timing marks 454 ?
Thread Starter
Drifting
Joined: May 2005
Posts: 1,909
Likes: 6
From: Lake Arrowhead - Georgia > 72 Base Coupe & 74 BB Roadster
timing marks 454 ?
Please take a look at the pic below. I realize the marks are not perfect at 12'oclock, but "close enough" considering the slack in that old timing chain.
Confirm that this "is good". My rotor button is pointing at the #1 position on the distributor. There is no tension on either rocker arm for cyl #1, which says both valves are closed.
IF this is truely TDC - compression stroke #1 - not exhaust.....I was expecting timing gear marks to be at 6'oclock (cam) and 12'oclock (crank). Not both marks at 12'oclock. I just want to be sure I "know what I'm doing"....
....before I get any deeper in replacing this camshaft.
I need a big blocks for dummies book!
Thanks for any input.
Confirm that this "is good". My rotor button is pointing at the #1 position on the distributor. There is no tension on either rocker arm for cyl #1, which says both valves are closed.
IF this is truely TDC - compression stroke #1 - not exhaust.....I was expecting timing gear marks to be at 6'oclock (cam) and 12'oclock (crank). Not both marks at 12'oclock. I just want to be sure I "know what I'm doing"....
....before I get any deeper in replacing this camshaft. I need a big blocks for dummies book!
Thanks for any input.
Last edited by fotyfobravo; Feb 24, 2007 at 02:58 PM. Reason: additional comment
Tech Contributor
Joined: Aug 1999
Posts: 14,380
Likes: 6,390
From: At my Bar drinking and wrenching in Lafayette Colorado
That's a common misunderstanding. On a Chevy, when the #1 cylinder is at TDC on the compression stroke, both timing mark dots point straight up (12:00 o-clock). When the crank is at 12:00 and the cam is at 6:00, #1 is at TDC on the exhaust stroke and #6 cylinder is in the firing position.
He's got both marks straight up (or pretty close), so that means the rotor should be pointing to the #1 plug wire location.
He's got both marks straight up (or pretty close), so that means the rotor should be pointing to the #1 plug wire location.
Thread Starter
Drifting
Joined: May 2005
Posts: 1,909
Likes: 6
From: Lake Arrowhead - Georgia > 72 Base Coupe & 74 BB Roadster
That's a common misunderstanding. On a Chevy, when the #1 cylinder is at TDC on the compression stroke, both timing mark dots point straight up (12:00 o-clock). When the crank is at 12:00 and the cam is at 6:00, #1 is at TDC on the exhaust stroke and #6 cylinder is in the firing position.
He's got both marks straight up (or pretty close), so that means the rotor should be pointing to the #1 plug wire location.
He's got both marks straight up (or pretty close), so that means the rotor should be pointing to the #1 plug wire location.
BTW Lars.....by the time we flew into Denver last week....went to "the springs".....then Breck.....I never had a chance to buy you that brewski I owe you. Next trip out there I will plan things better.
