Guest butlersZ Posted October 29, 2003 Share Posted October 29, 2003 How hard would it be to get these figures from a 283? Would it be possible without killing the engine? And yes I know, theres no replacement for displacement, but I'm looking for some gas mileage and high revs. Any suggestions with a $5,000 budget? Quote Link to comment Share on other sites More sharing options...
Phyte Posted October 29, 2003 Share Posted October 29, 2003 How hard would it be to get these figures from a 283? Would it be possible without killing the engine? And yes I know, theres no replacement for displacement, but I'm looking for some gas mileage and high revs. Any suggestions with a $5,000 budget? With a $5000 budget, why don't you find yourself an LS1/T-56? You'll get 20mpg+, and have all kinds of power low to high rpm, AND have money left over. Phyte Quote Link to comment Share on other sites More sharing options...
jonzer12 Posted October 29, 2003 Share Posted October 29, 2003 Small displacement doesn't always mean better mileage. You still need to burn enough fuel/air to produce the 400hp. You could achieve those specs on a 283 with either forced induction or an almost race setup engine. You would need to dump some serious dollars in your head/valvetrain/cam setup. What you would end up with would be a very expensive, high compression (NA) engine with probably a very steep power curve. If you went the > 350 CID route you would probably save some money and get more usuable powerband. I would suggest calling a well recognized engine building company and discussing it with them. Even if you are going to build it yourself just pretend you are interested in buying one. If you ask the right questions and they are in the know you will get your questions answered. Also what kind of you revs are you looking for? Getting a built smallblock to hit 7500 isn't very hard its just expensive. I have numerous friends with street/track cars that make peak hp very close to 7500rpm. If I were you I would abandon your two concerns, 400hp and fuel economy is an oxymoron and highrevs seem attractive but the reality of it is that high winding v8's are expensive and you will get used to your engine's character anyways. Build your engine around your budget, drivetrain and gear ratio selections, and the weight and general application of your car. If you match all of these up your will be happier with the end result. Quote Link to comment Share on other sites More sharing options...
Guest 400HP280z Posted October 29, 2003 Share Posted October 29, 2003 listen to jonzer12. very well put man. how often will you rev a motor to 7000+ rpm's ? thats not prctical for a street /daily driven car. Quote Link to comment Share on other sites More sharing options...
fl327 Posted October 29, 2003 Share Posted October 29, 2003 I would drop the 283 like a bad habit. a 350 weighs and sits the same and displaces 67 more cubes!!! I can understand wanting a high reving engine, that may not be practical on a pump gas street engine though. If you are going to go with a sbc, you should at least use the general standard entry level displacement small block---a 350. Quote Link to comment Share on other sites More sharing options...
Guest Nic-Rebel450CA Posted October 29, 2003 Share Posted October 29, 2003 Most people on this forum gave me the same responses when I started asking about my 302 I plan to build. Seems everyone wants to change your mind as oppose to giving you answers to your question... Yes, a 283 will get better mileage. It has a smaller bore so it will have less area for friction. It is shorter stroke, so it will have less loss there. Bottom line, the 283 will have a much lower BSFC if built right. You will get better gas mileage, 5 mpg or so can make quite a difference. Plus it is nice to know that you arent wasting as much so you are helping the environment at least a little. I am not sure how much you can build up a 283 N/A and still have it streetable. Yes, building 400HP will take it's toll on your mileage, but the key, of course, is going to be how much (or little) HP the engine makes when your foot isnt on the floor. I plan to have similar goals with my 302. I plan to get over 25 MPG, and around 300-325 HP at the wheels. Later, when I plan to move up my HP goals, I plan to go with a supercharger. I plan to have a centrifugal supercharger with an electronically controlled clutch so it wont always be on. This would probably be a good way to go for your 283. Another thing in my plans is to have a TBI setup with digital controls for AFM so I can run it a little leaner for better mileage when I am not racing around. I am planning to build my 302 with a 9000+ redline and it will be for street use. Sure, some will say this is not practical, just as much as I can say 300lb/ft of torque at the bottom-end of the RPM range is not practical for a 2400lb car. Build what you want to build! Feel free to PM me to compare notes. Quote Link to comment Share on other sites More sharing options...
Guest Nic-Rebel450CA Posted October 29, 2003 Share Posted October 29, 2003 BTW, change your avatar! Quote Link to comment Share on other sites More sharing options...
Mike C Posted October 29, 2003 Share Posted October 29, 2003 The 283 is not good for max power output because of its small bore. You are limited to a 1.94 intake valve, and even with that bore shrouding is a problem. 283 parts are more expensive than 350 parts so any mileage gain is offset by buildup price. You will have to drive a lot to make back that gain. The 283 is a fine little motor, same with the 302. But the 350 is the hands down winner $ for $. The smaller engines will require more gear to put the same torque to the wheels. This extra RPM negates the benefits of the smaller displacment. Bottom line is any of the 4" bore motors will get better mileage and power in a performance application, even if they do displace more. It takes a certain number of BTU for any work done, regardless of engine size, same power is required to move the car. That means if you can burn your fuel more efficiently for a given power output, you will get better mileage. The .060 283 was the hot ticket until 1960. Then when the 327 showed up it was all she wrote! Quote Link to comment Share on other sites More sharing options...
jonzer12 Posted October 29, 2003 Share Posted October 29, 2003 In response to Nic-Rebel450CA I just want to make few points. It was not my intention to try and change anyone mind or discourage the building of a small displacement smallblock. I really don't think people here intentionally try to discourage any particular project, its just that some setups are in all senses the best route to go. Personally I am not that experienced with building engines/cars but I have witnessed MANY projects and the difference I see is how much people enjoy them a fews years after there done. Gas mileage concerns screams daily driver to me and you can't tell me that a highly tuned 283 making 400hp and a 350 making the same 400 are not 2 very different things. Revs are great but reality is after a year of owning of the car the intense noise, pissed off neighbours and attention from police, etc that a screaming 7000 rpm smallblock makes get old very quickly. Tight powerpands, huge cams and very high compression don't make for a enjoyable daily driver and that is most likely what you are talking about with a 400hp 283. I have changed my original project plans hugely by coming to this site. My only point is that before you dump a pile of money into building a 283 think about the tradeoffs and is it the setup you will still want a few years down the road? Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 29, 2003 Share Posted October 29, 2003 Revs are great but reality is after a year of owning of the car the intense noise' date=' pissed of neighbours and attention from police, etc that a 7000 rpm smallblock makes get old very quickly.[/quote'] I so much agree! Tight powerpands, huge cams and very high compression don't make for a enjoyable daily driver and that is most likely what you are talking with a 400hp 283. I'll second that! To get 400 hp out of an NA 283, it will not be very streetable, and WILL NOT get decent gas mileage. The cam needed to make an NA 283 make 400hp will also make it have HORRIBLE mileage. If you want 400 hp and decent mileage with an NA engine, the way to do it cheaply is build a 350, 383, 400, etc. old style V8 with a mild cam. The more displacement, the milder the cam can be to get the 400hp, and the mileage will most likely be BETTER, even though the displacement is higher. Don't rule out an LS1, although that route is not as easy, it has been done in the early Z. Price depends on how good a deal you find. If you turbo the 283, it can stay mild, get good gas mileage, and make 400 hp. The other alternative is a somewhat mild 283 and N2O injection. Quote Link to comment Share on other sites More sharing options...
Guest Z-rific Posted October 29, 2003 Share Posted October 29, 2003 I'm with Pete. A turbo would make the 283 streetable and you would have the necessary power only when you spool the turbo up, allowing you better gas mileage when you're just putting around town. I have seen heavily built 283's. Big cams. Significant head work. Big carbs. What about this says decent gas mileage? Nic, I'm with you on answering questions and not trying to convince people to do otherwise. In this case, however, a NA 283 pushing 400 HP, (and bet it would be more than 300 lb/ft torque) would be a monster engine, a little pricey and not very "streetable". ....unless you turbo it. Which is $$$ too. Quote Link to comment Share on other sites More sharing options...
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