Performance with the setup as described above ?
-94.5mm piston, stock CR
-Stage 1 cam
-good flowing muffler, memory is fuzzy on stock or 1.75” OD header

I had a 4.9 sec. 0-60 and a 12.1 sec. with a speed of the high 80’s in the 1/4 mi., from a standing start.
That is the only hard data I had.
This was about 12 years ago.

It ran very well, easy start, smooth idle, no hiccups going to wide open, acceleration was quick, had to lean over the bars to keep the front wheel down on launch.  The standing start launch hampered the times a bit because of that.
After spending 30 minutes doing these runs I decided I needed to beef up the clutch so installed HD springs later.

On the road it felt like getting out of a VW Bug and into a small sports car.  Noticeably quicker with a little extra top speed.  Passing on the highway was made easy.  It was a blast to ride.

Makes me wonder why it exists.
Except for the fact that it sends bikes to the graveyard, in to shops, and sells chains..
Are we supposed to believe the factory never even tested the idea of no pawl?
Gutsy move, and really, Frikken smart, which is kinda rare for jerks.

No wrong numbers  ,my best guess is 26 degrees before TDC for the intake to be closed . And yes the valve is open as the piston rises that's why the torque peak doesn't occur until 3400rpm. the cylinder doesn't fill because the piston pushes the fuel air mix back into the intake passage.

OK I'm all wet  ! on the numbers but there's still 70 degrees of piston moving upward from BDC while the intake is open .the pressure  building in the cylinder only has to over come the pressure of the intake (14.7 psi) before some is pushed back.

Mike , sorry I forgot to say that the grooves aren't placed in the piston ,they're in the major quench areas of the head .directly between each set of valves  ,only two grooves for our 4 valve head . pointing at the sparkplug. Sommender Singh grooves is all over the web with pics

The Singh grooves cut into the flathead/sidevalve head do look like they would help the flame front travel to the far corners of the combustion chamber....the far edge if the piston is very far away from the spark plug.  The machining marks are a good indication they have cut the head down to reduce the combustion chamber size to increase compression in this engine.

I am not so convinced it would help the Savage much - the spark plug is central to the combustion chamber, and the size of the squish areas are very small....and the combustion chamber is mostly open as the piston is flat and the head is domed.  I don't see how the travel of the flame front is restricted in any way.

But......I am also not an expert in this area!  

Seems like the hp worked out to be about 42.  
I had some difficulty when I initially tried to use the program and came up with an odd assortment of numbers, but got the procedure down and got consistent numbers.  That is where 42 came from.
I do not remember the torque number.
Do the time, speed and hp numbers seem appropriate ?
12.1 sec, 89mph in the 1/4 mi. from 42 hp and with a total weight of 550 lbs. bike & rider ? ?

In response to Lancer’s questions “Do the time, speed and hp numbers seem appropriate?
12.1 sec, 89mph in the 1/4 mi. from 42 hp and with a total weight of 550 lbs. bike & rider??”

Not having swung a leg over the motorcycle in question, I can only comment based on my own limited experience modifying engines and play racing over the years, various books that I have, and readily available calculators that can be found on the internet.  I am by no measure an expert on the Savage, that’s why I hang out in this forum.

Lancer provided the following information on engine modifications.  Bore 94.5mm, CR stock, Stage I cam, good flowing muffler, stock carb with a dial-a-jet.   Looks to me like a very mildly modified engine with stock compression, free flowing exhaust and a mild street cam (about 220° duration).

Increasing the stock horsepower from 30 to 42 represents a 40% improvement.  That seems optimistic given that the cylinder head and compression ratio are stock.  Generally, modifications like this would probably result in a 10 to 15% improvement in HP.  For example, when I did the dyno run on my engine after installing the DR650 cam, modifying the muffler & airbox, machining the flywheel, and rejetting the stock carburetor, I had an 11% improvement.  I thought that was reasonable for the level of modification.  So, IMO the 42 HP predicted by the Vaypor computer is suspect.  That could be a result of any one of several variables (vibration, input error, issues with the download, corrupted data, erroneous data, bad satellite link, etc.).

The quarter mile speed seems out of line with the elapsed time.  I have a table from “The V-Twin Tuner’s Handbook” that correlates MPH & ET.  A 12.1 ET correlates to 108 mph.  If I go the other way, 89 mph correlates to a 14.51 ET.  I personally think that for the Savage, a 14 second quarter is respectable.  If you consider that road tests in motorcycling periodicals pegged it as a low 16-second/high 15-second econo-cruiser, runs in the mid 14’s are a big improvement.

If you use any of the readily available calculators on the internet, significantly more than 42 horsepower would be required to hurl the Savage through the traps in 12.1 seconds.  Those calculators align closely with a formula in the V-Twin Tuner’s Handbook.  That formula is:

ET equals 6.183 times the cube root of weight over horsepower.  

If you crank Lancer’s weight and HP value through that formula, you get an elapsed time of 14.5 seconds.

To arrive at a 12.1 second elapsed time, the formula predicts that you must increase HP to 73, or reduce weight to 320 lbs.

If you want to play with some of the calculators, here’s some links.  None of these calculators or formulas are perfect, but they are useful tools.

Estimate quarter mile ET from MPH

https://speedmaster79.com/tools/14et-mph

Calculate ET and trap speed from HP & weight

https://robrobinette.com/et.htm

ET & MPH calculator

http://www.wallaceracing.com/et-hp-mph.php

Formula for ET from HP & Weight

https://www.stealth316.com/2-calc-hp-et-mph.htm