Hi guys, here's the story. Swapped in a 350 (0010 block, high nickel 4 bolt main) with 642 heads (Chevy stock from the 70s) the bolt on goodies. The trouble i'm having is with the rocker arm set-up and the ignition timing. I set the arms up just like the instructions told me to do, and now the car doesn't seem to want to start and makes a weird noise when cranking (a kind of high pitched noise). When I had the rocker arms much looser, the car would start, but it wanted really high (like 40*) advance to run, and even then when you hit the throttle it would ping like mad. I had the covers off and was looking at the rockers while running, and it didn;t even look like the valves were opening as far as they should. Any thoughts, or similar experiences? Anyone who helps in the garage, cold beers in the fridge.

 

If you didn't remove your distributor or cam-gear, then your valvetrain shouldn't be out of time.
That means the rocker install wasn't done right, so instead of following instructions, I suggest finding someone experienced with adjusting Chevy valvetrain, and go from there.
You should probably set your initial timing to something close to stock 6* to 10* to start with until the problem is resolved.

 

Thanks very much for your reply. I did remove the dizzy because I swapped the intake manifold and the heads. the heads were off of a different motor, and I am using a Weiand 8004 Action Plus intake. I am running an HEI dizzy with an internal Accel Super Coil, and an Optima RedTop battery. I agree that the rockers are probably not adjusted correctly. Has anyone else had this problem with Crane Cams 1.5 ratio arms? I hope they are just too tight or too loose, something that can be fixed without too much trouble (would rather this than the lifters for example). I will try adjusting the rocker arms and see if I can get it running a little more smoothly. Any other suggestions?

 

im no expert on the valve train but what u are sayin sounds similiar to the problem i had after swapping the manifold. i had the dizzy 180 degrees off it started but needed lots of timing and ran like complete crap.

 

interesting that you should say that, because I've checked the dizzy a few times now. I have the rotor pointing at cylinder one when cylinder one is at TDC of it's compression stroke, so I believe it's in the right position. I will be checking the valve adjustment again shortly, and I'll get right back on here if anything changes. thanks again for your replies

 

haven't had a chance to adjust the rocker arms yet, that's this afternoon. How would I know that my dizzy was 180* out? would it still appear that I had it on right? Not sure how to verify that other than the obvious. Thanks for any input here guys.

 

my dizzy/roter was also at the number one when at tdc but it was the wrong stroke . i figured it out cause i was out of options , maybe someone else will chime in im not sure if you can hurt the moter by turning the dizzy 180 and see if it helps,there is no signs of problems with mine after i got it figured out.

 

Ok good to know, for sure mine was in the right spot then. Yesterday was productive, I adjusted the rockers, and they seem to work fine now! To clatter, but good response to revving the motor. I also set the timing yesterday. I set the total crank and mechanical to about 36* (without vacuum advance on) while revving to 2500 rpm. This seemed to work ok at idle, but when I dropped the car into gear, the engine stalls out. Now, I know this can be associated with low vacuum, so I checked for leaks and found none. So, I screwed my idle screw on the throttle side of the carb all the way tight, and advanced the timing just a bit (40* full) and then I could put it into gear without dying (but I'm idling in park at about 1500 rpm! craziness) So, can i conclude that I'm running too lean then? Because It only wants to idle properly when I max out the amount of fuel it gets at idle? I know I shouldn't have to idle that high. So the question becomes, with everything else set properly (valves, timing) should I adjust the q-jet to run richer? if so, how and how much? Or, just grab an Edelbrock 650 and be done with it? Thanks for the inout guys.

 

High idle and then dying when put in gear is classic vacuum leak.

That would also explain not being able to richen it up by adjusting the idle circuit on the carb.

Try plugging off ALL vacuum ports, and do some more testing.
Also, FYI, an intake valve hanging open will create a vacuum leak.


I take it that you are 100% certain the valve-timing is correct now?

 

No, i'm not completely certain that the valve timing is set perfectly. That will be another night this week, I'm thinking that you're dead on and that maybe one or more of my intake valves is still too tight (creating loss of vacuum). Ideally, I should be idling around 800 rpm, and then dropping somewhere near 500 rpm when in gear, correct?