3SFE Timing belt broken

[87manche]

So, I've got a friend with a 91 Camry. I told him last year that the timing belt was long overdue for replacement. It broke last week. Thankfully these aren't interference type motors.

So, I've alreayd gotten to the timing belt, no problems there, it's remarkably similar to my wife's 97 5SFE. I've seen conflicting information here about whether or not TDC on the #1 cylinder needs to be set on the compression stroke. Lots of people say no, but I assume they're replacing an intact belt, so all they have to do is line up the timing marks and keep them lined up. Obviously with the broken belt he tried to start it, so the crank and cam are no longer in the same relation.

Do we need to find TDC at the compression stroke for the #1 cylinder, and what's the best method to determine TDC?
Unfortunately my compression tester will not reach down to the spark plug hole, I'd also really like to avoid taking the valve cover off. Since that's another 2 hours of unbolting crap just to get to it.

Thanks.

[white90dx]

The compression and exhaust strokes don't matter until the timing belt is on.

You just need to make sure the correct mark on the cam gear is lined up when the crank is at TDC. If the motor is in the car, you will need a mirror.

The valve cover comes off with just the 4 nuts around the spark plug holes (32mm, I think?) and you should be able to remove the cover in a couple minutes if you want to verify anything inside.

-Charlie

[stanno]

When i changed the timing belt on my brother's integra... removed the #1 cyl spark plug wire and spark plug... and i put a long screw driver in the spark plug hole (so it would rest on the piston) then i used a power handle to turn the crank til i saw the screw driver go right upward to the point that it would have a momentary pause before going on the down stroke.... at that point i knew it was compression/power... but i believe timing marks are somewhere on the block... i believe u use the key on the timing gear to align with it... (don't quote me on that part tho)...

[fredk]

Doesent matter what stroke its on, you are telling what stroke or cycle its on when you put the belt on

[jaduncan]

Originally Posted by fredk

Doesent matter what stroke its on, you are telling what stroke or cycle its on when you put the belt on

fred, you sound like the type of guy who'd move the plug wires on a distributor that's 180 out.



Allen

[JOET/CAMRY]

Originally Posted by fredk

Doesent matter what stroke its on, you are telling what stroke or cycle its on when you put the belt on

fredk,
Is this true for all overhead cam engines? I am confused why some engines require you to set them at top dead center on the compression stroke when changing the timing belt and other engines (like the 3sfe) just require it to be set at top dead center (period)

JOET/CAMRY

[Jimnist]

Originally Posted by JOET/CAMRY

fredk,
Is this true for all overhead cam engines? I am confused why some engines require you to set them at top dead center on the compression stroke when changing the timing belt and other engines (like the 3sfe) just require it to be set at top dead center (period)

JOET/CAMRY

I believe so - since it's the camshafts that control whether it's on it's compression stroke or top of exhaust/starting intake. With OHC engine, well, the titles says all

[fredk]

YOU tell the motor what cycle its on when you time the cam to the crank

[white90dx]

If you are replacing a non-broken belt, it is best to set the motor to TDC, compression and work from there. If the belt was broken, there is no reference to whether the motor is on the compression or exhaust stroke and so it doesn't matter. This is true for ALL 4 stroke internal combustion engines...

-Charlie