Thread: Sbc 350 starting issue

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Yes I have checked cam, timing chain, bolts, and all. When I adjusted the valves I turned the motor over by hand and everything.

Not running

How about the roll pin in the distributor drive gear

i still think the valve adjustment is the issue .. if you can determine which cylinders are not running correctly back off the adjustment on those .. i would do the adjustment with the engine running .. it is a bit messy but more sure ..

Can you do a compression test?
That may tell you if the valve setting is to tight, holding a valve open.

I have done a compression test 150 per cylinder. Motor is bored .40 over line homed .10 over. Roll pin in distributer gear is good, bearing and all in distributor are good, I have checked everytime I have had it out. When I adjusted thevalves I did it with engine off, pulled valve covers and turned motor over by hand. Valve covers are all I pulled.

Welcome to CHR! We're a good bunch here and have a lot of knowledge and like a classroom full of eager third graders, we have a tendency to all "talk at once" sometimes. So grab a coffee and read through all the posts (including this one) and let's give it a new go!

In the first post you mentioned a compression test – 150 on all cylinders so let’s make an assumption that you’re okay there. I’m also assuming that the plugs and wires are either new or close enough and that the distributor is fine (you mentioned a Summit HEI – good unit that I have used personally for lots of builds. Make sure all your electrical connections are clean and tight.)

After reading through this thread, it appears that the easiest thing to do would be to back up a bit and start over. This will take some time and it’s nice to have a friend help you rotate the engine as you need to spin the push rods between your thumb and forefinger. This is a whole lot easier with the intake off but as your engine is assembled (and in the car), pay close attention not to pinch your fingers between the push rod and the rocker arm – it really hurts (ask me and any number of guys here how we know that…) and you’ll get blood all over your valve train.

Remove all the spark plugs. On a cylinder-by-cylinder basis with both valves closed, back off the adjusting nuts to where the push rod has no lash, but will still spin with just your fingers. Be careful not to get too loose or you will run the risk of a push rod coming out of its lifter seat and getting bent. Bring number 1 to TDC and when the exhaust valve just begins to open, adjust the intake valve. Tighten the adjusting nut on the intake until the slack is taken out of the rocker arm and push rod. Lightly turn the push rod with your fingers as you tighten the adjusting nut, and you should feel a point where there is little to no resistance (zero lash). Tighten the adjusting nut ½-turn past this point. While rotating the engine by hand in a clockwise direction (breaker bar on the crankshaft nut) observe the exhaust valves and repeat the adjustment in firing order, i.e., 1, 8, 4, 3, 6, 5, 7, 2. I’ve done a lot of valve adjustments and ½-turn is sufficient pre-load in 99% of all Chevy small blocks with hydraulic flat tappets - regardless of the cam profile.

Adjust all the intake valves, then go to the exhaust valves. Watch the intake push rod and stop rotating the crank when the valve is just past its highest lift. Now the exhaust valve can be adjusted – same ½-turn past zero lash. When all of the valves have been set check each valve again as you slowly rotate the engine starting from number 1 and proceeding in firing order.

Bring the engine to number 1 TDC. Take the distributor out and replace it with the rotor contact facing to the front of the engine – pointing at the water neck or slightly to the right. Make sure your number 1 spark plug (in the cap) wire lines up there and recheck – 1, 8, 4, 3, 6, 5, 7, 2 as you reinstall the spark plugs. Snug the distributor down but not so tight that you can’t rotate it. Disconnect the vacuum advance from the distributor (plug the vacuum side), Put a timing light on number 1 and have a friend crank it up. Set initial at 8-10 degrees BTDC. It should start and actually sound pretty decent. If not, there are other issues (besides valve adjustment and timing). When you get this far, report back!

Have Fun,
Glenn

Originally Posted by Pinball79

Ok, I have a mildly built small block that is a fairly recent rebuild. I put the motor in last year, and it ran like a bat outta hell. Ran it for 500 miles, went to adjust valves and changed oil. Went to start and ran like it was missing on several cylinders. Changed out lifter, plugs, pushrods, and rocker arms. Ran compression, 150 per cylinder all 8, checked spark, all spark hot and good, got fuel. Set everything up, went to start and had distributer as far as it would go and to to pump gas to keep running. Rotated 180 and wouldnt even start. Any ideas would be very helpful.

You say 'you had to pump gas to keep running.' That's interesting. Will it start up every time and die unless you pump the gas?

Verify plug wire routing.
After reinstall of dizzy, and the problem still occurs,
get a spray bottle of watter.
If you can keep it running for a minute or 2, lightly mist the headers or exhaust manifolds.
See if the water evaporates.
If it does not on some but does on others, you will know which cylinders are firing.
If all are firing, maybe check each plug wire for strength of spark.
??

( edit )
Holley type carb?
Check carb bowls float level.