Jump to content

Unofficial Home of Old Simplicity & Allis-Chalmers Garden Tractors

Briggs model # breakdown


littlemarv

Recommended Posts

Working on a Cast iron Briggs, 320421-0134-01-710420.   How many horsepower is this engine?

 

                                                         AND,

 

What determines engine horsepower in these single cylinder engines? Looking in a manual, I see the bore and stroke are the same for a cast iron 14, 15, and 16 horsepower engine. So where does the power differential come from, is it carb, cam, or cylinder head?

 

  • Like 1
Link to comment
Share on other sites

26 minutes ago, littlemarv said:

What determines engine horsepower in these single cylinder engines? Looking in a manual, I see the bore and stroke are the same for a cast iron 14, 15, and 16 horsepower engine. So where does the power differential come from, is it carb, cam, or cylinder head?

I've heard 2 main reasons for different HP:

Lower HP models are rated at lower rpm (like 3300) vs 3600.

Jets in lower HP models are smaller.  

I'm also waiting to be educated.

Link to comment
Share on other sites

I recently sold a 14hp Briggs.  You can see in this picture the throttle stop that was installed to limit the engine to 14hp.  It prevents the throttle from going to WOT (wide open throttle).  Removing this stop allows the engine to make full capable hp, which is 16.

Each engine should run at the same RPM; however when the load increases and the governor calls for more oomph the throttle plate supplies what it can.

z11.jpg

z1.jpg

Link to comment
Share on other sites

If you look at the parts, 14, 15, & 16, 32  CID are almost identical and on a dynamometer they would probably all pull 16 HP. It's more of a marketing thing by slowing rated speed of just saying it is either on of the three. You can always sell something for less of its potential but do the flip side and you're in trouble   that happened to Briggs years ago with their WB mower engines. That cost them in excess of 28 million dollars.

  • Like 1
  • Thanks 1
Link to comment
Share on other sites

Yup, sometimes it is just an RPM difference or just a sticker is the difference in horsepower.  As said above, you can slap a lower HP sticker on it and sell the engine in one market segment and keep the higher power sticker on it for another segment.  If memory serves me correct, the 18hp Command in my Sovereign is part number for part number the same as a 20hp, EXCEPT one small screw that limited the throttle and didn't allow it to go to 100% open when called for.  Guess what part my engine no longer has......   

Back in the late 90's, there was a Briggs Vanguard twin that had 2 horsepower versions sold by Briggs.  They had a 12hp and 14hp.  Exact same parts for the engines except the HP decal.  I knew a tractor puller that bought up some of the last 12hp versions of that engine so that he could put them on a light tractor that was in a class with a 12hp limit.  Some of the other guys in the club complained, but as far as I was concerned he was within the rules.  His engine numbers correlated to a 12hp engine per the manufacturer.  Pretty easy way to gain horsepower - just shop for the right Briggs type number.

With a Briggs, it is pretty easy to figure things like that out when you have the model, type and code.  The type number will indicate the intended RPM for that particular engine.

The lawsuit wasn't necessarily selling a 5hp engine as a 7hp engine when it only made 5hp as it was that all of the manufacturers were being pretty sneaky with their dyno figures and how they got them.  The standards were not what they should have been.  The engines were being run with 100% gasoline (generally speaking we are stuck with 90% gasoline and 10% ethanol - that is a whole other discussion and explanation), no air filter and no muffler, in some cases it was rumored that the engines were being run with flywheels that had no cooling fins on them which would free up lots of power.  Instant free horsepower when you run an engine like that.  However, if you ran the engine in that configuration on your equipment, your warranty would be void.  So, they had an engine that in real world trim would make 5hp, but in the dyno room would pull 7hp.  Well they put a 7hp sticker on the engine and eventually got called out for it.  That is why all small engines are no longer labeled with horsepower.  Now they are all rated with torque, which is the only real measurement you can take of an engine. We just are not as familiar with the number and what it means to us and what it will do for us like we knew horsepower.  Horsepower is a calculation that can be manipulated when someone wants to.

Everyone advertises how many CC's their engine is too - but that really isn't all that important or at least not meaningful to most people.  Your example is perfect for that.  32 cubic inches but 3 advertised horsepowers.  In our world a 7114 Simplicity was marketed as a 14hp tractor.  A 7116 was 16hp.  They used the exact same Briggs model and type number engine of 326437  0315-01.

  Take a 350 Chevy V8 engine.  They were made a long time and with many variations.  They were all 350 cubic inches, but varied in HP from about 150 to around 300 from the factory.  It depended on the year/configuration.   So many people want to know how many HP a certain CC engine has - size can't be correlated to HP with any accuracy.  You could make some generalizations, but that is it.  Otherwise you end up with a late 70's Caprice 2bbl smog engine in your Corvette that should have a 300hp TPI engine.

  • Like 1
Link to comment
Share on other sites

On 2/16/2018 at 10:03 PM, TimJr said:

Otherwise you end up with a late 70's Caprice 2bbl smog engine in your Corvette that should have a 300hp TPI engine.

Have that one.  At least it has a Rochester.

That is an excellent analogy.

 

  • Like 1
Link to comment
Share on other sites

On 2/14/2018 at 9:16 AM, BLT said:

If you look at the parts, 14, 15, & 16, 32  CID are almost identical and on a dynamometer they would probably all pull 16 HP. It's more of a marketing thing by slowing rated speed of just saying it is either on of the three. You can always sell something for less of its potential but do the flip side and you're in trouble   that happened to Briggs years ago with their WB mower engines. That cost them in excess of 28 million dollars.

Might even get 18 out of them ;) The cast iron 18 hp briggs being sold still overseas and cant be imported to the USA is also a 32 cube engine....

  • Like 1
Link to comment
Share on other sites

1 hour ago, rokon2813 said:

Might even get 18 out of them ;) The cast iron 18 hp briggs being sold still overseas and cant be imported to the USA is also a 32 cube engine....

I can't get a power curve, but I think they raised the RPM 200 revs to get it. Marine applications you can get away with that because of the steady prop load.

 

Link to comment
Share on other sites

On ‎2‎/‎16‎/‎2018 at 10:03 PM, TimJr said:

 

Tim believe it or not , it had to do with safe mower blade tip speed of 19.000 FPM. 21" mower blades are @ 3450RPM  24" blades , 3065 and 2800 for 26".  Briggs label didn't say their HP capability , they flat out rated maximum HP when in reality they were held down to blade rpm..

Link to comment
Share on other sites

I never heard that as one of the specific reasons behind the lawsuit, but it would fall into the same category of mislabeling.  In your example, which is completely true, you would not be producing say 5hp with a given engine since it may be limited to a lower RPM in the specific application it is in.  So, if you only have 4 useable horsepower in the trim level your engine is spec'ed to, then it shouldn't say 5hp on it.  Same situation as rating it with no air filter or muffler - gave a "false" peak horsepower.

Link to comment
Share on other sites

Hah!  I had not heard of the Briggs 18HP cast iron motor.  Here it is:

https://www.briggsandstratton.com/as/en_ph/product-catalog/engines/cast-iron-engines/cast-iron-ic-engine-531cc--18hp.html

Wish they'd start selling them again.  I'm sure the emissions could be engineered to conform to today's standards.  After all, if we can put a man on the moon...

Link to comment
Share on other sites

Here's the "spec" info:

5a8ef5594aa34_18HPSingleSpecs.JPG.0102ed3c937524c0e0c4203927ceb3a6.JPG

I'm confused about the "sleeve".  I thought the old single cylinder Briggs engines were solid cast iron - no sleeve.  Or am I wrong?

Is this "new" old school cast iron engine sleeved?  Meaning the block is cast iron, but of a lesser quality or something else?

Link to comment
Share on other sites

On ‎2‎/‎22‎/‎2018 at 8:15 PM, TimJr said:

So, is it 18hp because in the pic it doesn't look like a real air filter and that is a nice chrome header pipe for the exhaust :D?

 

18hp Briggs for overseas market.jpg

Tim, that is a marine engine and they don't require air cleaners.

 

Link to comment
Share on other sites

  • 11 months later...
On 2/19/2018 at 4:10 PM, BLT said:

I can't get a power curve, but I think they raised the RPM 200 revs to get it. Marine applications you can get away with that because of the steady prop load.

 

My "3116v" that I have @ my dads house to blow his drive free of snow is governed @ 3900 rpm no load. No problems yet.

Link to comment
Share on other sites

Governing is generally is  within 5-8% , so to get 3600 full load , 3900 no load is in the ball park. Springs don't not give real tight governing so it is possible that no two  engines built the same way would run exactly the same. Most power curves should have a (+)/ (-) and (%) along with a number indicating HP is within that range.

  • Like 1
Link to comment
Share on other sites

It maybe can make 18hp, but it didn't change the torque curve any.   As a tractor puller we were allowed to spin the stock engines to 4000 rpms.  This was an advantage for the Kohlers, but no advantage to the Briggs.  When a slight load was applied the Briggs engines would quickly drop to 3200 rpms and then hang there, and thus losing ground speed, while the Kohlers would hold the 4000 much longer, but when they dropped off, they dropped off down to 0 quickly.

Even though the Briggs could "lug it out" on a slow pull over the Kohlers, the ground speed  (because of higher torque with higher rpm) worked the best with transferring weight box pulling sleds.

Edited by MikeES
  • Like 2
Link to comment
Share on other sites

23 hours ago, BLT said:

Governing is generally is  within 5-8% , so to get 3600 full load , 3900 no load is in the ball park. Springs don't not give real tight governing so it is possible that no two  engines built the same way would run exactly the same. Most power curves should have a (+)/ (-) and (%) along with a number indicating HP is within that range.

No need to shout. 666

  • Haha 1
Link to comment
Share on other sites

55 minutes ago, dhoadley said:

No need to shout. 666

Dave,  spent a lengthy time finding the button to push to re-size the print, I finally thought "screw it",  my shoulders are big enough to take some heat. 4i

  • Like 2
  • Haha 2
Link to comment
Share on other sites

Mike - great description.  My 7016 puller with the original Briggs was set up with the governor well above 4000rpm no load to get some speed off the line, but it was quickly down to the 3000rpm range once there was a load on the drawbar.  The Briggs would definitely lug down even further and keep chugging compared to a Kohler that seemed to just nose dive once loaded enough.  If I remember right, a 16hp Briggs has about a 1 inch longer rod and deck height than the Kohler 16hp.  Probably a big factor in lugging power - much better rod angle.  Also why the Briggs doesn't eggshape the cylinder like a Kohler will due to the higher thrust load due to the increased rod angle of the Kohler.  The crankshafts have the same 3.25" stroke.  I always wanted to have some money to spend on an iron Briggs single to try a few things.  First,  would need a billet flywheel for safety, then have a cam made and then put a Kohler carb on a custom intake to get rid of the original updraft carb.  Get a few more RPM out of it and see what it would do.

  • Like 3
Link to comment
Share on other sites

On 2/13/2019 at 6:28 AM, BLT said:

Dave,  spent a lengthy time finding the button to push to re-size the print, I finally thought "screw it",  my shoulders are big enough to take some heat. 4i

You're fine around here, just some good natured ribbing. Do something similar on Facebook and see what vermin come out of the woodwork! Gotta love this place! dOd

Link to comment
Share on other sites

19 hours ago, TimJr said:

Mike - great description.  My 7016 puller with the original Briggs was set up with the governor well above 4000rpm no load to get some speed off the line, but it was quickly down to the 3000rpm range once there was a load on the drawbar.  The Briggs would definitely lug down even further and keep chugging compared to a Kohler that seemed to just nose dive once loaded enough.  If I remember right, a 16hp Briggs has about a 1 inch longer rod and deck height than the Kohler 16hp.  Probably a big factor in lugging power - much better rod angle.  Also why the Briggs doesn't eggshape the cylinder like a Kohler will due to the higher thrust load due to the increased rod angle of the Kohler.  The crankshafts have the same 3.25" stroke.  I always wanted to have some money to spend on an iron Briggs single to try a few things.  First,  would need a billet flywheel for safety, then have a cam made and then put a Kohler carb on a custom intake to get rid of the original updraft carb.  Get a few more RPM out of it and see what it would do.

Tim, you should contact member ACB12, Ron has modified a Briggs to be very competitive with the Kohlers.  He did put a heavier billet flywheel, messed with the cam, but the biggest improvements were an external adjustable prox switch for spark, and getting the right emulsion tube in the carb.  He had trouble running too rich at higher rpms.

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...