Broken rockers

[myfirst325]

I posted this earlier today but in the wrong forum. I just bought a 90 325ic with a known broken timing belt. It was only $700 and everything else on the car was in excellent shape including the paint - considering it's a 20 yo car. The car only has 55k miles and the PO said it was the original timing belt that snapped last month at a red light. I figured I would give it a shot knowing that I could always throw an engine in it. I just took the valve cover off and here's what I found...

[ZM Blue Devil]

get the head off and see if damage to block... if not should be easy as swapping in a new head.

[myfirst325]

Ok. Going to do that now just checking to see if there's a diy for removing the head. I'll post pics as soon as it's off.

[Kershaw]

here is a really simple diy...

step 1: keep removing bolts until the head is off.

here is a tip: the times i've removed cylinder heads i'll take off the intake manifold. but i've read it is not necessary. leaving it on there will definitely save you a bit of hassle. the bolts underneath are hard to reach.

[Len013091]

Take a look at that head again. Looks like the rocker shaft on the intake broke some of it's journals.

[stumble_t]

stroker!

[myfirst325]

The head is basically scrap. I'm hoping to find a good used head to throw in. I'll remove the head this weekend and hopefully the bottem end isn't that bad otherwise I'm looking at replacing the engine. Perhaps a good time throwin a 5 speed...

[ForcedFirebird]

Looks common to me. The rocker shaft bosses are broken, rockers are broken, when you pull it, you will see a bunch of bent valves as well.

I have welded the rocker shaft bosses back on to a few heads, but only after the guides check out. Cheapest way out for you is to find a used head and bolt it on providing the pistons aren't wrecked.

As far as taking the head and mani off together, works good, but it's a pain to put them back on that way since the alignment dowels and added weight don't mix when you are trying NOT to scratch the deck surface of the head :(

[clarkson]

here is a really simple diy...

step 1: keep removing bolts until the head is off.

here is a tip: the times i've removed cylinder heads i'll take off the intake manifold. but i've read it is not necessary. leaving it on there will definitely save you a bit of hassle. the bolts underneath are hard to reach.

Correct. Done it heaps of times. Only if you are doing an engine swap, or port matching intake to head etc, would I remove intake aswell as head. Not only does it save you time, but you are sure all all the connections on the intake side stay where they should be. Just unbolt intake from head and tie it back. I do it with every car, been a mechanic for 15 years and done more heads than had hot dinners.

[myfirst325]

So is it easier to unbolt the intake from head and tieback when removing the head? I thought I read that it's heavier but easier to remove the head with the intake manifold attached because the bottom intake-to-head bolts are hard to reach???

[ttrousdell]

^ive seen ppl do both. getting to all the intake manifold nuts is kinda a bitch an you always miss one.

[MR 325]

I always leave intake and exhaust manifolds on the head.

[clarkson]

Its hard but worth the effort. Good tools helps, stubby spanners; I think they are 11mm from memory, a quarter drive ratchet, long extension, universal and socket, magnet, torch, mirror. Think about the intake: injector harness, throttle cable, fuel lines, brake booster line (yuk), coolant hoses to throttle body, vacuum hoses etc. And the most important part of the job: lining up the head on the new head gasket (if you stuff this up everything has to be done again) is alot harder with the intake manifold on. Plus I like to eyeball the gasket all the way around the head to make sure it is seating properly.

There are many ways to skin a cat, this is the way I do it, I have done hundreds, and never had to pull one off again. My boss once gave me a $2000 bonus one year in a Christmas card with the the saying "headmaster" I guess I made him some money that year... It is one of my favourite jobs to do on a car, unless its a back to front SAAB, or an ALFA twin cam with no timing marks after the owner broke the timing belt.

[nando]

I always just pull the booster line out of the booster itself, it just pops right out in seconds. you still have to take most of that stuff apart anyway, and none of it is really that difficult. Leaving the intake on doesn't save enough time to me, except I guess you don't have to replace the gaskets. you can even do the top nuts from the passenger side of the engine where they are easier to get to (especially near the firewall).

[myfirst325]

So I was able to pull the head with the intake manifold on. Here's what I found. The car only has 55k miles so I was a bit surprised to find how bad everything looks. All the cylinders have the crescent moons on top of the piston heads. Is this normal? The intake side crescents are thicker than the thickness of a quarter coin. None of the piston heads have holes so I'm wondering if I can just clean up everything really well and throw in a rebuilt head.