Wrenchinjoe

Just hit my first BIG snag.

The machine shop called today and left a message on my answering machine that both heads have the beginnings of cracks forming He said something about being worried a valve seat could get loose. I did not get home in time to call him, will certainly do that tomorrow a.m

Not sure why I would have cracks??? I was meticulous about removing the cam and head bolts according to the FSM. I followed the bolt sequence, no more than a 1/4 turn at a time until all tension was off the bolts. They were not dropped or mistreated. BUMMER

As previously posted, the HGs were replaced under warranty @ approx. 90K miles. The head bolts were incredibly tight though... I had to get that first 1/4 turn to loosen almost every bolt with an extension for my ratchet giving it almost all I had. Is that normal?

Claxton Automotive Machine quoted $180 total to do the valve job and adjust the valves which sounded great to me and was less than my first quote. Given that price, my mechanic friend recommended buying a couple of used heads ($139 each with a warranty) and then letting the machine shop work that same valve job magic. That turns my $200 valve job into a $500 job, but I’m not sure I have a better option.

Any other suggestions?

Wrenchinjoe

Ok, so Claxton Machine informs me I have cracks right between the intake and exhaust valves for cylinders 1 and 6 - go figure.

I asked what could cause such cracks? He explained that these heads are known to be a bit fragile, but also that 17 years and 174,000 miles worth of expansion and contraction cycles just take their toll. They do not leak yet, but will eventually crack through to a cooling channel, so he advises it is time for some remanufactured heads

I found a couple of replacement options online:

http://www.aluminumheads.com/Toyota.html

http://www.sunwestautomotiveengines.com/ch-toyota.html

http://www.shop.headsonly.com/TOYOTA_c27.htm

The best price I found for remanufactured heads is approx. $550 after shipping and core return from Cylinder Head Int. , or $650 after shipping and core return from Aluminum Head Rebuilders and SunWest. These all arrive ready to bolt on. Anybody use these folks?

Dover Cylinder Heads can repair (weld) and reman my existing heads for $300 each, but shipping would push that price out to $700 total.

http://www.gishart.com/sites/dover/index.htm

Should I consider used heads as my mechanic friend suggests? A set of used heads and a valve job would likely keep me under $500... anybody have any better ideas?

99blackSE

iTrader: (1)

Darn, 650 clams. It's not possible to find a used motor for that price is it? Also..with 650 you're almost halfway to a rebuilt Oregon Engine Rebuilders motor.

Wrenchinjoe

Update: My mechanic buddy found me a couple of used heads locally for $100 each, with a warranty not to also be cracked.

The plan is to take those to Claxton Machine Shop and let him proceed with the valve job with a couple of good heads hopefully. This will keep the valve job around $400.

I suppose if that doesn't pan out, then I'll look into a couple of remanufactured heads next week.

Wrenchinjoe

Making progress. I picked up two used heads from Eddie's Auto Parts last Thursday on my lunch break. They look way more sludged up than the ones I pulled off my truck, but the machinist will let me know if they are good or not.

I dropped the used heads off at Claxton Machine Shop at lunch on Friday, Bert says he'll dig into them on Monday and hopes we have a couple of good ones to work with.

I had him show me the cracks in my old heads. He had sprayed the combustion chamber side of the heads with a light purple welder's dye of some sort. There were circular darker purple spots about BB sized in the small sliver of head casting between the valves on cylinders #1 & 6. Didn't look like much of a crack really, but Bert said those are like cavities in your teeth. They will only get bigger and would either crack through to a cooling channel or possibly lead to a valve seat breaking loose.

Hopefully the used set will get me back on track.

Wrenchinjoe

Got my heads back from the machine shop today. Used heads cost $100 each and the machine shop service cost $200 - total cost to get a couple of usable and reconditioned heads $400.






In case anyone is curious, here is a photo of one of the old heads and the indications of cracks the machinist was worried about. Both heads had similar cavities forming.



The yellow arrows point out the beginnings of cracks bewteen the valves. Sure didn't look like much of a crack to me, but this machine shop came highly recommended so I deferred to his advice.

Hopefully the effort to obtain a couple of new/used heads will result in lots of reliable engine miles.

TNRabbit

That die shows you where INTERNAL fracture lines are beginning.

Wrenchinjoe

So this thread was started to gather some information about having your heads machined while they are off. What does a machine shop do to your heads as standard practice and roughly how much does that cost? After working through the process here is what I have learned.


1) Selecting a machine shop: Ask around to get a sense that the machine shop you are using is good. I called several. The one I used came recommended by a mechanic friend who had worked with them for years. His shop was orderly and he knew the 3.0 valve clearances by memory. Those were good indications for me.

2) Services: A machine shop should clean and test your heads to check for warping and cracking, and also resurface prior to re-installation. They will also inspect the individual parts (valves, guides, springs, etc.) to ensure they are within spec, replacing parts if needed. Some machinists will recommend a valve job, some won't. I spoke to several and got mixed results on this one. If you feel confident that your engine has been cared for and the block components are in good condition, get a valve job. The majority of the moving parts in the engine are in the head(s), so don't skimp a mere few bucks, rather ensure the heads are tight and right.

3) What if: In my case, the machinist's tesing of the heads revealed the beginnings of cracks and he advised not reusing them. Although that sucked, you can get around this.

Remanufactured heads can be purchased from lots of vendors (Cylinder Heads International, Aluminum Head Rebuilders, Inc., Sunwest Automotive to name a few) ranging from $550 to $650 per set after shipping and core return. (see post #25 for links)

Or, you can have a salvage yard find some used heads, just make sure you have a warranty they are not cracked too. I went the used route and the machine shop did the valve job on those instead of my originals.

4) Valve Adjustment: Anyone familiar with these engines knows that adjusting the valves per the FSM is a complete PITA. Apparently the machinist CAN adjust the valve clearances on these heads in his shop. The rebuilt head vendors also state that the heads they ship to you are ready to bolt on with the valves already adjusted. My machinist told me the same thing, "ready to bolt on, just don't mix up the shims, leave them in place while you install the heads".

The FSM details the valve adjustments with the heads installed in the 'Tune-up' section, and does not discuss valve adjustment in the 'Cylinder Head' section where the heads are removed. But if you think about it, measuring the gap between the cam and the shims with a feeler guage (with the lobes pointing up) can be accomplished on the bench. Removing the cams and measuring the shims with a micrometer can also be done on the bench. Reassembly with the proper shims to bring the valve clearances within spec (.007-.011 in. for intake and .009-.013 in. for exhaust) can certainly be completed on the work bench too.

The machinist also has the ability to compensate for the shim thickness during the valve grind, so the same shims can often be reused. Several remanufactured head vendors and machinists gave me the same information about valve adjustments, but if I find that to be erroneous once I am up and running, I'll post back to say so.

5) Costs: The machine shop work which consisted of cleaning, testing and resurfacing the heads, and a valve job, cost $200 total. It would have only been $180 but he had to clean and test 2 sets of heads. Also, I supplied the valve stem seals that came with the gasket set.

The entire project obviously cost more... I had to spend $200 on a set of used heads, the OEM gasket set and knock sensor wire were $300, OEM timing belt and Aisin water pump were $90, new idler pulleys were $100, injector service through Witchhunter runs about $120..., looks like about $1,050 after buying some Permatex Ultra Gray and new antifreeze in all.

That is a lot of $$$, but with some luck my 3vze should have new life and be strong for a few years yet. Thanks TNRabbit and MudHippy for some great input in this discussion.

92 TOY

i gave you a THANKS for that excellent post.

i'm sitting here thinking about how much shipping would cost if i mailed our heads to your guy??......may or may not be something i will consider.

edeslaur

Have to admit, the "THIS TIME I WANT SOMETHING POWERFUL" is well placed.