my sonerai was a direct fit requiring no cowling modification other than the bump for the starter, and a very small bump (less than 1" tall) to clear the DIS-IX ignition system. The top 2 motor mount locations use the stock Sonerai motor mount locations that you'd use in an X-casting or diehl case setup. Only the lower 2 motor mount bushings were added, mainly because it was easier to add those bushing that it was to build a mount to use the stock locations.
The new Gen 2 stuff has the starter out the back of the engine like a diehl case and options for a front mounted alternator or rear mounted alternator, both belt driven.
The future Gen 3 will be a complete rear drive setup that will bolt in anywhere a diehl case will bolt in requiring no fabrication of custom motor mounts and all that.
I'll have Gen 2 conversion parts available shortly and I'll be looking for a guinea pig to help develop the Gen 3 motor mount.
My sonerai was sold in December of '05 to a guy from arizona minus the firewall forward. That firewall forward will be converted to utilize all the new Gen 2 stuff and is mounted in my new Avid Flyer Aerobatic Speedwing project.
I'll keep the group posted.
Chad
jwalin
Well-Known Member
- Joined
- Jan 7, 2007
- Messages
- 123
Can you tell me if the prop hub used a 4 or 8 dowel pin crank? Were there any issues?
I am going to use a Type 4 motor. The T4 flywheel end is a bit different from the T-1 if anyone doesn't know. Instead of a gland nut and dowel pins it uses a five bolt method, with only one dowel pin used for location purposes only.
My plan is to convert the five threaded holes to large, high tolerance dowel pin holes. I don't like the bolts being in tension and shear at the same time. Works fine in a car, but with the gyroscopic forces of a propeller I worry about cracks developing in the threads of the crank. In addition to the dowel pins, I plan on using a 'safety shaft' like William Wynne uses on the corvair powerplant. That way, the dowell pins will only be in shear, and the tension and all forward thrust will be taken up by the safety shaft, much like a gland nut on a T-1.
If anyone has tried to use a T-4 in a flywheel drive setup, or knows of one, please let me know......
Jeff
I am going to use a Type 4 motor. The T4 flywheel end is a bit different from the T-1 if anyone doesn't know. Instead of a gland nut and dowel pins it uses a five bolt method, with only one dowel pin used for location purposes only.
My plan is to convert the five threaded holes to large, high tolerance dowel pin holes. I don't like the bolts being in tension and shear at the same time. Works fine in a car, but with the gyroscopic forces of a propeller I worry about cracks developing in the threads of the crank. In addition to the dowel pins, I plan on using a 'safety shaft' like William Wynne uses on the corvair powerplant. That way, the dowell pins will only be in shear, and the tension and all forward thrust will be taken up by the safety shaft, much like a gland nut on a T-1.
If anyone has tried to use a T-4 in a flywheel drive setup, or knows of one, please let me know......
Jeff
privatepilot03
The guy with the Rear Drive VW
- Joined
- Jan 11, 2007
- Messages
- 359
I used an 8 dowl crank (with the larger size dowels), but only used 4 dowels.
I had a T4 on the sonerai. I'm not sure I follow what you're saying with the crank flange. I'm not that familiar with the Corvair stuff, but why not just add 5 dowel pins to the crank flange and continue to use the threaded holes as they are intended? The dowels will help with your shear and the bolts will take care of the tension much the same that the T1 gland nut and dowel setup works. I'm using a crank flange with simple threaded holes to hold the prop extension on with no issue.
The T4 is probably slightly easier to convert to rear drive due to the integral crank flange, but I don't think that feature makes it any better or worse than the T1. FWIW, my T1 outperformed my T4 engine by 20+mph and a couple hundred feet per minute of climb in the sonerai. The T4 swung a sterba 54x48 @ 3150rpm max and would cruise at 135 @ 3000 after the wheel pants were installed. With the T1 rear drive, I was swinging a Sterba 54x54 @ 3600 max and the plane would cruise at 155 indicated @ 3300 (165ish TAS) and would do close to 180TAS at WOT. Lots more power being made in the T1 than the T4 for less money with less weight.
Just my $.02.
chad
I had a T4 on the sonerai. I'm not sure I follow what you're saying with the crank flange. I'm not that familiar with the Corvair stuff, but why not just add 5 dowel pins to the crank flange and continue to use the threaded holes as they are intended? The dowels will help with your shear and the bolts will take care of the tension much the same that the T1 gland nut and dowel setup works. I'm using a crank flange with simple threaded holes to hold the prop extension on with no issue.
The T4 is probably slightly easier to convert to rear drive due to the integral crank flange, but I don't think that feature makes it any better or worse than the T1. FWIW, my T1 outperformed my T4 engine by 20+mph and a couple hundred feet per minute of climb in the sonerai. The T4 swung a sterba 54x48 @ 3150rpm max and would cruise at 135 @ 3000 after the wheel pants were installed. With the T1 rear drive, I was swinging a Sterba 54x54 @ 3600 max and the plane would cruise at 155 indicated @ 3300 (165ish TAS) and would do close to 180TAS at WOT. Lots more power being made in the T1 than the T4 for less money with less weight.
Just my $.02.
chad
Schmleff
Well-Known Member
I can vouch for chad's cruise numbers. He and I did a formation flight at 3000ft and I was indicating 155mph. He was right off my wing the whole time.
jwalin
Well-Known Member
- Joined
- Jan 7, 2007
- Messages
- 123
can you give details on the T4 you had? was it a bone stock 2.0, 1.8, or 1.7? what heads and cam did you use? compression? and I am assuming the T1 is a 2180? I am not trying to dispute your numbers, jsut gathering info to consider. I haven't gone too far down the T4 road to abandon the T1 yet! I need to learn more!!!
I am interested in the T4 mainly for the extra cooling capacity, and the better designed case. I know the T1 has much more performance potential due to the aftermarket research, but I think VW was trying to solve many of the problems of the T1 with the T4 design. And I can't see a reason the T4 would be at that much of a disadvantage in our application. The T1 heads typically flow better due to the exhaust port design, but I think at our RPM's this is not that much of an issue....maybe I am wrong.
I plan to use a 2056 with stock 71mm crank and rods, 96mm forged pistons (special squish enhanced from LN Engineering)hoping to be able to run 8:1 or slightly better compression, my own design prop hub, and the cam is still unknown. All I really want to do is be somewhere between a GPASC 1915 and a 2180 for power, and maybe increase reliability.
what do you think?
Jeff
I am interested in the T4 mainly for the extra cooling capacity, and the better designed case. I know the T1 has much more performance potential due to the aftermarket research, but I think VW was trying to solve many of the problems of the T1 with the T4 design. And I can't see a reason the T4 would be at that much of a disadvantage in our application. The T1 heads typically flow better due to the exhaust port design, but I think at our RPM's this is not that much of an issue....maybe I am wrong.
I plan to use a 2056 with stock 71mm crank and rods, 96mm forged pistons (special squish enhanced from LN Engineering)hoping to be able to run 8:1 or slightly better compression, my own design prop hub, and the cam is still unknown. All I really want to do is be somewhere between a GPASC 1915 and a 2180 for power, and maybe increase reliability.
what do you think?
Jeff
privatepilot03
The guy with the Rear Drive VW
- Joined
- Jan 11, 2007
- Messages
- 359
My engine is a 2332cc T1. The type 4 was 2400cc, so my T1 was 68cc smaller in displacement. I believe it was 72mm crank with 103mm pistons, but don't quote me on that. It was a 2.0L to start with with stock 2.0l heads and a stock cam. Performance was very lack luster. I tried a new cam and it picked up maybe 50rpm or so. I didn't want to put the time into making horsepower in an engine that I new little about so opted for the lighter and (in my experience) more powerful T1. The strengths and weaknesses of the T1 are well known, however opinions vary wildly from person. The people with the stongest opinions in most cases are the ones that have not actually built and flown their own VW conversion and base all of their statements on what other people have told them or what their own perceptions are.
I'm not trying to talk you out of the T4, but in my opinion, you'd be happier with a T1. My T1 running 8.7:1 compression and 93 octane pump gas with more timing than the most say you should run had no problem keeping cool in the sonerai. An extended climb on an 80 degree yielded 315 degree head temps that would immediately fall to 290 or so in cruise config in this airplane. This is with the probes under a head nut rather that under a spark plug by the way.
In a nutshell, I was very disappointed in the performance of the T4 in my sonerai. I should also mention that I tried 2 different carbs along with a reworked prop and never really got the performance I was looking for. The other pitfall was the extra weight of the engine made getting the W&B hard to get right.
Another fun fact about my plane is that is weighed 652 pounds empty when done (the guy that built it was 6'2" and made changed to the plane to get it to fit him) and still performed very well.
The FWF weighed 158 pounds complete minus oil.
Study hard and make the decision that is best for your installation.
chad
I'm not trying to talk you out of the T4, but in my opinion, you'd be happier with a T1. My T1 running 8.7:1 compression and 93 octane pump gas with more timing than the most say you should run had no problem keeping cool in the sonerai. An extended climb on an 80 degree yielded 315 degree head temps that would immediately fall to 290 or so in cruise config in this airplane. This is with the probes under a head nut rather that under a spark plug by the way.
In a nutshell, I was very disappointed in the performance of the T4 in my sonerai. I should also mention that I tried 2 different carbs along with a reworked prop and never really got the performance I was looking for. The other pitfall was the extra weight of the engine made getting the W&B hard to get right.
Another fun fact about my plane is that is weighed 652 pounds empty when done (the guy that built it was 6'2" and made changed to the plane to get it to fit him) and still performed very well.
The FWF weighed 158 pounds complete minus oil.
Study hard and make the decision that is best for your installation.
chad
