Building a SBC for both POWER AND MPG

[robertwb70]

Yep, that's a pretty big issue, and those vortec intakes are still pricey but they are getting to the used market now. The vortec heads can be drilled for the older intakes but I believe it doesn't match up as well as a new intake would(never seen a set drilled in person), there are some companies that sell them pre-drilled even so maybe it works out OK.

Thing is those open chamber (76cc) heads really are about the worst heads for efficiency or power. The older L98 corvette heads would be almost ideal too if you could find a set of those (and they are aluminum, if you like that sort of thing). Dart SR torquers would be another good choice, and still cheaper than Edelbrocks. Not that you'd be going wrong with Edelbrock stuff, it's really good stuff but If you're like me you have to watch the budget too.

[robertwb70]

Originally Posted by halflingsrock80

With the 64cc chamber can I still run 87 octane?

Also, I notice this is not "50 state legal"meaning no heat cross over for EGR. So any idea if the fact this is a more efficient head design makes EGR obsolete?

Yes 87 would still work if tuned properly, check out Hot Rod Magazine, they've done a few dyno builds/ tests with these heads and cheap gas.

As far as EGR I'd say "kind of", it would be nice to keep the EGR but SBCs run fine without it, none of mine have ever had it. I think the heads have EGR provisions so it depends on the intake to keep it functional but it should be pretty easy to have EGR if you want it.

*Looks like I posted at the same time you did.

[Tygen1]

I would recomend you get a good EFI set up. I tuned carbs for years (for power) and it is so hard to get them right. Most end up overly rich because it will run ok in most situations that way. It is so hard to get a carb right, and then the temps drop/rise 20 degrees and you are wasting fuel or not running right if you were running corectly to start with. I have a 1988 Mustang GT with a 302 mass air flow EFI motor. We routinely got 17 mpg city and 24 mpg highway with no thought at all about getting better mpg. That's with a non lock up torque converter and quite a bit of idling to keep the baby asleep. Boy that V8 makes babys sleep good

[Frank Lee]

I know I've seen SBC "econo" build-ups in the past. Why try to reinvent it based on not much more than speculation?

[theycallmeebryan]

Not everyone here hates power. I have a 84 Buick Regal T-type with 87 drivetrain.... turbo 3.8L V6

Over 20mpg highway and over 700hp..... no wonder god drives a Turbo Buick!

[robertwb70]

IIRC it was Car Craft that did a "Real Street Eliminator" challenge once with a 80s ElCamino and that turbo Buick 3.8 swap, it ran low 12s in the 1/4 and during the ride and drive (100 some odd miles) it got 30+ MPG, they were amazed. Turbos are crazy things.

EFI is nice but it usually costs 10 times more than a carb (which he already has). But if it's an option you might want to look into GMs ram jet set up for small blocks, looks like it sells for $1600 on Jegs, but that doesn't include ECU, wiring harness, or sensors...but it is a cool setup.

[comptiger5000]

The low 1st gear of the 700r4 would actually be an advantage. It would allow slightly taller rear gears to keep highway RPM low, and still give a good launch from a stop when desired.

If the engine can make its torque low enough, I would see no problem with turning around 1600 rpm @ 60 mph. My Jeep turns about 1800 @ 60 mph, and it's geared a little low IMO, considering it'll pull comfortably in OD with the TC locked from about 1050 rpm, even when climbing a hill. By 1200, it pulls pretty darn well.

[Phantom]

If you want to get the best MPGs I would go EFI. If the bolt pattern is similar to a later model 90s GM V8 I would pull the Lower and Upper Intake manifolds from a junk yard along with the fuel rails, injectors, MAP sensor(should be in the Upper intake), Throttle Body (with all sensors, the PCM and its wiring harness, then buy a new O2 sensor. Depending on where the injectors run to you might need heads also (if injectors run to the heads instead of lower intake).

Have a local tuner delete the missing codes out your are in Chicago so that should not be a problem look at HP Tuners Bulletin Board - Powered by vBulletin for a tuner.

You will just need to research what parts will bolt on to your block and what year PCMs can be edited.