Originally Posted by SB (Post 4216396)

It's all about how much air get's in the combustion chamber.

More cid's has more room for more air. It doesn't necessarily get you more air.

Originally Posted by Full Force (Post 4216409)

A buddy of mine just did 502 CI engines with fully ported Edelbrock oval ports, 9.5:1 compression Cams from Bob M. and 850 CFM carbs, did 621HP and 644Tq, I forget rpm, but those are good numbers for N?A 502's... its all in matching parts up good...

Originally Posted by MILD THUNDER (Post 4216392)

Back in the 70's, they used to install "Economy" meters in cars. I remember as a kid our family car was a 1975 Bonneville. In the instrument cluster, it had the "economy" gauge. It started out in the green while cruising down the highway. Upon acceleration, it would swing towards the red. Harder you accelerated, further into the red it got. lol, all it was, was a vacuum gauge.

High vacuum=low load
low vacuum= high load

To get back on topic though, there is something to be said about having an engine package that operates efficiently in your cruise range. Like I stated earlier, you wouldnt want to slap some huge 345/360cc port heads on a mild 454 engine, with a cam that would make peak power at 7000RPM, in an engine you don't plan on spinning past say 5400RPM.

There are alot of options though nowdays, as far as engine combinations, that give you a bit more flexibility. We have great valvetrain components available, that will allow you to safely turn that smaller CID engine, a bit faster to make up for its lack of CID.

I'll use my friend Joey's engines we recently built up as an example here. He had 522ci shortblocks to work with. Really nice components in them. He had Lunati Signature series blower crankshafts, oliver connecting rods...He like any of us, wanted to make good power. He had his sights on 1000HP.

Him and I talked alot about his build options. At the time, he had Edelbrock marine performer heads, and was purchasing 1071 blowers and intercoolers. I just knew, his edelbrock heads were not going to allow him to meet his goals, at least without an insane amount of boost that is.

A couple of his buddy's told him he really needs to go to a 4.25 stroke, to make them 555ci. I disagreed, and thought he could hit his goal, but it would take the right cylinder head/cam/boost/rpm combo.

Thats when I recommended he get in touch with Bob Madera, and look into some AFR heads, cam, etc. After working with Bob, Joe decided to go with the AFR 315 cylinder head, Bob did a cam for him, and the right valvetrain components to go with the setup.

When it came down to dyno day, the results were what we hoped for. The engines made their target number, within the target RPM/BOOST levels. The torque was outstanding as well.

Now just for comparison purposes, or to go deeper into all this. Our other buddy had recently dyno'ed his blown combo. His was a 540ci, 345 Dart heads, also a 10-71 blower (its what he had to work with). While this build had the cubic inch advantage, it made less power. With both engines at 8lbs of boost, the smaller 522ci, made 37 more HP at 6200RPM, and quite a bit more torque thru the rpm band. Same dyno, same dyno headers.

One would think that the larger engine would have made more torque, along with more power. I was really surprised at the torque production from this 522, not only was it a very flat curve, the numbers were really great for what it was. The key was the 522 simply had a better package. With that being said, the iron headed 540ci making 893Hp at 8lbs of boost, is/was nothing to turn you're nose to. Its just a comparison. But if they were both 540ci, Joey's engines, would have made around about 70HP more lb for lb of boost. Keep in mind those 345 Darts, are tremendously better at moving air, than a GM rectangle port casting. So, if that 540ci deal had a set of GM heads, that 37HP gap, probably would have been closer to a 137HP gap. Point, theres more to building a good package, than simply throwing cubic inches at it. Same goes for N/A engines as well.

Originally Posted by MILD THUNDER (Post 4216421)

Couple key things there. Key word, fully ported. lol.

Mike Tkach has done a few 502 Builds using the edelbrocks and had similar power number results. Around 600ish, but the heads had no port work.

I think the edelbrock heads are a decent bargain, but they are simply not that great of a head for moving air. Their new E CNC heads look impressive though.

Heres a nice article with a 502 with AFR 315 heads. It does have a fairly aggressive solid roller, , but 740HP from a 9.6:1 502 engine is pretty good!

http://www.sporttruck.com/techarticl...ylinder_heads/

Originally Posted by ICDEDPPL (Post 4216442)

It would be interesting to see if my 540`s would close that gap vs. Joey with:

1. Wedges to increase velocity
2. Same (bigger carbs)
3. intercooler or matching intake temps
4. same compression
5. Bob cam

Last day today before I put the winter cover on Joe, sure you don`t want me to pull it so we can experiment?