CAMQUEST - Can I substitute Big Block CI for Stroker SB?

[YoungBlood]

http://www.camquest.com/

As you most already know, Camquest allows you to input certain engine variables to provide a camshaft suggestion and the rough dyno numbers thereof.

Camquest is far from perfect, but still somewhat helpful.

A big down-side to me is it's lack of engine options; it only provides factory engine displacement and strokers aren't taken into consideration.

To get down to it, would it be at all accurate too substitue a big block 383 for a 318-based 392 stroker in Camquest?

383 BB = 4.25 Bore X 3.38 Stroke
392 SB = 3.94 Bore X 4.00 Stroke

Comp recommended me a cam for a 392 build that I am having trouble accepting as the 'best choice', so I started messing around in Camquest with little choice but to use the 383 as the platform.

My concern is that, although close in cubic inch displacement, there would be a real-life difference in hp and torque. The bore on the '383 BB' is bigger and so are the valve-size options, but the '392 SB' has a bigger stroke (in terms of swing).

For example: Would the same cam for both engines make more horsepower in the '383 BB', but have greater torque in the '392 SB' ?

Can I safely use the 383 numbers in my cam choice or are these motors waaay too different of animals to be comparing?

And, VERY IMPORTANTLY, can I assume power bands are similar between the two engines with the same cam?

Thanks!

 

[moper]

The single biggest variable that affects the resulting power output and rpm ranges is the stroke. The displacement means little, the bore means little in "the big picture". I don't use camquest but it would surprise me if you could not just input the bore and stroke. Big or small block means nothing with those two numbers plugged in.
so:
"For example: Would the same cam for both engines make more horsepower in the '383 BB', but have greater torque in the '392 SB' ? Similar power yes, but the longer stroke will make it at a lower rpm, make peak horsepower at a lower rpm, and have flatter power curves for both.

Can I safely use the 383 numbers in my cam choice or are these motors waaay too different of animals to be comparing? In my opinion, way different animals and cannot be compared apples to apples.

And, VERY IMPORTANTLY, can I assume power bands are similar between the two engines with the same cam? Similar, but different in crutial ways. See answer to example 1...

 

['64 Cuda]

Just select the 318 engine for your buildup. Then go to the bore & stroke fields & type in your new bore & stroke. Be sure to hit enter after you type in each one. You can change the info in just about every field that way. If you save the combination you can pull it back up anytime you want to & play around with different combinations. There's also a way to input your own cam specs but it's a lot more involved.

 

['64 Cuda]

YoungBlood, just wondering if you got a chance to try this out & got it to work for you.

 

[rumblefish360]

You can change the displacement by clicking on the bock that the bore or stroke is in and hitting enter after the change is typed in.

 

[YoungBlood]

Hey guys; no I haven't. These bore & stroke blocks aren't on the site. There are no option to change the numbers.

Could we be talking about two different programs?

Does anyone else go to the link below and only see fixed numbers for the bore & stroke after they choose their engine?

http://www.camquest.com/

 

[YoungBlood]

Nevermind! I have been going to the quick and easy version on the Comp homepage and it was just brought to light there is a downloadable version.

Thanks guys!

 

[rumblefish360]

OK, so you can change things around now right?

Notice how the difference in stroke makes the power band curve differently?
Notice where peak power is between the 2 engines with the same cam?
Interesting huh?

 

[YoungBlood]

OK, so you can change things around now right?

Notice how the difference in stroke makes the power band curve differently?
Notice where peak power is between the 2 engines with the same cam?
Interesting huh?

Interesting and EYE-OPENING. I don't think I'll ever consider a big block for a street car again (maybe not? who knows?)

I'm so friggin addicted now.

And man, that 4" crank in a small block really gives hell early.

 

[rumblefish360]

Well, stroke a big block to 500 and see what happens. Enter in some flow numbers from like, ummm, lets say, Indy or Hughes engines and add a roller cam.