Author Topic: Cylinder Head Timing (Read 4480 times)

e30jr88 · « **on:** December 27, 2011, 10:50:34 AM »

Hey guys I'm new to the forum, but i've been a lurking the forum since I got my e30 during the summer. Recently I had a failure somewhere and the car overheated making the Headgasket fail. I took everything off since I knew that the car had overheating for a small period of time I took it to a shop to get pressure tested and resurfaced.

When recieved the head all looked well only thing is I noticed that the guys didn't leave the head at TDC. My question is how do I get the head to be a TDC (cam lobes to face each other) when the head is still off the car?
Do try to remove the cams or do I rotate the cylinder head to try and find TDC and if so how do I rotate the cylinder Head when off the car?

Any info will help, thanks

Geoff · « **Reply #1 on:** December 27, 2011, 12:25:27 PM »

You can rotate the cams with the head off or on the block, dont remove the cams themselves. It may be easier with the head bolted down to the block, but you should be able to get the block set with #1 piston at TDC, and have the head pretty close just by having the cam lobes at number 1 pointing to each other and facing up, it will then be pretty close and all you have to do is make minor adjustments when you install the chain.
Geoff

e30jr88 · « **Reply #2 on:** December 27, 2011, 12:42:11 PM »

Quote from: Geoff;109190

You can rotate the cams with the head off or on the block, dont remove the cams themselves. It may be easier with the head bolted down to the block, but you should be able to get the block set with #1 piston at TDC, and have the head pretty close just by having the cam lobes at number 1 pointing to each other and facing up, it will then be pretty close and all you have to do is make minor adjustments when you install the chain.
Geoff

Thanks for the reply Geoff, do you have any idea on how I would be able to rotate the head while off the block? That's what i would prefer to do since I would be get as close as possible then adjust it when the head is on the block. I would think I could either make it rotate from the front there the cam gears go because the back on the cams seems like a bad idea.
Just not sure how to go by doing it since I don't want to break anything.

bmwman91 · « **Reply #3 on:** December 27, 2011, 12:52:27 PM »

It is fine to rotate them from the square ends on the back. I forget what size wrench fits on there, but I usually just use a large crescent wrench. If you are still uncomfortable with doing that, then you can probably grab a sprocket with a rag & turn it by hand, and then make fine adjustments from the square back end. You will probably need to do them with one sprocket on at a time so you don't get your fingers caught between them!

Geoff · « **Reply #4 on:** December 27, 2011, 01:51:37 PM »

yeah, those square parts at the back are perfect for a large adjustable. I will usually lay a couple of 2 x 4's on my work bench, to keep the vavles from hitting the table. probably would not hurt anything if they did, but thats what I do. then usually a helper to hold the head down firmly while you rotate the cams. you can also install the cam gears and just grab em with both hands, that will turn them but is not as precice and controllable as a wrench.
Geoff

e30jr88 · « **Reply #5 on:** December 27, 2011, 01:52:56 PM »

Quote from: bmwman91;109193

It is fine to rotate them from the square ends on the back. I forget what size wrench fits on there, but I usually just use a large crescent wrench. If you are still uncomfortable with doing that, then you can probably grab a sprocket with a rag & turn it by hand, and then make fine adjustments from the square back end. You will probably need to do them with one sprocket on at a time so you don't get your fingers caught between them!

Awesome this will help alot and thanks on the heads up, don't want to have my fingers jammed in there lol. I will get some wood and make someting to keep the head elevated so that I can rotate it with a wrench which I think is a size 27 from what I noticed in a pic online.

e30jr88 · « **Reply #6 on:** December 27, 2011, 02:13:55 PM »

Quote from: Geoff;109195

yeah, those square parts at the back are perfect for a large adjustable. I will usually lay a couple of 2 x 4's on my work bench, to keep the vavles from hitting the table. probably would not hurt anything if they did, but thats what I do. then usually a helper to hold the head down firmly while you rotate the cams. you can also install the cam gears and just grab em with both hands, that will turn them but is not as precice and controllable as a wrench.
Geoff

Thanks alot for the fast response and helpful information hope I finish this project before the end of the year!

Geoff · « **Reply #7 on:** December 27, 2011, 03:30:25 PM »

good luck with the project:)
Geoff

e30jr88 · « **Reply #8 on:** December 27, 2011, 03:49:00 PM »

Thanks, now I just have to go shop for a torque wrench. Always fun to shop for tools just sucks to pay for them!

victor.askew · « **Reply #9 on:** December 27, 2011, 08:50:37 PM »

If the head is off of the block you do not want to have it sitting on a flat table where the valves can make contact with the table top surface and bear the weight of the head (Possible bent valve stems end results). Place wood blocks( Hokey pucks) under the head to support it in an elevated position in relation to the table top surface.

e30jr88 · « **Reply #10 on:** December 28, 2011, 11:25:34 AM »

Quote from: victor.askew;109205

If the head is off of the block you do not want to have it sitting on a flat table where the valves can make contact with the table top surface and bear the weight of the head (Possible bent valve stems end results). Place wood blocks( Hokey pucks) under the head to support it in an elevated position in relation to the table top surface.

Thanks for the advice didn't know that, good thing I put some wood to keep it at an angle.

e30jr88 · « **Reply #11 on:** December 29, 2011, 02:27:24 PM »

Anyone know where I can get a good tap tool? One of the bolts on the water pump snapped and my dad FAILED in trying to get it out. So now I need to rethread the hole and fit a bigger size bolt in there. what would be a bigger bolt size that would work on there I believe the size right now is M6x20

Geoff · « **Reply #12 on:** January 05, 2012, 05:41:25 AM »

are you still wrestling with this? broken bolts are a bitch.. sometimes an insert is better than just a rethread, especially in aluminum. cast iron takes a rethread a little better, if you have to.
Geoff

e30jr88 · « **Reply #13 on:** January 05, 2012, 05:17:53 PM »

Quote from: Geoff;109401

are you still wrestling with this? broken bolts are a bitch.. sometimes an insert is better than just a rethread, especially in aluminum. cast iron takes a rethread a little better, if you have to.
Geoff

Yeah still looking into it since I havent had time to get much done lately, what type of inserts were you talking about?
I will actually have to rethread the cylinder block since its one the bolts that hold the water pump.

Geoff · « **Reply #14 on:** January 06, 2012, 11:42:14 AM »

theres a couple of different types, I think official names are "thread saver" and "time-certs " but dont quote me on that. Basically, you make the buggered up hole bigger, then thread the steel insert into the hole, some types are held by threads and some sort of epoxy. the outside threads of the insert hold it in, and there is a threaded hole in the center, which can be the same as your original, so you can use the stock hardware over again. The insert, being steel has strong threads and can take being torqued up to the proper spec. This job is not a complete walk in the park, tho, the insert has to be level and correctly installed or more night-mares will ensue.
Geoff