The Stovebolt Site Forums The Shop Area The HiPo Shop Engine swappers- - -how about a giant leap backwards?

It's been close to 20 years since any car/truck engine has been produced with a carburetor and/or a distributor without computerized timing controls. I'm wondering if some of these late model, sometimes low-mileage engines that are clogging up the salvage yards might be reverse-engineered for carburetion and a centrifugal/vacuum advance distributor? It would be relatively simple to adapt the crankshaft hub on most engines for a Gilmer belt system (toothed timing belt) and bracket a conventional distributor onto the front of the engine where a power steering pump or air conditioner compressor would normally mount. Follow up with a tunable carburetion system like Webers or something similar with replaceable venturis and a wide range of jets available, and it seems it would be possible to come up with a completely non-computerized version of a modern-day engine grafted into a stovebolt truck. A 300-something horsepower twin overhead cam V6 with a 7K RPM redline in an AD truck- - - -wouldn't that be a head-turner at the local show and shine event? How about a Toyota Supra turbocharged inline six with a 5 speed overdrive transmission behind it, and no computer controls?
Jerry

I know that they are making an intake manifold that uses a carburetor for the Chevrolet LS engines. They also have a controller box that runs the ignition. I've read a few articles about it and the results are impressive.

Nascar still runs carburetors which means it can be done. It was common to do that with throttle body about 25 years ago. I'm not sure what all would with today's port injection. The last 3 GMC pickups I had were with the 6 Liter engine. I never even bothered to look under the hood. Just put fresh synthetic oil about every 6 months and got rid of them before they had 50k miles.

When you think about it, a carburetor is an amazing piece of engineering. Such a simple technology that utilizes the airflow through it to function. It doesn't require any electrical energy (with an electric choke being the exception) nor a high pressure fuel pump and can provide varying quantities of fuel in a nearly seemless delivery to an ICE from idle to WOT and all points in between.
The engr's at the time used their design and manufacturing techniques to cast the body and drill the minute passages at just the righ positions within the venturi for progressive fuel flow then seal it all up, plus made it serviceable & rebuildable. Their metals and techniques for the most part has stood the test of time, impressive.

Then you look at the timed spark delivery system, i.e. the ignition system. It's so simplistic in operation and yet like the carburetor very precise that it too has stood the test f time.
Basically the engr's take a low DC voltage then convert it to a very high DC voltage (or is it AC voltage?) so as to deliver an arc of electricity into a closed combustion chamber at the exact time it's needed at all rpm of the ICE. Amazing.
They do this by both mechanical and electrical theory.

To go a step further, add a magneto ignition and you don't even need a battery source.....

What we tend to forget is these systems that still work today were devised, designed and manufactured without the assistance of any artificial intelligence, i.e. CAD/CAM or computer generated interfaces, just man using his GOD giving gifts.

I can work on this stuff as it was designed for the avg man to be able to service it.
Granted modern fuel and ignition systems require little service and do last, but when they require maintenance, ohh boy Katey bar the door...... Seems they could have designed a way to read those blasted codes without separate test gear, but I digress...
So I agree w/ HRL and would like to apply these old subsystems on a modern day power plant.
And a redesigned Stovebolt head that's been discussed before.

Anyways, don't mind my waxing poetically, carry on

Dave

There's nothing wrong with computerized fuel and ignition systems- - - -Manufacturers have to use them to meet the ridiculously strict CAFE and emissions standards Big Brother imposes on them. They're also getting 10 pounds' worth of power out of a 5-lb. sack by optimizing the output of the engines with computers.

Reverse-engineering these wonderfully efficient engines to eliminate the computer, the high pressure electric fuel pump and port injectors, and the electronic ignition timing might be a Luddite approach to the situation. It would also open up a whole new realm of possibilities about what kind of engines and transmissions that could be available to breathe some modern life into the old iron we love to tinker with.
Jerry

A development of the computer controlled sequential port fuel injected, electronic ignition engine is the most significant feat in automotive history. According to my late grandfather, up until that, the most significant feat was tires that actually held air reliably.
The rub for me has been that most drivability issues which I have encountered with the computer engines has been due to non-functioning sensors and not engine components. Trouble shooting can be a nightmare, and god save you if the problem is in the spaghetti-like wiring harnesses.
Carl

Carl, have you ever seen a computer leak coolant? Back in the late 1980's I attended a trade school instructor's summer seminar sponsored by General Motors. They told us to watch out for coolant in the floorboard of some of their vehicles which was NOT caused by a leaky heater core. It turns out they got a bunch of bad coolant sensors from a supplier, and with the very tight seal of the Weatherpack connectors they were using, coolant leaking through the sensor would follow the wire insulation to the computer and drip out, resulting in a coolant odor and wet carpeting under the ECM mounting area! The fix was to replace the sensor and the computer, cut the wire off at both ends, and run a new wire on the outside of the harness!
Jerry

I have heard about that. I don't like to think about things like that!
Carl

Jerry, over here Landrover had a similar thing. The electrically operated injectors on the TD5 direct injection diesel are inside the rocker cover, and on early vehicles the loom wasn't sealed properly.

The result was that engine oil ran through the loom back to the ECU under the driver's seat, and filled the area under the driver's seat with oil. Result, apart from a mess, was poor starting, misfiring and loss of power. Remedy was a new front loom at £800!

To your original question, that sort of thing is done quite commonly for motorsport and fast road cars, so no reason it can't be used. We have a GM engine over here called the C20XE, a 2 litre 16 valve 4. It's used in all sorts of performance engine conversions, not only in GM stuff, and it's common to remove the injection system and fit carbs.

Replacing the ignition with distributor is less common, and I'd have thought it's something there'd be less good reason to do.

The only thing I wonder is whether with some engines going back to the past on induction and ignition would result in a significant loss of power / efficiency.

My idea on the ignition swap was to use a timing advance system that does not require a computer and a bunch of position sensors to get spark timing. One of the side effects of dropping the mechanical/vacuum advance distributors (or distributors altogether) is to make it necessary to have a fairly sophisticated computer program to get spark advance. My goal was to go back to a no-computer situation for guys who don't want to deal with electronics and the necessary wire harnesses and computer(s).
Jerry

Adding to Don's comments; the non-VVT 4.8 and 5.3 GM LSx family engines are becoming plentiful in wrecking yards.
Edelbrock makes carby intake manifolds for them and if you don't want to mess with the programmable MSD box, there is a front-mount distributor drive setup available from GM that makes it look sort of like an older Ford pushrod V8 when installed. I think some other people make distributor setups for them too.

Mike

MSD makes programmable control units to allow carb manifolds to be used on the GM LS and the late model Mopar Hemi engines (possibly Ford Coyote V8s too). If you want to thorow out computer controls all together, GM Performance offers a distributor drive setup that involve a Ford style distributor at the front of the engine. Combine this with either the Edelbrock or GM-Performance 4 barrel intake, and you're in an analog (low fuel pressure) world again! 8-) Mike V

I love efi/dis stuff. I dont have to mess with it when the weather changes. I understand why guys prefer tinkering with carbs though, there is something cathartic about twiddling with wrenches all afternoon to make a precisely timed and fueled engine run.

carbs are kind of a bugle though, with one efficient note and other less efficient octaves. when the engine comes running with all the efi hardware attached, I would be hard pressed to change it just for some looks at a car show. just an opinion.

most modern engines dont come with a distributor hole or drive, so that is a wrinkle, because the stuff to run the dis is pricey. do what you like though!

How about making an angle drive to run off the snout of the cam and then use a magneto?

lubricated, able to contain said lubrication, not wear, and at 7k rpm? sounds... improbable. but I know guys with lathes and mills in their garage that would salivate at the challenge.

7K engine RPM is 3500 distributor RPM. Sealed ball bearings in a lot of electric motors run that speed for years at a time. Anybody with a lathe and more than 3 brain cells to rub together should be able to fabricate a 1/2 speed Gilmer belt driven HEI distributor setup with centrifugal and vacuum advance in one afternoon.
Jerry

well, take lots of pictures and lets see what you have at 5pm!

just kidding. unless you are really going to build one tomorrow? I would like to see it!

Here's the rub as I see it.
If you take out the ECM, Drivetrain Management System, Distributorless Ignition System, catalytic convertor, oxygen sensors, and sequential port fuel injection, won't that leave you with the equivalence of a 1972 under-powered, gas guzzling, obnoxious polluting engine?
It would be a place to start to make something nice out of, but at what cost?
I have done something similar to a 1983 Trans Am. Had a computer controlled quadrajet and distributor, and a nightmare of vacuum lines, and a notorious vapor lock history.
In a fit of rage after a multitude of problems, I begun to snatching out vacuum hoses, wires and whatnot, replaced the E-q-jet and vacuum advanceless distributor with old school versions. That process unleashed a beast under the hood.
The difference in my scenario is that the '83 Tran Am engine control system was a horrible idea to begin with. I don't feel the same about the current modern systems.
Carl

My 34 Chevy 5w coupe has a Ford 4.6 4v DOHC engine with a Modular to Windsor intake manifold adaptor and a 1942 flat crab style distributor driven off of the exhaust cam on the left side. I can use any induction system designed for the 289/302 engine and convert the distributor to electronic if the points give trouble. I didn't want a snake pit of wiring nor a tire smoker but do like the looks of the big hemi heads with spark plug tubes in the cam covers. The Chrysler hemis are out of sight price wise.

o.k who,s going to be the first say what piece of junk.?here is my idea.i want to put a258 ovh AMC eng.in my 1955 chevv panel.i would also like to use 5 speedchev trans.what would you gurus suggest?

There are pieces of junk but the 258 AMC engine sure isn't. Used in Jeeps until just a few years ago. It has a 12 port head which is way better than the Chevy/GMC engines. Have also used 225 Chrysler and 240/300 Ford engines in Chevy's for the same reason IF mods were on the menu. In stock factory form the old Stovebolt six is hard to beat. Now we stay with Chevy with the introduction of the Atlas(4.2/4200) OHC six. Pretty peppy stock and a real tire smoker with a turbo. There a two distinct camps on old cars/trucks; the "Put them back exactly like factory" and "Lets change everything". Were fortunate to have a forum that accommodates both.

anyone else want to see this? I sure do, sounds amazing!

Here's a couple of shots. Have many build pictures.

http://s32.photobucket.com/user/coilover/media/Mod%20carb%20adaptor%20001.jpg.html

http://s32.photobucket.com/user/coilover/media/Mod%20carb%20adaptor%20002_2.jpg.html

Is that front suspension a home brew setup, or somebody's kit? I'm building an Excalibur roadster that I got as a partially-complete project in a horsetrade and I don't like the front suspension setup it's got.
Jerry

Jerry,
It is a Heidt's ifs set up. They have a good product but their warranty is useless. I now use Fatman or Chassis engineering units.

thats super cool! do you have any pictures of the distributor setup?

RJD,
My distributor mount needs some work. I have to make an alignment eccentric to exactly center the drive with the exhaust cam sprocket bolt. Google: (4.6l dohc frt. mount distributor) and you can see several on running engines.