head resurfacing and timing, techs wanted

[BAlbertiX]

Thanks golden. haha no, will not be painting anything in the engine bay. Actually the faded yellow of the factory rust coating over metal has grown on me. Yah, the stock heads are known for their tick, a "sewing machine" as some put it. Start with a loose .010", if they're still ticking, try a tight .010 before going to a .009", no less than .008. I can also note that the 10W-40 also made quite a difference in engine noise. Good luck sir.

[goldenbb]

Actually, it was really interesting because I just did the same work. I had no height issues being that the head was skimmed for the first time, but I did have the valves adjusted too tight at first--I set them with the head off and why would it make any difference? But it did--I had to loosen things up just a hair and then then the engine ran a lot better. I will probably re-adjust in a couple of months since they do tick a little, but am not sure how much is just normal.

I also had the crank and cam sensors hooked up backwards and it ran that way, just very badly!

Also, don't paint your headers--even high temp paint burns right off and freaked me out when all that rank-smelling smoke came out of the engine bay.

I used 5w-30 semi-synthetic. I agree that it is too thin and I am seeing some weeping around the cam seal even though that seal is new. I will get some 10w-40 and replace it. God damn oil is like $25/5qt. though!

[BAlbertiX]

Re:

She's ALIVE!!! Tick free and purring.

A sticky intake valve on cyl6 was definitely the issue. As far as lessons learned go, carefully inspect valves, guides, and tubes for burrs, wear debris, and leftover valve grinding compound when rebuilding or refreshing a head. I still don't know exactly what caused the valve stem to bind, but am aiming towards leftover grinding compound...

A few other notes.

While I had the head out, again... was able to get some numbers off it, and the average height of the head was under the lower limit by .008" at 4.901. Granted I would have welcomed the added compression, but the +.031 thicker head gasket certainly brought some piece of mind on first start. For what it's worth, I was originally under by .008" with a stock headgasket and experienced no interference.

This is certainly not the most most exciting repair thread, but I hope makes a good reference for those with similar head problems.

Thanks r3v.

[BAlbertiX]

re:

Compression test results:
1 150
2 125
3 120
4 140
5 60
6 130

Leakdown showed cylinder 5 to be head related. Soooo I pulled the head again tonight assuming I'd find a bent valve on 5. Nope, intake valve on 6 was sticking... Not sure from what, but a SS pipe brush took care of it.

AND, both valves on cylinder 5 looked fine, not bent, seats were good... I'm done asking questions.

Reassembling this weekend. Hopefully more good news to follow.

[BAlbertiX]

Turns out the stripped eccentric screws were not the issue. The head is still ticking. Again here are the knowns:

Crank and cam set to tdc
Brand new eccentric screws and nuts tightened to spec
Brand new valve guides, and guide tubes polished
Eccentrics free of excessive wear
Rockers and cam lobes free of excessive wear or pitting
Valve clearances set to a loose .010"
Rockers centered on valve heads
Head sprayer working
Head bolts torqued to 45lbs, waiting on final 90deg torque down

http://youtu.be/kwE6vPHLHHk

The ticking is coming from the front of the head, does not change with engine temp, and certainly gets louder with rpms. Given how smooth the idle is... a sticky exhaust valve coming back up late?

Thoughts?

Compression test to follow.

[BAlbertiX]

Torque specs on the eccentrics? Those little guys? It must be in inch pounds!

Believe it or not, 7.38lbft [10Nm] to be exact

[goldenbb]

Torque specs on the eccentrics? Those little guys? It must be in inch pounds!

[BAlbertiX]

Re:

Forgot calipers at work so could not get a height number... still went ahead, set TDC again, and fired it up. As expected, there was tapping coming from the engine. Going through the head, it turns out two eccentric screw nuts, on the exhaust side of cylinder's 5 and 6, were stripped. Given 4x4's words of wisdom, and how smooth the idle was, I'm definitely not worried about interference anymore. The eccentrics must not of floated much, just enough to make plenty of noise. New screws and nuts on order. Lesson of the day, torque specs are set for a reason.

[BAlbertiX]

You need to check the overall height of the head. 4.929" is stock, 4.909" is the limit. I'm at 4.909" and kept everything the same cam timing wise, the clay test showed I had plenty of clearance. So I'm down -.020" and have no timing issues what so ever, you should be fine as well.

Did you get any numbers off the clay?

Thanks 4x4, this sounds like good news. I will measure this weekend.

[4x4_e30]

You need to check the overall height of the head. 4.929" is stock, 4.909" is the limit. I'm at 4.909" and kept everything the same cam timing wise, the clay test showed I had plenty of clearance. So I'm down -.020" and have no timing issues what so ever, you should be fine as well.

[BAlbertiX]

I might have to, but would rather not have to tear it down again. Searching through posts it looks like every cam gear advances or retards the engine 7.5deg, and from what I've read valves will find interference quicker retarding timing than advancing. I'm curious if advancing timing 7.5 degrees is too much on a stock setup.

I set the cam one tooth ahead last night, and for what it's worth, turning the crank by hand with plugs out, I don't hear or feel interference.

Started the car last night with 7.5deg advance (1 tooth) on the cam, and can at least report there was no interference, but idle was fairly erratic; idling high and surging.

I'm going to tear down the timing side of the engine this weekend, set both cam and crank to tdc, and set head clearances to .010, again. If all else fails, +.30 gasket will be on order.

[BAlbertiX]

Thicker head gasket if needed maybe?

I might have to, but would rather not have to tear it down again. Searching through posts it looks like every cam gear advances or retards the engine 7.5deg, and from what I've read valves will find interference quicker retarding timing than advancing. I'm curious if advancing timing 7.5 degrees is too much on a stock setup.

I set the cam one tooth ahead last night, and for what it's worth, turning the crank by hand with plugs out, I don't hear or feel interference.

[uturn]

Thicker head gasket if needed maybe?

[BAlbertiX]

Yes, you should feel resistance. It may be more than before because of you new head gasket. Take the plugs out and turn it over if it makes you feel better.

You will feel the engine STOP if you crunch a valve

that will certainly take compression out of the equation, might as well... Thanks Spec.

[SpecM]

Yes, you should feel resistance. It may be more than before because of you new head gasket. Take the plugs out and turn it over if it makes you feel better.

You will feel the engine STOP if you crunch a valve