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GPU w/ 520 Jugs

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What is required to stuff 520 jugs on a GPU. It's my understanding the 220 GPU is basically an O-470 engine with a deep sump and down or side draft carb and single mag.

What about the crank, cam, rods & etc.? Do they all work with the 520 Jugs?

Is this a sensable conversion? Does it give a worthwhile power/performance increase?

Food for conversation & education. I have never messed with a 6 cyl aircraft of any kind so I am trying to get an understanding of this.

Scotty
 
you can put 520jugs on a gpu case. first you ahve to figure out if the crank has been turned if so you have to get it reharded because the military does not harden the crank when they turn it. if the crank is standard you can do the conversion pretty easy. you first have to send the case to the machine shop and get the cylinder holes bored from 0-470 to 520. change to intake system from top feed to aircraft carb. put another mag if only have one on the gpu. get a set of new headers and you are off. it is simple I have done it and the proformance change is unbelivable it goes from about 175hp to around 275 depending on the crank adv. if you have a worn out gpu this is the way to go. the difference tis the gpu clyinder sleeves are steel and the aircraft cylinders are crome and alot better quality. change from pump gas to av gas and you are on your way. the biggest thing is the crank if has not been turned you can do the conversion esaily if it has you have to get it rehardened.
 
Can cutting the case out simply be done with a fly cutter on a heavy drill press or 6" laythe or does it require a milling machine?

Is the rehardening done with a flame or heat hardening process or a chemical hardening?

Sounds reasonable to me. Ragged out GPUs seem to be readily available everywhere.

Scotty
 
i've seen them do it with only one mag just have to put a plug in extra spark plug hole.doesn't change performanc much.
 
scotty


yes it can make a gpu come to life. the total cost for me was 2150 and you have a motor that is just below and if set up right will out run the 540's


I would reccomend you have the case done with a milling machine to get a more precise cut out.

the hardening process I don't know I sent mine to tx. but I can find out for you.
 
really all the extra spark plug is going to do is smooth out the idle.

I would recommend going with the dual mag because of the pistons.
 
Mountain man, yes, I'd like to know what process is used for the rehardening. If it is chemical it can be done in a big pot of Amonia on a fish cooker. Outdoors of course :)

I assume this same conversion can be done with the 4 cylinder GPU as well with a similar increase in performance.

Scotty
 
It would be a lot easier and cheaper to just put 470 angle valve cyls and pistions they run very strong .
 
Sorry folks, my focus here is on a 4 cylinder GPU , I think thats a PE-90 maybe?

Looking for close to 200 HP maybe.

Not ruling out a PE-150 nust not my primary focus.

Scotty
 
I'd think a 90 gpu with GTSIO 520 jugs would be an awesome little motor.

It could even be reducted with a rotator box, and with the right wide slow blades. It might run like a direct drive 260 horse 540 on the right hull.

It would cost some $$$$, but might pay back over a reasonably short time time at the fuel pump. Depending on how often you run it. Plus with the box, you don't have the thrust loading on the crank anymore.

I heard a rumor that they may come out with a Rotator "light" version for aircooled engines that will weigh less than the standard box. Don't know if that will actually happen though.

I like the 90gpu's. If I was gonna get one, I know who I'd be talking to about it, and it ain't me.

I'm not an expert on it.
 
Whos is the expert Cowboy? Im asking all this stuff out of ignorance not stupidity. I'm not an aircraft mech but I have built tons of DYD 11000 Allis Diesels. Built a few automotive engines for trucks and several Buick engines for airboats. Several VW engines too.

Are the cylinders press in fit or drop in fit after the block is machined?

I'm likeing the numbers I'm seeing pricewise. Still researching.

Scotty
 
J.C. Stanley is big into the gpu's.
Theres another guy in Lauderdale, or perhaps thats his name who does allot of GTSIO conversions. RDM20470 knows his name.

I bet Larry knows, or perhaps has a more informed opinion about a hot rod 90 w 520 jugs.

The folks who built this motor sure would know. They told me they were working on a four banger for somebody.

100_0780a.jpg


It's a GTSIO gpu, and it is flat bad to the bone.

Here's another bad gpu. Not GTSIO, but it's a hot rod gpu.



JC1.JPG


I think a four banger set up like these would kick!

I believe that the jugs should bolt up after the case is bored out to accept the larger cylinder sleeve.

Your original post said you thought it was the same as an o-470. Perhaps it is, but I believe that the GPU is prone to wear from thrust loading the crank. It is an industrial engine, so It never was intended to get the crank shoved on that hard.

They deal with it, but not as well as an A/C engine. I'm not slamming the GPU. Heck we've got one out in the yard right now.
 
Jim Lauderdale in Bushnell FL 352 569 1066
Don Davis in Homestead FL unknown phone #
Mike Thurman in Ft Lauderdale FL 954 600 5181

Jim Lauderdale and Don Davis are both great Continental and GPU engine builders. They both get great HP out of their motors, both 4 and 6 cylinders. Mike Thurman might work on Continental and GPU but I do not know, I know he is the go to guy for Lycoming.
 
you have to have the case bored on the 150-gpu, to put 0-520's on it. This will make about 200 Horsepower. It will make a strong motor!
 
Yeh, in my original post I mentioned the 220 cause I wasn't sure, I already had heard the PE-90 was mostly o-320 parts.

This looks more doable every day. Theres an all STD PE-90 on trader and theres jugs for sale here on the forum. If they are the "right" jugs and the GPU is all STD as advertised, and if prices are a bit negotiable it could happen. Might sit in my shop for 6 months til I get back but would solve one issue ahead of time.

Now to find a FI system for it like in Cowboys top pic above. Gotta find it all at once or it all falls apart.

Scotty
 
if you need the parts to build this motor i can help you, i have all the parts and the people to hook you up with to do all the machine work, i have done this once or twice, there are some secrets to do this the right way and you need to no these things right off the bat, you can call me or email me anytime whitebear,you helped me in a way so i can return the act of kindness to you and make sure you dont get taken advantage of, not that anyone will do that but sometimes you never know, its your money so you can pick out who you want to do this, lauderdale and davis and thurman are good builders thats for sure, but its your decision to go with who you fell comfortable with, thanks
 
Thanks Westside. I'll be doing the build up myself btu will send parts out for machining as necessary. Any recomendations are more than welcome. I won't learn it without doing it, if I screw up its on me.

Ill email ya this coming week and well exchange ideas.

Thanks so much

Scotty
 
I know this will sound strange to some, but I got Southern 520's jugs! And nice ones they are :)

So now to find the RIGHT deal on an all STD GPU.

Onward n Upward.

Scotty
 
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