gasoline

I had some clearance problem with the plug cable on the cowling when iwas about to install it.My question is is there going to be problem when i install the engine inverted (carb facing downwards and exhaust facing upwards?) I willhave to custom make a header pipe in a "L" shape and exit throught the bottom of the cowl,will having a straight flow exhaust without any canister give me any problem running the engine beside the noise which is going to be very loud.I am going to mount it on a 30% extra.I just don't want to buy another engine since all the work to install this engine is done on the firewall.Please any engine guru,please give me a piece of advise on this matter.[]

tkg

My Feedback: (1)

If you mount engine upright, how much smaller does the spark plug need to be to fit.???
With an NGK spark plug you can turn the metal top over and cut in half. Also the spark plug rubber cap only helps to hold on the wire. It makes no RF protection, so you can cut the top the the rubber boot down some. Do both and you can gain about 5mm more room

Antique

My Feedback: (4)

We run the enignes both ways in our F1 race planes, makes no difference at all in performance...

gasoline

I may need another 1/4 inch of space,you see the problem in my country is you can't really get access to thing in U.S. Basically if you fly something big , stuff have to be imported and it takes time.For spark plug,we just buy it from shop that sells grass cutting machine, so we would really consider ourselves lucky just to find a plug with a "R" (resistor type).Anway I did forgot to mention , evendo if I am able to mount upright I will face problem with the throttle linkage. I have read somewhere once , somebody mention always find a plane first and decide on the motor later. In my situation,this saying is very true.So I hope to all the engine guru please understand the situation I am in for sourcing parts.Basically if there is no problem mounting the motor inverted with a straight flow exhaust I think my problem is solve.Please give some advise on this.Will really appreciate it.

gasoline

Thank you for the reply Rcign1,it was such a relieve to hear that , can you tell me the diameter of pipe you use? Currently I have decided to use the same diameter as the original exhaust which is 20mm.Can you advise me on this.

Antique

My Feedback: (4)

We run open pipes up to 8 inches long on some, the diameter is eother 3/4 or 7/8...20 mm should be Ok...

gasoline

Thank you for the info, I don't know whether I am asking the right question, you run open pipes in pylon racing where you take off and full throttle till the end of the race(correct me if I am wrong) where as my application is more to aerobatics flying which uses from low to high throttle quite often. I don't really know will this give me any problem.By the way why you all run open pipes in pylon racing?does it give more power or its a rules and regulation?

Antique

My Feedback: (4)

The rules prohibit tuned pipes, so the next best thing is open pipes...Chenging the rpm for aerobatics is not a problem with open pipes...We run around 9000 rpm in the air in the stock class and 11,500 rpm in the methanol class...
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korky

C& H ignitions sells an adapter so that you can use a small plug such as used in 3W and deserat aircraft engines. I think the cost is $7.50 each they also have the small plugs at $4.95 each.
Korky

gasoline

Thank for the info,anyhow I did manage to solve the problem by inverting the motor and custom build a pair of open pipe.As I mention earlier its quite difficult to source for parts you mention in my country.I know the exhaust is going to be loud but we do not have any noise restriction over here.I will try and post some pictures when the thing is done.