86-95 Trucks & 4Runners 2nd/3rd gen pickups, and 1st/2nd gen 4Runners with IFS

Building my first engine, have a couple of questions

Old 06-16-2019, 06:32 PM
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Building my first engine, have a couple of questions

Hey guys, been a little while. Blew up my 3VZE and was gonna sell the rig, decided to build a new (craigslist) motor for it, but was delayed by work and real life. So at this stage I have the block decked and bored and the rotating assembly is installed and I'm happy with the bottom end. Now, before I tore down this motor I checked the valve clearances and most of them were out, but given that I have two additional engines worth of shims and buckets I figured I'd be able to get together a set that worked but I wanted to get the block apart first to make sure it was good and make sure I could even get the thing in spec. Now at this point I got the block back after 2 months, they did a great job but as it took so long I had go fever, and bolted the heads straight back on, didn't mess with the valves because they looked alright and I figured all I would need to do is shim them once I had the heads back on. I did use the old sandpaper technique to flatten the heads out, worked surprisingly well. Anyway, I've selected the best set of cams from the six I have (least wear and cleanest) and no matter what I do the exhaust valves are significantly too tight. I even took a random shim and ground the thing almost till it was flush with the bucket and I still can't even get a .008" gauge in, clearance is .009-.013. So questions
1.) I know the valve seats do tend to recede especially on the exhaust side but is it possible they're so far out that they can't be shimmed?
2.) If I take the heads back off to service the valves, can I re-use the head gaskets after I've already torqued them? I know I'll need new head bolts.
3.) Is there actually anything wrong with grinding the shims on the back sides just using a bench grinder? This would leave the upside of the shim smooth against the cam but reduce the thickness.
4.) If I pull the heads and have them done, should i take them to a dealer or a machine shop?
5.) If the valves are serviced will they be able to install the cams and shim them without the block or should I just have the valves done and adjust them myself?
6.) Anyone have experience with servicing valves at home? The FSM says just have a pro do it but I always love to learn something new.
Thanks in advance folks
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Old 06-16-2019, 07:58 PM
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Tight Exhaust valves

I'm curious, is it all of the exhaust valves, or just a couple?
Is there any clearance at all, or are they bound?
What about the intake valves, are they tight or bound also?


You said, when you initially checked the valve clearances that "they were out"
What do you mean by this? Too tight/Too loose.
Before you take the heads off again, I suggest that you put the two original cams back on them and start over.
That will take the unknown item out of the equation.
Good luck

Last edited by ZARTT; 06-16-2019 at 08:05 PM. Reason: Additional question
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millball (06-16-2019)
Old 06-16-2019, 09:21 PM
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Using a precision surface grinder on shim backs is acceptable.

Hand grinding them flat and parallel is near impossible.

Most machine shops throw whatever shims in that are too tight, and grind the valve stem ends to make clearance.

Hand lapping valves is the stuff of model T Fords and lawnmower repair.

A professional three angle valve grind and fly milling of the head surfaces is the way to go, if you expect good, long lasting results.

Once a head gasket has been torqued down, it is foolish to reuse it.
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Old 06-16-2019, 09:49 PM
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2. You can't reuse the head gaskets, but you don't need to replace the bolts. (Toyota has a TSB that says you can reuse the head bolts. Or you can believe anyone else.)
3. You can grind shims on a (very expensive, but not hard to find) precision surface grinder. No, you'll never get an acceptable shim on a bench grinder.
4. I doubt any dealer owns their own valve machine; they'll send it out to a machine shop. You could ask at the dealer who they use, but in the end, it's a machine shop you need.
5. The machine shop I used had the shim set, so they got each valve dead-on. Even with two engines worth, I'll bet you end up having to use a few shims that are off a bit. You won't save much money doing it yourself, either, but it's an interesting process so you might like it.
6. As millball says, about all you can do to "service" valves at home is lap them, and that went out with tube radios. If you have a problem with a valve seat (sounds like you do), you'll need a valve machine, and that's WAY too expensive to justify buying one for just 4-5 engines. So either get a machine shop with such a machine to do it, or don't bother at all.
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Old 06-17-2019, 04:45 AM
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Thanks for the replies everyone, this is pretty much what I expected, sucks that its gonna be another chunk of change but thats the nature of the beast and I knew that going in. For the record, when I first checked out the valves before teardown I think 1 intake valve was too tight and 4 of the exhaust valves were tight. Unfortunately midway through the teardown is when I had to move out of the shop I was working in and everything got totally mixed up and scattered. Right now I have the drivers side cam in spec on all the intake valves but the exhaust valves can barely fit like a .006 gauge. I'm gonna try and check the passenger side one at a time without torqueing it down because the threads on that back bearing cap are barely holding. I saw a video online where you can check the clearances one valve at a time without bolting the cam in if all the other buckets are out, seems legit and will same some time/headache. Anyway it looks like the heads are coming back off and going to a machine shop at some point soon. I'd love to know that I did everything myself but I'd prefer and engine that runs good. Thankyou again everyone I really appreciate y'all.
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