Onan, 18 or 20?


Jon Usher <fedxav8r@...>
 

As stated earlier I recently purchased a Q1 kit. How can I tell if
the Onan engine is the 18 or 20 hp version? (I would like to use a
different powerplant than the Onan. Any suggestions would be
appreciated) THanks....Jon


Ryan <rryan@...>
 

Hi Jon,

The VW engine only adds 75# to the completed aircraft.

Ryan Q1


--- In Q-LIST@..., "Jon Usher" <fedxav8r@y...> wrote:
As stated earlier I recently purchased a Q1 kit. How can I tell if
the Onan engine is the 18 or 20 hp version?
(I would like to use a different powerplant than the Onan. Any
suggestions would be appreciated) Thanks....Jon


David J. Gall
 

Jon,

The only way that I know of to tell the difference is to look at the
paperwork... :)

Seriously, the "20 hp" was listed as "22.5 hp" by QAC and was the result of
shaving the cylinder heads for higher compression, and a minor modification
to the carburetter. The shaved heads are junk -- don't use them. Use the 20
hp heads manufactured by Onan specifically for the B48M engine. (These heads
came out after QAC pretty much stopped selling Q1 kits.) Whether you start
with the 18 hp or the "22.5 hp" engine, the new Onan 20 hp heads will give
you a more powerful, more reliable engine. These new heads also require a
special graphite head gasket -- don't skimp!

If you stick with the Onan there are some definite changes ("deviations from
the plans") that need to be made to help reduce vibration and to control
temperatures. The installation given in the plans is very likely to result
in an overheated engine; read the back issues of QuickTalk/Q-Talk for the
mods.

Alternate engines? The most popular and successful have been the Rotax 447
and Rotax 503 engines. The 503 "SuperQuickie Solution" plans by Jinx Hawks
and Brock McCaman are available on the Yahoo site files area.


David J. Gall

-----Original Message-----
From: Jon Usher [mailto:fedxav8r@...]
Sent: Tuesday, June 03, 2003 1:07 PM
To: Q-LIST@...
Subject: [Q-LIST] Onan, 18 or 20?


As stated earlier I recently purchased a Q1 kit. How can I tell if
the Onan engine is the 18 or 20 hp version? (I would like to use a
different powerplant than the Onan. Any suggestions would be
appreciated) THanks....Jon


Keith L Welsh <welshq1@...>
 

A little clarification. Hope you don't mind David.

The only way that I know of to tell the difference is to look at the
paperwork... :)
The block has some tell tale signs that it's a 20hp model. Also the true
OEM 20's have a different carburetor and is very noticable. It sets up
higher and
is about half again as large. Bigger venturi, 5 air vents to the float
bowl, larger
fuel tube.

Seriously, the "20 hp" was listed as "22.5 hp" by QAC and was the
result of shaving the cylinder heads for higher compression, and a
minor
modification to the carburetter.
QAC never used a 20hp engine. They didn't appear on the market till 1983
and
then as the B48M-GAO20 which is the predecessor to the P220 and the
Linamar
LX 790. The 22.5hp was a modified B48M-GAO18 and was the only version QAC
used.
It's predecessor is the P218. Each engine is based on the 47.7 CID block.

Incidently that 47.7 CID block is the only one available in two hp
versions.

The shaved heads are junk -- don't use them. Use the 20
hp heads manufactured by Onan specifically for the B48M engine.
(These heads came out after QAC pretty much stopped selling Q1 kits.)
Those heads originated with the OEM 20hp engine. Big difference is the
placement of the spark plug and the domed combustion chamber. Note
that only the 22.5hp versions had problems the original 18hp engines
didn't
and had the same heads. Moral is don't shave or anything else to a set of
heads.

Whether you start with the 18 hp or the "22.5 hp" engine, the new Onan
20 hp heads
will give you a more powerful, more reliable engine. These new heads
also
require a special graphite head gasket -- don't skimp!
Sorry but I haven't been able to see a power difference between the
shaved
heads and the 20hp heads. And it takes much more than just the heads
to produce additional power. Without additional air and fuel, which the
new
carburators can produce, additional power is just imagination.

If you stick with the Onan there are some definite changes ("deviations
from
the plans") that need to be made to help reduce vibration and to
control temperatures. The installation given in the plans is very
likely to
result in an overheated engine; read the back issues of
QuickTalk/Q-Talk
for the mods.
Keep in mind you don't read much about the original 18's just those
stupid
22.5's. Terry Crouch proves the original baffeling works just fine and I
imagine
most Onans still sport the same as well. My problems came about to the
thinner valve stems found in the newer engines. They can't take the heat
without warping that the older ones could. The vibration was controled
with
the optional Kevlar engine mount in place of the aluminum one. It came
standard with the 22.5 option.

Hope this helps
Keith Welsh


David J. Gall
 

Keith,

I don't mind at all; I'm glad you jumped in here. Lots of good info, and I
learned some, too! But I'm still not an "engine guy." :)


David J. Gall
PS Maybe I'm a "wannabe engine guy" ;^}

-----Original Message-----
From: Keith L Welsh [mailto:welshq1@...]
Sent: Monday, June 09, 2003 1:02 AM
To: Q-LIST@...
Subject: Re: [Q-LIST] Onan, 18 or 20?


A little clarification. Hope you don't mind David.

The only way that I know of to tell the difference is to look at the
paperwork... :)
The block has some tell tale signs that it's a 20hp model. Also the true
OEM 20's have a different carburetor and is very noticable. It sets up
higher and
is about half again as large. Bigger venturi, 5 air vents to the float
bowl, larger
fuel tube.

Seriously, the "20 hp" was listed as "22.5 hp" by QAC and was the
result of shaving the cylinder heads for higher compression, and a
minor
modification to the carburetter.
QAC never used a 20hp engine. They didn't appear on the market till 1983
and
then as the B48M-GAO20 which is the predecessor to the P220 and the
Linamar
LX 790. The 22.5hp was a modified B48M-GAO18 and was the only version QAC
used.
It's predecessor is the P218. Each engine is based on the 47.7 CID block.

Incidently that 47.7 CID block is the only one available in two hp
versions.

The shaved heads are junk -- don't use them. Use the 20
hp heads manufactured by Onan specifically for the B48M engine.
(These heads came out after QAC pretty much stopped selling Q1 kits.)
Those heads originated with the OEM 20hp engine. Big difference is the
placement of the spark plug and the domed combustion chamber. Note
that only the 22.5hp versions had problems the original 18hp engines
didn't
and had the same heads. Moral is don't shave or anything else to a set of
heads.

Whether you start with the 18 hp or the "22.5 hp" engine, the new Onan
20 hp heads
will give you a more powerful, more reliable engine. These new heads
also
require a special graphite head gasket -- don't skimp!
Sorry but I haven't been able to see a power difference between the
shaved
heads and the 20hp heads. And it takes much more than just the heads
to produce additional power. Without additional air and fuel, which the
new
carburators can produce, additional power is just imagination.

If you stick with the Onan there are some definite changes ("deviations
from
the plans") that need to be made to help reduce vibration and to
control temperatures. The installation given in the plans is very
likely to
result in an overheated engine; read the back issues of
QuickTalk/Q-Talk
for the mods.
Keep in mind you don't read much about the original 18's just those
stupid
22.5's. Terry Crouch proves the original baffeling works just fine and I
imagine
most Onans still sport the same as well. My problems came about to the
thinner valve stems found in the newer engines. They can't take the heat
without warping that the older ones could. The vibration was controled
with
the optional Kevlar engine mount in place of the aluminum one. It came
standard with the 22.5 option.

Hope this helps
Keith Welsh


Mark/Pat Pearson/Pound <wlkabout@...>
 

David:
What did you say the serial no. of your Q1 is? Mine is 0229 and I
know I had the 18HP Onan -- I'm pretty sure the modified engine wasn't
available until after I bought my kit. I have replaced mine with a
Rotax 532, though I know where my original engine is, if you want a
spare or a parts engine.

Mark A. Pearson

"David J. Gall" wrote:

Keith,

I don't mind at all; I'm glad you jumped in here. Lots of good info,
and I
learned some, too! But I'm still not an "engine guy." :)


David J. Gall
PS Maybe I'm a "wannabe engine guy" ;^}

-----Original Message-----
From: Keith L Welsh [mailto:welshq1@...]
Sent: Monday, June 09, 2003 1:02 AM
To: Q-LIST@...
Subject: Re: [Q-LIST] Onan, 18 or 20?


A little clarification. Hope you don't mind David.

The only way that I know of to tell the difference is to look at
the
paperwork... :)
The block has some tell tale signs that it's a 20hp model. Also the
true
OEM 20's have a different carburetor and is very noticable. It sets
up
higher and
is about half again as large. Bigger venturi, 5 air vents to the
float
bowl, larger
fuel tube.

Seriously, the "20 hp" was listed as "22.5 hp" by QAC and was the
result of shaving the cylinder heads for higher compression, and a
minor
modification to the carburetter.
QAC never used a 20hp engine. They didn't appear on the market till
1983
and
then as the B48M-GAO20 which is the predecessor to the P220 and the
Linamar
LX 790. The 22.5hp was a modified B48M-GAO18 and was the only
version QAC
used.
It's predecessor is the P218. Each engine is based on the 47.7 CID
block.

Incidently that 47.7 CID block is the only one available in two hp
versions.

The shaved heads are junk -- don't use them. Use the 20
hp heads manufactured by Onan specifically for the B48M engine.
(These heads came out after QAC pretty much stopped selling Q1
kits.)

Those heads originated with the OEM 20hp engine. Big difference is
the
placement of the spark plug and the domed combustion chamber. Note
that only the 22.5hp versions had problems the original 18hp engines
didn't
and had the same heads. Moral is don't shave or anything else to a
set of
heads.

Whether you start with the 18 hp or the "22.5 hp" engine, the new
Onan
20 hp heads
will give you a more powerful, more reliable engine. These new
heads
also
require a special graphite head gasket -- don't skimp!
Sorry but I haven't been able to see a power difference between the
shaved
heads and the 20hp heads. And it takes much more than just the heads
to produce additional power. Without additional air and fuel, which
the
new
carburators can produce, additional power is just imagination.

If you stick with the Onan there are some definite changes
("deviations
from
the plans") that need to be made to help reduce vibration and to
control temperatures. The installation given in the plans is very
likely to
result in an overheated engine; read the back issues of
QuickTalk/Q-Talk
for the mods.
Keep in mind you don't read much about the original 18's just those
stupid
22.5's. Terry Crouch proves the original baffeling works just fine
and I
imagine
most Onans still sport the same as well. My problems came about to
the
thinner valve stems found in the newer engines. They can't take the
heat
without warping that the older ones could. The vibration was
controled
with
the optional Kevlar engine mount in place of the aluminum one. It
came
standard with the 22.5 option.

Hope this helps
Keith Welsh

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To unsubscribe from this group, send an email to:
Q-LIST-unsubscribe@...

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David J. Gall
 

Mark,

Mine is kit #545. It came with the "22.5 hp" engine but without an oil
cooler. I've put a lot of work into removing the casting flash from the
outside of the block to promote better airflow around the valve areas. I've
also torn it down and balanced all the internals, removed the governer
parts, etc., and put on electonic ignition and the "20 hp" Onan heads and
gaskets (GA020). I think I'll just fly with this until I can't stand it.
Then I might put in the P224/Linamar LX990 or ...?


David J. Gall

-----Original Message-----
From: Mark/Pat Pearson/Pound [mailto:wlkabout@...]
Sent: Monday, June 09, 2003 11:57 AM
To: Q-LIST@...
Subject: Re: [Q-LIST] Onan, 18 or 20?


David:
What did you say the serial no. of your Q1 is? Mine is 0229 and I
know I had the 18HP Onan -- I'm pretty sure the modified engine wasn't
available until after I bought my kit. I have replaced mine with a
Rotax 532, though I know where my original engine is, if you want a
spare or a parts engine.

Mark A. Pearson


Mark/Pat Pearson/Pound <wlkabout@...>
 

You really do want to be an engine guy!! Success!!

"David J. Gall" wrote:

Mark,

Mine is kit #545. It came with the "22.5 hp" engine but without an oil

cooler. I've put a lot of work into removing the casting flash from
the
outside of the block to promote better airflow around the valve areas.
I've
also torn it down and balanced all the internals, removed the governer

parts, etc., and put on electonic ignition and the "20 hp" Onan heads
and
gaskets (GA020). I think I'll just fly with this until I can't stand
it.
Then I might put in the P224/Linamar LX990 or ...?


David J. Gall

-----Original Message-----
From: Mark/Pat Pearson/Pound [mailto:wlkabout@...]
Sent: Monday, June 09, 2003 11:57 AM
To: Q-LIST@...
Subject: Re: [Q-LIST] Onan, 18 or 20?


David:
What did you say the serial no. of your Q1 is? Mine is 0229 and
I
know I had the 18HP Onan -- I'm pretty sure the modified engine
wasn't
available until after I bought my kit. I have replaced mine with a
Rotax 532, though I know where my original engine is, if you want a
spare or a parts engine.

Mark A. Pearson

Yahoo! Groups Sponsor



To unsubscribe from this group, send an email to:
Q-LIST-unsubscribe@...

Quickie Builders Association WEB site
http://www.quickiebuilders.org



Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.


jzvbike
 

David... how did you install the electronic ingnition? i have the 18hp and
one magnet in the fly wheel is broken....how do you find parts for the engine?
once I intall the engine I will be ready for some taxing thanks Joaquin


jzvbike
 

Thanks David.


David J. Gall
 

Joaquin,

The electronic ignition was a bolt-on offered by the factory that I bought
from a local Onan dealer. It was called the "Magna-arc" or "Magna-spark"
ignition, or something like that. It replaces the breaker points with a hall
effect sensor, that's all. The hall effect sensor is triggered by a small
magnet mounted on a nylon arm and swung by the same little pushrod that
triggers your points now. I also bought the updated, smaller, more powerful
coil, but I'm not sure I'll use it yet.

Broken flywheel magnets? I have no idea. Parts? I have no idea. I have the
old parts manual, but I think all the part numbers are obsolete by now. I'd
start at the local Onan (Linamar, John Deere?) dealer, though.


David J. Gall

-----Original Message-----
From: HMBNZERS@... [mailto:HMBNZERS@...]
Sent: Saturday, June 14, 2003 1:10 PM
To: Q-LIST@...
Subject: Re: [Q-LIST] Onan, 18 or 20?


David... how did you install the electronic ingnition? i have the
18hp and
one magnet in the fly wheel is broken....how do you find parts
for the engine?
once I intall the engine I will be ready for some taxing thanks Joaquin


jzvbike
 

thanks Welsh .... my worry also is do the magnets have to be lock in a
specific position or this will not affect the timing on the magneto? Since the
flywheel is lock in a fix place?


Keith L Welsh <welshq1@...>
 

Haven't heard much about the magnets in the Onan flywheel in years.....
BUT in the past magnets coming loose have been known to lock
up engines.
The magnets were originally glued to the housing with spaces
in between. They really need to be better secured. What can be
done is to apply JB Weld between, on top and bottom thereby
locking them in place by sorta encasing them as a unit.
Any chance of any one magnet shifting is eliminated.
One of my magnets had come loose and I got lucky enough
to find it before the worst happened. And that was many
years ago. The engine has been off the plane several times
since and will be again after Mattoon and the JB all still looks as
it did the day it was done.

Welsh


David J. Gall
 

The flywheel has nothing to do with the ignition timing. The timing is
triggered on top of the engine.


David J. Gall

-----Original Message-----
From: HMBNZERS@... [mailto:HMBNZERS@...]
Sent: Sunday, June 15, 2003 12:40 PM
To: Q-LIST@...
Subject: Re: [Q-LIST] Onan, 18 or 20?


thanks Welsh .... my worry also is do the magnets have to be lock in a
specific position or this will not affect the timing on the
magneto? Since the
flywheel is lock in a fix place?


Keith L Welsh <welshq1@...>
 

my worry also is do the magnets have to be lock in a
specific position or this will not affect the timing on the magneto?
Since the flywheel is lock in a fix place?
An electrical person will have to explain the necessity of the
equal spacing of the magnets. Since they were done that way
at the start I would make sure I kept them that way. And balance
might be another concern.

Keith Welsh