1FZ-FE - Cylinder Head Replacement

[12bit]

I am in the process of tearing down my engine to do a head gasket job. I have acquired a new OEM cylinder head & am planning to swap it & reuse the parts from the original head.

This is likely a dumb question, but is this a task that can be done without bringing it to a machine shop? Would specialty tools be needed to populate the head with the old parts & measure clearances, etc?

The vehicle in question is a 1997 FZJ-80 CE.

 

[TurboDennis]

If you're contemplating doing this yourself, you will be just fine. Not a rocket science to populate the head with parts. Just follow the FSM. It's very good and detailed. You will want to measure the oil clearances in cam journals.

As for valve clearances, you will probably need to order some shims to adjust them to spec. If you outsourced this job to a machine shop, they would likely just grind the tips of the valves to adjust them to spec, and this is a TERRIBLE practice that should be avoided at all costs.

 

[Malleus]

Why is it necessarily terrible? I'd be glad to lose 0.002-0.003 on my vavle stems to save a head.

If you're grinding so much off the stem that you can see it, your head needs to be replaced anyway.

 

[TheBussman]

Can it be done? sure but it's nice to have your old valves ground and vaccum checked to the new head to make sure they seal good. Nothing wrong with grinding the tops of the valves down for clearance either. If you don't take it to the machine shop your going to be messing with the shims quite a bit to get things in spec. Special tools needed: valve spring compressor. if you really want to skip the machine shop i would buy all new valves too, make sure you get good seal. What's wrong with the old head?

 

[manofthewoods]

Can it be done? sure but it's nice to have your old valves ground and vaccum checked to the new head to make sure they seal good. Nothing wrong with grinding the tops of the valves down for clearance either. If you don't take it to the machine shop your going to be messing with the shims quite a bit to get things in spec. Special tools needed: valve spring compressor. if you really want to skip the machine shop i would buy all new valves too, make sure you get good seal. What's wrong with the old head?

I shimmed mine with out any special tools.
Easy. Especially since the head was out (engine was too, but, not necessary for this).

Steps...
On the bench install shims, buckets and cams.
Measure each gap. Take notes. Where out of specification. Remove cams. Swap those that are wide with narrow, etc. I used a spreadsheet.
You may have to purchase some new ones (I needed a half dozen). After moving, replace cams, Measure again to verify.

The above requires rotation of the cams. Use assembly lube and rotate to measure. Easy.
Pulling the cams isn't difficult.

 

[mehbohdi]

In my experience of building many engines over the years, you shouldn't just drop in old valves in new head (if it didn't come with valves) there is a reason the head is going bad if your replacing it. Can you do it ,Yes. Should you do it, No. The minimum is to lap old valves to new seats, not ideal. New valves would be the best long term solution, they should be checked for good sealing before installing on block. Set head chambers up, level on bench. Fill each chamber with water, solvent, light oil let it sit for 15 mins, check for leakage in intake/exhaust ports. If it doesn't leak install it (even new valves should be lapped in). Valve clearances can be done as discribed above. If you have a machine shop close, that does head work. You might be able to exchange your shims for the right thickness ones you need. Good luck

 

[TheBussman]

I shimmed mine with out any special tools.
Easy. Especially since the head was out (engine was too, but, not necessary for this).

Steps...
On the beach install shims, buckets and cams.
Measure each gap. Take notes. Where out of specification. Remove cams. Swap those that are wide with narrow, etc. I used a spreadsheet.
You may have to purchase some new ones (I needed a half dozen). After moving, replace cams, Measure again to verify.

The above requires rotation of the cams. Use assembly lube and rotate to measure. Easy.
Pulling the cams isn't difficult.

I agree complete. Very likely you going to have to buy some shims and wait for them to come in though, I have a bank of shims because I do so many but most don't. The main concern is valve seal, shimming is just a bonus.

 

[12bit]

What's wrong with the old head?

I bought the truck with a blown engine last year. The seller claimed the head was cracked, but I haven't confirmed that. It starts and runs, but there is definitely coolant getting into the oil, so I haven't ran it much, if at all. I ordered a new OEM head assuming warpage may be too bad to reuse the existing head (even if it isn't actually cracked). I have also accumulated a mountain of 'while you're in there' parts.

Since it seems I may need to use the help of a machine shop either way, I may bring in the old head and have it inspected and see if I can just refresh that one. I have no problem sticking the new OEM head in storage. I tore off everything but the head last night and plan to actually pull the head off tonight. Can't wait to see what the cylinders look like.

The truck may have also been driven a fair distance (hour or more) in an overheated state. Are there any other things to worry about being damaged by the extreme heat ((like the power steering pump seals)? The engine itself runs smooth in spite of the failed head gasket.

Thanks to all that have replied so far. Each reply has been helpful.

All that said, does anyone have any good machine shop recommendations in the Minneapolis metro area?

 

[TurboDennis]

Why is it necessarily terrible? I'd be glad to lose 0.002-0.003 on my vavle stems to save a head.

If you're grinding so much off the stem that you can see it, your head needs to be replaced anyway.

Can it be done? sure but it's nice to have your old valves ground and vaccum checked to the new head to make sure they seal good. Nothing wrong with grinding the tops of the valves down for clearance either. If you don't take it to the machine shop your going to be messing with the shims quite a bit to get things in spec. Special tools needed: valve spring compressor. if you really want to skip the machine shop i would buy all new valves too, make sure you get good seal. What's wrong with the old head?

Grinding the tips of the valves is a big no-no. It's common practice by machine shops for one reason only - because they're lazy and can't be bothered to "mess with the shims".

These valves are case hardened. Once you take a few thousands off the tip, you're exposing the soft metal bellow the hardened surface. This will result in GREATLY accelerated wear, requiring you to re-adjust the clearances regularly (by "messing with the shims") - precisely the thing that you tried to avoid in the first place by taking that shortcut.

 

[Malleus]

The case depth extends all the way through the stem; it's only a case on the valve end.

I don't know about Canadian machine shop practices, but a good machine shop here wouldn't cut a valve to skip grinding it on the other end.

 

[TurboDennis]

The case depth extends all the way through the stem; it's only a case on the valve end.

Where did you hear this nonsense? The hardened layer on these valves is typically in the 0.25mm (0.010") range. It absolutely doesn't extend all the way through the 7mm-thick stem...

I don't know about Canadian machine shop practices, but a good machine shop here wouldn't cut a valve to skip grinding it on the other end.

No engine builder (anywhere in the world) that takes pride in their work will ever consider it to be acceptable practice to tip the valves on engines that are meant to be running for years after the job.

 

[Malleus]

If you can find me someone who can case harden a Ø1/4" bar 0.010" deep, consistently as has to be done in production practice, I want to meet him.

Break a valve stem and look at the core.

 

[12bit]

New valves would be the best long term solution, they should be checked for good sealing before installing on block. Set head chambers up, level on bench. Fill each chamber with water, solvent, light oil let it sit for 15 mins, check for leakage in intake/exhaust ports. If it doesn't leak install it (even new valves should be lapped in).

Is it possible to avoid going to the machine shop if I order all new valves for the new head?

 

[Brindleboxer]

Theoretically but you still have to follow the setup/install advice above to get it right. Also, if you haven't already downloaded the FSM from the resources section do so before starting. IMO this should be your 1st step. Read through the procedures and know what to expect and what tools you will need before you even touch parts.