sbc 350 questions
08-28-2009, 10:07 AM
#1
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sbc 350 questions my buddy put an engine together and when all was said and done the harmonic balancer was off, meaning it was 180 degrees off (he put the crank in upside down) what will it take to fix it? can we just pull the timing cover and then the chain and roll it over until its right and then put it back together? or does more of the motor need to come apart? Thanks for any help.
08-28-2009, 10:47 AM
#2
??? Not sure what you're trying to say, but I'll give it a shot. 
You can't put the crank in upside down cause there is no upside down, and you can't put the balancer on 180* off... not unless you leave the crank key off and purposely install it 180 off. It is possible to be off significantly if you have a balancer/timing tab mismatch, but not 180*.
I presume engine won't start on this fresh build if so:
It is common for the timing to be off 180 on a new Chevy build, even if you're careful aligning the dots on the timing set, etc. Don't know why this happens, but it does.
I usually leave the intake manifold off for this reason when I drop the engine in, or swap a cam. When I run thru the rough valve adjust, leaving the intake off makes it obvious if the engine is at #1 TDC firing or #6 TDC firing when the mark on the balancer aligns with the tab zero. It is obvious because certain lifters will be up depending on it being at #1 or #6. Once you determine where engine timing is by the lifters, pop on the intake, set the distributor/wires accordingly.
Easiest fix for you... shuffle the wires on the cap, i.e. Swap #1 wire to spot currently occupied by #6 wire, then move the rest of the wires in relation to your new #1 position.
Correct fix: pop up distributor, turn rotor 180, drop it back down. If you have problem putting it all the way back down cause the oil pump drive tang won't align with the oil pump drive rod slot, just let the distributor rest of it's own weight, bump the starter, distributor will drop down on it's own when tang aligns.
You can't put the crank in upside down cause there is no upside down, and you can't put the balancer on 180* off... not unless you leave the crank key off and purposely install it 180 off. It is possible to be off significantly if you have a balancer/timing tab mismatch, but not 180*.
I presume engine won't start on this fresh build if so:
It is common for the timing to be off 180 on a new Chevy build, even if you're careful aligning the dots on the timing set, etc. Don't know why this happens, but it does.
I usually leave the intake manifold off for this reason when I drop the engine in, or swap a cam. When I run thru the rough valve adjust, leaving the intake off makes it obvious if the engine is at #1 TDC firing or #6 TDC firing when the mark on the balancer aligns with the tab zero. It is obvious because certain lifters will be up depending on it being at #1 or #6. Once you determine where engine timing is by the lifters, pop on the intake, set the distributor/wires accordingly.
Easiest fix for you... shuffle the wires on the cap, i.e. Swap #1 wire to spot currently occupied by #6 wire, then move the rest of the wires in relation to your new #1 position.
Correct fix: pop up distributor, turn rotor 180, drop it back down. If you have problem putting it all the way back down cause the oil pump drive tang won't align with the oil pump drive rod slot, just let the distributor rest of it's own weight, bump the starter, distributor will drop down on it's own when tang aligns.
Last edited by angel71rs; 08-28-2009 at 10:53 AM.
08-28-2009, 06:48 PM
#4
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so in order to fire on number 1 the dots have to be? bottom bottom not bottom top (lined up)? you guys seem to understand what i meant to say. his balancer has the timing marks on the opposite side so we think its firing on 1TDC on the exhaust side of the lobe rather than the Intake side of the lobe. Its hard to explain, the point is the timing marks are 180 off and it doesent run right, but it does run.
