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Frantz

Cylinder head rebuild advice

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I've helped assembled motors before, but this will be my first full rebuild. 1954 Ford 239. I pulled the heads and am soaking them to get them clean. Car had 70k+ on it and lots of carbon on the valves. I plan to clean and polish them but reuse them if they look straight. I have a straight edge to check the head, but I'm not planning anything more than a stock rebuild so I suspect I shouldn't need any machining. Might do a little port work, but more focused on polishing and smoothing things out.. it's a 130hp engine after all. Other than lapping the valves, checking the deck, checking the springs is there anything else I should be looking at/doing for the heads? I tend to believe that these motors just need cleaned and put back together but I'm not experienced at it.

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I would think that a minimal "stock rebuild" would normally include new rings and a regrind of the valve seats and faces, with modest milling of the head. With 70,000 miles on it, I would be surprised if you didn't also have some cylinder wall taper and wear on the valve guides, as well as the rod and main bearings.  So at minimum, unless you're not planning on driving the car, I think you need to measure all the wearing surfaces and assess the overall condition, and only then decide on how extensively you're going to rebuild the engine. A fill rebuild shouldn't be very expensive on that engine -- nowhere near what I'm used to on my older cars. And money spent now might well save you from having to spend more later. 

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59 minutes ago, jrbartlett said:

I would think that a minimal "stock rebuild" would normally include new rings and a regrind of the valve seats and faces, with modest milling of the head. With 70,000 miles on it, I would be surprised if you didn't also have some cylinder wall taper and wear on the valve guides, as well as the rod and main bearings.  So at minimum, unless you're not planning on driving the car, I think you need to measure all the wearing surfaces and assess the overall condition, and only then decide on how extensively you're going to rebuild the engine. A fill rebuild shouldn't be very expensive on that engine -- nowhere near what I'm used to on my older cars. And money spent now might well save you from having to spend more later. 


Thanks... Ordered a hole gauge set as I don't think my bore gauges go quite that small. My wife never believes that there are tools I don't have yet. If funds weren't any issue I'd be fine blueprinting and paying to have it done good as new... but I'd like to do as nice of a job as I can without sending it out if possible. Few a few thousand miles a year, getting it back on the road is the priority, and once it's on the road I can consider taking it to the next step. I have a spare motor I can always work on at that point too.

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I was going to tell you the same thing jrbartlet told you but he beat me to the draw

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CYLINDER WEAR

 

clean the carbon off the top of the cylinder bores going around 3/8" down into the bore, then feel if there is ANY ridge at all at the top of the bores. if there is, it must be rebored for the new rings to seat properly so it does not smoke. if there is no ridge, the bore could still be ovaled and/or tapered a little. if the combined total of out of round and taper is .0025" or less, you "can" just hone it and use it as is if you use cast iron rings, but this is still not ideal. If the combined total is .0015 or less, it will be fine to reuse for your intended purpose.

 

 

VALVE AND VALVE GUIDE WEAR

 

As far as checking for valve guide wear goes, you really should have an experience head shop check it because it is hard to explain how to do it, plus it is more of a "feel" thing when checking them, but here's one way to check them.

 

measure the valve stem to insure it is not worn more than around .0005".

 

make sure the tip of the valve is not concave or mushroomed out beyond the diameter of the valve stem.

 

stick the good valve in the head holding the head of the valve around 1/2" above the valve seat.

 

move the the head of the valve from side to side in both a 1 to 6 o clock position and a 3 to 9 o clock position. if the head of the valve moves more than a total of 1/32" in any direction, the guide is bad and needs a new guide liner at the minimum. if it is worn more than 3/32", it needs a new guide. knurling a worn guide to reduce the play is nearly worthless, but it will make a nice lubrication channel for the oil to run down right into your engine.

 

NOTE: If you do anything to the inside of the guide to tighten it up, you must regrind the seat and valve face.

 

 

HEAD DISTORTION

 

Measure straight across the middle from one end to the other, then measure both "kitty corners". If there is less than .002" clearance under the straight edge at any point, AND there is no excessive erosion of a water passage that might not properly seal wit the head gasket, there is no reason to surface it.

 

 

BLOCK DECK DISTORTION

 

Check the block the same way.

 

 

 

 

 

 

 

 

 

 

 

 

Edited by barnett468
added more info (see edit history)

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I think valve to guide clearance should be a max of .010" side to side to play get .005".

1/32" is way too much wear in any valve guide.😏

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22 minutes ago, c49er said:

I think valve to guide clearance should be a max of .010" side to side to play get .005".

1/32" is way too much wear in any valve guide.😏

 

Not for his particular app/requirements, and I have seen hundreds of heads that had that much play and more that came off good running engines, but I would prefer less myself.

Edited by barnett468 (see edit history)

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Thank you all. I used the term "rebuild" a bit too loosely. My intent is really more of a refresh if possible and I feel you have pointed me in the right direction to better assess my situtation. I'll hope to get some time at the shop this weekend.

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So thanks again! I'll need a little more work than I wanted but better to know than assume 🙂

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Are you pulling the engine or only doing an in-frame refresh? If heads come out I’d consider new guides. You can do you own valve grind by hand if you are patient. Lap in the old valves if they are good. New valve stem seals, if it utilizes them? New spring retainers.  While you are at it, do you drop the oil pan and roll in new main and rod bearings? How about the front and rear seals? Front cover gasket?...Hard to stop when you are in that far. 

 

I get it though. A couple thousand miles a year. Just some limited work makes financial sense. I was in the same position 2.5 years ago. Did a valve grind. Should have done some valve guides at that time. I didn’t. However 3700 miles later I’m certainly enjoying the car. It burns some oil thru the guides but not too bad. 

Edited by keithb7 (see edit history)
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Hi. I also have a '54 239 Y block. Mine's never been rebuilt...66k miles.

 

If you haven't done so already, I'd suggest going over to fordbarn.com and checking in the "late 1954+" forum. There's a lot of specific knowledge over there, and although they may not be quite as friendly as the people here, they've helped me immeasurably. (Many people just as knowledgeable here, of course, you just may not find the concentration of Y block knowledge that you will over there. )

 

I'd think about replacing the valve guides on your car. My car always smokes a little when started up...and always stops smoking when driven a few blocks and as long as it stays warm. Compression is fairly good (though certainly not like new) so I've been told it could be valve guides. Not bothering to pull heads on it just yet. With your kind of mileage it might be worth doing while the heads are off.

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I bought an old Sioux valve grinder today with a seat resurfacer too. I am pulling the motor. This one had way too much gunk and when I cleaned up the carbon the ridges were more than I had thought... and 54 Ford engines are really pretty painted. I just want to do as much of the work myself as I can.

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you will need a 45 degree angle on the seats then make them the right thickness with a 60 and 30 degree stone or cutter etc as needed.

 

make the valves 44 1/2 - 44 3/4. this improves sealing. you need to move the face of the valve back and forth across the stone as you are grinding it with the coolant running on it.

 

test the springs . if they are a little weak you can put shims under them.

 

you can also check the valve stem height, but unless you have a sunken valve seat, this isn't really necessary in your case.

 

if the guides are worn and are replaceable, you can replace them with a special driver and a 3 lb mallet or the correct impact gun, however, as i previously mentioned, if they are just a little worn you can reem them out and install a "guide liner". this is easy to do, but either process must be done before cutting the seats.

 

if the engine has a rope type crank seal and you convert to a rubber seal, you must remove the small seal retaining pin in the main cap, otherwise you will be very unhappy when your engine oils your floor.

 

if your wrist pins are a press fit you will need to have a shop install the pistons.

 

 

Edited by barnett468 (see edit history)

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The service manual says to check the springs at 1.821" which is awful precise... but then allows a 10% loss for serviceability and a range of 54-62# =-D

I have one of the vice pressure testers... do I just get close to 1.821" and see if I'm in spec? Again, just a service rebuild, not going for major performance gains.

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1 hour ago, Frantz said:

The service manual says to check the springs at 1.821" which is awful precise... but then allows a 10% loss for serviceability and a range of 54-62# =-D

I have one of the vice pressure testers... do I just get close to 1.821" and see if I'm in spec? Again, just a service rebuild, not going for major performance gains.

 

Post a photo of the tester.

 

All the spring testers I have seen and used have a stop on them. If yours has a stop, you just set the clearance to 1.821 using the stop. You can do this with vernier calipers. You can also just use a tape measure to get it reasonable close, but it needs to be within around .020".

 

54 - 62 lbs is ludicrously low, and if that is the correct spec, and your springs are within that range, I would still install shims under them. The shims are cheap.

 

 

   
Edited by barnett468 (see edit history)

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Spring tester I had picked up awhile back

No stop, just a pressure gauge. Given the range it's perhaps not precise enough for the job.. and time to buy another tool!

Specs come for the factory service manual, but it's the first time I've ever looked at such specs so IDK what normal is for motors!

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5 minutes ago, Frantz said:

Spring tester I had picked up awhile back

No stop, just a pressure gauge. Given the range it's perhaps not precise enough for the job.. and time to buy another tool!

Specs come for the factory service manual, but it's the first time I've ever looked at such specs so IDK what normal is for motors!

 

You can make a stop by simply cutting a 5/16" bolt to the correct length, then place it in the tester next to the spring.

 

Even though the 54-62 pressure may be correct, it is still ludicrously low and using higher pressure would be better overall.

 

If you need new springs, Egge Machine has them for $1.56 each.

 

https://egge.com/part/sbi-1305-160-1120/

 

Here is Egge's spring pressure.

  75@1.780

 

 

 

 

 

 

 

 

Edited by barnett468 (see edit history)
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7 minutes ago, Frantz said:

Spring tester I had picked up awhile back

No stop, just a pressure gauge. Given the range it's perhaps not precise enough for the job.. and time to buy another tool!

Specs come for the factory service manual, but it's the first time I've ever looked at such specs so IDK what normal is for motors!

 

Are you going to reuse the cam and lifters?

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Not sure yet, haven't tore into that that to check condition. If they are okay then I plan to.

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5 minutes ago, Frantz said:

Not sure yet, haven't tore into that that to check condition. If they are okay then I plan to.

 

Ok, just in case you don't know, you must keep the lifters in order.

 

As far as the valve spring shims go, they cost nearly half as much as new springs do, so you would be better off getting new springs if your current ones are even just a little low. If it was me, I would buy new ones anyway, instead of buying a spring tester.

 

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Yeah, springs are pretty darn cheap. I do have a few of the trays for lining everything up as I know things wear together. I'm not in a rush. Trying to save money, but also trying to learn the process. Thanks for taking the time to respond.

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