Hey guys wanted to post about what I'm studying in tech school on GM's old mechanical injection units from the 50's and 60's. Pretty interesting stuff and ingenious how it was designed. Anybody ever mess with one of these or have any stories on it?
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Hey guys wanted to post about what I'm studying in tech school on GM's old mechanical injection units from the 50's and 60's. Pretty interesting stuff and ingenious how it was designed. Anybody ever mess with one of these or have any stories on it?
That older stuff is pretty neat. I have never messed with the Rochester, I remember as a youngster my Dad was still messing with it, early 1980's. I believe that it was on the Corvettes, in the 50's or 60's? I did have a mechanical injection system I planned on using on my drag car but I sold it off before ever getting to involved with it. Someone needed it a lot more than I did based on what they paid me. The system I had, if I am remembering right, drove the injection pump off the cam, it had a special timing cover. It was for a Big Block Chevy, which I didn't even have one at the time!
The one on the Corvette and 57 Chevy were driven off a cable from the distributor and had a fuel bowl that was fed by a mechanical pump. Pretty interesting setups. The 1963-1965 with the removeable upper plenum is the best. The 365 HP 327 had the biggest injection nozzles IIRC. Its more a novelty item for a period correct Corvette/Chevy restoration than a performance item. By 1965 the single 4bbl holley equipped 327 made 10 HP more.Quote:
Originally Posted by BLG355
i've always wanted to play with an old hillborn, they polish up real nice.... but like most mechanical injection systems, the results are junk compared to a carb. they're both just mechanical fuel computers...
Other way around, the injected L84 327 was rated at 375hp, and the carbed L76 327 was rated at 365hp.Quote:
Originally Posted by Fast355
The reason is the Ramjet is a single plane setup that helped out at high rpm.
Here is a shootout between the 2.
http://www.superchevy.com/how-to/vem...o/viewall.html
Dad bought a crate L76 back in the day. It ran well in his 57 with 5.13 gears, and a 4 speed.
peace
Hog
I posted a link here to the old rochester FI system repair manual. You can see almost all of the modern EFI functions included in the mechanical system. It's no wonder carby guys failed miserably at FI repairs.
Yea it's too bad nobody took the time to figure it out. Makes me wonder how much things would have been different had GM kept up on this system. It's my understanding that properly maintained, as all cars even today should be, it worked quite well. I figure GM would have been far better prepared for the emissions era than Ford and as I understand it Dodge had a similar system that took it a step further and made it a true sequential injection system with dual magnetos running the whole deal.Quote:
Originally Posted by 1project2many