iflyg450

Its a toss up between this GP-18 and the Magnume 15xls. I know the Mag 15 is well respected for being a nice powerfull engine, I have never owned one. I have had many thunder tiger engines and I love em all. So whats the deal with the GP-18 like to know what some one thinks of the GP-18. The plane is my VERY LIGHTSure Shark XV.

controlliner

The GP 18 is a real nice engine, I love the design.[8D] It would work in the sureshark, but the Magnum XLS 15 is ball bearing and it would perform better.

skaliwag

My Feedback: (1)

It is a very nice piece.. User friendly. Likes low nitro. Light.

Not a screamer but turns an APC 9.5 X 4.5 @ 12,600 on 12.5% nitro 23 Castor

That's 1000 rpm more than Chevy43's PAW 19 diesel does.

Tach #'s added.

ffkiwi

Any good reason why it turns an APC 9.5x4.5 faster than a 9x4?

'ffkiwi'

skaliwag

My Feedback: (1)

The  9X 4 is really chunky.   other than that ....????

skaliwag

My Feedback: (1)

A customer was going to put it on a Lil Exrta, but he went to the other side.

iflyg450

I went with the Mag 15. I didn't like the idea of special glow plug needed for the TT-18. 

skaliwag

My Feedback: (1)

The TT 18 uses a regular plug.

aphexian

Ilove thunder tiger engines, but my GP-18 impressed me so much after some break-in runs that Iput it back in its box and forgot I owned one until this thread. Anyone got a OS15FPto trade for it?=)

In all seriousness, its not all that bad, I'd just rather use a lighter/smaller engine in its place. After reading this thread, I might get it back out and try some bigger props just to see what happens. Idon't think I propped it with much more than an 8x4 initially.

-Mitchell

Mr Cox

I'm pretty sure an old Veco 19 would match those numbers too...

What is the "green" thing they mention in the marketing of the TT?

microsprint9

I think that relates to the low parts count on these engines and no bolts are used, everything screws together, ie: the backplate screws in, the head screws on and the carb is also part of the crankcase, i guess they call this "green" becuase less parts will more than likely take less time to make, so less time means less electricity to run machines, no bolts means no shipping to get bolts on site ( no fuel used). That's my take on it.

controlliner

Bingo!

rainedave

My Feedback: (1)

Yes, it all adds up. It's interesting to know that burgers have one of the largest carbon footprints of anything we consume (I love burgers, BTW).

This is worth reading:

http://openthefuture.com/cheeseburger_CF.html

David

controlliner

MMMMMMM......Burgers................burgers......c arbon...? blech[:'(]

rainedave

My Feedback: (1)

To be honest, I like my burgers rare or almost raw in the middle and burt on the outside. Carbon and blood just seem to go together with certain foods.

David

coopster88

My Feedback: (45)

Do you know the Crankshaft thread size on the GP-18?

skaliwag

My Feedback: (1)

An educated guess would be M6 X .8 pitch.
What plans do you have for this engine? Don't expect it to be a screamer... It's a slugger. See post #3 for my numbers.

Mr Cox

I don't have this engine myself but just a comment on the threads size, the M6 is usually 1mm in pitch (the magnum XLS has M5 x 0.8)

I have a 30 year old Veco that turns a 9x4 at 12500 rpm, and it weights about 7.4 oz including the muffler (IRC, will have to check my notes). Now that's a "green" engine as it last for ever...

skaliwag

My Feedback: (1)

The M5 is too loose but the .8 sits in the thread. A M6 X 1.0 starts but only catches.

Mr Cox

Okay, you're probably right, and I'm sorry if I'm causing more confusion here, but...

M6 x .75 is a regular occurring fine thread rather than 0.8 (there is also an M6 x .5, while the regular one is M6x1)

jeffie8696

All my GP engines are awesome, havent tried any of the new Green ones. If you dont like yours Iwill trade you "something" for it.

tweedy

My Feedback: (1)

I bought 3 of them when they first came out have not run them yet I'd like to find a good twin project.

Jeffie your profile pic. looks like you might have paid a visit to Fort Benning GA. I spent 2.5yrs in the 82nd B Co. 1st 325th Infantry

Airborne!

andybenton

i have an early 90s magnum gp  not sure it applies in this forum but its a .25

ive got it proped with a 9x6 but i dont have access to a tach, does that sound about right?

sory to high jack the thread but i figured with talk of green engines and cheese burgers it couldnt hurt XD

my wife is a manager at mcdonalds, and she wants to be "green" im sure she would probably quite her job if she ever saw that page on burgers haha

buzzard bait

A 9x6 is a good prop for a lot of 25s, but it can be a little too much load for others. I think my OS 25 FP runs better on a 9x4, but my TT Pro gets a 9x6. You just have to try, and the combination with the plane makes a difference too. Of course, there are other prop choices too.

Jim

jeffie8696

Yep, Ft Benning. Made it the first week of airborne then blew out my knee. Then stationed there for a year.

And in the infinite wisdom of the US Army they transferred me to a strait leg (light infantry, yea right) unit .

GP 25, yea I would test as many different props as you can before deciding. Not all props are created equal so an APC 9X6 will not act like a Master Airscrew 9X6 etc etc. Might look into the new Sig props, they are kinda cool.