Hey guys, yet another mpg's thread...sorry! I'm starting a new project (always exciting) for a '67 impala. My goals for the drivetrain are durability and drivability. I'm wanting to put LOTS of miles on this car. That being said, I wouldn't mind enough hp to merge with traffic on the on ramp without any issues.
Obvious things I'll do: Electric timing, electric fans, modern A/C (must have A/C) match peak torque to cruising speed (and try to get peak torque to lower rpms via intake and exhaust mods), add lots of insulation to the cab. Aftermarket modernized tranny with locking overdrive.
Still debating between a spread-bore carb and EFI. Spread-bore sounds cheaper to buy and easier to instal, but EFI sounds cheaper to run and easier to maintain, so any feedback on that would be appreciated.
It has a 327 that hasn't been run in ages, so I'll start by opening that up once I get it in my shop and seeing what I'm starting with, but I wanted to ask you engine guru's about what you would do, trying to keep the end price as low as possible. That being said, a crate engine might be the cheapest, but I've heard they only last for about 12k miles between rebuilds and are built with hp in mind, not mpg.
If the 327 is within specs so that I don't have any machine fees, I might just rebuild it with new pistons and a new cam. get my compression ratio to 8.5 and put in a "towing cam" (I don't know much about cams though, does anyone have a good resource to study that?). If the 327 measurements are out of spec and it will have a high machine shop fee I'll most likely replace the whole thing with a junk yard engine which brings me to a HUGE set of options and questions, the biggest 2 shown below:
Question 1: Can I rebuild a chevy bbc/sbc from the 80's/90's without having that cars computer? replace intake with aftermarket ect. or do I need to stick with my generation of block?
Question 2: It seems like a bbc would get significantly less mpg's, but I've read on some forums that a bbc tuned for mpgs can get pretty close to that of a sbc. If that is true (I can get close to the same mpgs as a sbc) then I might go with a bbc just for the wow factor when you open the hood. Granted, I'd still only get like 290 hp, but hey, it looks cool!
So ya, sorry for the massive post, but if any of you guys have experience with tuneing these v8's for economy let me know! Especially about the spread-bore vs EFI, and with EFI, multiport vs uniport.
Thanks,
Matt
Obvious things I'll do: Electric timing, electric fans, modern A/C (must have A/C) match peak torque to cruising speed (and try to get peak torque to lower rpms via intake and exhaust mods), add lots of insulation to the cab. Aftermarket modernized tranny with locking overdrive.
Still debating between a spread-bore carb and EFI. Spread-bore sounds cheaper to buy and easier to instal, but EFI sounds cheaper to run and easier to maintain, so any feedback on that would be appreciated.
It has a 327 that hasn't been run in ages, so I'll start by opening that up once I get it in my shop and seeing what I'm starting with, but I wanted to ask you engine guru's about what you would do, trying to keep the end price as low as possible. That being said, a crate engine might be the cheapest, but I've heard they only last for about 12k miles between rebuilds and are built with hp in mind, not mpg.
If the 327 is within specs so that I don't have any machine fees, I might just rebuild it with new pistons and a new cam. get my compression ratio to 8.5 and put in a "towing cam" (I don't know much about cams though, does anyone have a good resource to study that?). If the 327 measurements are out of spec and it will have a high machine shop fee I'll most likely replace the whole thing with a junk yard engine which brings me to a HUGE set of options and questions, the biggest 2 shown below:
Question 1: Can I rebuild a chevy bbc/sbc from the 80's/90's without having that cars computer? replace intake with aftermarket ect. or do I need to stick with my generation of block?
Question 2: It seems like a bbc would get significantly less mpg's, but I've read on some forums that a bbc tuned for mpgs can get pretty close to that of a sbc. If that is true (I can get close to the same mpgs as a sbc) then I might go with a bbc just for the wow factor when you open the hood. Granted, I'd still only get like 290 hp, but hey, it looks cool!
So ya, sorry for the massive post, but if any of you guys have experience with tuneing these v8's for economy let me know! Especially about the spread-bore vs EFI, and with EFI, multiport vs uniport.
Thanks,
Matt