Z P-38 wood or glass
 

I just ordered a set of Ziroli P-38 plans. Should I look into building from wood or buy the glass parts? Which one is lighter? What engines would be best?

Thanks, MEMPHISBELLE

RE: Z P-38 wood or glass
 

I don't know which would be lighter, but i can tell you that my Z P-38 weighs 40 lbs, and is all balsa except for the cowls and nosebowl. It has a pair of Brisson 3.2s which is more than adequate power, and they are completely enclosed within the cowls.

RE: Z P-38 wood or glass
 

Here are some pics of my friends Ziroli P-38

He bought it used/unflown already built. He loves the way it flys.

RE: Z P-38 wood or glass
 

Thanks for the reply. Do you know if it had fowler type flaps or just split flaps.

Thanks , MEMPHISBELLE

RE: Z P-38 wood or glass
 

Precision cut kit provide a wood kit and a kit with fuselage and boom's in glass. If you want to use glow engines, saito as the "220 Zeus" and it fit the cowl, the saito turm a 20x10, and this schould be enough for the P-38.

Gilles

RE: Z P-38 wood or glass
 

Hey,
I have built 2 P-38's. and wood framing, balsa sheeting and .6 oz. cloth are lighter than fibreglass, although you have to resist the urge to buid a "boat" and keep the resin 50/50 with glass (by weight) ..
by the way, what engines did your friend use?
I am now buiding off of Ziroli plans this time.
DBK

RE: Z P-38 wood or glass
 

here is a few pics of my z p-38. mine was built with the glass booms available from ziroli.
building a p38 is a big project, it's like building 2 models at the same time and the glass booms save some building time.
mine is powered by zenoah g-45's and weighs about 40#

mike

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RE: Z P-38 wood or glass
 

To Mr SJN, and anyone who can help!
What type engines did your friend put in his Ziroli P-38?
I am researching engines for best reliability and performance, (and fit in cowl).
I have G-62's , but they need too much trimming!
thanks,
:)Dabigkahuna

RE: Z P-38 wood or glass
 

If I had to do it all over again, I would go with the glass booms. They are not fun to build, a huge time savings by using glass and much stronger. Mike, nice job with the detailing, she looks fantastic.

RE: Z P-38 wood or glass
 

Dear Capt. Hook,
what engines did you use in your P-38?
I'm thinkin of selling my g-62's and using your suggestion of glass booms.
I've already done the long way with wood sheeting & glass!!
Are the booms poly or epoxy resin?
thanks for any help
DB Kahuna :)

RE: Z P-38 wood or glass
 

Dear Mr. SJN,
Could you please identify propellers and engines on your friend's P-38J?! (prior post)
I am in need of good engines and props!!
Thank you very much
DBK:)

RE: Z P-38 wood or glass
 

I know the guy that has the P-38 SJN posted pics of. It´s powered by DA-50´s with MenzS 20x12 3-blade props. The mufflers are homemade by the owner.
It flies very well with these engines, although the props are too big, so they lug the engines down quite a bit when doing vertical manouvers. I think he said that they did about 5500rpm on the ground.

RE: Z P-38 wood or glass
 

Thank You,
Mr. Nielsen!
You have helped emmensly!!
Wishing you much Aloha.
DBKahuna :)

RE: Z P-38 wood or glass
 

Hey fellas,
I noticed that on Ziroli plans the r/hand engine is 2 degrees outboard.
Is this necessary? All other twins I've worked on were 0 degrees.
thanks,
DB Kahuna :)

RE: Z P-38 wood or glass
 

outboard thrust on twins are supposed to help reduce the effects of an engine out situation. it is common to have out thrust on both engines. the z-p38 has this on only on one side. i am going to guess this has something to do with torque effects of the engines.

because of engine torque i have noticed my z p-38 turns better one direction than the other when doing a normal aileron turn. in one of the directions you have to do a pylon type turn to get it around. with my p-38 i have learned to turn with rudder only crossing the ailerons the other direction to prevent the the plane from rolling too far. the turns look much better and it turns tighter with this technque.

mike

RE: Z P-38 wood or glass
 

Thanksfor the reply Mike,
This is a lot of airplane(s) to deal with. The Lazer lizard cut my kit for me (Texas) did a great job.
I spoke some years ago (while building Art Johnson's 95" p-38L) with Clarence Lee (k&b & engine expert) who actually has logged a bit of time in the type A/C! He said that the sink rate is noticeable on turns. And the engines tend to cancel each other. But with an engine flame-out!! whoa baby..
I'm not going change the design on Zp38 , it's proven. But it's good to know about the cross-controlling, this will help. I am going to go with fibreglass booms. the last time it took me 3 weeks just to frame up & sheet the booms!
May I ask what size and pitch props you are running with the g 45's? and anything to pay attention while building? Any quirks or tricks?
Any help is greatly appreciated.
Cheers, Kala DBK :)

RE: Z P-38 wood or glass
 

the props i am using are bolly 20x10 3 blade. they originally tached around 6500 rpm. i cut a 1/2 inch off the tips to get the engine to tach at 7000 rpm which is the sweet spot of this engines power band.

my first flights started with some serious problems with the engines. they ran great on the ground and the take off climb out was normal, but once leveled off and it picked speed up the engines would go rich. one engine was worse than the other. my engines were of the new carb adapter style which the block turns the carb to allow a straight shot of the throttle linkage. this puts the fuel metering diaphram facing the front of the airplane. this caused the air pressure of forward flight to act on the diaphram causing the carb to flood the engine with fuel. i tried soldering the hole and drilling a new one on the other side of the cover closer to the engine, but this made things worse and the right side engine went so rich that it eventually died in flight. this was a very scary situation that i would not care to ever go through again. a p-38 is a nightmare on one engine. the best way to react to this situation is to cut the power and get it down into a clear area promptly.

i solved this problem by soldering a nipple onto the diaphram cover and running a gas fuel line to a brass tube glued into the firewall.
this supplies calm stable air from inside the booms to regulate the air pressure on the diaphram. since this modification was performed the engines have been running very stable with no problems.

one ritual i perform every time i dissasemble and assemble the plane at the flying field is to count the turns of the hand crank fuel pump when i empty and fill the fuel tanks trying to catch any problem before they cause an engine out situation.

when building, one thing i did different from the plans was to put the bolts that hold the booms to the wing from the bottom of the booms with the blind nuts in the wing. this allows the fiberglass cover on top of the wing to be glued permanently onto the wing resulting in a pleasant clean finish.

mike

RE: Z P-38 wood or glass
 

Hey Mike,
Thanks for the response.
You have shed light on a number of important points.
I am moving ahead at a slow rate, but moving ahead..
I'ts been sometime since I've built, kids, etc.
My last project is at www.burbanksign.com /catalogue/glacier girl.
I would like to share something in return.!
Thanks again for the info and photos, your bird looks great!
Kala :)