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Discussion Starter #1
Finally got to fire up my completely rebuilt 302 the other day. To cut a long story short, I think I have the wrong weight flywheel and harmonic balancer. I ran it for several minutes on tickover, until hot, which felt OK, plus a few blips on the throttle, which is when the shake became apparent.
What concerns me is that some oil leaked out of the front crankshaft seal, even tho its all brand new.
Could I have wrecked something already?
 

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Do you have an early or late engine? Do you have a 28 ounce or 50 ounce crank balancer and flywheel?
 
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The oil leak on the front crankshaft seal may be from a worn shaft on the HB. Did you replace the harmonic balancer or is it the original one??

If it's the original one, in time a grove will form on the shaft of the HB where it contacts the seal. If you overlook the groove, when you reinstall the HB with a new seal, the new seal will leak since there is a gap between the seal and the HB shaft.

You can get a sleeve kit for the HB shaft which a few people have had luck with but I don't mess the sleeve kit and just replace the HB. Chances are if it's the original HB the rubber is dried out anyway so its time to replace.

Even if the HB was new, the leak could also be from the seal being dry if no oil was put on the seal surface before the HB was installed. if this was the case, on initial start up the seal could have been damaged (melted / burned / scored / deformed, etc) and it leaked.
 

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Discussion Starter #5
The HB was new, hence it may not be the right weight. The engine came to me with nothing, so I didn't have an old HB or flywheel to go by.
I did smear oil on the HB when I fitted it.
 

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Is this a stock crankshaft?
If it is, do you recall or have pictures of any stamping on it?
That may help determine balance.
At front of crankshaft on counter weight.
 

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Discussion Starter #7
The crank is stock, but do not recall any markings.
My concern is, could I have wrecked the main bearings, causing excessive play, and that is why the oil leaked? It's hard to imagine such damage so quickly, but the way my luck has gone so far with this build, who knows!
 

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I doubt you destroyed the engine. But you'll never be sure you have the right weights until you remove the oil pan and record the numbers on the crankshaft and connecting rods.
 

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Chances are your leak at the front cover is the result of it not being "centered" on the balancer when installed.... that, or the balancer installed with the seal and sealing surface "dry" or, finally.... the spring behind the seal lip knocked out during balancer install.
 

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Discussion Starter #11
Here are some pics of my crank before the engine was rebuilt. Can any of you eagle eyed experts spot anything that tells you whether I should have 28oz or 50oz flywheel and harmonic balancer please?
 

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Not sure. Why? Is that another clue to it's identity?
Yes, plus the side dipstick and main cap bolt with threads for mounting the rear sump bracket. Of course, somebody could have taken a 28.8 oz/in crank and machined the oil slinger off, but those counterweights give it away. Betting the block also doesn't have a equalizer bar pivot ball hole.
 

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Discussion Starter #19
I have a real dilemma now! I had accepted your comments and observations about my crank, and it had all reinforced my thinking that I need to swap my flywheel and HB from 28oz to 50oz.
Now, something has thrown a spanner in the works, and put a huge doubt in my head. After several hours work, I managed to remove the flywheel (engine in car, on axle stands!) and when I looked on the back, the counterbalance weight is missing. It appears to be a bolt in type, and there are two holes, but no weight. My delema is, is the missing weight the sole cause of my shake, and it is a 28oz crank, or is it a 50oz crank, and this just added to the problem?
I need as many opinions on this as possible please, as I cant face putting it all back together wrong.
The pic shows the rear face of the flywheel I've just removed.
757120
 
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