5 dollars a gallon i would leave germany.
just kidding.

 

If gas mileage is what your after, then I would stick with the 283. It`s hard to move up the performance mark in cubic inches and retain mileage. I would rebuild the 283 with the following pieces:
Flat Top pistons with the correct compression height, with the quench distance set at .040
A comp cams 240H camshaft, made for small cubic inch engines with high axle ratio`s, it`s RPM band is idle to 4600.
I would use the edelbrock performer intake
I would also suggest the use of a Rochester Quadrajet carb, It`s small primary`s are ideal for low end torque and fuel efficientcey.
I would retain the headers and exhaust, but I would add a crossover pipe with the size about 75% of the overall pipe size and add it to the hottest section of the exhaust.
Upgrade the iginition system with top components, such as a HEI with a pertronix flame thrower coil and module, and add a set of Spiral core spark plug wires, take your time and route them correctly. if your running a points ignition, throw it in the trash and make sure you route a new wire for the HEI that has a solid 12 volts.
Use a K&N air filter.
Fill the rear diff with royal purple gear lube, this will cut rolling resistance. Repack the front wheel bearings with sythetic grease.
Lower cruise RPM`s equal better mileage, and i`m betting with this combo, you`ll reach around the 21 MPG mark or better.

 

350 Chevy tuned to about 250-300 HP@5000rpm and a set of 3.0 gears for the back. The bigger cubes will get that weight moving and the rear gears should get you into the 20's for mileage. Use a Quadrajet if you can, they are great mileage carbs.

Forget about 30MPG, not going to happen unless you go diesel. Whats wrong with a turbodiesel Benz V8 or BMW? Probably lying around the junkyards there, they would probably still get you into the 10's from 0-60.

 

Good looking ride!

Pricewise, rebuilding a 350 is cheaper than a 283, but those cubes also require more petrol. I would check PAW for 283 parts. They're about the only one I can think of right now that probably still handles 283 parts.

Whatever your choice, I would try to stay in the 8.5:1 compression ratio area, with cam with no more than 200-210 duration range. The Comp Cams' XE252 might be a good choice. I would also keep the dual exhausts.

I agree with the above comments about a Q-Jet. It's economical if you can stay out of the secondaries. With your 200R4 and a lower (numerically) rear end, you should see better mileage.

 

How about a later factory hydraulic roller 350 with Vortec heads, Q-jet (or EFI), & a tiny roller cam such as this one:
http://sdpc2000.com/cart.asp?action=prod_detail&catid=989&pid=2146

 

Hi guys, thanks for the input so far. I have a few things to add to my posting:
I have an HEI and will upgrade to Pertronix or Direct Hits (a similar product)
I will use all synthetic oils and fluids.
Have a K&N filter.

Have had experience with a 69 olds with 350 ci (stock, with highway gears) no overdrive or lockup that got consistant 19 mpg on the highway. With an overdrive and lockup it would have been in the low 20´s. So a Q-jet is a good idea.

Gasoline is much higher quality here than in the US. Regular and Super is nearly the same price so I´ll run Super. That means 9.5:1 compression will be used.

My goal is 23-25 mpg. Diesel is not an option because of very high annual licence fees for diesel powered vehicles, plus I just don´t like them. The swap would be much too difficult too.

Wouldn´t a lower diff (say 3:08 or so) cause the engine to lug or cause a too slow air velocity through the carb to be efficient?

How do you determine the hottest part of the exhaust pipe (for the crossover pipe)?

I´d like to hear from folks that have switched to roller cams and vortec heads, whether that impacted economy. What heads would be best for my purpose?

Thanks again.

 

You can use a gun that you just point and pull the trigger and it will give you the temperature of the targeted item. There is also a paint you can put on the pipes that will turn different colors signifying different heats. Its about 1:30 am here and the names of both products has escaped me. I have never used the paint however I do have the temperature gun and it works great.

I used to live in Ireland so I know what you mean about petrol prices.

 

I live in the states but my Olds 455 in my 81 Cutlass is drinking alot of gas. I'm getting tired of 10 mpg! So, I'm in the process of gathering the parts together for a TBI system. They are all over the place, resting quietly in the junk yards and they look like a carb. No one will ever know that you have fuel injection (except for a wiring harness that will snake away from under your air cleaner). You and I both know good fuel milage isn't just highway cruising. There's the start up and then stop and go driving both of which simply can't be managed perfectly with the carb...including the "Q-jet". I've gathered 75 percent of the parts that I need for my TBI conversion and plan to do everything for about 500 bucks. I really think TBI would be perfect for what you're trying to achieve! Anyway, I'm going to try it...good luck.

 

Hello Bel Air,

I am going to point out the obvious and suggest EFI. There are several DIY(do it yourself) controllers that can be used with junk yard parts to build a very cheap EFI system. You can get more information on two controllers here:
http://www.bgsoflex.com/megasquirt.html
http://www.squirrelpf.com/msavr/

The first is the original Megasquirt and the second is a newly stemed project. The first only does fuel control and is available cheaper and with firware that is proven. The second is bleeding edge new and is what I am working on myself right now.

If you do not mind spending some money Holley and Edelbrock both make some very nice bolt on systems. Unless you are a master tuner, you will never see the mileage that you will get with EFI. EFI can monitor fuel ratio and constantly adjust it while cruising which is where you will really get the good mileage.

I agree with most of the above information about engine dynamics. You want to keep lsa high and duration low to maintain good cylinder pressure in the low RPM range. Also, you do not want to go overboard on the heads port size. Keep compression as high as possible on the fuel you have available. With EFI, you can get away with a little more because you can more easily monitor and tune around it. Optimize everthing else as for a performance engine so the engine will be as efficient as possible.

Chris

 

Nice 55 Bel Aire!!! I'm with Kevin on the EFI. Edelbrock makes a total package Pro Flo with 2 barrell air valve that will give you at least 6 MPG over anything you can build with a carb on it. Roller cam, rockers and lifters will decreas the friction in your valve train drastically and that translates into more hp or fuel economy. The vortec heads will help your fuel economy also. They are just more efficient. Throw your total package together on the little 283 and I can see 25 MPG as atttainable. Get a summit catalogue and look at what Edelbrock offers and even go on line (edelbrock.com) to their tech services and address your questions to Gary. I have the bigger setup on a 383 motor that is producing 475 HP and I'm getting 21.5 MPG and still tuning for economey(think I can squeeze out another 2.5). Course its in a 2700# vehicle, but we are talking 100 more cubic inches and a 1000 CFM air valve vice the 600 CFM two barrel air valve.

Trees

 

edelbrock advertises some pretty good increases in HP and economy. Honestly, you want smallish port heads with small, efficient combustion chambers. Get roller everything, cam, rockers etc. Not to disagree, but its not the fact that they reduce very much friction that makes them so desireable, its that the ramp designs can be more efficient because they're not limited by angle that makes roller valve gear so desireable, its a common misconception. You can underdrive your pulleys, you can get rid of your fan and put an electric one on there, and you can get a two in one water pump alternator if you want to really go for it. K&N filter all the way. Do some searching on what carb to use, I'm not sure a quad is the best way to go. I'm sure they're great if you're going to keep your foot out of it all the time, but they hog it down pretty good if you ever get into it. In fact, most of them are rated 780 and higher CFM, which is quite a lot for that motor. You don't need anything bigger than 600 (and don't let anybody tell you otherwise).

K

 

A Quadrajet will not "overcarburate" your engine. It has small primaries with extra "booster" venturis, which is good for mileage due to better fuel atomization. If the motor doesn't need the full 750cfm of air flow, the secondaries just won't open all the way. EFI would still be better. As far as rear end gearing, my 3700lb '88 T-bird w/302, tiny roller cam (~180*@.050), high-swirl heads, & EFI came with a 2.73 rear end & AOD overdrive trans, & it got nearly 30mpg (highway) when it had an intact body. Cruised comfortably at ~1800rpm at 70mph. Severe front end damage knocked off about 4mpg. A 3.45 gear knocked off 2 or 3 more. 0-60 was ~12sec., now it's ~11.

The temperature paint is called Tempilaq, but you have to know at what temperature you want it to melt. It costs ~$12/bottle, & comes in several melt temperatures from 400* to 1500*.

http://www.brownells.com/aspx/NS/store/ProductDetail.aspx?p=13124&title=TEMPILAQ~

 

I would put a nice 355 in there with Castiron Vortec heads. Use the stock crank (maybe get it cut) stock rods (very good rods) and put in some hyperutectic pistons. A nice comp cam 1500-6000 rpm. A hydrolic should do the trick I dont think you need a roller. I'd top if off with a Performer RPM intake (airgap if you wana spend a little more and look cooool) I had a similiar motor in my Nova a year or 2 ago and it went pretty good. You could probably drop that rearend gear to some 3.08 or 3.55's because this motor will make enough torque to get ya moving down low. A friend of mine has a 355 iron headed vortec motor and is high 7's in the 1/8th mile all motor in a 97 fbod (pump gas). Not the lightest car either. With an overdrive trans and highway gear you should have good gas mileage and still be able to get going when you gotta.

Also..these motors generally put out 375-425 hp. Compression,carb size, and head work are the variables. And roller cam or not. The 383 stroker with vortec heads was putting out 500hp+ with a hydrolic roller cam on 94 octane pump gas about 10.1 compression.

 

i live in Denmark where gas prices are about the same as our southern neighbour. and let me tell you "its not the miles, but the smiles per gallon that count" i wouldnt expect more that 23 miles per gallon (10L/100km) with such a heavy and aerodynamically-dysfuncional car. In my opinion a lt1/lt4 engine out of an 91-94 camaro with fuelinjection is your best bet for performance and mileage. they cost arround 3300 euro with wireing loom and cpu. they will definately get you from 0-60 faster than a MB 320 CDI and run just as smooth.

 

Looks like everyone has made some really good suggestions for your Belair.

Late model heads like vortecs will burn fuel more efficiently and make more power provided you get the compression ratio and quench set correctly. Fuel injection is the obvious choice for maximum mileage as well as the free flowing exhaust. A mild roller cam would be a great choice for both economy and performance if money is no object.

Lastly the 283 would probably be the best foundation to apply all this mileage boosting trickery to as the smaller the cubes the less fuel it will use.

My fuel injected 5.0 Mustang has a 2.79 axle ratio plus a 5 speed with overdrive and it runs fine at any speed over 50MPH in overdrive and it logs excellent fuel economy, about 24.5 MPG with mixed driving(80MPH highway and stop and go in city) on my daily 43 mile commute to work(each way). A 3.0 axle with overdrive would work fine on your shoe box.

My 350 powered 78 Camaro with 3.15 gears and turbo 350 automatic gets around 13mpg on the same commute. It has 600cfm holley, weind intake, 2-1/4" dual exhaust and a mild SSI cam. The Camaro is not that much quicker than my stock Stang either but then again it weighs about 3600lbs but gets about half the mileage.

Keep in mind that unless you drive this cream puff allot the pay back in fuel economy on all these fancy parts would probably be years before you break even, although my Mustang paid for itself in less than two years based on the fuel I would have used if I drove my Camaro on my original 130 mile daily commute(stole the Mustang for $1200.00).

What's the cost of LP gas in Germany?

 

Trees, Kevin, Deuce and others who are suggesting EFI are correct. That is the only way to truly maximize your efficiency under normal driving conditions.

 

You may want to check into the price of Propane like golduster suggested. Converting an engine to propane is a very simple process and you could set it up to run on gasoline or propane. Keep in mind that propanes octane rating is in the 100's so it will tolerate higher compression.

Good Luck

John

 

the thing is that we cant get propane on gas stations in europe, only as camping gas, or for forkloaders (only in bottles) but we cant refill anywhere, so cruising beyond the capacity of the tank would be a no-no i stand by my lt4 recomentadion. alternatively you could find a 200 Hp vortech V6 from an astrovan, but it would be a crying shame to loose the v8 sound in my veiw

 

Hi guys,
Thanks for all the ideas, your responses have been a great help. After carefully mulling over all your suggestions it occurred to me that the solution is staring us all in the face.

Which small displacement (for good economy) Chevy V8 provides the most torque (i.e. long stoke) to get my lead sled shoe box moving? Not the 283 of course, but rather the Rodney Dangerfield of SBC´s, the one everyone loves to hate THE 305!!! By the way, I forgot to mention that 1 Power Pak cylinder head is cracked on the 283, a replacement would have to come from the US and the shipping alone would be a killer).

Now, if I want an economical rebuild (machine shops and parts in Germany are WAY to expensive) with roller cam and nice flowing, small valve heads (again for the torque) this points toward a rebuilt 1996 or 1997 Vortec 305 crate motor from one of the big re-builders stateside. It would just (maybe) need a better torque oriented roller cam, any concrete suggestions? Built to about 9.5:1 CR, with a crossover H-pipe, smaller 2 " dual exhausts (needs replacing anyway), with all the other items I already mentioned would be an ideal engine for my purposes IMHO. What kind of power and torque would this combination make?

For now I´d start with the 500 CFM Edelbrock carb I already have (will a carb work well on this motor?) but I´d like to change over to a TBI/Megasquirt setup sometime in the future (thanks especially to Chris for this new-to-me idea). Could this be done with one and the same Performer Vortec intake? Would it require some kind of adapters?

The expense of an after-market EFI can´t be recouped in a reasonable time frame with the gas savings alone, that´s why TBI/Megasquirt is the way to go for me, plus it should be more fun as a DIY .

I´ll leave off the mechanical fan and rely on the thermostatically controlled electric fan that already is on the car.

Goldduster, what exactly did you mean about getting the quench and and CR right?

The last thing I´ll try is to drop the differential ratio a couple of numerical notches lower (if I ever find a suitable pumpkin in Germany LOL).

Does what I´ve just written make sense, or am I missing something? Thanks again, hoping to get my last few questions cleared up before I start...

Steve

PS I checked out my idea about the 305 and as you all knew already it was no good. So I ordered a late 90s roller cam Vortec 350 stateside today . I will probably put that Ram Jet cam in it suggested earlier in this thread. Sometimes the shortest answers are the best ones But I will do all the other things to it it too. When its all in I will report back on how it went...

 

Bel Aire, a 3.08 is the highest gear ratio you can get in the 55-64 Chevy housing, and would work good for you. Not easy to come by for you though, so you may want to look else where. Many threads back was a mention of using Volvo rearends. Your advantages would be availability. The disadvantage is that you would need to convert to disc brakes on the front. You will find very desirable ratios available in what we call posi units (don't know what the Swedes call them).

Trees

 

Goldduster, what exactly did you mean about getting the quench and and CR right?

The compression ratio will have to match your cam selection and fuel octane you plan to use. Follow the cam manufacturer's suggestions for matching their grind to the engine's compression ratio. This will also be dependent on whether you use aluminum or cast iron heads.

The quench is the distance between the piston top and the cylinder head where it would make contact if it were not for the thickness of the head gasket and how far the piston is down in the hole at TDC. .040" seems to be the rule of thumb. This allows enough room for bearing clearance and rod stretch as engine is being revved up. In theory the tighter the quench the less sensitive the engine will be to spark knocking. This will allow the engine to run the leanest possible mixture and the most spark advance which should contribute to both power and economy.

Most performance re-builders like PAW "zero deck" their engine blocks to provide .040" quench distance with standard composite head gaskets. This requires cutting down the decks of the engine block to make them almost flush with the pistons when they are at TDC.

 

Hi guys,
For now I´d start with the 500 CFM Edelbrock carb I already have (will a carb work well on this motor?) but I´d like to change over to a TBI/Megasquirt setup sometime in the future (thanks especially to Chris for this new-to-me idea). Could this be done with one and the same Performer Vortec intake? Would it require some kind of adapters?

The expense of an after-market EFI can´t be recouped in a reasonable time frame with the gas savings alone, that´s why TBI/Megasquirt is the way to go for me, plus it should be more fun as a DIY .
Steve

The DIY EFI is certainly not an easy task, but a very valid one for those of us who are budget challenged. You can certainly to the EFI with a performer intake. As a matter of fact, you can get fuel injectors and sensors dirt cheap in junk yards as well as carbs. There are some guys out there converting the manifolds to MPEFI with junk parts and megasquirt. There is a site out there I wish I had saved of a detailed buildup like this. He used a Holley carb as a throttle body(air valve) and integrated TPS sensor.

I hope to fire my megasquirtAVR controlled turbo engine this weekend. I am still waiting on firmware issues to be resolved. One of the down sides to the AVR is that alot the support is overseas right now and via email only. Once I get mine up and running, I will be able to help anyone interested. I want mine working before I preach too much

Have fun.


EDIT: I found a like similiar to the one I remembered....enjoy.

http://www.mez.co.uk/ms2.html

 

If you are going to run the motor carbed first and this engine you pick up doesnt have an intake manifold make sure you order the vortec style intake. The intake bolts are in different locations for vortec heads.

 

i live in Denmark where gas prices are about the same as our southern neighbour. and let me tell you "its not the miles, but the smiles per gallon that count" i wouldnt expect more that 23 miles per gallon (10L/100km) with such a heavy and aerodynamically-dysfuncional car. In my opinion a lt1/lt4 engine out of an 91-94 camaro with fuelinjection is your best bet for performance and mileage. they cost arround 3300 euro with wireing loom and cpu. they will definately get you from 0-60 faster than a MB 320 CDI and run just as smooth.

LT1s came in the 93-97 camaros I would actually opt for a ls1 instead of the lt1 theyre more powerful and the vettes with them get close to thirty. In one instance ive heard of 32 mpg with an ls1 in a c5 vette.

woops my bad i was searching for something when i found this post didnt mean to drag something up from the dead

 

Put a 700r4 in it.

The gearing will get you off the line and cruise gear is nice at .7:1.

Do the math with your tire size and trans gear ratios and try different rear gears combos to see were your rpms are at different speeds. Doing the math first will save money latter.