Do I need a flywheel dowel pin?
05-08-2006, 06:52 PM
#1
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Do I need a flywheel dowel pin?
I just got my engine back from the rebuilder and was going to mount the flywheel and noticed no locating dowel pin. I have a hole in the crankshaft where a pin could go and a hole in the flywheel that would line up with a pin. I'm not sure if I had a pin when I dropped off the block to be rebuilt. My question is, do I need to have a pin in the crank? Or should I just align the two holes?
Thanks in advance for any feedback.
6coupe4
Thanks in advance for any feedback.
6coupe4
05-08-2006, 07:40 PM
#3
Race Director
I'm not so sure it's a critical issue as long as you maintain alignment. I suspect more engines don't have one anymore, than do have one. Some others may want to weigh in on this - if I'm wrong I'm wrong.
Dan
Dan
05-08-2006, 08:02 PM
#4
Melting Slicks
Was any crank work done? Was it balanced? The crank should have the dowel pin unless it was balanced without one. Check with your rebuilder. If, as you say, it is drilled for one, I would use one as it positively locates the flywheel and keeps things from working loose.
05-08-2006, 09:54 PM
#6
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To late to add one unless you want to tear down the whole motor to rebalance the crank.... Don't sweat it most people here on the board never even see 5000 rpm and you'll never have a problem... I put one on this motor I just built but I regularly bounce off the 6500 rpm pill in my 6AL.... To each his own... Dave
05-08-2006, 10:08 PM
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Originally Posted by youwish2bme
To late to add one unless you want to tear down the whole motor to rebalance the crank.... Don't sweat it most people here on the board never even see 5000 rpm and you'll never have a problem... I put one on this motor I just built but I regularly bounce off the 6500 rpm pill in my 6AL.... To each his own... Dave
I agree with you. I'll never see 5000 rpm. I'm going to contact the rebuilder tomorrow. I would think he balanced it without it and if I add it now it would be unbalanced.
thanks,
6coupe4
05-08-2006, 10:51 PM
#9
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Originally Posted by StickShiftCorvette
You want a dowel pin. I really doubt that you would have a balance problem. The hole is at a small radius and the pin is not THAT heavy.
Care to put that to the test on your own motor?
05-08-2006, 11:50 PM
#11
Originally Posted by DansYellow66
I'm not so sure it's a critical issue as long as you maintain alignment. I suspect more engines don't have one anymore, than do have one. Some others may want to weigh in on this - if I'm wrong I'm wrong.
Dan
Dan
05-08-2006, 11:55 PM
#12
Le Mans Master
Originally Posted by 67L36Driver
The only SB or BB I've ever had that had a dowel pin was my '56 Belair 265, of the couple dozen since none had one. 
I think all (maybe most) external balanced motors had the dowel (400 SB and 454 BB). To make sure the weights on the flywheel line up.
05-09-2006, 08:37 AM
#13
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Originally Posted by 67L36Driver
The only SB or BB I've ever had that had a dowel pin was my '56 Belair 265, of the couple dozen since none had one.
Same here. I don't think they were a production item after 265. Not sure about the 400 sb. I'm gonna' look to see.If you add the dowel, it's so close to the crank centerline, I wouldn't worry about balance.
I'm guessing the dowel hole was an index reference for the crank machining operation. But, I don't know that.
05-09-2006, 09:29 AM
#14
Safety Car
Originally Posted by knight37128
I think all (maybe most) external balanced motors had the dowel (400 SB and 454 BB). To make sure the weights on the flywheel line up.
05-09-2006, 04:32 PM
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You don't need a dowel pin unless it's an externally-balanced 383/400 or 454; your flywheel should have been zero-balanced anyway by itself before balancing the complete rotating assembly so you can change it down the road without affecting engine balance. 
05-09-2006, 07:37 PM
#16
Race Director
Originally Posted by youwish2bme
To late to add one unless you want to tear down the whole motor to rebalance the crank.... Don't sweat it most people here on the board never even see 5000 rpm and you'll never have a problem... I put one on this motor I just built but I regularly bounce off the 6500 rpm pill in my 6AL.... To each his own... Dave
Dan
05-09-2006, 09:31 PM
#17
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Originally Posted by DansYellow66
I'm afraid if your doing something to the engine that those grade 8 bolts don't hold the flywheel, I don't think a dowel pin is going to make any difference.
Dan
Dan
05-10-2006, 12:24 PM
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Originally Posted by DansYellow66
I'm afraid if your doing something to the engine that those grade 8 bolts don't hold the flywheel, I don't think a dowel pin is going to make any difference.
Dan
Dan
