Edmunds Answers



  • MrShift@Edmunds 10/28/09 12:36 pm PST

    Not easy to answer because we don't know what it is you want to do with the car. The type and size of the engine you choose can radically alter the car's driving characteristics, as well as its most appropriate use. So first of all you have to decide if you are going for:

    daily driver, close to original stock characteristics as intended by Chevrolet in 1968.
    daily driver with some grunt
    pro-touring, a comfortable long distance car with good fuel economy
    fun-level drags once a week
    serious street racer/pro street car
    a radical monster show car, complete with blower, flames and outrageous noise.

    My advice would be to visit some of the onlline vendors selling already rebuilt "crate engines", and read over their descriptions of the various horsepower levels they offer. You'll learn a lot.

    Also there are very good books on AMAZON. Search for "How To Hot Rod Your Chevy" and you'll find any number of interesting titles.

    Most newbies don't think out their projects before they start them, and this sometimes leads to a lot of pain and not much gain, or, worse yet, a car they really don't want to drive.

    So set your goals, work out your budget and THEN start tearing the car apart.

  • karjunkie 10/28/09 12:46 pm PST

    If I were you I'd create a clone version of the Chevelle 396 cubic inch SS. This was the most powerful engine available on the car in its time. The 375-bhp L78 had solid lifters, big-port heads, and an 800-cfm Holley four-barrel on a low-rise aluminum manifold. The engines you mention are just too heavy to put in there and the 396 L78 is going to give you a very fast car that handles reasonably well. I'd get a rear end with positraction for any high output engine with the 4.88:1 drag cogs.

  • tony78 10/28/09 12:48 pm PST

    I think my friend had a chevelle and it had an ohv inline 6, it had adequate acceleration but it got close to thirty miles per gallon on the highway.

    I had to add that because i noticed that mr shift right left out the high mpg / fuel economy factor.

    Oh, and the chevrolet inline sixe's were real workhorses, very durable engines.

    I think they were 173 cu.

    The info book is in the shop and im too lazy right now to go look it up.

  • countrychevy 10/29/09 12:10 pm PST

    well see I just want her to purr. She is for fun and show. My car is already pulled apart I have to rebuild everything honestly it is not my first car to take apart so I mean its just I have problems deciding on the engine because when I got this car it looked like someone had started to plant a garden inside this car. I mean really I do not wanna depend on anyone else's already redone engine I may be a girl but I can put an engine together. I have an idea of what I want but I'm not sure I mean I have to rebuild everything and I want it to be a mix of comfort fun and show I mean I want her to fly down the highway but I want her to sound amazing. This is my baby.

  • MrShift@Edmunds 10/29/09 7:32 pm PST

    Well if you rebuild it yourself you're still going to have to rely on outside machine shop work--so there's still plenty that's not going to be in your control. I think a 350 block will be just fine for you---you can build it to go as fast as you want.

  • countrychevy 10/30/09 11:17 am PST

    I understand that thigs will be needed from outside shops thing is I'm only 17 I have 3 jobs and still not enough money for the exhaust and brake system I need/ want

  • MrShift@Edmunds 10/30/09 3:14 pm PST

    Okay so you'll have to do this one thing at a time as you have the money. First thing I'd do is talk to a machine shop that has a good reputation and that has built engines for local people. If you don't have good people supporting you, you'll end up making mistakes.

    Once you have a machine shop all lined up, you can buy your core engine and starting taking it apart for devlivery to the machine shop. You can also do your homework then about how you want this engine built---for low end torque, for economy, for mid-range grunt, whatever. This is why it's good to talk to the machine shop and learn all the options.

    You have to look at an engine as ONE LONG TUBE from the air cleaner to the tip of the exhaust. No sense changing one part of the tube if you don't do things to the rest of the tube. Keep that in mind as you buy/change stuff.

  • countrychevy 11/02/09 12:24 pm PST

    ok now about the mpg situation how bad is it gonna hurt if I have this 502 big block how much more gas is it gonna eat up

  • karjunkie 11/02/09 12:41 pm PST

    A LOT! Assuming you're gonna put a big a$$ carb or multicarb setup on that engine, don't expect better than 8-10 MPG. A modern transmission will be the biggest improvement in gas mileage

  • MrShift@Edmunds 11/02/09 2:14 pm PST

    And if you put a 502 in there you're going to have to figure out how to put that kind of power to the ground. If you don't work on suspension and tires and differential, all you are going to do is a) make tire companies rich while your car stands still and, b) break things in the drivetrain.

    More power requires more suspension and more braking and more *strength* to everything in the driveline.

  • eph678 11/19/09 6:00 pm PST


  • zaken1 12/03/09 8:19 pm PST

    It sounds like you could benefit from some information about the differences in the basic characteristics of the various engine sizes that are potentially options. Chevy V-8s are made in two different basic configurations; small block (262 to 400 cubic inches) and big block (396 to 572 cubic inches). 1968 Chevelles were originally available with both engine types; original options ranged from a 250 HP 327 cubic inch small block, to a 375 HP 396 cubic inch big block. All the big block engines weigh about the same, and all the small block engines weigh about the same. The basic difference between the big block and small block is that the big block is larger and heavier, and has a greater cooling system capacity (to handle the higher power output of the larger engines). The big block heads also have larger ports and valves; and more radical cams. And all those differences combine to reduce the fuel economy and roughen up the running of the big block motors.

    What those differences mean in terms of your goals is that a big block engine would typically sound more radical than a small block; and would get significantly worse gas mileage. It would also typically have more low end power; but a well set up small block would not be that much different at high RPMs. Because of these differences, and because you can build or buy a 383 cu in small block that makes more power, is similar in displacement and stroke length to the 396 big block, and is less expensive to buy and uses less fuel than the big block. I would personally go with a 383 small block. Having worked on both small block and big block Chevys for over 40 years, I definitely feel that the small blocks run more consistently, and are more reliable.

    But, if you want to go for more power than a small block, I would suggest a 427 big block. 427s have a shorter stroke than the 454s and 502s; and this means the 427 revs more freely, which makes it sound nicer when you get on it. The 427 will also get better fuel economy that the larger motors (assuming you don't put too big a cam in it).

    Many people don't appreciate the need to balance and coordinate the internal parts in an engine. Putting a big cam in a motor which has a stock compression ratio will usually make it run WORSE than it previously did. In order to get the advantage of a performance cam; the compression ratio, porting and valve sizes, exhaust system, and intake system all have to be upgraded to a comparable extent. And even after this is done; the modified engine will then have to have the ignition advance curve and fuel mixture recalibrated to match the engine modifications (by running the motor on a dynamometer, experimenting with different combinations of parts and adjustments, and measuring the changes in power). Dyno tuning is the secret of getting outstanding performance (and that great sound); but it can be very time consuming and expensive.

    For this reason, I would suggest not guessing about what parts combinations would work best; and instead buying a performance crate engine which has already been researched, tested, and manufactured with proven combinations of parts. A GM Performance parts ZZ383 crate engine produces 425HP at 5,400 RPM and 449 ft-lbs torque at 4,500 RPM. It also has aluminum heads, a roller camshaft, and a 9.7:1 compression ratio, which will run well on pump gas; along with hydraulic valve lifters, which will not need periodic adjustment. This motor is available from Summit Racing (part # NAL-12498772) for $5,159.95 plus shipping. It comes assembled; but does not include an intake manifold, exhaust manifold, distributor, ignition system, or fuel system.

    If your budget is not that high; rather than trusting your pet project to the mercy of the local machine shop, I would strongly recommend having a remanufactured engine custom built by the best remanufacturer in the country, at a lower price than you'd pay for comparable work locally. This wonderful company is called Hiperformer Engines, and is in Spokane, Washington. They are the sole supplier of replacement engines for NAPA parts stores, and have the lowest return rate in the industry. Their engines come with a 7 year, 100,000 mile warranty and their prices are a joy to behold. They will custom build a motor to your needs, and ship motors at very affordable prices to anywhere in the U.S.. So by all means, phone the contact number on their website, and speak with their experts directly. 

    Source: www.hiperformer.com

  • MrShift@Edmunds 12/03/09 9:48 pm PST

    I think a 383 stroker crate engine would be perfect...wham, bam and you're done, AND you have a warranty.

  • swampfox09 12/16/09 7:45 pm PST

    if it was mine would be a big block 396

  • hdny03 12/22/09 9:16 pm PST

    the chevy 350 easy to find and parts are cheep to buy the best bang for your buck

  • obyone 01/03/10 8:04 pm PST

    LOL!! You old coots keep forgetting that this is a 17 year old whether it be boy or girl on a limited budget.

    Cheap I'd go the 383 stroker. You want return on investment go with the 396 and a full restore should net you around $50K return.


Top Engine Experts View More

Rank Leader Points
1. MrShift@Edmunds 31935
2. zaken1 29570
3. karjunkie 27555
4. Stever@Edmunds 5360
5. tony78 4935
6. texases 4870
7. 0patience 4455