jdstoledo

Hello everybody! I have a problem. My timing belt broke on my 90 civic si and it killed the cylinder head. Well, I was lucky enough to find a replacement cylinder head on ebay for $100, but I have a problem.

I don't know where TDC is. I understand that it's for cylinder #1 which is the one closest to the drivebelts. I understand that it's when the piston in cylinder one reaches the very top of its arc....but I don't know how to determine which revolution it's on without using a compression tester (trying to avoid purchasing). The revolutions being 1.intake 2.exhaust... I don't know how to avoid being 180 degrees off.

My main question is this. If I'm going to completely change heads it seems logical to me that I need to do three things:
1. set cylinder #1 to the top of its arc with the head off so I can actually see the piston
2. install the head with the lined up TDC marks on the cam attached to the head
3. bolt up

Basically, my thinking is pistons go up and down while the cylinder head controls the intake and exhaust...if the exhaust involved the block i wouldn't think like this, but I don't believe that's the case.

Anyone help me on this???
Sorry for the length...very tired.

b19coupe

Just a little info on installing a cylinder head. The way cams work in relation to the crankshaft is this:for every complete revolution of the camshaft, the crankshaft rotates two times.
Before you install the cylinder head, set the cam gear at TDC. On a 1988-1991 SI , there is a mark that says "up". Obviously you want the "up" to be right side up. (you'll have to forgive me if my description isn't exact, I left Honda in 99 to work on Acura, so It's been a while since I've done this) There are two hash marks that roughly line up with the plane of the cylinder head, one on each side of the cam gear. The difference between a 1988-91 1.5L and a 1988-91 1.6L (SI) is that the hash marks line up perfectly on the 1.5L. On the 1.6L (SI) there is another mark on the cam gear at about 7:00 (picture a clock) that lines up with a notch on the rear upper timing cover. That is the mark that you use for the 1.6L. Verify that all of the valves for number one cylinder are closed.You are now ready to install the head.(of course you have a new head gasket installed)
When you install the cylinder head, have #1 piston at TDC. Slip on the timing belt after you have torqued the cylinder head bolts, loosen the tensioner, rotate the engine counterclockwise two turns (by hand-use a large ratchet and socket on the crank bolt) and tighten the tensioner.Verify that the white mark on the crankshaft is lined up with the pointer on the lower timing cover, and the cylinder head is at TDC as outlined above.If it all lines up, you are good to go.Good luck.
Note:if it feels like something is hitting when you try to turn the engine over, don't force it, a piston may be hitting a valve-doublecheck your settings.