Thread: 350 sbc wont start

Tweet

ill have to re check wires and distributor position again tomorrow

When you checked the distributor rotor "...still pointing at #1" did you pull your #1 plug and move it to TDC with your finger or thumb blocking the plug hole to verify you were on the compression stroke? It sounds to me like you may have the distributor in 180 out of phase, pointing at #1 when the piston is at TDC of the exhaust stroke.

was by myself but what i did was put a piece of paper towel in the hole, bumped it over when it blew the paper towel out of the hole assumed that was compression stroke?

Originally Posted by camaro8484

was by myself but what i did was put a piece of paper towel in the hole, bumped it over when it blew the paper towel out of the hole assumed that was compression stroke?

I can see myself doing that, and in theory it should be OK but the problem is if you're using the key to bump it's hard to know for sure working alone, watching for the flying plug of paper. You really need to pull all of the plugs and put a breaker bar & socket on the dampner bolt so you can slowly bring the engine around to align the marks at TDC compression for #1. If you're in a hurry get a remote starter swicth and bump the engine until you get #1 compression on a thumb or finger, and then use the bar to align the marks exactly.

Another possibility is that your harmonic dampner may have de-laminated, allowing the outer ring to shift relative to the keyed center ring that's tied to the crank. If it's still backfiring after you ensure the distributor is stabbed right you might want to verify your timing mark alignment. One way to do that is in this thread - Finding TDC Read the lead method, and then also read the one that Tech linked from the Crankshaft Coalition.

Let is know what you find.

im gunna get over there and im gunna put it up on tdc #1 again and check to make sure it was on compression ill pull the valve cover and watch the intake valve, and ill get this figured out. i was afraid it was a crank bearing or something downstairs. but with it cranking pretty good with the plugs out and backfiring last night kinda relieved the thought of it being bearings. thanks for the info!

It's also easier to stab the distributor if you align the oil pump with a large screwdriver.

Well here's what happened today pulled balancer again pulled chain cover put it on tdc 1 still lined up with the dots at 12 both of em so I redid the distributor. Pulled plugs out she cranked good put plugs in wirednip the wires and bam slow cranking no matter what way you turn the distributor. No idea kinda pissin me off thinking of just selling the dang car

Back to basics, have you gone back and re-checked your plug wiring per the firing order and clockwise distributor rotation? It's easy to be off one space, or for someone to wire it backwards...

I got the wires clockwise / cclockwise. Backwards once, thought I was going to wear out the starter figuring it out. Now, if I have any question, I'll watch the dizzy rotor while I bump the motor, and I know for sure the rotation.

I just saw something....

You say both cam gears have their " dots at 12 "

Someone chime in on this one, but as my feeble brain is telling me that Chevy says the dots point to each other- cam at 6, crank at 12

Originally Posted by firebird77clone

I just saw something....

You say both cam gears have their " dots at 12 "

Someone chime in on this one, but as my feeble brain is telling me that Chevy says the dots point to each other- cam at 6, crank at 12

Times 2... SBC I think is like you say crank at 12 and cam at 6, put the dots together.

Here is how you want your timing marks


http://ww2.justanswer.com/uploads/Vi...3432_marks.jpg

Originally Posted by 34_40

Times 2... SBC I think is like you say crank at 12 and cam at 6, put the dots together.

Charlie & I were typing at the same time. The instructions I've seen for a Gen 1 SBC are install dot to dot to be sure of alignment, which puts #1 at TDC exhaust stroke, and #6 at TDC compression. When you're ready to drop the distributor in place rotate the crank 360 degrees, putting the crank dot back at 12, but the cam dot now at 6 (TYPO - SHOULD BE BOTH AT 12 - See below). #1 is now at TDC compression stroke. Use a big screw driver to set the oil pump slot just a bit early on rotation, and drop in the distributor ending with it pointing at #1 on the cap/body. Correct me if I'm wrong.

Ok, Roger . . . you asked for it. You were right except that the cam dot would now be at 12. Foolproof: Install dot-to-dot, and #6 will be at TDC on the compression stroke and #1 will be at TDC on the exhaust stroke. Rotate the crank one turn, both dots will be at 12:00 and cyl. #1 will be at TDC on the compression stroke. Put your thumb over the #1 spark plug hole to verify that it's coming up on compression.

Originally Posted by Henry Rifle

Ok, Roger . . . you asked for it. You were right except that the cam dot would now be at 12. Foolproof: Install dot-to-dot, and #6 will be at TDC on the compression stroke and #1 will be at TDC on the exhaust stroke. Rotate the crank one turn, both dots will be at 12:00 and cyl. #1 will be at TDC on the compression stroke. Put your thumb over the #1 spark plug hole to verify that it's coming up on compression.

Ooops! You got me, Jack!! I was 'thinking' 12 and typed 6 I guess I'm just a dumb ass after all....