ps374

Was the FI L84 that much faster than the L76 in straight line performance since it cost 5 times as much? Was the FI more novelty than performance in drag and street racing events?

wmf62

my opinion, and my observation; given that they were identical engines except for intake systems; the FI engine had more 'seat of the pants' lower end torque (probably due to the longer straighter intake runners ram effect), better throttle response, and more mpg...

i know for a fact (again my observation), that i can run a much higher ratio rearend with FI than i can with a carb.
Bill

sub006

The difference between 340 (or 365) carbureted horsepower and 360 (or 375) injected horsepower, given equal vehicle weights, rear end ratio, tires, etc. was not that much.

If the FI was set up properly it would outrun the carbed car. A super-tuned carb car might equal or nose out an average-tune FI car. And you have to factor in driver skill as well.

Fuel injection was mainly about elminating fuel starvation during extreme cornering in road races and solo events.

A bonus which would pay for the FI option quickly at today's gas prices was the potential of getting 20+ mpg in conservative highway driving vs. 15 or less with a carburetor. Of course, those figures were achieved on 100-octane fuel.

Let's hear from some owners with specific street or drag racing experience "back in the day"!

MikeM

I think most people would agree that the total driving experience with the FI engine resulted in greater satisfaction than the near identicle carburetor engines. They were smooth at low speed, good power on top end, good fuel mileage and throttle response was instantaneous.

I'm not speaking of price or service. Just the driving "feel".

Just curious. Why are you asking and what do you mean, "it cost 5 times as much"?

ps374

The FI option in 65 $538.00 the L76 was $129.00. With a $4,300.00 car thats a lot of 1965 dollars for a option that wont do much unless your on a race course. As I remember seeing a Fuelie was a big deal. It was considered the ultimate performance car. Little was thought about the L76 being almost if not equal in straight line racing. The words Fuel Injection had some kind of magic on a C1. Rarely seen I only remember seeing one , and that was the 61 my Dad brought home and I rode in at 13 years old. That ride stayed with me and still does today after 46 years.

bb62

The cost differentials between carbs and FI have less to do with the systems as designed than the volumes manufactured. Fuel Injection was used on on only about 12500 Corvettes over a 9 year period of time. And there was little production outside of the Corvette (a few 57 Chevies and a few Pontiacs if my memory is there). This equates to a huge investment allocation to each unit sold for both engineering and tooling costs. On the other hand, there were thousands upon thousands of Holley carbed vehicles. And these engines were used frequently among many other Chevrolet and GM products. The price differential is no surprise when considering these volumes.

1KULC7

If the FI were such a great deal, then why did MANY of the owners take them off and replace them with Carbs? The FI units are hard to keep tuned, finiky with humid conditions, had some serious issues with vapor lock, and if they got hot hard time to start the engine.

I remember really well MANY 63 FI units being replaced with carbs and manifolds because of all the problems with the FI units.

Anybody there back me up on this,,, When I looked for my 63 I went for the 340 L76 Engine and am VERY HAPPY with it, and have NO REGRETS on purchasing this engine. I love to look at and see the FI cars, but I am glad I own an L76...

Anybody out there going to back me up about the FI engines, unless you had an EXCELLENT Chevy Mechanic back in 63-65, then chances of getting it to run good were nill... I come from New England originally and I know they were hard to keep tuned...

sub006

People who don't follow the factory starting drill will frequently have difficulties, especially on hot re-starts. As I recall the hot or cold procedure was to FLOOR the gas pedal and hold it down while cranking the engine, releasing the accelerator when it started. Exactly the opposite of today's electronically-injected cars! People who bought two-year-old injected C2s were not always instructed by the used car lot salesmen, who themselves may not have been aware of the unusual starting ritual. Many times the owners manual was missing.

Mechanical FI units rarely need attention. Any good mechanic who patiently FOLLOWS THE FI MANUAL will have no problem getting one of these cars to run well.

Back in the day, when an FI Corvette had a drivability problem, many would automatically assume it was the injection that was at fault. They would start fiddling, twisting adjustment screws and in most cases creating a new problem that did not exist before.

Unless a qualified tech was called in to re-set the FI and diagnose the original problem, owners would give up and have a carburetor intake set-up installed. When the car still didn't work right, the embarrassed "mechanic" would quietly replace the fuel filter or whatever the real problem was before turning the 'Vette over to his customer.

Biggest problem from the early '70s on has been getting filters, gaskets and other small parts. Has the repro after market taken care of this?

wmf62

everything you've said is/was true; and multi carb cars are a PITA at times too, and C1 & C2's have a tendency to leak like a sieve when it rains...

so, what's your point? you're happy with your carb, i'm happy (sometimes moreso than others...) with my FI...
Bill

MikeM

The best thing to do was to keep everybody's hand off FI units. The biggest single thing I remember causing running problems in that era was spark plug fouling due to leaded gasoline and too cold heat range of spark plugs. That's where most of the problems started.

This myth of all the problems with FI engines is just as false as saying KO wheels will fly off on their own if the sun comes out.

jerrybramlett

That's a good question. Since I've used a few of the NOS and reproduction parts that are available these days, I thought I would give my opinion of them.

I'm convinced a significant number of GM assembly line and service FI parts were poor quality when new. I talking about '63 - '65 spiders, '58 - '63 Cranking Signal Valves, '63 - '65 Forward Balance Tubes, '63 - '65 Choke Modification Kits, and several others. A healthy number of such FI parts just weren't suitable for use right out of the box. I certainly don't expect these parts to be in useable condition when they are found as "NOS" these days.

Then there were the "bad idea" FI design flaws such as the tight-clearance '57 - '62 spill valves, "stepped" '57 - '61 Cold Enrichment Systems, overly-restrictive (and hot air sucking) '57 air cleaner, percolation-prone '57 - '62 low pressure idle system, super-sensitive recirculating '63 - '65 spider feed system, easily warped / cracked '63 - '65 die-cast plenums, etc., that were never properly redesigned by Rochester because FI production was an over-rushed money loser for them. But I digress... the question was about modern reproduction FI parts.

Modern reproduction FI parts are pretty darn good. Most all of the wear parts are available to those willing to shop with several suppliers. No one source sells everything now made, but John DeGregory and and a few others come close.

My biggest problem these days is finding reproduction parts that have been recently discontinued. Have you tried to buy good reproduction '57 - '62 "choke" bakelites, '57 - '62 nozzle blocks, 236 / 201 vacuum canisters, or '63 - '65 spiders in the last few weeks or months? Good luck with that!

MikeM

And lest we forget, the carbureted engines of that era were not exactly trouble free either....................