I have an old Allis-Chalmers b10 garden tractor with a 9hp briggs &
stratton cast iron engine. I was looking at replacing it with a new
briggs vanguard engine...maybe 16hp or so. When I compare the engine
specs, my old one has a 3.5 inch bore and a 3.2inch stroke, where the
new 16 hp has a 3 inch bore and 2.6inch stroke.

I know that is it overhead cam/valve and all, but will this deliver the
same kind of power that I am used to? That old briggs has been a
workhorse, and I don't want to downgrade power/torque..etc. Did
something change in horsepower ratings?

Looks like the old one was heavier-better built, isnt that the trend in
most everything. I wonder how the new motor compares to hp ratings on
build size alone to your old b&s, likely 8 hp. So they shove in more
fuel and up hp.

unless they did something to significantly change compression, I think you
can assume
the new one will have less torque.
Their marketing trick on this may be that some newer equipment that uses the
new engine
is configured to operate at much higher rpm's, thereby having a higher hp
rating.

bill



wrote in message
oups.com...
I have an old Allis-Chalmers b10 garden tractor with a 9hp briggs &
stratton cast iron engine. I was looking at replacing it with a new
briggs vanguard engine...maybe 16hp or so. When I compare the engine
specs, my old one has a 3.5 inch bore and a 3.2inch stroke, where the
new 16 hp has a 3 inch bore and 2.6inch stroke.

I know that is it overhead cam/valve and all, but will this deliver the
same kind of power that I am used to? That old briggs has been a
workhorse, and I don't want to downgrade power/torque..etc. Did
something change in horsepower ratings?

"Commodore Joe Redcloud©" wrote in message
news
On 27 Dec 2005 06:27:46 -0800, wrote:

I have an old Allis-Chalmers b10 garden tractor with a 9hp briggs &
stratton cast iron engine. I was looking at replacing it with a new
briggs vanguard engine...maybe 16hp or so. When I compare the engine
specs, my old one has a 3.5 inch bore and a 3.2inch stroke, where the
new 16 hp has a 3 inch bore and 2.6inch stroke.

I know that is it overhead cam/valve and all, but will this deliver the
same kind of power that I am used to? That old briggs has been a
workhorse, and I don't want to downgrade power/torque..etc. Did
something change in horsepower ratings?

The Vanguard is a commercial duty engine. It's the Top of the Line for
Briggs & Stratton. It is a V-Twin, which means TWO cyclinders to your
old engine's one.

Well, that's completely different. Nevermind.

Smokey also said "torque wins races - hp sells cars", check the specs, the
newer motor likely developes more torque and maybe they spin it faster. Hp
is a function of torque delivered over time - what you are looking for is
equal or more torque in the rpm band you most often operate the machine in
wrote in message
oups.com...
I have an old Allis-Chalmers b10 garden tractor with a 9hp briggs &
stratton cast iron engine. I was looking at replacing it with a new
briggs vanguard engine...maybe 16hp or so. When I compare the engine
specs, my old one has a 3.5 inch bore and a 3.2inch stroke, where the
new 16 hp has a 3 inch bore and 2.6inch stroke.

I know that is it overhead cam/valve and all, but will this deliver the
same kind of power that I am used to? That old briggs has been a
workhorse, and I don't want to downgrade power/torque..etc. Did
something change in horsepower ratings?

wrote in message
oups.com...
I have an old Allis-Chalmers b10 garden tractor with a 9hp briggs &
stratton cast iron engine. I was looking at replacing it with a new
briggs vanguard engine...maybe 16hp or so. When I compare the engine
specs, my old one has a 3.5 inch bore and a 3.2inch stroke, where the
new 16 hp has a 3 inch bore and 2.6inch stroke.

I know that is it overhead cam/valve and all, but will this deliver the
same kind of power that I am used to? That old briggs has been a
workhorse, and I don't want to downgrade power/torque..etc. Did
something change in horsepower ratings?


While engine size has some influence on HP there are many other factors.
Just look at car engines you can find 350cuin chevys with 230HP and you can
find them with 300HP. Your new engine is prob fuel injected, with electric
ignition, better designed heads, etc. Is the 9HP single cyl? The new one is
prob 2 cyl.

If you're asking whether or not the work equivalent of 1 HP has
changed, then: No. HP is still HP and is still equal to 550
ft-lb/second.

More HP doesn't necessarily equal more torque though. Mass-produced
engines today have better materials, better designs, and are
manufactured to tighter tolerances, allowing higher rpms. This,
coupled with lower friction losses, lighter components, and improved
combustion chamber design can result in a higher horsepower from a
smaller displacement engine, though torque might be lower in your new
engine due to it's smaller bore and shorter stroke. If you're already
thinking of modifying the tractor to accept the new engine, you might
consider the operating RPM difference (if there is any) between the
engines and change the gearing accordingly.

wrote in message
news
Smokey Yanuck (race car mechanic) used to say the only way to beat
inches is with inches.

Smokey said "you can't beat cubic inches", and the reply was "and cubic
inches can't beat cubic bucks".

Flatheads in general have much lower compression-ratio than ohv/ohc
engines are capable of. This translates to lower volumetric efficiency
and lower mechanical efficiency, besides torque curve biased toward the
bottom end.

Boiled down: oldie bigger, heavier, thirstier for given power output
rating. One place where cast-iron is beneficial: cylinder bore, for
lube retention. Some aluminum engines have cast-iron cylinder-liner(s).

And ... you really don't want to approach rated power anyhow.

J

wrote:

I have an old Allis-Chalmers b10 garden tractor with a 9hp briggs &
stratton cast iron engine. I was looking at replacing it with a new
briggs vanguard engine...maybe 16hp or so. When I compare the engine
specs, my old one has a 3.5 inch bore and a 3.2inch stroke, where the
new 16 hp has a 3 inch bore and 2.6inch stroke.

I know that is it overhead cam/valve and all, but will this deliver the
same kind of power that I am used to? That old briggs has been a
workhorse, and I don't want to downgrade power/torque..etc. Did
something change in horsepower ratings?

Hi,
No possibility of rebuilding the b10? New ones are not built like that.
While rebuilding you can improve it somewhat as well.
Tony