# QUESTIONS concerning Spyder Corvair Engine Conversions.....Azalea Aviation

Discussion in 'Corvair' started by Bill Clapp, Apr 6, 2015.

1. Apr 7, 2015

### RonL

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My mind keeps seeing the Harley Davidson heads and the dome chamber with canted valves, single heads for each cylinder on the Corvair, looks to be a way to remove weight, plus a much greater flow volume.
A few other possibilities, but not much can be done to shed weight.
If a Harley two cylinder can pump out 100 HP.......I'm digging for information?

Ron

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2. Apr 7, 2015

### Vigilant1

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Bill,
Weight of the 100HP Spyder? I looked around a bit on your web site and couldn't find a "specs" page that contained the weight (and what was included in it). I'm talking about the "as offered" $10,500 engine. Please just supply a link to the spot, if that is easiest. Mark 3. Apr 7, 2015 ### Vigilant1 ### Vigilant1 #### Well-Known MemberLifetime Supporter Joined: Jan 24, 2011 Messages: 4,042 Likes Received: 1,792 Location: US But at 3000 RPM? Regarding exotic head/valve designs: Yes, good flow is important, but it's not nearly as critical (or hard to achieve) at 3000 RPM as at 6000-7000 RPM. There's just not a whole lot of payoff for getting exotic to improve breathing at low RPMs, especially if it comes at the cost of complexity, reliability, weight, or$$. akwrencher and Pops like this. 4. Apr 7, 2015 ### Bill Clapp ### Bill Clapp #### Well-Known Member Joined: Feb 17, 2015 Messages: 297 Likes Received: 290 Location: Valdosta Ga Weight of the 100HP Spyder? I looked around a bit on your web site and couldn't find a "specs" page that contained the weight (and what was included in it). I'm talking about the "as offered"$10,500 engine. Please just supply a link to the spot, if that is easiest.

The standard weight (without carb or exhaust is typiccally 215 lbs. I have made lightweight versions under 200 lbs using steel sleeved aluminum cylinders and a lightweight oil pan but there can be issues with the cylinders because of the compression they are under. Our fix for the lighter engine is a new case and heads. That is still in R&D - however the cost then goes up. There is a balance between cost and weight...most weight saved in the homebuilts Ive seen lately can be removed from the pilot.....(touchy subject)

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5. Apr 7, 2015

### don january

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Bill. I think your thread for questions on the Spyder conversion's has been very helpfull.

6. Apr 9, 2015

### don january

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Bill. I have a question about the cranks. you have came up with a strong crank in the 8409 number has there been any upgrades on the earlier 5607 crank?

7. Apr 9, 2015

### Bill Clapp

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Bill. I have a question about the cranks. you have came up with a strong crank in the 8409 number has there been any upgrades on the earlier 5607 crank?

THe 8409 is the strke and forged crank from GM after 1964. Some were nitrided as well. Our New Crankshaft is a new design that is counterweighted.

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8. Apr 18, 2015

### don january

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Bill was wondering if you sell the engine with the option of rotation direction of the prop? And before the fellas get in here and chew this question up I understand there is a way to modify the engine to get either direction on the prop rotation right? I can hear them now singing: here the prop goes round and round, round and round :gig:

9. Apr 18, 2015

### Bill Clapp

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Bill was wondering if you sell the engine with the option of rotation direction of the prop?

Yes Don. We currently are doing a reverse rotation engine for a Tailwind installation. It is not as common but very doable. It is an important part of our future as a company since we currently are designing two twin engines airplanes that will utilize this capability.

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10. Apr 24, 2015

### don january

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Bill was wondering whats the lightest weight that can be expected of the spyder engine

11. Apr 24, 2015

### Bill Clapp

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I responded to another thread about this....I have buillt engines at less than 200 lbs. Most that we build come out at 210-215. There is more to an installation than just the weight...Id have to look into the particulars about the installation to determine usability.

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12. May 10, 2015

### don january

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Bill do you run a muffler on your spyder engine or just straight stacks ? also what is your recommendation on safty cableing your engine to the mount ? I'am just trying to find the most popular way to go and if a muffler hurts engine performance.

13. May 10, 2015

### TFF

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You planing on throwing a prop?

14. May 10, 2015

### don january

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Prop loss is never planned, but does happen. I've personaly seen wood and metal props go by.by

15. May 11, 2015

### DaveP

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I haven't seen a Corvair cabled down, but it shouldn't be hard to do if one wanted to.

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16. May 12, 2015

### don january

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I have read the concern from William Wynne in my manual, I think under risk managment and after many years of manual sells I would like to get a rough Idea on how many builders took heed of his advice. I did install one on my KR. I myself think it's a good safty option, and Richard Finch pushed the issue of mufflers alot, and thats a nother idea I think is good if it does'nt hurt performance on the Corvair engine. Weight gain is always an issue on our plane's. I wonder if Azalea Aviation has advice regarding these topics for there Spyder engine

17. May 15, 2015

### Scarecrow56

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where are the block assembly coming from? Are they still making them?

18. May 15, 2015

### Vision_2012

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By block assembly, do you mean the case? The left and right halves that contain the cam and crank?
They come from "donor" engines from the 1.8 million made between 1960 and 1969. Check craigslist and Corvair clubs. I have second donor engine, for sale at \$200. It's missing 1 pushrod and had a bad valve, which can be replaced with new parts.

19. May 15, 2015

### Bill Clapp

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Yes, the cases we use (or blocks) come from donor engines - we use engines from 1965-1969 for our buildups for aircraft. The heads and crankshafts are also reused...most everything else is new. Our 120HP or couterweighted 100 HP can have optional new crankshafts. There are plenty of cases around...we hold on to about 40 extra engine at any given time. Most are usable in planes but some of ours are for cars as well. Our IFB is a new CNC piece...however we are looking into developing a new case for aircraft use only....

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20. May 15, 2015

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