Good day all. Question, I reinstalled timing belt after a head gasket change. All alignment marks were lined up. Is it necessary to rotate the crank clockwise one full turn after installing the belt? I rotated the crank but the alignment marks didn't line up. The crank is at 0, but the cam gear is 180 out. Is this normal?

It is not necessary to rotate the engine one turn after installation. My test of the timing belt installation is to rotate the engine one turn clockwise, and then one turn counter-clockwise. Then the marks will line up - or should.

Usually what I find is that the tensioner bolt isn't tight enough and the belt slips a tooth or two. Rats! But better to fix it now than later.

Once the engine runs, the marks may never ever line up again. The marks are only for belt installation, after which they are meaningless.

Good Luck,

Bob

:>)

As Lucid said, The Marks on the Belt are a 'one time only' refernce. They will not continue to line u0p as you cranke the engine around. The Markings from Sprocket to Block shoulkd line up every teo revolutions. The 180 out that you mentioned is during an exhaust stroke.

--
'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me http://home.no.net/ebrox/Tony's%20cars.htm

The reason that the marks didn't line up after one rotation of the crankshaft is because the camshaft and the imtermediate shaft only run at 1/2 speed. You would need to rotate the crankshaft twice for the marks to line up. If you noticed, the belt sprocket on the crankshaft is much smaller than the sprockets on the intermediate and camshafts.

Bill

The marks are for initial installation only.

Even assuming everything is done correctly, they won't line up again for an unbelievable number of revs, due to a combination of sprocket teeth and the number of teeth between each of the 3 marks.

Someone calculated it with an explanation here once, but I don't recall the specifics.

P.S. Off topic but I used to know a stickbuilder named Hale Wallace. Was he before your time? He did a couple scale models of the Steen Skybolt, then went on to the real deal and eventually owned the company. Built Knight Twisters too, I think.
He died of cancer at the top of his game -- late '90s I think.

Thanks to all you guys who responded. I purchased the crank pulley tool from IPD, I recommend it to all, very nice and makes the job so easy. I aligned all the timing marks, put everything back together, it runs alittle smoother, but it still shakes and putts sometimes. Anything else I need to look at?


rvoll88@yahoo.com

I would double check the timing marks, especially if it is harder to start or more sluggish than before the TB replacement.

Try to better describe the shaking and putting, when does it do these things? Dan

Hi Dan, I didn't replace the TB. It starts fine, then it shakes alot less than before. I replaced the head gasket, wires, plugs, distributor, rotor, flame trap, oil trap and water pump. It almost sounds like when you whistle, blow and breathe. I can't really descripe it any other way.


Darryl

Sounds as if you may have missed the ignition timing by one tooth. Get the engine on Top Dead Center again, and make sure that the rotor is pointing at #1,

Bill

That's were I was going with the hard start and sluggish performance. Maybe check that the plug wires are in the proper order also.
There is a tick mark on the metal part of the distributor that lines up with #1 spark plug wire. If that is good check the cam timing marks, it is very easy to get a tooth off.
Dan

Can you drive it so you can tell if it feels like normal power? I can't address the shaking, does it do it all the time? Dan

Not before my time, I have done a few Skybolts, and Knight Twisters, but the S series Pitts are my favorites of that type. I basically only do large Scale Waco YMF's now.

Bill
--
Those who beat their swords into plowshares will surely plow for those who did not.

All three need to be on the timing marks, the camshaft has to be on the mark with both valves for #1 cylinder closed. Open the oil filler cap and verify cam lobes on #1 cylinder are up indicating the valves are closed. If not rotate the cam 360 degrees and check again. See FAQ's below. Dan

http://www.brickboard.com/FAQ/700-900/B230FTimingBeltAlignment.htm