So far, I've flown two GP-38 powered aircraft and I can say for a fact that the power is absolutely insane. Easy starts, smooth power transitions, and an impressive presence at the airfield. This will be a great engine for not only 3D aircraft, but also warbirds and other sport aircraft.

This engine is a fantastic match for Extreme Flight's new 78" Extra 300 V3, the Pilot 73" laser, AJ Aircraft 73" laser 200, and many, many more aircraft.

Reserved for future info/ posts

1: I tried out a Xoar 20x10 and its definitely not the ideal pop for this engine. it will swing it, but its really not hitting its true top end and ended up having less performance than a 20x8 or 20x9. That being said, I would suggest to anyone interested in the 38 to stick with a Xoar or Falcon 20x8 or 20x9 prop.

2: When production began the 38‘s were shipped with a Pitts style muffler. Since then however there have been multiple people that I’ve had the Pitts style mufflers break right at the base of the stacks. They can be welded back together however it can be very difficult. Because of this all GP 38‘s are now being shipped with traditional side dump mufflers which are much stronger and produce a little bit more power.

If you would like to continue to use the Pitts style mufflers that came with the earlier engines, I suggest cutting off the stacks near the base and replacing them with a nylon or silicon stack with a hose clamp similar to the DLE mufflers to reduce vibration and weight hanging below the engine.

Originally Posted by cale10

So far, I've flown two GP-38 powered aircraft and I can say for a fact that the power is absolutely insane. Easy starts, smooth power transitions, and an impressive presence at the airfield. This will be a great engine for not only 3D aircraft, but also warbirds and other sport aircraft.

This engine is a fantastic match for Extreme Flight's new 78" Extra 300 V3, the Pilot 73" laser, AJ Aircraft 73" laser 200, and may, many more aircraft.

I will back up everything you're saying. I put one on pre-order with Aviator Plus and it was sent out quickly when the first shipment came in.

I had a DLE35 in an Extreme Flight 74" Laser and it was fine but not impressive power. I swapped in the GP38- have 30 flights on it now and power is clearly much better - ear to ear grin good power. Very happy. Now that plane is a real "hot rod". Compared to the other 35cc singles I've personally seen the GP is clearly stronger. Other flyers ask me what I "have in there" after seeing it go.

Starts easily. After the first flight I don't even choke it- I just flip it and it usually starts on the first flip. Workmanship is top notch, muffler works great.

I only have a couple of negatives.
1) with all of that power it puts out, I am seeing vibration-related wear in places where I didn't with the DLE. The tabs on the front of the hatch were wearing so I redesigned with dowels/brass sleeves and it's fine. Also, I've broken off the mounting tabs on two throttle servos... so I had to re-engineer my mounting a bit. But I would not go back- any vibration related issues are worth the performance and just need to be monitored.

2) The prop mounting bolts are NOT the same as a DLE35. They are off just a bit. I wish that this was standard across all similar sized engines. Here's a picture with the backplate drilled for the DLE35 on the hub of the GP38.


Also- Prior to the laser I had the DLE35 in an Extreme Flight 78" Extra. My opinion was that this plane didn't have a "perfect" gas engine. The available 35cc engines didn't give quite enough power and the 50cc engines are (in my opinion) too much/too heavy... I agree with you- I think this GP38 is the perfect match for that plane.

I have that plane with a DLE35RA as well, and couldn't agree more for it being the perfect candidate for a power upgrade with the GP38.

Maybe the engine has a different harmonic vibration, maybe the two resonated the components differently to create the perfect storm. Not sure - just a thought.

I should have ordered one yesterday, I see they are out of stock already.

Looks like a great engine. GP seems to be making great products based on the testimonials I’ve read. They really need to produce their own line of headers though.....or specify which brands to use with each of their engines.

Originally Posted by Motomazzo

Looks like a great engine. GP seems to be making great products based on the testimonials I’ve read. They really need to produce their own line of headers though.....or specify which brands to use with each of their engines.

+1

I just got mine today What prop have you found to be best ? Putting it in a pilot laser 73" also .

Originally Posted by bbezayiff

I just got mine today What prop have you found to be best ? Putting it in a pilot laser 73" also .

Currently im borrowing a Falcon carbon 20x8 to run on mine, but Orel recommends a Falcon carbon 20x9. However I have a Falcon woodie 20x10 on the way and I imagine it will perform just as well as the 20x9. Ive seen DLE and VV 40's with the Falcon 21x8 prop and I'm tempted to give that a try eventually, but as far as I know no one else has tried that one yet.

What is the street price for this engine?

Extreme Flight 78 "Extra V2 was EME35 20x8 7400 rpm, didn't like how it flew. Replaced it with DA50 22x10, the model flew perfectly.

EF Extra300 78”/DA50/22*10 (6 min 51 sec)

$430.00 https://www.aviatorplusrc.com/product/gp-38cc/

i have a xoar 20x8 im going to try before i buy anything else. I fly at 4500ft so that makes prop sizing a little more difficult. I just cant seem to get the performance everyone else is getting . Thanks for the input . let me know what works for you please

Any more feedback on these?

Tony