Modifying a O-300 for more hp.
in...@lasertronics-sfx.com
power?
This engine produces 145hp at 2700 rpm at very conservative low compression
and should easily be able to be modified .
CC
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"CC" Milne D Pocock
012 668 1989 / 082 490 5721
www.lasertronics-sfx.com / www.lasertronics.co.za
www.bushair.com / www.bushair.co.za
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highflyer
>
> Anyone have any experience modifying a Continental O-300 to produce more
> power?
>
> This engine produces 145hp at 2700 rpm at very conservative low compression
> and should easily be able to be modified .
>
> CC
>
The O-300 will produce 175 HP at 3200 RPM. This unfortunately runs the
prop a bit fast for efficiency and you effectively lose much of what you
gain because of lowered power to thrust conversion at the higher
propellor RPM.
The easiest way to accomplish this power increase is to trade the O-300
for the factory hopped up version, the GO-300. Expect lowered TBO and
more problems with sticking valves resulting from the higher temps in
the cylinder area caused by the higher power density. :-)
--
Highflyer
Highflight Aviation Services
in...@lasertronics-sfx.com
I am removing the O-300 from a C172 but I want to keep the engine to put
into an experimental A/C.
I would like to up the compression by skimming the block and modifiyng the
cam and and a few other minor mods like a tuned exhaust stack. I am sure
that all this will give me a big increase in hp at around 2700 RPM. I am
conservatively guessing at around an extra 25hp. I have no doubt that at
least an extra 5-10hp should be obtainable just by fitting a proper exaust
system.
However I would like to hear other opinions.
CC
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"CC" Milne D Pocock
012 668 1989 / 082 490 5721
www.lasertronics-sfx.com / www.lasertronics.co.za
www.bushair.com / www.bushair.co.za
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"highflyer" <high...@alt.net> wrote in message
news:3C862C8C...@alt.net...
highflyer
>
> What is the TRUE red line RPM with a standard prop on the O-300?
>
> I am removing the O-300 from a C172 but I want to keep the engine to put
> into an experimental A/C.
>
> I would like to up the compression by skimming the block and modifiyng the
> cam and and a few other minor mods like a tuned exhaust stack. I am sure
> that all this will give me a big increase in hp at around 2700 RPM. I am
> conservatively guessing at around an extra 25hp. I have no doubt that at
> least an extra 5-10hp should be obtainable just by fitting a proper exaust
> system.
>
> However I would like to hear other opinions.
>
I am curious about what you mean by "skimming the block" on an aircraft
engine?
Also, what do you mean by a "proper" exhaust system?
Rich S.
news:3c88c...@batman.vip-za.com...
> What is the TRUE red line RPM with a standard prop on the O-300?
>
> I am removing the O-300 from a C172 but I want to keep the engine to put
> into an experimental A/C.
>
> I would like to up the compression by skimming the block and modifiyng
the
> cam and and a few other minor mods like a tuned exhaust stack. I am sure
> that all this will give me a big increase in hp at around 2700 RPM. I am
> conservatively guessing at around an extra 25hp. I have no doubt that at
> least an extra 5-10hp should be obtainable just by fitting a proper exaust
> system.
>
> However I would like to hear other opinions.
Sounds like you need to talk to the airboat guys. Do a Google on airboat
engines and you should come up with all kinds of hotrod tips.
Rich S.
Cy Galley
height.i.e... distance from wrist pin to piston top.
The exhaust system in most aircraft are fairly free flowing as the
restriction is generally in the cylinder exhaust port. Porting the cylinder
head might produce more power, but one might loose strength and develop
cracks.
One might get more power by increasing the cam lift and overlap. Increasing
the lift means there are several other areas to check. Springs for complete
compression, Cam toe to lifter diameter.
Matching intake elbows to cylinder heads might help as well.
--
Cy Galley, TC - Chair, Emergency Aircraft Repair, Oshkosh
Editor, EAA Safety Programs
cga...@qcbc.org or experi...@eaa.org
Always looking for articles for the Experimenter
"Rich S." <n7...@nospam.harbornet.com> wrote in message
news:6k4i8.96$ay5.1...@newsfeed.slurp.net...
cl...@snyder.on
wrote:
>Most CR changes in our aircraft engines are done by changing the piston deck
>height.i.e... distance from wrist pin to piston top.
>
>The exhaust system in most aircraft are fairly free flowing as the
>restriction is generally in the cylinder exhaust port. Porting the cylinder
>head might produce more power, but one might loose strength and develop
>cracks.
>
> One might get more power by increasing the cam lift and overlap. Increasing
>the lift means there are several other areas to check. Springs for complete
>compression, Cam toe to lifter diameter.
>
>Matching intake elbows to cylinder heads might help as well.
A properly tuned exhaust can have a similar effect to a low boost
supercharger - so smething other than the "low restriction" stacks may
free up an extra 5 - 25 HP
in...@lasertronics-sfx.com
It appears as if the engine block/ casing could be skimmed down over the
flanges were the jugs bolt on. Obviously one would need to measure available
clearances etc first. This would then allow the cylinders to seat lower down
into the casing thus resulting in a higher compression in the combustion
chamber(?).
A "proper exhaust" would be a well tuned branch system with tail pipe/s out
to the rear into the best vacuum area under the airplane. Similar in design
to Powerflow systems(?)
CC
--
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"CC" Milne D Pocock
012 668 1989 / 082 490 5721
www.lasertronics-sfx.com / www.lasertronics.co.za
www.bushair.com / www.bushair.co.za
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in...@lasertronics-sfx.com
real easy if there were pistons available off the shelf. Having special
pistons made up would probably be too expensive.
However I think that one could raise the compression by easily skimming down
the engine casing were the cylinder bolts on thus slightly increasing the
comression in the chamber. However the problem here is that the valve
clearances would decrease and the push rods would "become longer" due to the
cylinders being moved down.
The cam should not be too much of a problem as there are a few good cam
shops around and building a good tuned free flowing exhaust stack is fairly
straight forward.
I also agree that matching and polishing around the ports also should be
done anyway.
CC
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"CC" Milne D Pocock
012 668 1989 / 082 490 5721
www.lasertronics-sfx.com / www.lasertronics.co.za
www.bushair.com / www.bushair.co.za
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"Cy Galley" <cga...@qcbc.org> wrote in message
news:a6asr...@enews3.newsguy.com...
in...@lasertronics-sfx.com
CC
Cy Galley
case and the stud threads themselves. High CR pistons are available just by
using the C-85 piston. Has a higher deck height and fits as the same
cylinder is used on all C series engines.
--
Cy Galley, TC - Chair, Emergency Aircraft Repair, Oshkosh
Editor, EAA Safety Programs
cga...@qcbc.org or experi...@eaa.org
Always looking for articles for the Experimenter
<in...@lasertronics-sfx.com> wrote in message
news:3c8a2b27$1...@batman.vip-za.com...
Tom Frey
Tom Frey
<in...@lasertronics-sfx.com> wrote in message
news:3c852...@batman.vip-za.com...