In preparation for installing my new 383, we decided to swap the cam out with a 224/236-114. We lined up the two gear marks to each other (upper one at 6:00, and lower at 12:00), pulled the old cam, installed the new cam and sealed everything back up. What seems odd to me is that when #1 piston is at TDC, the alignment arrow on the crankshaft pulley is at about 2:00. Should the crank pulley arrow still point at 12:00 when at #1 TDC? Is this a problem or normal due to the differences of the 383??

It's a Trickflow crank, 6" rods, JE -31cc pistons, and the block has been decked so that the piston sits .025 below at TDC. The crankshaft pulley is from Thunder Racing. Could it just be that the keyway isn't in a specific spot? If nobody has any other possible explanations, I'll pull it back off and check that.

I need to figure this out before I put it back in the car and kick myself later. Any ideas appreciated! Thanks!!

 

On a stock hub or pulley, when the arrow is at 12 o'clock (#1 or #6 TDC), the keyway on the crank is at 1:30 o'clock.

Are you using an actual key and keyed hub? The stock hub is not keyed.

 

Oops, when I said the "crankshaft pulley is from Thunder Racing", I meant to say the KEYED HUB. So based on that, it's normal? <fingers-crossed>

 

With #1 or #6 at TDC, the arrow should be straight up at 12 o'clock.

 

Ok...so does this sound reasonable? If the keyway is at 1:30, and I'm using a keyed hub....then the only way the arrow on the hub would be pointing at 1:30 with #1 or #6 at TDC is if the keyway in the hub is machined right behind the arrow?

Is it safe to assume the keyway in the aftermarkey crank is in the same location as the stock one? Why wouldn't they just put all the keyways at 12:00, so everything lines up?

Sounds like I'm gonna have to pull the hub back off to verify the keyway location...I'm SO confused. I'm just paranoid about firing it up the first time and want to understand the relationship of the various alignments.

Thanks for your assistance!!!

 

I have the keyed billet crank hub from thunder and the mark is on the Key, not on the usual LT1 12 o clock position.

 

That's what I suspected. I have no idea why they would do the LT1 hub that way.

 

I thought the same thing, threw me off a couple times at first.

 

I pulled the hub tonight and you are indeed correct, the mark on the face of the keyed hub indicates where the keyway is. Thanks! You guys are awesome...