stockA4

There's really nice website out there ran by some Pontiac lovers that has every race car calculator you could ever imagine, I feel like we need something like that in the sticky on this site so when people are changing compression ratios and camshafts they could try to figure something out with the calculators on their own before they come here with camshaft and compression questions.

Most of still do it backwards in my opinion I I certainly do, when we build something different though, we pick the bottom end, pistons and then the heads. Usually in that order.

So then we are left figuring out how to cam it, when the camming is what determines the behavior and nature of the engine, and we're lying to ourselves if we don't agree that's really what we're all after, an engine that behaves and sounds the way we want. And that's the best part about all this hobby is that's different for everyone.

In my opinion now this is the best way to build an engine.

We should start by picking our displacement that we need want or can afford

Then we can pick out the cam timing we want based on weight and RPM range and the type a vehicle and the way we are using it and the way we want said engine to behave.

This is supposed to be the fun part and if we do it this way it always is.

Then after we know our displacement and the kind of camshaft we want we can then pick the pistons and heads to match the displacement and compression target and get most out of our cam choice for our said combo,

Shelf cams are usually just fine if you do it this way however It's perfectly fine to color outside the lines a little bit if you want so long as you at least somewhat adhere to the basic rules you'll find in those calculators

99 Black Bird T/A

iTrader: (4)

Interesting discussion question for sure A+++

In my opinion and random thoughts, for a NA build, most critical; first deciding what one wants out of the engine and second resources. What one has to work with budget wise in skill, time & money is big factor. As mentioned often someone picks out the Cam of the Week or for "sound" then tries to match the rest of the build to a cam that's suboptimal for the application.

1. Deciding what one wants, rock crawler, tow truck motor, daily driver, street strip, hot street, drag race engine, drift, road course, circle track etc is the next step. Basically what type of intake manifold supports the goal ie rpm range that's critical for your application. With a LS engine that's often a Fast 92/102 or MSD, ideally ported by a master like Tony Mamo.

For forced induction this is probably less critical to pick early.

2. Figure out best cylinder heads for intended application and budget. Stock, rectanglular, cathedrals, ported stockers, as cast, aftermarket etc. Valve train needed for desired rpm. What type of rocker (roller tip/non-roller tip) is required for heads etc

For forced induction cylinder heads are probably less critical to pick early other than keeping desired compression ratio in mind.

3. Displacement, getting at least 6.0 to ~ 7.0+ liter ideal sweet spot if possible without breaking the budget. Bore, stroke, pistons crank & rods.

For forced induction bottom end is important to pick early, keeping desired compression ratio in mind and durability for intended power level in mind.

4. Cam selection, tailored to the above combination of parts. How much lift, what rockers etc. Knowing how much overlap you can put up with in a daily driver etc can definitely play a role etc. Race car rough idle and more overlap less of an issue etc. Talking with a Cam Guru to help often very beneficial.

In practice, my projects go like this:
1. What can spend?
2. How much power can I make?
3. What have I got to upgrade on car? Fuel System? Rear End, Clutch, Brakes? Suspension?Gears? Tires? Cosmetic Appearance? Weight Reduction?

4. Oops can't afford to upgrade AND build new engine. New plan, upgrade car, then build new engine. Ends up taking between 4 to 14 years to complete all upgrades depending on car.

5. Rinse repeat

SoCalDave

I was going to try to write a detailed explanation, however I will stick with simple. Big cubes and monster flowing heads, works for me. One thing I would change on my '01 Camaro would probably be 4.10s instead of the stock 3.23s; that would be fun. I'm just a big fan of top shelf cylinder heads; I've seen the difference a good set of heads can make so they are always at the top of a build list for me.