Going for bang for the buck

chromebumpers

chromebumpers

solid fixture here in the forum
Staff member
I have a 1971 350 4spd. The last owner installed Hooker headers and side pipes (I don't know what kind of muffler is inside the side pipes), everything else is stock. Lars just completed an overhaul/rebuild of the Q-jet, next week he will rebuild the distributor and I will time the ignition by Lars method. From that point, as I understand, the car should be running 100%. I really want a little more "push back in the seat" feel but I don't want get upside down in this car should I decide to sell later. (no NO2)
For the first time I'm thinking about a cam, but there maybe an aftermarket cam in there now I don't know. There is fresh looking RTV around the timing cover and a replaced water pump. is there anyway of detecting if there is any other cam that's not the OE without pulling everything apart?


Rich
 
the answer to finding out the current installed cams lift and duration while only removing a valve cover and the accessories drive, pulleys and a few other things in the way, so you can install and read a degree wheel depends on both the tools you have and how well you know how to use basic tools like a dial indicator and degree wheel, the the basic bottom line is that an experienced mechanic could pull the front end down far enough to remove the timing set, and read any number on the aftermarket cam in less than 1 hour on most corvette and have it back up and running in another 1.5 hours.
personally, Id just pull it down and look if I wanted to know and I have the tools, its just not that hard
 
So, in other words, if I want a better than OE cam just install a new on, it'll take nearly the same amount of time. But what cam? do I have to change the intake? Is the rebuilt Q-jet usable? What performance gains are we talking about?
 
with out knowing what transmission and rear gear ratio , your compression ratio, what cylinder heads your using, and if the car needs to pass emission testing, and as many other factors as I can get, suggesting a cam is going to be difficult
 
grumpyvette said:
with out knowing what transmission and rear gear ratio, your compression ratio, what cylinder heads your using, and if the car needs to pass emission testing, and as many other factors as I can get, suggesting a cam is going to be difficult
Click to expand...


Stock M20 4spd, stock 3:36 rear. What ever stock is on a 71 for compression (8.5:1)? and there's no emission testing on antique cars and trucks here.
Benchmark here would be to perform as good or better than the 1970's LT-1
 
http://www.cranecams.com/product/cart.p ... il&p=23967
crane110911.jpg

heres what ID have used, a 350-383 can easily reach 6600-6800 rpm if its set up correctly with the correct matching springs etc.

While you may or may not what to hear this, Id strongly suggest NOT using any HYDRAULIC flat tappet lifter cam if your goal is maximizing performance.
using a hydraulic flat tappet lifter cam your effectively limiting your engines power to below 6300rpm in most cases, where a mild solid lifter design on a tighter LSA should easily add 400-600 plus OR MORE RPM, thru better valve train stability and better low in restrictive stock heads
obviously a hydraulic roller cam would give you more mid rpm power but still limit the rpms compared to a flat tappet solid lifter that costs easily $700-$900 less

btw that cam matched with 3.70 rear gears would work even better

http://www.ecklerscorvette.com/corvette ... -1979.html

http://garage.grumpysperformance.co...-descriptions-dont-tell-you.12357/#post-61139
 
Last edited by a moderator:
So you're saying go to a manual lifter set up and save $700 to $900, what will this cost? Aside from cam, lifters and rods, do I need to change anything else? intake, carb, heads? I don't want to go too far for LT-1 performance.
 
chromebumpers said:
So you're saying go to a manual lifter set up and save $700 to $900, what will this cost? Aside from cam, lifters and rods, do I need to change anything else? intake, carb, heads? I don't want to go too far for LT-1 performance.
Click to expand...


you should be able to re-use the stock push rods, but your going to need better valve springs, the cam and new lifters, the cam will have a noticeable lope sound and breath better in the mid and upper rpm ranges


REPLACEMENT VALVE SPRINGS
http://sdparts.com/details/scoggin-dick ... ter/sd1005




read thru these threads
viewtopic.php?f=52&t=181

viewtopic.php?f=52&t=4283&p=15765&hilit=replacing+valve+springs#p15765

viewtopic.php?f=52&t=4957&p=13739&hilit=spring+bind#p13739

viewtopic.php?f=52&t=1716&p=4245&hilit=replacing+valve+springs#p4245

viewtopic.php?f=52&t=1005&p=1818&hilit=replacing+valve+springs#p1818

viewtopic.php?f=50&t=903&p=10020&hilit=rope+springs+valves#p10020
 
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