250 balancer/timing? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

sixbangr · 06-08-2010, 03:19 PM

engine is out of a '76 olds, it is a Chevy 250. The orange balancer appeared to be broken . i just got one from a '75 Chevy, marks seem in the correct place. With the old one , the timing had to be advanced about 2 inches past the timing tab to run so the new one looked correct. It runs best at about 2 inches on the other side of the tab. The gears line up fine and when i put the old one on it matches the timing marks on the tab. Very confussed. How many balancers did these have? The new black one is also thinner and much lighter.

68gmsee · 06-08-2010, 04:06 PM

To answer your question re. how many balancers:

I believe there were a lot of balancers that would fit the crank that there were made for other small block and six cylinder engines.

What you need to do is find TDC on the number one piston and make a mark at "0" on the timing chain tab. I've used a file and/or piece of hack saw blade to scribe the mark.

sixbangr · 06-08-2010, 05:42 PM

well i did find out they changed them from '74 and '75. The newer one I just bought won't work,it is a '74, needed a '75+. Still don't know why my timing is so far off. Truck runs ok, just can't set the timing with the marks, so don't really know what it is set at.

68gmsee · 06-08-2010, 07:34 PM

I just took another look at your timing tab on the timing chain cover. It looks like it's different than what we have on our year trucks. The tab seems to be on the opposite side as mine is on my 250. Am I seeing it correct?

Maybe Oldsmobile covers and pulleys were different. Try to find a cover at a junkyard or buy one from one of our vendors. Chevy dealer may still carry them in some places.

sixbangr · 06-08-2010, 08:00 PM

that's because GM decided to change it in '75-'76. The one from the '76 250 has 9/16 between the grooves. The early one, like the one they sent, and yours has 1/4" between the groves. Also the marks are on the other side.

06-08-2010, 03:19 PM	#1
sixbangr Registered User Join Date: Jan 2002 Location: Texarkana, Texas Posts: 261	250 balancer/timing? engine is out of a '76 olds, it is a Chevy 250. The orange balancer appeared to be broken . i just got one from a '75 Chevy, marks seem in the correct place. With the old one , the timing had to be advanced about 2 inches past the timing tab to run so the new one looked correct. It runs best at about 2 inches on the other side of the tab. The gears line up fine and when i put the old one on it matches the timing marks on the tab. Very confussed. How many balancers did these have? The new black one is also thinner and much lighter. Attached Images __________________ 1961 Apache short step. Last edited by sixbangr; 06-08-2010 at 03:21 PM.

06-08-2010, 04:06 PM	#2
68gmsee Active Member Join Date: Jul 2007 Location: Centrally located between Houston, Austin and Waco. BCS area. Posts: 7,947	Re: 250 balancer/timing? To answer your question re. how many balancers: I believe there were a lot of balancers that would fit the crank that there were made for other small block and six cylinder engines. What you need to do is find TDC on the number one piston and make a mark at "0" on the timing chain tab. I've used a file and/or piece of hack saw blade to scribe the mark. Last edited by 68gmsee; 06-08-2010 at 04:06 PM.

06-08-2010, 05:42 PM	#3
sixbangr Registered User Join Date: Jan 2002 Location: Texarkana, Texas Posts: 261	Re: 250 balancer/timing? well i did find out they changed them from '74 and '75. The newer one I just bought won't work,it is a '74, needed a '75+. Still don't know why my timing is so far off. Truck runs ok, just can't set the timing with the marks, so don't really know what it is set at. __________________ 1961 Apache short step. Last edited by sixbangr; 06-08-2010 at 05:43 PM.

06-08-2010, 07:34 PM	#4
68gmsee Active Member Join Date: Jul 2007 Location: Centrally located between Houston, Austin and Waco. BCS area. Posts: 7,947	Re: 250 balancer/timing? I just took another look at your timing tab on the timing chain cover. It looks like it's different than what we have on our year trucks. The tab seems to be on the opposite side as mine is on my 250. Am I seeing it correct? Maybe Oldsmobile covers and pulleys were different. Try to find a cover at a junkyard or buy one from one of our vendors. Chevy dealer may still carry them in some places. Attached Images

06-08-2010, 08:00 PM	#5
sixbangr Registered User Join Date: Jan 2002 Location: Texarkana, Texas Posts: 261	Re: 250 balancer/timing? that's because GM decided to change it in '75-'76. The one from the '76 250 has 9/16 between the grooves. The early one, like the one they sent, and yours has 1/4" between the groves. Also the marks are on the other side. __________________ 1961 Apache short step.



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