 Bill Clapp and I working on Goliath's engine just before the first start. Note the size of the prop. This was the original prop, a 54x66 as I recall. We could not get it above 2,000 RPM. Goliath is running an Aerocarb, which was actually fairly easy to adjust once I got the hang of it. I asked Bill to come out and help me with my engine. The original engine was built by William Wynne and Corvair Authority. The WW engine had unfortunately been assembled using the wrong size bearings for the crank. The result, sadly, was an engine that completely destroyed itself in 43 minutes of running. So, back to the drawing board! In a conversation on the phone, WW suggested I send the motor back to him and he would be happy to replace it. This was an excellent offer, but at the point I was at in final construction, it made sense to me to have an engine I understood and could work on myself should something go wrong down the road. At WW's suggestion I had Bill Clapp come out to look at what I had and help me build a new engine. WW sent me another crank. On disassembly Bill and I found the crank had "10-10" in marker on one end. It was actually ground 10-20 based on the damage marks. The consequence of using the wrong bearings was predictable. The crank, cam, and case were completely destroyed. LEARNING POINT No matter what your crank is stamped, plasti-gauge it so you know for sure what tolerances you are working with. The potential result if you do not do this step is a great looking plane with a great looking display-only motor. Bill and I found an engine core in a guy's backyard in Fallon, NV. It was missing three jugs, full of dirt and sand, and was home to all manner of bugs and mice. Thirty-two hours later we had a superb running engine, using parts from the original and the "new" core. Actually, Bill built it, I just helped and learned as much as I could absorb. Thanx Bill! LEARNING POINT / OPINION The original engine purchase was based on my then-limited engine experience. I wanted a Corvair motor for quite a few reasons. I bought an engine from the only place I could get one pre-built at the time. This has since changed with the arrival of AeroMax www.aeromaxaviation.com. This is a great thing for any new builder or pilot who is looking at the Corvair motor. Competition is what makes our country run. It means builders have options, which increases the overall quality of products, types of products offered, and reduces their ultimate cost. Proof of this is the new 5th bearing Aeromax has developed along with competing designs by other highly skilled experimenters. Ultimately, the best design(s) will be validated and move forward as builders chose what is working best and who provides the best service. It is my view if one does buy an engine he should make sure he understands enough about it to work on it himself once it arrives and is installed. This is the classic get a fish or learn to fish concept. Bill was the part of the equation I did not have in my original plan, and his willingness to teach me on site made all the difference in my own experience. Bill is now at Aeromax. New builders have several different suppliers/builders/options to choose from. CHOOSE WISELY. Talk to different people and get a feel for a vendor's quality, service, responsiveness, and most importantly availability to field your questions/problems when you call with a major helmet fire and need help yesterday. Throughout the photos below you will see various parts from WW on my engine. They work just as they have from the beginning. Down the road a year or two I plan to have my engine upgraded with the Aeromax 5th bearing. For now the current configuration is working well.  The Aerocarb (not visible) is in an updraft configuration right behind the lower part of the engine block. Fuel is pulled from the wing tanks via a mechanical fuel pump and Holley pressure reducer/regulator. Goliath does not have electrical fuel pumps because far more things can go wrong with an electrical system or electrical pumps than can go wrong with the mechanical pump. We have flown in 110+ degree weather and have not experienced vapor lock, so I think the decision was a good one.  The dual coils and ignition selector cap can be seen in this shot, along with the John Deere generator and voltage regulator (behind the firewall). This photo was taken early on, well before the 40 hours were worked off. Note the battery and other items are mostly on the right side of the plane. A few things have changed. Specifically: - There is no longer a primer line (red plastic line in the foreground) because it is a total waste of time. The engine starts in a few seconds on the ground, and the two times I have had to relight it airborne it has come to life as soon as I set the mixture and cleared the problem. I recommend you save the expense, effort, and weight for something not really needed. - The exhaust in this photo is straight down. It is now angled back toward the firewall to reduce drag. - An NO2 sensor has been added to the left exhaust stack, ala Mark Langford's set-up http://home.hiwaay.net/~langford/corvair/o2meter/ . Goliath prefers to fly with two green lights on the indicator illuminated. In Mark Langford's aircraft this would be a rich condition. Should you use the same indicator as he and I, make sure you take off rich the first few times and sort out what indication works on your set-up while the engine is under less load. If you blindly follow the readout on the gauge you are likely headed for detonation problems. 9/09 Update: I have since removed the NO2 sensor from my engine. It was an interesting experiment, but in the long run did not prove to be worth the weight and extra "thingy to look at" in the cockpit. - A heat shroud has been added to the left stack. This is a simple wrap around affair. It is not even sealed all the way around so plenty of air is able to enter it. I did not find the need to put a spring or other heat transmitting surfaces inside the shroud. I can tell you it keeps me plenty warm, as the air enters the cockpit between my feet and blasts up past my legs to my chest. Warm toes make for good flying (one of the universal concepts every military aircraft I ever flew failed to take into account).  A better shot of the rear of the engine showing the fuel pump and the top of the oil adapter. I chose to use the stock oil adapter, which forced me to push the engine mount forward 15/16". I am satisfied with how it all works out, though it took a bit of practice to figure out how to remove the oil filter without spilling the oil inside it! All the fuel lines have fire sleeve around them. Both oil and fuel lines are covered in braided stainless steel. One other note this photo brings up. Zip ties are no longer allowed on certificated aircraft engine compartments. This ruling does not affect EXPERIMENTAL aircraft. You have a choice to make before the FAA inspector or DAR shows up to look at your aircraft. You can either tie everything in the engine bay, or you can choose to remind the inspector your aircraft is experimental and does not fall under the ban. My inspector did not care. Your mileage may vary. Get a scouting report if available on your DAR. Make sure you use fuel hose for the rubber connections on your intake! If you use radiator hose eventually it is going to dissolve if you use MOGAS! Long before you detect the degradation it will be leaving contamination in the cylinder heads. While I am not sure what that this will ultimately do, I do not want to find out. At the parts store, ask for fuel tank filler hose.  The right side of the engine is where the Holey fuel pressure regulator went. Originally we had it shielded from the heat of the exhaust, but the shield has since been removed (no need). This photo also shows the blocks we used to extend the engine forward. These are solid aluminum. They add no additional strain on the firewall and actually disperse the load over a greater area of the wood than the original mount. Just behind the rocker cover bottom is the pressure sender for the fuel pressure gauge. I have this set up to see the pressure coming from the fuel pump vice the regulator. My thinking on this is if the fuel pump starts failing, it will be a long time before it is detected on a gauge if that gauge is reading 2 PSI after the regulator. Fuel pressure from the pump is normally 5 - 5.5 PSI. I did experiment with Super Trap tips to reduce the sound coming from the engine. William Wynne used to recommend these. I do not know if he does now. They were better than nothing, but are heavy in my opinion. I found a great way to reduce the sound is to drill holes in the end of the exhaust pipes and sandwich down the end of the pipe itself to about half size. This is known as piccolo effect, and it works great! This is a really cheap way to reduce sound, and it is reversible if you decide a louder cockpit is what you want (or if you need more performance in the summer months).  Now that I have given the pitch on this carb, make up your own mind as to what will work best for your installation! Do not take my word for it! Go out and see what others are using. I suspect many will also swear by their set-up. This is good as it gives you lots of choices and the experience of others to tap into before you commit to your own choice. As General George S. Patton Jr. said, "No one is thinking if everyone is thinking alike." One other thing to note here is the location of the cabin heat airbox. It goes straight through the firewall, right to the feet. A good place to have warm air on cold winter flights. CHANGE RECOMMENDATION. The lines coming from the rocker cover go to the oil breather. The top line is outgoing, the lower line is the return. Down the road I will put the return line higher up on a new cover. That way, when it is time to take it off no oil has had a chance to pool in the hose from the bottom of the rocker cover (messy). |
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