I ran ethanol in my OT thunderbird turbo car, I loved the added power but the fuel economy was 20 mpg instead of 23 on high test. The upside was the cost was $.50 a gallon less than regular. I quit running it because I had to drive out of the way to run it. If it were readily available I would use it.
Detunning an engine will not get you better gas mileage. Proper gearing and tunning will get you better gas mileage. If you want to make it smaller your options are a different crank amd or sleeves to make the bore smaller. If you look around long enough you may find a large journal 327 crank, then a set of pistons and you are there you got a 327. Or you could contact a company like **** or the like and get a 283 crank for it, then you could come up with a 302. You are not going to get any better mileage than 20-22 out of either without a computer to controll them and 20-22 is what I have gotten out of my 355 since the day it rolled out my living room door in '97. Good luck with whatever you decide.
1/3 scale and it produces 6 hp - watch it run here.... http://www.chevy********.com/news/video-fully-functional-13rd-scale-chevrolet-350ci-small-block/
This SBC is 1/6th scale and it runs.... www.chevy********.com/news/video-worlds-smallest-running-327ci-small-block-engine/
When I read the ***le, the first thing that popped into mind is the Ford 351M which was a destroked 400, a boat anchor, a gas guzzler, a fuel consumer, a pig, and anything else thats not efficient. My opinion is, buy a smaller engine, or make the 350 more efficient.
I still like the idea of a 3.00" stroke crank in the 350 block and a set of canted valve heads from Trick-Flow... I'm sure that little hummer would scream!!!..
Its a FIVE wire hook with a stand alone harnes. 1,2,3,4,5 ! Its about as hard to plug in 5 toasters. A stock junk yard harness can be worked into a stand alone harness in about 5hrs. It may take you 15 hrs on your first one because of the wiring diagram study. A plug and play harness can be purchased if you don't have 5-15 hrs to spend or don't understand electrical issues. You will need to have the ECM unlocked and the security system disabled at a minimum. Then perhaps retuned to suit your swap. The 5.3 swap is very difficult to beat on all levels. Even future & unknown fuel & gas issues are covered
You've got to be loving the price of gas today in California. You can pay for a lot of gas before you pay for a new motor. But, at $5 a gallon, I just don't know.
This is true, I've run into it firsthand with factory spec settings on my late model beater trucks. One year Fed emission standards changed; GM's answer was to detune the motors; so everything that year gets worse fuel milage. I got one four years older and it gets the best average MPG of any of the beaters I've had over the last five years. I also agree, low 20s is about the best out of a V8 without a computer control system unless maybe it's a really lightweight car.
Displacement is only one of many factors that impacts fuel economy. Case in point... in the mid 80's Jaguar redesigned their V12's head to a swirl design. It's called the May Fireball head. It's a good case study in fuel effeciency becasue the fuel consumption improved 20% and everything else including cam timing and displacement stays the same. ZZ4 cam is the wrong cam for a short stroke smaller displacement motor too. It will be a pig because there will be too much over lap and not enough piston speed. Below is my recipe for fuel effency first and power second. - small displacement long stroke. The long stroke keep the piston speed up at lower RPM's so you dont have to wind it up to get power this works well with a mild cam. - mild roller full roller cam. (205@ .050) The rollers keep friction down and allow for aggressive valve ramps for flow while the conservitive timing keep the static compression ratio high and prevents unburned fuel from exiting out the exhaust valve. - A modern Vortec or swirl head is very important for fuel consumtion. Consider the LS series design and the historical May fireball combuston chamber. - Minimize parasitic loss. Small bore motors do this well, less ring area means less friction. Consider a V6...6 rings have less drag than 8. Swinging around less weight helps too. - propper gearing and a 700R4 or 200R4 setup to lock the converter in 3rd and 4th gear. Taller gearing works well here so you can loaf aroung in 3rd gear locked up on local roads and 4th gear locked up on the highway. - Fuel injections and a closed loop O2. When you think about it for awhile you end up the same place GM did... a full roller 305 with TPI or the chevy 90 degree V6 with MFI.
Don't blame you for balking at the price of gas. Almost ****ped my pants when I heard the CA price north of $5 buck in places. After four pages of suggestions you have a few things to consider. Bottom line is making a ZZ4 350 "smaller" is not going to get you where you want to be. I considered a 4.3 for my "A" coupe but when I heard one with packs sound like a vacuum cleaner, I thought otherwise. To keep it V8, the 283 with a Qjet will work. The 305 with a TBI setup (heads and all) with get you there. And as many have suggested lower rear gears will help. Me, I went with a 215 Buick but that's another story.
My sedan has a fast burn zz4[385 hp], 700 r4, 3.73 gear. Gets 22 to 24 all day at 80mph on the highway.And its fast. By the time you get a crank and swap the other parts, you could buy a lot of gasoline.
Hee it just occured to me send the small block to me. I'll get the missus to wash it, I swear that woman could shrink a cast iron pot.
I'm gonna wade into some deep,dark water here...but this thread has my head spinning.. I know you can calculate an engine cruise RPM using axle ratio/tire size/trans final ratio,etc.. Using that info,how do you then arrive at the HP/Torque needed to do that ? Once you get HP info, how do you determine the engine size needed to do that? What I have in mind for my next project is a 3100#/305" or 350"/ 200-4R combo This would help in buying rear axles,tires size,and most of all engine size...
I don't know about hp or torque, but there are plenty of web sites to help you out. From what I've heard, 1800-2000 rpm at your desired highway cruise speed seems like a good target goal for a V-8. Gary http://www.roadkillcustoms.com/hot-rods-rat-rods/Differential-Gear-Ratio-Calculator.asp https://www.hgmelectronics.com/display/hgm/Gear+Ratio+Calculator
Gary, That cruise target is only valid if your V-8 is making torque in that RPM range, if you don't start climbing up on the cam until 3K for instance then that is pretty much where you want your cruise to be. Your engine operates most efficiently withing its torque band. Many of the engines that we run, we being you and I forget about the rest of them, would be lugging @ 1800-2000 rpm hard on the engine and terrible for fuel mileage. One of the things that we seem to forget is that a lot of what we here is mainly applicable to late model computer controlled engines. The LS in the wifes truck will pull strong right off idle through its 6K redline. But it has things that were only dreamed of when our old carbureted engines were in common use. Variable cam timming, variable ignition timming, variable fuel flow all controlled by the computer by readings from vairous sensors thoughout the system. The 355 that was in my 65 C-10 before it found a home in the ravens roadster makes a little over 400 Hp and right @ 444 peak torque. now one must bear ( or is that bare someone help me out here) in mind that the truck was a 4,000 lb brick (I weighed it at the truck scale with me in it). I was knocking down about 20-22 @ 3K, below that my mileage dropped off considerably. In answer to Turbo26T's question I go completely backwards to figure my gearing. I know when my engines start to make torque and I try to keep them right at the bottom of the power band or close to it. Then I determin what speed I want to cruise at and gear accordingly. There are formulas that give a torque and or HP target to reach a specific speed that get used all the time by racers, for instance it has been determined that in a non streamlined roadster it take between 600-700 HP to go 200 mph on the salt. Somewhere there in one of my notebooks there are formulas for determining that type of information, one must have several parameters to come to a conclusion and they are only ballpark. But you would be way better off to find a calculator on the HAMB then to depend on me to find them for you.
My very rough rule of thumb for non smog engines is; torque is 90 to 100 % of non-smog engine displacement with factory equipment and good tune. I start in the range of 100 ft/lbs for 1000 lbs of vehicle.
'******:I agree with you on the 1800-2000 being hard on m0st hortrod engines...and I know you can figure back & forth to arrive at what target you're after...(rear ratio,cruise RPM ,etc) . So ,I wonder how you would spec an engine to have the right torque/HP for a certain desired cruise RPM i.e: 1800-2000 cruise RPM for example Damn ,this water may be too deep for my shallow ***.. Stan
Water isn't too deep just have a different puddle for each engine choice. Then swing the calcs on desk top dyno. Most torque at least Cfm is the goal.
******, In my case, I chose 2000-2200 rpm as my target cruising rpm for my V6 pickup based on what I had heard from friends, web, etc.. and tried to work the problem backward with factory specs. When the fat lady sung, I ended up with 2200 at 75 mph, close enough for DOD work. I have a stock 4L60, 3.50 gear and 28" rear tires. Looking at my factory engine specs, what would you have done? My motor isn't a high rever and with about a 1500 rpm difference at each gear change, I figured that at a modest 5000 rpm shift point, that would drop the engine speed back around the peak torque numbers to accellerate again. But all speed racer stuff aside... I definitely know from Interstate trips, that if I chose a higher cruise rpm, my mileage will suffer, so going that way seems fruitless. In my only other build, my stock 302 Ford / C4 (only a 1:1 final drive) only got 20 mpg at 70-72 and with a 3.08 gear it ran up at 2600-2800 rpm. I hated that. Gary
If you want your cruise RPM to be 1800-2000 you will need to build your engine for mostly low end torque. Most stock cams or even RV cams build their torque on the bottom. You wil seriously hurt your mid to top end power on an engine like this and it may not want to rev past about 4400. Think truck engine. Theoretically long stroke small bore engines develop most of their torque down low and do not want to rev real high. Think 307 Chevy here, they are pretty much all in by about 3K. They can be made to rev but it is way more work than to make say a 283 rev. Gary, You are correct in your thoughts with the V6. Most of them other than the new offerings make all their power down low. We actually had to lower the gear in the ravens roadster to get an mileage out of it. he was running a 2.89 gear and with the AOD he had rto run well over 100 mph to get it into its power band. We dropped his gear to a 4:11 and it will cruise comfortably @ 75-80 and his mileage doubled (literally). He went from two tanks to one tank on the trip to joplin and back, all highway (about 3 hours).
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