Lurch is on hold and will not be accepting questions at this time.

Eric "Lurch" Schaapveld
Page 1: Questions 1-24, click on links or browse page.
Q1 Quadra 35 identification and breakin ? Q13 Super Tiger 75 for a Top Flite Corsair ?
Q 2 105 cc gas inline twin carb adjustments ? Q14 Saito 91 fuel delivery and tank location ?
Q3 Top Flite P-51 engine size ? Q15 Saito 100 four blade prop ?
Q4 What radial for Meister Corsair ? Q16 RCS 215 radial for Balsa USA Stearman ?
Q5 Mackay radial experience ? Q17 Gas engines for a Don Smith TU-95 Bear ?
Q6 Husky engine info and sales ? Q18 68" Cub engine size ?
Q7 Soft mounts for a G62 in a Top Flite P-47 ? Q19 Opinion on Fuji BT-64 engines ?
Q8 1.8 four cycle big enough ? Q20 Q52 rpm and prop sizes ?
Q9 Q40 enough for a 26lb warbird ? Q21 Drive shaft for rear pusher engine ?
Q10 Robart radial carburation ? Q22 G62 compression low ?
Q11 Cline pump information ? Q23 YS 63 four stroke question ?
Q12 G62 enough for a 102" P-51 ? Q24 Robart radial engine ?

Question 1: "Okay "Lurch" I'll be the first I guess! I purchased an early version Byron P-51 this past summer and while the kit was still in original boxes and never started, there is no paperwork for the supplied engine. I'm assuming it's the Quadra 35. So, I have two questions for you; 1) What would you recommend as a start up and break-in procedure? an 2) How can I find out exactly which motor I do have, for peace of mind anyway? Thanks in advance. Mark C. Thompson "

Lurch: "If it has a 2 piece case i.e. the cylinder is part of the upper crank case and it has a cup shaped bottom crank case its a 35,41,or a 42. If it has a separate cylinder i.e. the cylinder will unbolt and the crank is still in its own case then is probably a Q-50. Most of the Byron stuff was a Q-35. A Q-35 or 42 will barely fly a Byron mustang!!! a G-62 will fly it very nicely. I have seen one on a sachs 4.2 w/reduction and a 4 blade prop sounded very scale and man what vertical!!!! hope this helps and sorry it took so long to respond. For break-in use a cheap oil like lawnboy or poulon 32-1 about 1-2 gallons slightly rich at first. Then you can go to a good synthetic 40-1 or 50-1 mix. Thanks lurch

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Question 2: "Hi Lurch I need your help. I have a Clark industries 105 cc gas inline engine, I would like to know how to adjust the carbs. I can't get them right, what is the best way to do this. Thanks a lot Pat Williams"

Lurch: "The way I adjust my 200cc and Randys 240cc is I make sure the plane and or engine can not move!! use a tach and adjust one at a time adjust for peak on the front cylinder then back it off 100-200 rpm then do the back and if you don't have direct cooling to the back cylinder go an extra 50 rpm off. This should give you a safe mix. As far as idle do it basically the same just remember to redo the high end after you do the bottom. Good luck and thanks."

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Question 3: "Just ordered a Top Flite Gold Edition P-51D Mustang .61-.90. Although I am not even close to getting an engine in there, I like to have the entire process organized in my head before I start(this also helps me budget my $$!) The info in the manual says a 2 stroke .61 has enough power to fly the plane, and actually goes so far as to claim that the .61 has comparable horse power with the .90's. The tech notes tell me that a .90 will not allow the muffler to fit into the cowl. Throughout my modeling experience, getting the largest engine the plane will allow is a rule of thumb. But, this is my first warbird so I'm not sure. An OS .61 is offered w/ the combo and I want to fit it all into the cowl. What's the best engine for this plane? Also, what's schnuerle exhaust??? (this is also recommended for this plane. Does the OS .61 have schneurle?) Thanks! LIAM"

Lurch: "If you keep the weight down a .61 will fly it ok. if its a os .61fx then it is a schnurle ported engine which means it has 3 intake ports in stead of just one. If you plan on using retracts and flaps you might want to consider a .90 I have heard that the st.90 works very well. Or you could go with a .91-120 4stroke they do sound very cool ya know. Thanks and have fun. Lurch"

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Question 4: "Lurch, I am trying to decide on what engine to use in my Meister Corsair. I plan on radial power, which seems unheard of---at least no one I've been able to learn has ever built one with the radial. There are several options, of course. What do you recommend? Karl"

Lurch: "I would say Saito 450 cyl radial. I have seen them run they are very reliable and the power is just about rite. a 325 5 cylinder might be a little low on power for a 100" plane. Good luck and thanks. Lurch"

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Question 5: "Hi Eric, I was wondering if you have any experience, or know of anyone who does, with the 215 cc 5 cyl radial offered by Stuart Mackay and which he recommends for his FW-190? I purchased this combo earlier this year, and hope to begin construction within the next month...I hope! Any input on this powerplant/combo would be appreciated. Thanks, Rob Bailey"

Lurch: "I'm very sorry Rob I have not had any dealings w/that engine or have I talked to anyone who has. Lurch" Editors note: "I have seen this engine in action and you will be very happy with the power it puts out. I watched as it was run in a Balsa USA Stearman. They ran a 36" prop and it was all you could do to hold on to the plane. I think you could use a scale three blade with this engine and have plenty of power"

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Question 6: "Where can one find information about Husky engines and where to buy them? I have seen numerous references to the 240cc for several RC applications. Thanks Jay"

Lurch: "Husky engines you say. Randy runs a 240cc inline twin in his corsair unlimited oh what a sound!!! Russle Stoltz of challenge tool .1-847-640-8085 makes the best in the business. And I think he is the only one still doing them. Thanks Lurch "

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Question 7: "Lurch, I am building the Top Flight Giant P-47. It is coming along nicely (this is a nice kit!), and I am almost ready to mount the engine. I have a Zenoah G-62 and a Slimline Pitts Muffler. The Kit instructions recommend using soft mounts, which I have, but I was looking at the instructions for the Slimline muffler and it says NOT to use soft mounts, or else you void the warranty on the muffler. I know the vibration could damage the airframe over time, but which do you recommend.... Soft mounts as the kit says, or No soft mounts, as the muffler says??? Sonny Stokes"

Lurch: "I'm probably the wrong person to ask about soft mts. Since I'm a racer I hate anything that robs power!! A G-62 is a fairly smooth single and I think it would take a long time for it to do any airframe damage. Using a soft mt concentrates all of the vibration to the engine and muffler that's why they void the warranty. So my vote would be nay on the soft mts. hope this helps. Lurch "

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Question 8: "Hi, Well I'm new to big scale plane,and maybe you can help me out with the engine. I am going to build a Fairey FireyFire 80" wing span, and it should weigh in around 18 lbs, The plans call for a 1.20 to 1.8 4-stroke or 1.08 to 1.4 2-stroke. I have a mvvs .77 It said the engine puts out as much power as most .91-1.08 size engines,and it is the size of a .60 size engine. What do you think?"

Lurch: "I think you will need a bigger engine. At 18 lbs a 1.80 4c will be a just enough power. Lurch"

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Question 9: "Eric, I've been struggling for some time now trying to make a decision on my first gas engine, which will go in a warbird that "should" come up between 24 and 26 pounds. I don't want a speed demon but I want to be able to to good, large military loops from level flight. I'm bouncing around between the Quadra 40 and the Zenoah G62 (I know, big spread). Since the G45 and the G62 are the same physical size, I figured I'd go with the G62 for the extra power, but after reading more, I don't want it to be a "rocket" at half throttle. Also, I want to minimize or eliminate hacking up my radial cowl, so the Q40 is attractive in that respect. Any opinions? Will the G62 be overkill and a rocket, or will the Q40 be a whimp when I try to go vertical or pull through a complete loop? Thanks, Tom"

Lurch: "Q-40 would be kind of wimpy. If you use a single go w/the G45 min a G-62. or you could go with a 50cc or so twin like a fugi or a zdz. Lurch"

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Question 10: "Lurch, maybe you can answer this question since the people at Robart haven't responded for a week. I plan on using their radial in a 100" Corsair (F4U) and wanted to know about intake ducting. What I asked them is, is it advisable to fabricate a suitable intake system for this by either using the wing root intakes or a chin (under-cowl) intake since the carb is updraft. I asked about fuel and if it needs a pressurized tank and if the carb is jetted sufficiently to handle a more direct flow of air. I am an ASE Master Technician in the automotive field so the shop talk is ok, and I know what the consequences can be. I don't want to lose an engine or an airplane.Thanks, Karl."

Lurch: "Just talked to Bob walker of robart. He said its not a good idea to run presurized air to the carb. Also he recomends using a cline pump regulator system. Hope this helps. Thanks Lurch "

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Question 11: "Thanks for the help on the radial intake question. Now, could you explain the cline pump system you mentioned and how it works. That's a new one for me.Thanks, Karl."

Lurch: "Its bacically a regulated fuel pump system. Go to www. billsroom. com there is a link to the cline site. "

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Question 12: "i am building a 102" p-51.it started out as a bud nosen but i have made updates.is the zenoah g-62 i have going to give me scale flight? you might get this email twice,sorry about that .thanks mike"

Lurch: "I think the G-62 will fly fine it won't be a hotrod but it should fly it scale, yes"

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Question 13: "hello I have just finished building the top flight gold corsair. I have robart retracts and flaps. Will the super tiger 75 be enough to fly scale like? I really don't care to have a hot rod. Thanks Harley"

Lurch: "T ST .75 and the ST.90 are a very good choice for the tf corsair. The .75 will fly well and the .90 will give you a good reserve. Good luck Lurch "

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Question 14: "Hi Lurch, I need help! I have a Brand new Saito .91 which I plan to mount in a Pica Focke Wulf 190D. I have had plenty of 2 cycle Glow engines, and can always seem to make them sing. The Saito will be my first 4 Cycle, though and I have a few concerns:
The spray bar in the Saito's carb is low compared to that of a 2 stroke front intake type. I have had to use a narrow & tall fuel tank in this plane to deal with space limitations. The fuel level will drop almost 3 1/2 inches from a full tank to empty. The level of the spray bar is about 1/4 inch above the 1/2 full mark on the tank. I have bench run the Saito only & find fuel will drip from the carb if the throttle is much above 1/4 open with the engine NOT running and the tank full. (My test bench uses a standard square 10oz. pylon tank.) Here again the fuel level could be a maximum of about 1 inch above the spray bar when full and about 1 inch below when empty. Is this normal?
Will a standard muffler pressure tap be enough to deliver fuel when the tank gets low? ( Like landing @ lower throttle settings)
What size of fuel tubing would be recommended for this setup. Any other Ideas or suggestions would be welcome. Thanks....Ken"

Lurch: "Hi Ken its not uncommon for fuel to start a suction if the level is higher than the spraybar. You will usually not notice it in an upright carb as the fuel will just fall into the engine, maybe you fuel your plane and then let it sit only to find it flooded later on. You should be OK w/this set up on muff pressure only you can try to simulate this condition on the bench. But as you portably know everything changes in the air. You may have to start out a little rich so it will not lean out to much towards the bottom of the tank. Also you can have it in the plane on the ground then just put in a couple of ounces of fuel run it and do the nose up nose down test to get an idea of what it will do in the air. Good luck and thanks. Lurch"

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Question 15: "Hello, I am completing an AMD P-47 with a Saito 100 and I was wondering if anyone makes a 4 bladed prop that has a some want scale look. I know you can get dummy props but i want to fly with one. Thanks, Joe"

Lurch: "The only 4 blade prop i know of that works is an APC. but i dont think they look very scale. Lurch "

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Question 16: "I am building the BUSA Stearman. I would really like to put a radial in it, and it sounds like the RCS 215 might be a good choice. I have to decide if I am willing to part with the $2500 to do it. Otherwise, a more realistic choice might be something like a 3W150. What can you tell me about the characteristics of them. Such as; how easy/difficult are they to keep in adjustment. How prone to failure, etc. Thanking you in advance, Laurence W. Calkins, Sterling Il"

Lurch: "I know the 150 3W is very easy to maintain and very reliable. I have never seen or messed w/the 215 radial. Just keep in mind that the more moving parts the more potential problems." Editors note: Contact Balsa USA, they have used this radial in one of their Stearmans with great success.

Update by John Ferrara: "This in answer to L. W. Calkins request for info on the 215 in the Balsa USA Stearman. When he finishes the Stearman and has the engine mounted and running he will walk around with a smile on his face every time he takes it out. The engine is very dependable. It will always start by the third flip, the vibration is nil. the exhaust noise is very subdued. There is internal circuitry within the ignition unit that will prevent exceeding red line RPM. He must also be prepared to answer a lot of questions. You are right about power, we haven't gone much over half throttle yet and the Stearman weighs about 54 pounds. you could pas this on to Mr. Calkins for what it is worth and I am also including my E mail johnrc0000@aol.com if he wants to get ahold of me as I have quite a few construction pictures of the A/C.
John Ferrara "

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Question 17: "Hello, I am building a Don Smith Tu-95 "Bear" 202" WS 187" L. I would like to get 4 gas engines to fit in the 6.25" Dim. cowls, however all the ones I know of will stick out, ie Fuji, G-23-26, US, Robie, Do you know of any that would fit or know if anyone is working on a smaller gas engines that maybe out sometime later this year? Charlie"

Lurch: "Sorry i dont know of any thad are any shorter that are on the market. other than maybe some of the zdz or rcs stuff. Ymight try to find a weedeater feather lite plus and measure the height. they are 21cc and very lite. "

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Question 18: "lurch, i have a question for you please.i have got a piper cub j-3 done in military color with invasion stripes.this is my first warbird and only my second plane.it has a 68 inch wingspane,wing area is 651 inches,43 inch lenght,and a weight of 2300g to 2600g (do not have the conversion,sorry)engine recomended is .40 to .46 2c or .48 to .70 4c.i have been looking at the saito 56 or 72.i think both will fit but i dont want to overpower so i was leaning more to the 56.will this be enough.what is your thoughts.thank you very much for your time. david"

Lurch: "I would say go with the bigger engine as you can always throttle back but its very hard to get more power in an emergancy "

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Question 19: "Do you know anything about Fuji BT64 engines? "

Lurch: "not personaly but i have heard very good thins as for as power and ease of operation. "

Update: Merlyn Graves emailed this info; "I have two Fuji 32's that I am putting in my new Bronco. I have run them up on a test stand since I haven't installed them yet. They start easily and are very smooooth. They turn a three blade Mejzlick 18-10 prop at 6300 rpm, which is the same as a Quadra 42, so I would say that they are very strong for their size."

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Question 20: "Can you tell me what is the RPM range and prop recommendations for a Q52? Thanks. Regards, Tim Banasiak"

Lurch: "It should do a 20x10 6500-7200 I think "

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Question 21: "Hi Lurch, I am considering a model of the Dornier Do 335 "Pfeil". This is a warbird with a normal engine upfront, and a pusher in the rear. I would like to loose some weight at the end, and would like to put the rear engine more to the front. (at least 10") Do you know if this is possible with an extended drive shaft, ball bearings, etc.?
Thanks, Hans."

Lurch: "Possible yes practical no! I would just go with a smaller engine on the rear. The main reason is that the shaft and bearings will weight a bunch and the maintenance will be hell."

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Question 22: "Hello Lurch, I purchased a Zenoah G-62 on Ebay, when I turn this engine over by hand I see air bubbles coming from around the rings as the cylinder compresses. Is this normal? Also, how much compression should this engine have? I can turn it over by spinning the prop hub (no prop on it). Not to easy but not what I expected. I don't have any experience with large engines, can you help?"

Lurch: "this is normal more so if its been sitting a while. Also G-62s take a long time to seat the rings so if its low time (less than 5-6 gal of gas) I would base my opinion on how it runs more than how it feels. Hope this helps. "

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Question 23: "I have recently acquired a ys .63 4 stroke engine . I would like to here your opinion on this motor"

Lurch: "YS make a quality engine the only tip I have is make sure your fuel tank and lines are in good shape. Also they tend to Richen up in the are."

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Question 24: "Hello, Eric. I have another radial question. The last one I asked was months ago and my research since has led me to reconsider brands. I have learned some valuable information regarding how plane mod's can add weight, and how it can quickly eliminate what was the best choice at the beginning of the project. Now I am looking into the Robart offering. I can tell you what I think but I need your input. It's going in a Meister 100" Corsair. What can you tell me? Thanks, Karl."

Lurch: "I have been to Robart and seen where Bob walker builds these radials and all i can say is wow!! they are a work of art. i know they will fly a Byron AT-6 very well so a 30-40lbs f4u should not be a problem"

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