QuestionQUESTION:
"I replaced the timing chain and gears as they were in bad condition and the chain appeared off only one tooth. I am wondering now if the chain had possibly sliped 180 degrees as the gears are lining up at #1 TDC I think on the exaust stroke. I have a haynes manual and am pretty good with motors but can you assure me please, on this motor are the exaust valves adjasent the exaust ports and shouldnt the intake valve have just been closing prior to the timing marks lining up with the #1 coming up to TDC on a compression stroke? If so then shouldn't I rotate the crank 180 degrees? There are other problems due to the car dieing as I was on the highway traveling to Canada with my wife and 2 dogs on board and tried to limp back into the city and beleive the valves may be burned etc. The compression is 25 to 30 lbs in all cylinders but I need to get past this timing problemm first. Thank you very much. PS, I live in a small town in Mexico where good help and parts are not to easy to come by. Dale"
ANSWER: At tdc, both valves in #1 cylinder are closed. The intake valve closed 180 deg. ago and the exhaust will start opening in another 180. TDC is the top of the compression stroke, followed by the power stroke. Technically, the 3.3 is an interference engine, but the valves would have to be fully open as the piston hit TDC. I would suspect more the chain guides or tensioner is at fault here.
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QUESTION: Thank you. This engine has no guides or tensioner.Please can you tell me how best can I put the #1 piston at the top of its compression stroke about to begin the power stoke with out using the timing chain gears as a referance? Thanks again. Dale
AnswerBefore removing the front pulley, align the timing mark of the pulley with the the indicator on the cover. This will get you within a few degrees of accurate. Once you have the pulley and timing cover off, make sure the timing mark of the crank sprocket is straight up at the 12 o'clock position. This mark should be in direct line with the timing mark on the camshaft sprocket. The proper installation
procedure is as follows:
Position a new crankshaft sprocket onto the shaft, then install the sprocket with a suitably-sized socket and a rubber or plastic mallet. Be sure that the sprocket is seated in position.
Rotate the crankshaft, if needed, until the timing mark is in the 12 o'clock position.
Situate the timing chain on the camshaft sprocket and hold the camshaft sprocket so that the timing mark is in the 6 o'clock position.
Align the dark colored links with the dot on the camshaft sprocket, place the timing chain around the crankshaft sprocket with the dark colored link lined up with the dot on the sprocket and install the camshaft sprocket onto the end of the camshaft.
Using a straightedge, check the alignment of the crankshaft and camshaft timing marks.
Install the camshaft bolt and washer. Tighten the bolt to 40 ft. lbs. (54 Nm).
Rotate the crankshaft 2 full revolutions. The timing marks should line up. If the timing marks do not line up, remove the camshaft sprocket and realign it.
Check the camshaft end-play. With a new thrust plate the specification is 0.005-0.012 inch (0.0127-0.304mm). The old thrust plate specification is 0.012 inch (0.31mm) maximum. If not within these limits install a new thrust plate.
Install the timing chain snubbers. Tighten the retaining screws to 9 ft. lbs. (12 Nm). rocedure is as follows:
When setting up the valve timing, what makes the piston be at the top of its intake stroke is the position of the camshaft only. The piston is at the top of its travel and its the camshaft that decides which stroke is occuring. So, if the chain was installed exactly 180 deg. out, the engine would still operate correctly.
