74" shovelhead performance

[Revelator]

[Sky]

Of course a proper tune will get "the most" HP out of a given pile of parts.
But the final gearing determines wheel speed at a given RPM.
So, if two bikes with the same rev limit
And same final drive ratio
But different HP outputs
Hit the dragstrip
Their 0-60 times would be different
But thier top speeds would be the same
(given enough track)

No one mentioned power to weight yet...
Again, this will only affect acceleration, not top speed.

[Sky]

Haha! Revelator beat me to the punch by five minutes.
Put that bike on a diet!
And tell these chopular guys horizontal stripes are not slimming

[chopprs]

Of course a proper tune will get "the most" HP out of a given pile of parts.
But the final gearing determines wheel speed at a given RPM.
So, if two bikes with the same rev limit
And same final drive ratio
But different HP outputs
Hit the dragstrip
Their 0-60 times would be different
But thier top speeds would be the same
(given enough track)

No one mentioned power to weight yet...
Again, this will only affect acceleration, not top speed.

Not necessarily true. The one with more horsepower would have greater ability to overcome wind resistance at speed and would likely gain a few mph with the extra power.

[Tattooo]

Windows 10 ....

I bought the Wingnut updates ....

It's ok Jesse he's just jealous....

[chopprs]

It's ok Jesse he's just jealous....

That is it! I am caught...yep, you got me!

[Tattooo]

That is it! I am caught...yep, you got me!

Hell it's obvious.....

[907Mike]

I'm running a 29.5 pilot jet & a 70 main jet, revlimiter set at 5500, I got the accel pump turned off until dialed in which I think it is, running straight pipes, 9 to 1 wiscos, v-thunder cam 485 lift, I'm not sure of the gearing but its high. It sounds like 74's are dogs & my problem is not enough power. We can fix that. This is my first time to post & thanks for the information

[907Mike]

Well most near stock 74's won't do much more than that but there are some questions. Is the main jet correct? Why do you have the pump turned off? Is the rev limiter set too low on your electronic ignition? What exhaust do you have? If all is correct and the bike is running right I would suggest a little more compression which can be as simple as some thinner head and base gaskets, depending on what you have...or some new pistons. Of course, more inches will always do it but my 80"er will do over 100 easy...

I'm running 29.5 pilot & a 70 main jet, revlimiter set at 5500, accel. pump turned off while tuning which is pretty much done, straight pipes, 9 to 1 wisco pistons, v-thunder 485 lift cam, & gearing is high don't know ratios. It sounds like it is what it is, a dog. I'm afraid I won't be able to kick this thing if I bump it up th 96".

[farmall]

Dragstews, lets see what an Andrews A grind rates using that program.

A GRIND OPEN CLOSE DURATION at .053 VALVE LIFT
SHOVEL PAN

Intake 21 Deg. 43 Deg. 244 Deg. .450 .470
Exhaust 43 Deg. 21 Deg. 244 Deg. .450 .470

I'm afraid I won't be able to kick this thing if I bump it up to 96".

Compression releases are an option as are longer kicker arms. If your engine is freshly rebuilt and you want to build a stroker it might make more sense to buy a set of aftermarket cases and sell or stash the stock engine. You could even go alternator/generator cases for vintage sexy with the advantage of an alternator and easy magneto mounting if into mags.

[Dragstews]

The 96" kit from S&S is rated at 9:1

[chopprs]

The 96" kit from S&S is rated at 9:1

I would not buy a "kit" from anyone. It limits you to whatever their bean counters think is appropriate. In this case you get stuck with the generic S&S stroker piston which is made by Wiseco...who makes pistons that have had issue lately.

The alternative also does not always have to be more expensive. In this case it is not. Ultima wheels are STEEL and exact copies of the S&S wheels. Ultima rods are super nice, super strong and super cheap, opt for the unsized ones and make it perfect! S&S does make nice shafts and I like to use them. For pistons the KB forged units are indestructible and come packaged like jewelry with moly coated skirts for safety against problems during break in.
You get more strength, more compression, better finished product and spend less money...oh and more power too!

[Dragstews]

Dragstews, lets see what an Andrews A grind rates using that program.

Let's let chopprs run the program...

Being he talks the talk, lets see if he can walk the walk ... ??

Your up Big Boy ... Have at it .

[chopprs]

Why, I already know the answer?...you were the one that seems to want to find out so go ahead.

[Tattooo]

Why, I already know the answer?...you were the one that seems to want to find out so go ahead.

LOL Yea right..... Just the answer I expected from you..........