Is my Tiller really 20 HP?

CJBOTA · Mar 5, 2012

I bought a Troybuilt Horse Tiller a couple tears ago. It has a Briggs Intek engine and the maual doesn't say anything about HP. It does say it is 305 CC's. I found online a formula that says you divide CC's by 15 to get HP. That makes this thing 20 HP, Is that possible? I have been telling people it is 8 hp. There must be another formula!
CJ

BCSSHOP · Mar 6, 2012

CJ,

That's an 8hp engine but they aren't rating engines by horsepower as much any more. The horsepower rating was often so inflated as to be misleading. Engine displacement is good measure of comparing similar types of engines. A 270cc engine from Honda is rated at 9hp but its real useful output is more like 8hp. Enjoy your Horse tiller. I sold them for 25 years.

GregbkH · Mar 6, 2012

Dividing CC's by 15 or 16 gets you in the ball park for CI's (cubic inches).

I have a 305 briggs on my log splitter. It is rated at 14.5 foot/pounds of torque. No hp rating. Probably 8 or 9 hp.

2manyrocks · Mar 8, 2012

I have no clue what you have, and so what I say may have nothing to do with your machine.

There are some other TBN threads about some manufacturers putting higher HP labels on the same displacement engines that used to have lower HP labels. I have read some apparently are avoiding putting HP labels and using displacement sizes labels now as a result of legal disputes over challenges concerning the true HP.

And with the sorry gasoline we have now, who knows what the HP is.

farmeratheart · Mar 8, 2012

... about some manufacturers putting higher HP labels on the same displacement engines ...

My Grandfather told me a long time ago (I was about 5 or 6), "You know boy-paper (or in this case plastic or metal?) will hold still and let you write whatever you want on it!"

Frank

2manyrocks · Mar 8, 2012

So the OP should just print a label that says "125 HP" on it and brag to all his friends....

RandyT · Mar 8, 2012

The other issue that arose out of horsepower ratings was on push mower engines. The horsepower rating was a 3600 rpm, but the engine only ran 2800-3200 rpm in most applications thus lowering the actual horsepower output.

Was told at one of my engine update seminars that you can take the cc rating and divide by 29 to get horsepower.

bcp · Mar 8, 2012

HF says a 346cc engine is a replacement for an 11 hp engine.

Predator 346cc OHV Horizontal Shaft Gas Engine - Certified for California

They do the same on their other engines, too.

Bruce