I have an O470L and the compressions are in the tank. Several options are out there. Could get new Titons or OH my cylindars. Has anybody OH the top and put in IO470 pistons from lets say a Bonanza (250HP). A bit higher compression. The idea has come and gone several times in the last several years.

The stock propeller would work just fine but what about the carb

I would have ponked it but I spent that money on a boat.

Tim

Over the years I've had several good mechanics tell me that if all of the cylinders need overhauling, then probably the whole engine needs overhauling. Since I'm not a mechanic, take that for what it's worth.

Cary

qmdv wrote:I have an O470L and the compressions are in the tank. Several options are out there. Could get new Titons or OH my cylindars. Has anybody OH the top and put in IO470 pistons from lets say a Bonanza (250HP). A bit higher compression. The idea has come and gone several times in the last several years.

The stock propeller would work just fine but what about the carb

I would have ponked it but I spent that money on a boat.

Tim

You need to check into the Norland STC which is pretty reasonable. It will give you 260hp like the Cessna 205's, early 210's and 310's. If memory serves me correctly, it may state that you begin with an IO-470 and remove the fuel-injection. Essentially you would end up with your carbureted engine with high-compression cylinders, continued time if you don't want to overhaul. Cheap way to get more power. Your I-80 climb outs would be macho indeed.

,
'Round here 470s with cylinder trouble are sorta normal. How many hours on the engine?

800 on the engine. Guy before me flew it not to much and most likely did not lean it enough.

Tim

Tim
I recently talked to the guy at norland and asked about high compresion pistons in a o470s. He said that the crank shaft is different in the io engine to acomidate the high compresion pistons. I am somewhat in the same boat as you. The o470j I have we did a top on it, it has chrom cylinders and
my break in did not work and it uses oil. My optoins are to redue the top again or go to a o470R, or somthing like that. My thought is if I go that route it's only anothier $2100.00 for the norland stc giving a guy 260hp. So if anyone out thier has a i0470-d,e,f,h,m,n,s core that they would part with I would be intersted in it.
46tcrft

You might look around and see if anyone has the STC to put 520 cyls on your 470, same compression, just more cubes.?
Anyone out there have a field approval?
Good Luck GT

M6RV6 wrote:You might look around and see if anyone has the STC to put 520 cyls on your 470, same compression, just more cubes.?
Anyone out there have a field approval?
Good Luck GT

you gotta machine the case to accept the 520 cyls

He was talking about looking for a core and thought if it was going to go that far, he might want to consider, was all?
It is a nice easy way to get some horsepower without much more stress on the crank and case.
GT

Buy a maul
Hi compression, more stress, no more mogas. Low compression(not as low as what you got, maybe a used Pponk,or other O-520???)might pay for itself if you work it right.

shortfielder wrote:Buy a maul
Hi compression, more stress, no more mogas. Low compression(not as low as what you got, maybe a used Pponk,or other O-520???)might pay for itself if you work it right.

You mean a "Mall"?

46TCRFT wrote:...The o470j I have we did a top on it, it has chrom cylinders and my break in did not work and it uses oil.....

Chrome cylinders are notoriously hard to break in, you might have to pull them back off,re-hone, & try again. Run it hard. I have also heard that the 470-A & -J's go through a lot of oil unless you put 4 ring pistons (one more than original) in them.

hotrod150 wrote:

46TCRFT wrote:...The o470j I have we did a top on it, it has chrom cylinders and my break in did not work and it uses oil.....

Chrome cylinders are notoriously hard to break in, you might have to pull them back off,re-hone, & try again. Run it hard. I have also heard that the 470-A & -J's go through a lot of oil unless you put 4 ring pistons (one more than original) in them.

What I was told about the chrome cylinders was that after replacing them with new or re-honed, I should break them in hard just as you mentioned, Hotrod. I was told to take off from Caldwell and fly full power to Portland (or someplace over 2.5 hours). Have lunch. Then full power back to Boise. Should be about good.

Any opinions about running some chrome and not chrome cylinders (mixed) on the 470?

Pat
Your best opinions in breakins would probly come from the best engine shops. Give 'em a call. Pponk/Lycon/Westernskyways etc. I think Rob (OrygunMall)wrote up a pretty good report on his breakin.
gary

Shortfielder, why would you use such language?
Hotrod you are correct, rehone and new set of rings.
I'm still fighting the two stud exhaust flange leaks.
I don,t have a desire to use auto fuel and was lead to believe
that the higher compresion engine does a better job of burning the
lead in the fuel, thus less valve sticking. And someday if the planets
aline properly I would like to come out west and fly the back country
with some of you. Then I could call myself a back country pilot and buy
a t-shirt from Zane!

I am building up the 0470 - K for my Stinson. It was going to cost me about the same to rebuild my cylinders as it was to buy new ones. We pay a high price for living here in Alaska when it comes to airplanes.
I will be getting 3 of them tomorrow and will order the other 3 next month. I sent the block out to have it cleaned and check to make sure it is in good shape. I had the crank turned and picked up a new cam for it as well.
New rings , rods and bearings . I got the prop last month with the governor. I will be glad when it is done.

Ken

qmdv wrote:800 on the engine. Guy before me flew it not to much and most likely did not lean it enough.

Tim

Just do what I did Tim. Bite the bullet and do a major over haul. I feel your pain.

qmdv wrote:800 on the engine. Guy before me flew it not to much and most likely did not lean it enough.

Tim

I'm no expert, but maybe check your cam lobes. From what I understand, particularly in the 470's if they don't get used a lot the lobes will die remarkably quick. (corrosion, hard facing damage etc..)

Could possibly be linked to the cause of cylinder compressions on the blink.

Going to pull all jugs then check the cam. If cam is good then new jugs or OH the old ones. If cam is bad then who knows.

Tim

Don't get too excited yet.

When you put air to the cylinders where it it leaking from?
Can you hear it through the exhaust , intake or crankcase?

The cylinders may be repairable.

Maybe you can just get the valves ground ( or possibly just lapped) and or re hone the cylinders.

Bad cam wouldn't cause bad compressions. (although it's worth looking at as long as you are apart).