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Cost of a head job?

O

outlander

NAXJA Forum User
Location
Columbus,Ohio
Well,that got your attention,didn't it?Seriously I want to have the head rebuilt on my 89 4 liter while I have the intake and exhaust manifold off(cracked exhaust manifold r&r).

How much can I expect to pay to have the head totally rebuilt?
 
What do you need done? You can do a lot of work on your own, unless you have a warped deck or something. Most of the work involves cleaning up the valve sealing surfaces - and a lapping will usually handle that (as long as a seat isn't etched or a valve isn't cracked.) The cost of the valve spring compressor and lapping set will be less than paying the machine shop - and you'll learn something doing it yourself - and feel good when it all works.

If you end up needing parts, you'll still come out ahead - you can use most of the same sources THEY do, so you don't end up paying machine shop markup.

So, figure out what needs doing first. If you're just doing your manifold gasket, you might not need head work. If you've got a lot of mileage, you don't WANT to do head work without doing a re-ring as well - or you'll end up doing a re-ring anyhow. It's pointless to reseal the top end without resealing the bottom end - so do both jobs at once if you're going to do one of them.

The head is rebuildable, but I don't want to hear you paid for work that created more work later - NOT the machinist's fault, either. It's just the way things work.

5-90
 
If you do a valve job, make sure and have the valve guides sleeved. Never knurl the guides.
 
5-90 said:
What do you need done? You can do a lot of work on your own, unless you have a warped deck or something. Most of the work involves cleaning up the valve sealing surfaces - and a lapping will usually handle that (as long as a seat isn't etched or a valve isn't cracked.) The cost of the valve spring compressor and lapping set will be less than paying the machine shop - and you'll learn something doing it yourself - and feel good when it all works.

If you end up needing parts, you'll still come out ahead - you can use most of the same sources THEY do, so you don't end up paying machine shop markup.

So, figure out what needs doing first. If you're just doing your manifold gasket, you might not need head work. If you've got a lot of mileage, you don't WANT to do head work without doing a re-ring as well - or you'll end up doing a re-ring anyhow. It's pointless to reseal the top end without resealing the bottom end - so do both jobs at once if you're going to do one of them.

The head is rebuildable, but I don't want to hear you paid for work that created more work later - NOT the machinist's fault, either. It's just the way things work.

5-90
Click to expand...
The reason I want to do this now is I'll have the head free after I remove the intake and exhaust manifolds to fix the crack,and this motor has 170,000 miles on it.Plus the valve train sounds really sloppy.I'm also hoping to gain a little performance...might even drop a performance cam in while I'm in there.

So you think I'll need to re-ring in the future because of the new head?Any one else have a opinion on that.....I'm not saying you don't know what you're talking about,5-90
 
Think you'll need to do it? I'm sure you'll need to do it!

The good news is that a rering shouldn't take too much work - you'd pull the pistons, measure the bores (to check for top cylinder ridge and make sure you don't need oversize rings or cleanup work,) and use a stone hone or a "berry-ball" hone to break the cylinder glaze and restore the original cross-hatch pattern to aid in ring seating.

I'm speaking from experience here - I've known quite a few people who didn't listen when I told them this, then they came to me to ask about a re-ring job within a week to two months.

Fortunately, the RENIX 4.0 is a rock solid block - I'd hate to tell you some of the thing I've done to mine (I've got four.) I had to pull the head on my 87 because I lost the oil pump (twelve flat lifters, eleven scored crankpins, and broke the #6 rod.) There was .001" of total ridge (meaning that the ridge proper was only .0005" high) after 220K miles of pure abuse, I patched the hole in the side with the piece that fell out and some JB-Weld, and replaced the bum parts.

Drove it for another six months - didn't do any head work at all. Then, I managed to blow up the transmission, promoted it to "Long-Term Project," (it's the Project: REDSHIFT I refer to from time to time...) and bought my 88.

I bought the second 89 because the 89 Limited needs more than a week-end's work to get back up to scratch - so I'll be restomodding it for the next little while.

Seriously, tho, with a relatively minimal tools investment and some careful reading, you can do just about all the work yourself unless there's something seriously wrong. I'm not downing machine shops (I plan on opening one!) but I think people who do their own work and understand more about how things under the hood work, become better drivers and vehicle owners. Call it a quirk.

5-90
 
Thanks alot guys...I really mean it.I had no idea that this job is interrelated in such a way,my dad didn't even pay any mind to the lower end when I mentioned rebuilding the head only,and he is a proficient mechanic(i.m.o)
I was just thinking that I could do a valve job,cam and lifters without having to pull the motor and then when I get my garage here in about a year I could pull the motor and do the lower end at that time.

Just when you think you're a decent mechanic someone gives you more knoweldge that confirms you're not as good as you think you are.

btw. is it possible to leave the manifolds attached to the head and pull the entire assembly all at once?
 
I had a '95 head resurfaced and new valves and spprings put in. They were SBC valves. The labor was $170 as I remember. I would think a regular valve job would be less. That $170 included the valve stem seals but no other parts.
Tom
 
jeepdeepfreak said:
Did you rering at that time as mentioned above?
Click to expand...
No, I replaced the motor with one that had 3K on it. You could have the cylinder bore meassured with a telescoping bore gage. Then figure from there if it needs rebuilt or not. Most motors with 80k would need rebuilt, but you never know. The top ridge ring will be a good indicator. If your fingernail can catch its probably .005-.010 of wear and probably needs rebuilt for best performance. Also the concentricity can be distorted. With a bore gage this can be measured.
Tom
 
This is something I am considering myself, It look like it 's about the same for pricing.
It looks like you can get a remaned head for about $200 and it looks like the cost to rebuild a head is about the same. For me the big difference would be buying one I could have it put in right away verses waiting for the rebuild job.

5-90 Do you have to pull the engine to do the lower block work, (pistons, re-ring, honing)? I guess it would make sense to do this since you are already half way there.
 
jeepdeepfreak said:
So you think I'll need to re-ring in the future because of the new head?Any one else have a opinion on that.....I'm not saying you don't know what you're talking about,5-90
Click to expand...

Think of it this way....both top end and bottom are wearing at the same rate...

You strengthen the upper end considerably more (read almost new condition)
over your bottom end. At 170K your going to have alot of pressure in the upper end that the bottom end WON'T be able to handle.

It would be like going 6 rounds with Tyson, and then saying You'll go a full 13 with Ali ( in his prime of course)

You will blow the bottom end out. Do them both, at the same time, and you'll come out with a brand new motor with no problems.
 
this turned out to be a dissapointing thread given the title
 
BskisXJ said:
This is something I am considering myself, It look like it 's about the same for pricing.
It looks like you can get a remaned head for about $200 and it looks like the cost to rebuild a head is about the same. For me the big difference would be buying one I could have it put in right away verses waiting for the rebuild job.

5-90 Do you have to pull the engine to do the lower block work, (pistons, re-ring, honing)? I guess it would make sense to do this since you are already half way there.
Click to expand...

Depends on what you find out once you get in there. If all you need is to run a stone hone down there and clean things up, then no.

If you find an excessive ridge (I'd be surprised,) or a lot of taper or belling of the bores, then the block needs to come out. I've done re-rings without pulling the block - it mainly depends upon the condition of the bores, and I can't tell you about that without actually looking and measuring myself.

Oh - and I find it easier to pull the head and manifolds as a unit, service the manifiolds while you've got the head off, and install them as a unit. The manifolds give you some extra "handles," and you don't have to fight with the lower back manifold bolts. Get help when lifting, unless you REALLY know how to lift awkward objects...

5-90
 
5-90 said:
Depends on what you find out once you get in there. If all you need is to run a stone hone down there and clean things up, then no.

If you find an excessive ridge (I'd be surprised,) or a lot of taper or belling of the bores, then the block needs to come out. I've done re-rings without pulling the block - it mainly depends upon the condition of the bores, and I can't tell you about that without actually looking and measuring myself.

Oh - and I find it easier to pull the head and manifolds as a unit, service the manifiolds while you've got the head off, and install them as a unit. The manifolds give you some extra "handles," and you don't have to fight with the lower back manifold bolts. Get help when lifting, unless you REALLY know how to lift awkward objects...

5-90
Click to expand...
the lower end is good shape....I've done a compression test and that yielded surprisingly good numbers...the engine consumes no oil and does not smoke.The oil pressure is good too.The only problem is the valve train.

Now I just need to decide if I should do a complete rebuild.I've got the cash,I just don't have a suitable place to do it....
 
OK, I'm somewhat in the same boat with an 89 4.0L that's got 177K and a cracked exhaust header. So, if I decide to rebuild the head and re-ring, should I stop there? What about the crank bearings and oil pump?

Where do you stop?
 
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