Ok, so I bit the bullet and decided to get the head from that 240 from 1990 that had only 97k km's on it. Described here.

Anyway, the reason for getting the head is that I've decided to expand my project and go ahead with putting on a rebuilt head. Might as well be this one, from a low mileage wrecked car.



I've never undertaken a head rebuild before, on any car. But I have taken several apart in the past, and am familiar with how it all works. Being a mechanical engineer helps a bit too. But I don't have access to factory Greenbooks and am basically doing this all with knowledge gathered from the internet, with this board being the main source.

My philosophy with car repair like this has always been to keep a known working part, while replacing it with a new/rebuilt one. So at this point, I still haven't taken the head off my car. Here's a picture:



I'm still a bit reluctant to undo those bolts. I'm aware of the risks of broken head bolts, etc. So I want to work on the new head, and then just swap them when it's all ready to go on.

I should also outline my goals with this project. It is basically to get 5 good years, or about 100000 km's out of it, and reliability is the key. So I think that by replacing the head gasket, and at the same time renewing the head and clearing the crud off the tops of the valves is worthwhile if I can do it economically. I'm not interested in a $1000 machine shop bill, and I do have the resources to do certain low-level tasks myself. I work at a non-destructive testing company and can have it dye-checked for free, for example. Here's the "new" head:











I've read all the old posts I could find on rebuilding heads (surprisingly few of those) and the relevant FAQ sections already. I don't have a good enough straightedge to be able to check flatness myself, as a starting point.

So by starting this topic, I thought if anyone has any ideas on what I should do to get started, in terms of evaluating the goodness of htis head for service, or to just scrap it, I would appreciate those. Then, using your suggestions, I'll get started and prepare the head for installation (or scrapping), and get this over with. At first I just wanted to describe this new head, but this post sort of turned into a description of my whole project and philosophy with this project - sorry about that. But hopefully we can put together a definitive head-rebuilding faq with all the comments people may add. I know about things like cleanign up the valves with a wire-wheel on a bench grinder, but there must be more details...

I'm eager to go get a valve spring compressor and start taking apart those valves. Can i go ahead with that? Through contacts at work, I may be able to get it cleaned for free, and then liquid-penetrant dye checked before starting machine work. And I'm putting together a list of questions to add to this topic - I'll add that tomorrow (it's late now, but I wanted to get this discussion started).

Thanks in advance.
--
1991 740 automatic, sedan, B230F Burgundy/Tan Leather

Thanks, Shannon, for the link to my galleries.

I would agree with Bruce's evaluation: with ~60K miles on the head you pulled at the yard, it really should not require a lot of work. But, some things would be very good to do while it is off.

Looking at the pics you posted, the deck looks like it is still flat: the fire rings look like they were not compromised. The areas around the coolant passages show the typical discoloration/corrosion that happens during the ~19 years it has been in service.

Chances are decent that that head has not been shaved. [which is why it was suggested to measure the cylinder head height thickness: to confirm if, or how much has been shaved.] Unshaved is good....more metal in the deck; stronger deck.

I suggest that you clean the deck. A fine bristle wire wheel, or a brass bristle wire wheel in an electric drill, can clean the HG residue and coolant residue off the deck without gouging the deck surface. Then, check for FLAT. Just to make sure that it IS, or that it is not. If only warped a few thou, you 'could' go with it as is. That is a judgement call.

[...I'm running a SCP head on my B21FTi that had a 'perfect' 5 thou warp. It's doing fine after 15K+ miles.]

If warped more than about 4 or 5 thou, you do need to check the cam bearing journals for alignment. The 'rule of thumb' max allowable misalignment for OHC cam journals is 4 thou.

[...which affects partly why I chose to install the 5 thou warped head: to have had the head surfaced to restore FLAT, I would have then needed to have the cam journals align honed. As it turned out, once the head was back on and torqued carefully and properly, the cam journals came back into perfect alignment.]

Chances are VERY good that the valve stems and the valve guides are fine. I have yet to have to replace any valve guides on any of the SOHC heads....if the head was otherwise usable [not cracked or badly warped]. The valve to guide clearance specs for our SOHC heads allows for a considerable [comparatively speaking] amount of clearance. Normally the clearances will run about about 1 and a half thou or so on the intakes, and 1 and a half to 2 and a half thou on the exhaust. The max allowable clearance is 6 thou. I like to have ~2 thou on the intakes, and ~3 thou on the exhausts...especially for a boost motor.

Regarding valve spring compressors: you can use a C-clamp type compressor, with an adapter to get down inside the head. I have, use, and love my Schley valve spring compressor. It is perfect for the job. Which to go with is yours to choose.

Replace the intake valve stem seals...you are there. New ones won't hurt; and they come in the HG set. New hushers....of course.

Lap the valves as a minimum effort. If you 'want' to do a valve grind, or go for a 3 angle grind, that is a choice for you to make. With that few miles on that head, lapping the valves to the seat will bring the sealing back up to like new.

If you want to do some 'smoothing and blending' on the bowls and transitions to remove the imperfections and excess metal left over from the factory machining when the head was built originally, I can tell you that such 'smoothing and blending' does help flow, and does give a bit better performance. You do not have to get crazy with the carbide burrs. Just smooth and blend.

Do make sure that there are no sharp edges in the combustion chambers. If you do have the head surfaced, be sure to radius the sharp edges aound each combustion chamber. Sharp edges make for glowing hot spots, which can result in pre-ignition or detonation. So: NO SHARP EDGES in a CC!!!

If you find that the head is flat, and you want to make the deck nice, clean and smooth, you can 'lap' the deck with some very fine wet-n-dry paper. I use a 1 X 1 X 11 inch parallel bar with different grits �𖑔 to 1000] to gently lap the head deck so that it ends up really SMOOTH. I need them that smooth for when I install a MLS HG. But, I like the decks to be that smooth just cuz it helps the HG to be able to seal the coolant passages better as well.

Regarding the head bolts in the motor in your car: chances are very good that you will NOT have any problem with any of them breaking. I haven't had a Volvo HB break off yet [fingers now crossed/knock on wood]. I have had some of the 'old' style HBs [in hex 10mm head] round off the in hex, and NOT want to come out; but have never had a problem with the 'new' style HBs that your motor has.

You do not have to worry about valve rotation: they DO rotate. As do the tappet 'buckets'. And they are supposed to rotate.

Regarding camshaft choice: the M cam that you have is 'okay'. But, if you would like just a bit better off-the-line 'pull', a T cam would be better than the M. Changing camshafts does necessitate checking and adjusting the valve lash.

It looks like you found yourself a good replacement head. With some careful attention, and some careful work, it can give you a lot more than 100,000 Km of good service.

good luck. And I hope you find my galleries to be assistive.

TF

First I need to say Thank-you for your message, Stealthfti! I am continually just blown away by all the helpful advice that I get from this board. Your post here was especially useful - now I really feel like I can do this myself. And let me extend those thanks to the others who have posted, and to Randy as well. Without this I'd be lost... stuck like everyone else driving a newer car, making huge payments, going to the dealer for repairs. Doing this myself (like I've done for about 10 years now, since I got my first car) is so much more rewarding. Yes your site is very helpful.

Anyway, I read your post, Stealthfti, but need to re-read it to digest everything - lots of information there! So I printed it and will read it as bedtime reading tonight.

But let me just make a quick reply, with a picture of the one valve I successfully extracted tonight, in the midst of other obligatory activities I had to take care of:



I also measured along the stem with an expensive micrometer I borrowed from a machinist friend, and found it to be 0.3135" in diameter all along the shank. I am serious, the mic only goes to 0.001" but the line always lands around 0.3135! And it didn't feel too loose in teh guide either.

So I need to think about how far I want to go with this project. When everythign was assembled on my engine last week, I got decent compression values. Number 4 cylinder appears to have a bit of oil contamination on teh spark plug threads. I hope it's just a leaky stem seal, which will be remedied with this new head.

I believe my camshaft is an "L" grind. And the cam in the new head is too - both have same part number stamped in: 1000132 and there's an "L" stamped on both shafts, too. For some reason, this number is not found in that camshaft chart someone posted on scribd.com (sorry I can't remember where to find it).

Ok, I need to get to bed. I'm on this message board way too much! Need to limit my usage at work too...

But thanks again for all the advice. I will keep in touch with new updates and thoughts. For now, let me soak this all in...
--
1991 740 automatic, sedan, B230F Burgundy/Tan Leather

Regarding your replies so far:

I wouldn't touch a thing except to swap cams, check/adjust valve clearances, and replace gaskets.

If the 240 hadn't been smacked, that head would be still doing fine 100K miles or more from now.
Even 200K is a reasonable expectation, IMO.

This is actually very good news and food for thought. It's what I needed to hear, really. I just want to make sure this thing is solid, and cleaned up before putting it in. I hope I can put it all back together as-is, but cleaned up of course.

Regarding the following: At a minimum, check the mating surface for true, the minimum distance from the deck mating surface to cam cover gasket surface, the valve guides for wear, install new seals, and lap the valves to the seats at reassembly. You will need shims to adjust the valves. IPD has a kit they will rent to you and charge only for the shims you use.

I think this is what I'd like to do with this head. I have a micrometer and can check the valves for wear, and so forth. No dial gauge though, so see how much wobble the valves have in the guides. And I appreciate the links - that other guy's site is pretty detailed. I started reading it all just now, but I'm at the office and need to limit my internet time...

Anyway, a quick question before I get to work on things tonight: I'll go buy a valve spring compressor tonight. But while taking the valves out (and yes I'll store them all individually and identified) do I need to note the "rotational" position of them as they are now, and re-install them the same way later on? I can't imagine this would be necessary, but you never know. Do they rotate in the guides, during operation? I doubt it, but don't know for sure. I can't wait to get going on this thing tonight.

But now, reading that other guy's site regarding the head rebuild he did, I'm tempted to try that polishing idea...

I wouldn't touch a thing except to swap cams, check/adjust valve clearances, and replace gaskets.

If the 240 hadn't been smacked, that head would be still doing fine 100K miles or more from now.
Even 200K is a reasonable expectation, IMO.

--
Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.

Howdy,

Go to http://www.pbase.com/stealthfti. Scroll down to: to find some good aluminum, headbolts, headwork, and Tight Squish...NA style. Be sure to click every picture and every link in those articles. Good stuff, man. There is other good stuff there too. Those articles mentioned are appropriate to your immediate needs.

Then you can ease over to http://www.k-jet.org. Navigate to the Green Books for the 200 series. Find TP30170-2 engine reconditioning. It is a two part download. You are most interested in Part 2. It has the information on reconditioning the head. There are differences between your B230 and the B17-B23 engines in that book. Don't fret over that; it is the general procedures and information that is most valuable to you from those publications.

At a minimum, check the mating surface for true, the minimum distance from the deck mating surface to cam cover gasket surface, the valve guides for wear, install new seals, and lap the valves to the seats at reassembly. You will need shims to adjust the valves. IPD has a kit they will rent to you and charge only for the shims you use.

A Bentley manual for the 240 will be helpful. As would a Haynes manual for the 740. You could also subscribe to www.alldatadiy.com. I do for my wife's Ford and my 1982 245.

--
Mr. Shannon DeWolfe -- I've taken to using mister because my name misleads folks on the WWW. I am a 53 year old fat man. ;-)