Head replacement due to damaged valves

[jimzdat]

Haven't had any experience with that particular seller, but that's a pretty good price on the head - likely a rebuilt unit if I were guessing.

Don't forget to order new head bolts as well; they are not reusable, as they are a torque-to-yield design. You're also going to want a decent torque wrench and a "breaker bar" for torquing - since the head bolts get torqued to a set ft-lb value, then additional degrees of rotation. You'll want the torque wrench for that initial torque, then the breaker bar for additional - not good for the torque wrench to use it for those steps, as it can damage the internals (if using the click style - if the old beam style, go for it).

You also want to grab a torque angle gauge (around 10 bucks), for accurate tightening. Great Neck/Torque angle meter 25424- Read6Reviews onGreat Neck #25424

[xintersecty]

jimzdat advice on the torque bolts is correct. I followed the instructions and it seemed to work. Torque once, then follow the pattern on each degree rotation.

[Troller]

Thanks for the info, the head is rebuilt and there is no core charge. They send a return shipping label for the old head to send back to them once the new one comes. I found all the other parts on Amazon, including a kit for $75 that comes with all the gaskets and new head bolts to change the hear. I just learned about the plastic thermostat housing on these cars so I am ordering a metal one while I am at it.

[xintersecty]

Thanks for the info, the head is rebuilt and there is no core charge. They send a return shipping label for the old head to send back to them once the new one comes. I found all the other parts on Amazon, including a kit for $75 that comes with all the gaskets and new head bolts to change the hear. I just learned about the plastic thermostat housing on these cars so I am ordering a metal one while I am at it.

I had an issue with mine new tstat housing. I ran about 100 miles hard and then it failed. Once you get everything together monitor oil pressure and water temp carefully for about two weeks. When my tstat failed I had to use the dump the heat in the cabin trick and still it ran too hot.

I had to go back to my OEM from chevy. Has not failed yet.

BTW here is my drama thread: http://www.aveoforum.com/forum/f82/e...top-end-19864/

[Troller]

Have you dealt with the pieces of tubing that go between the block and head? The drivers side one is in my block and the passenger side one is stuck in my old head. I cant find these anywhere to purchase and was thinking they might not be necessary.

Any advice would be greatly appreciated.

[jimzdat]

Those are necessary to maintain proper alignment - you don't want to eliminate them, as it will allow the head to shift slightly, and damage the gasket; which will result in doing the job again.

If you soak them with a good penetrant, then use a pair of vice-grips to rotate them, they will come out - if they get a little gouged, it's not the end of the world, just clean them up with a file and reinstall them.

They may appear to just be tubing, but they are actually spring steel if memory serves - think of them as a big roll pin almost, but not as tight fitting.

[Troller]

Those are necessary to maintain proper alignment - you don't want to eliminate them, as it will allow the head to shift slightly, and damage the gasket; which will result in doing the job again.

If you soak them with a good penetrant, then use a pair of vice-grips to rotate them, they will come out - if they get a little gouged, it's not the end of the world, just clean them up with a file and reinstall them.

They may appear to just be tubing, but they are actually spring steel if memory serves - think of them as a big roll pin almost, but not as tight fitting.

Thanks, do you know where the get ne ones if I fail to get the old one out?

[jimzdat]

Not seeing them in my normal aftermarket sources, may be a dealer item only, or check with a local machine shop to see if they have any that are the correct dimensions

[Troller]

Hey guys, I finally have time to get the car back together and have another question. I should have counted the crank rotations with the head off , but didn't. Can you tell me if I need to get a specific cylinder to TDC, then align the crankshaft timing mark? I cant find a manual for this car and am not sure of one crank shaft rotation completes a full piston cycle.

Thanks again for all the help.

[jimzdat]

You could turn the crank 876 times with the head off, that's irrelevant - as long as you put the crankshaft at TDC for cylinder #1 (closest to the timing belt), and put the camshaft marks at TDC as well, all is fine.

With any 4-cycle engine, 1 rotation of the crankshaft will move all pistons from the top of the cylinder to the bottom and back up - or from the bottom to the top and back down. The difference is the camshafts - they move at exactly half the speed of the crank, thereby opening and closing the valves in the correct order, coordinating with piston placement.

Each full combustion cycle requires 2 rotations of the crankshaft - hypothetical, assuming a single cylinder, starting at TDC:
- Piston goes down, intake valve open - fuel and air enter cylinder
- Piston goes back up, both valves closed, sparkplug ignites fuel/air just before TDC, burning fuel pushes piston back down
- Piston forced down, both valves closed, transmitting power to crankshaft
- Piston goes back up, exhaust valve open, pushes exhaust gasses out the tailpipe

There's the 4 cycles, in simplest terms - just repeat lots of times every minute, and add on more cylinders accordingly.

Somewhere online, there's a good step by step on all the marks and setting timing properly, just don't remember if it's on this forum or if I found it somewhere else...