1975 750S --why can't Guzzi do 70 hp now?

[not-fishing]

Depending on where you look the Crank horsepower is 70-90 back in 1975.

Why can't Guzzi do it now with all the whiz-bang-computer technology and advances in the last 35 years?   

Is it the gasoline is not as good?

and I admit when I had hair I was a blond it this question seems a little dumb

Mark

[LowRyter]

you're comparing the small block heron head to the big block hemi.

[Lannis]

Depending on where you look the Crank horsepower is 70-90 back in 1975.

Why can't Guzzi do it now with all the whiz-bang-computer technology and advances in the last 35 years?   

Is it the gasoline is not as good?

and I admit when I had hair I was a blond it this question seems a little dumb

Mark

If the "where you look" included the Motorcycle Magazines of the times ... they used to lie like big dogs about "horsepower"; I get the impression they would measure it at the rear wheel, extrapolate it to the piston crown, and report THAT as the "horsepower".

On the other hand, no one makes a gasoline-engined car any more like my 1990 Kia/Ford Festiva (Mazda 121) that gets 44 MPG overall, either, so maybe a combination of modern heavier weights and bad gasoline is part of the culprit ....

Lannis

[mgfan]

I think they were using slide rules to compute block hp and rounding up by 15.    :BEER:

[oldbike54]

 In the 60s an English moto journalist asked the Montesa importer haow much power their new 250 MXer made .
He asked "How much is Bultaco claiming , our's makes one more"  ::)
 
  Dusty

[Antietam Classic Cycle]

Depending on where you look the Crank horsepower is 70-90 back in 1975.

That "70 hp" is/was actually around 50-55 hp at the crank.

[pyoungbl]

I suspect we could get 75 hp at the crank if we bumped the displacement up to 830-850cc and replaced the Heron heads with something that allowed better breathing.  Ed Milich is the guy to ask.

Peter Y.

[guzzisteve]

you're comparing the small block heron head to the big block hemi.

This,  Small bock (Heron Head) is no match for Big Block, it was designed to be a 350 & 500cc. Even the 4V and 2V Hemi head stuff is prone to blow up if you don't shift 1K rpm before redline. Even the drivetrain is small contact area's. It's ASS CANDY for the marketing part of the company.

[sib]

The reason why small block Guzzis have Heron heads is because they are best for the job they are called to do.  Small block Guzzi buyers don't want to go 150 mph.  They want even, high torque over a wide rpm range, non-finnicky fuel requirements, long engine life, and relatively low cost.  My '13 V7 Stone will go 110 mph.  What would 20 more hp give me?  125 mph?  Dandy.  If I needed to go faster than 110, I'd opt for a different bike and make sure my living will is in good order.  I'd then be trading increased hp for increased problems.  No thanks.

[rocker59]

70 BHP   (brochure horse power)    :BEER:

[Gliderjohn]

To help be realistic My T-3 is a big block of course but even punched out to 1,000cc and other significant mods it's RWH on a dyno measured out at 56hp and 54 pounds of torque. Runs real nice for an older Guzzi however. ;-T
GliderJohn

[Vasco DG]

To help be realistic My T-3 is a big block of course but even punched out to 1,000cc and other significant mods it's RWH on a dyno measured out at 56hp and 54 pounds of torque. Runs real nice for an older Guzzi however. ;-T
GliderJohn

Which sounds about par for the course. Stock 948cc Smallvalve engine makes around 45-46 with 30mm VHB's and *Unobtrusive* pipes.

Pete

[huub]

i've had three V7sports on the dyno, never seen more than 50 hp.
having said that , a smallblock probably struggles to reach 40 hp.
i have had quite a lot of trouble getting the clutch to last on my v65tt, i dont think a smallblocks drivetrain would last very long with a  a real 50 hp.

having said that , it would be fun to try , as much power as the V7sport with 50 kilo less should be enough to annoy loads of big bikes on twisty roads

[Rough Edge racing]

If the "where you look" included the Motorcycle Magazines of the times ... they used to lie like big dogs about "horsepower"; I get the impression they would measure it at the rear wheel, extrapolate it to the piston crown, and report THAT as the "horsepower".

On the other hand, no one makes a gasoline-engined car any more like my 1990 Kia/Ford Festiva (Mazda 121) that gets 44 MPG overall, either, so maybe a combination of modern heavier weights and bad gasoline is part of the culprit ....

Lannis

 
  Yeah, the bike magazines like to use the Dynojet because it inflates power figures.....And is the least expensive dyno...Although no dyno is cheap.
  Somewhere in the late 1990's emission standards tightened requiring a specialized 3 way  catalyst convertor on cars and some light trucks. To work properly the 3 way convertor needs a  Stoichiometric fuel mixture of 14.7 at part throttle. Your older vehicle can operate on leaner mixtures around 16-1. Can't be the gas because you're using the same gas as newer vehicles...

[Dilliw]

On the other hand, no one makes a gasoline-engined car any more like my 1990 Kia/Ford Festiva (Mazda 121) that gets 44 MPG overall, either, so maybe a combination of modern heavier weights and bad gasoline is part of the culprit ....

Lannis

Modern cars can still perform while putting up with all the safety regulations.

Your Festiva has 73hp, weighs 1750 and if you are doing better than the EPA est of 37mpg then good for you.
http://www.edmunds.com/ford/festiva/1990/features-specs.html

My Mazda3 has 150hp, weighs 2969lbs, and I average 35mpg plus get over 40mpg on most trips.
http://www.edmunds.com/mazda/mazda3/2012/st-101413981/features-specs/

[guzziownr]

To help be realistic My T-3 is a big block of course but even punched out to 1,000cc and other significant mods it's RWH on a dyno measured out at 56hp and 54 pounds of torque. Runs real nice for an older Guzzi however. ;-T
GliderJohn

Dang, I only got 55.  What was Mike Rich's phone #?  I had it here someplace...

[Rough Edge racing]

 My 51 Willys 4x4 truck has 71 HP gross hp ,weighs 3150 lbs on the scale and gets about 15 mpg and has a cruising speed of about 45 mph with the stock 5.38 gears.  ;D

  
  

[Gliderjohn]

Quote from guzziowner:

Dang, I only got 55.  What was Mike Rich's phone #?  I had it here someplace...

HA! HA! Beat you by one. ;D
GliderJohn

[cruzziguzzi]

you're comparing the small block heron head to the big block hemi.

I know it's apples-oranges and... other kinds of oranges but:

Where does the Lario fit in? Small block sure, but better head performance.

Todd.

[Greg Field]

Good lord.

[Penderic]

Oh Boy! And get 70 miles per gallon, and weigh less, and cost the same, and .......




 ~;

[lucydad]

This one goes to 11.

[Rough Edge racing]

To help be realistic My T-3 is a big block of course but even punched out to 1,000cc and other significant mods it's RWH on a dyno measured out at 56hp and 54 pounds of torque. Runs real nice for an older Guzzi however. ;-T
GliderJohn

Interesting,my 650 Triumph race bike on a Superflow dyno makes 55 rear wheel HP @7300 rpm ,45 ft lbs of torque at 5100 rpm. The engine isn't too radial,starts on one kick and idles steady with a lope at 1000 rpm. The Triumph is a 1930's design with all the limitation of vintage British engine. I know dyno readings can't be compared but I would think a modified 1000 Guzzi hemi head would make a lot more power......

[Cheese]

Interesting,my 650 Triumph race bike on a Superflow dyno makes 55 rear wheel HP @7300 rpm ,45 ft lbs of torque at 5100 rpm. The engine isn't too radial,starts on one kick and idles steady with a lope at 1000 rpm. The Triumph is a 1930's design with all the limitation of vintage British engine. I know dyno readings can't be compared but I would think a modified 1000 Guzzi hemi head would make a lot more power......

What's the difference in losses between chain to shaft final drive as tested on a rolling road? Couple horses there. What modifications? As you said, different dynos too. Every little thing matters. And it's tough for the average Joe to measure at the crankshaft. I like to ride the torque personally so HP is not that important to me. Also, manufacturers lie about horsepower because it's so easy to mess with the measurement parameters. How much does your bike weigh? Well, what's included? Look at what recently happened with garden equipment. Big kerfuffle over HP. No more HP figures quoted now but just cubic volume. Always a good topic!

Peter

[huub]

Interesting,my 650 Triumph race bike on a Superflow dyno makes 55 rear wheel HP @7300 rpm ,45 ft lbs of torque at 5100 rpm. The engine isn't too radial,starts on one kick and idles steady with a lope at 1000 rpm. The Triumph is a 1930's design with all the limitation of vintage British engine. I know dyno readings can't be compared but I would think a modified 1000 Guzzi hemi head would make a lot more power......

i have seen a v7sport tuned to over 90 hp, at wich point it ran at close to 10.000 rpm , and blowups were pretty predictable.
As you probably know getting power is one thing , getting it reliable enough for a roadbike is another.
i dont think commuting on you racing triumph would be a good idea

[kevdog3019]

I know it's apples-oranges and... other kinds of oranges but:

Where does the Lario fit in? Small block sure, but better head performance.

Todd.

Ahh... about 38hp at the tire. My Milich Lario all tarted up is 44hp @the wheel. It's a light bike (and mine's even lighter) so it's pretty zippy.

[Gliderjohn]

My T-3 three mods were:
1,000 cc kit
36mm round slides
Port and polished heads
V-7 sport cam
Heavier valve and clutch springs
K&N filters
Just run cheap Emego mufflers, but they sound nice.

Nothing radical and now have around 30K miles since engine was redone anvil like reliability so far.
Here was the dyne graph:

GliderJohn

[skromfols]

My 05 Nevada showed 38.30 hp and 35.82 tq stock and with head work, increased displacement, open intake and exhaust and a good dyno tune (with power commander) measures 51.23 hp and 50.20 tq.  I've only got about 1,500 miles on it since the engine work, but the clutch seems to be handling it with no problem.

[Cheese]

My T-3 three mods were:
1,000 cc kit
36mm round slides
Port and polished heads
V-7 sport cam
Heavier valve and clutch springs
K&N filters
Just run cheap Emego mufflers, but they sound nice.

Nothing radical and now have around 30K miles since engine was redone anvil like reliability so far.
Here was the dyne graph:

GliderJohn

That's a thing of beauty! I'd be riding it mostly between 3500 and 5000. Do you find the need to go higher?

[Gliderjohn]

Quote from Cheese:

That's a thing of beauty! I'd be riding it mostly between 3500 and 5000. Do you find the need to go higher?

Not really. Do run it up at times just for the sound of it. ;D Certainly no reason to run it above 6,500. Since it is a police model it does not have a tach so just go by sound and feel. It does have a very nice midrange and rarely have need to downshift to pass.
GliderJohn