Advice needed-'58 Nailhead

[bhclark]

After giving up on getting my '58 to run right, I sent it off to the mechanic last week.

I got their recommendation on Friday. They advise an engine rebuild due to it only running on 4 cylinders.

After adjusting the dwell, points gap and timing, they got the engine to idle, but according to their engine test, 4 cylinders are not firing properly. They said the spark is ok. They did not give me their compression numbers, but I tested it before I sent it off and had 1 cylinder at 120 with the others betweek 140 and 165. That's virtually the same as my '59 with similar mileage and that car has driven us all over the country with no problems.

They said they tested the compression and several cylinders went up with addition of oil, which I believe.

I realize optimal compression would be all 8 cylinders above 150, but would compression of over 100 fail to fire?

The mechanic is not a nailhead expert by any means, so I am leary of having them do a full rebuild, plus the cost is going to be prohibitive.

One piece of advice I've received is do rebuild the heads and go from there.

3 questions:

-On a budget, would you just rebuild the heads? (This has to be done anyway if we continue with a full rebuild and should cost little additional in tear down/assembly if we have to do the next step, right?)

-Where would you source replacement parts if needed? I have read other threads that have horror stories about modern rebuild parts. Again, budget is a concern so I may not be able to use Carmen Faso, Russ Martin, or Tom Telesco parts.

-What is a reasonable cost for having the heads rebuilt?

I have to call the mechanic tomorrow and let him know my decision.

Worst case, I drive it home and wait until I can afford the rebuild.

[Roadmaster75]

HI Brian,

Based on your own findings and theirs ..... I would question the need for a complete rebuild.

Sounds like they are stating that it is firing erratically on 4 specific cylinders..... that sounds

like a big leap for to a complete rebuild; without eliminating other sources of miss firing or "missing".

Ask them if the observed miss firings cylinders are the same ones with the low compression readings.

High mileage motor? Visibly burning oil on acceleration? (might be rings).... Blue smoke on de-cceleration ( might be valve guides)

Other stuff: Vacuum leaks, vacuum advance (stuck?), failing ignition components (coil/condenser/wires/cracked cap, etc)

stuck heat riser, slop in the distributor?

IF all checks good then maybe it is reason to do a cylinder head job. Warped or badly seating valves can indeed

cause "misses" and lower than normal compression readings on specific cylinders.

I'm skeptical the the "bottom end" is causing your problems at this point.

mike

[bhclark]

100,000 miles on car, unsure if engine has had prior work. Car has only had about 3000 miles put on it in the last 25 years from what I understand. I've had it 3 and barely driven it 100 miles. No visible blue smoke on deceleration that I have noted, black smoke/soot when starting cold though.

There is no vacuum advance, not sure if it is stuck or not working. I was getting a reading of 10 on my vacuum gauge off the manifold. Could not find a value in the manual that it is supposed to be.

Heat riser is stuck, but in the open position.

I will ask them to confirm the misfire cylinders/low compression cylinders and ensure everything related to spark has been double checked.

If the cylinder walls look good when the heads are pulled, is it ok to just do rings on these engines, along with the heads of course? Moly rings, right?

Any worries with rebuild part quality on the heads?

[old-tank]

Just a couple of things to watch for: Don't put shims under the valve springs---replace the springs if they are needed. If you just have to use shims be sure that the shims under the outer springs don't cover the recessed pocket for the inner springs ( the resultant valve bind destroyed one of my engines---bent and broken pushrods, rockers, rocker shaft, camshaft and webbing around the cam).

Don't install hardened seats unless the seats are already recessed to the point of being unusable---stainless steel exhaust valves are available that will make the engine compatible with unleaded gas. Although I have had no problem with seats in the early (322/264) nailhead others with the later engines have claimed that penetration into water cavity when installing the seats ruined the heads.

Inspect and measure cylinders when the heads are off and make the decision and moly rings are the right choice.

Willie

[Smartin]

You should have at least 15" of vacuum at idle.

I spent $800 on the heads of my buddy's 60...that was valve guides, 9 valves, and a valve job.

I spent $450 on the Limited heads...that was a pretty standard valve job with one new exhaust valve.

I just spent $380 on the Roadmaster heads.

[bhclark]

Thanks guys, waiting to hear back from the mechanic.

Here's what I've got so far from this thread and my searches:

-Have the heads reconditioned as needed. Replace bad valves, lap the rest. Goal is to tighten up the top end, but not so tight as to cause bottom end problems.

-Inspect bore and pistons while apart, hope for the best.

Tips for the machine shop:

-No valve guide seals

-Only cast iron valve guides

-no shims on valve springs, replace if necessary.

-No hardened valve seats

Tips for Mechanic:

-Use Best or Victor head gaskets for reassembly

-15-17" of vacuum at idle

-10 degree timing

-Bosch single platinum plugs, gap .045

-ensure no arcing of plug wires.

Parts from Tom T, Carmen F, or Russ M.

[Pete Phillips]

Brian,

At 100,000 miles it's time for a valve job, but shouldn't be time for a complete rebuild of the engine.

P.S.: I'm disassembling a stuck 1958 364 engine that still has a few good parts, if you need anything.

Pete Phillips

[Roadmaster75]

HI Brian

Sounds like a plan! Also, consider removing your distributor while

the head work is being done & use the guide starting on page 10-46 of your 58 shop manual.

Pretty straightforward things to check and eliminate after all that nice head work! There is also

a nice chart to check, when you are re-timing. Shows at what RPMs the vacuum and centrifugal

advance mechanisms cut in.

After 100,000 miles I'm guessing it could use a good check up with any new parts as necessary.

mike

[bhclark]

Estimate from the mechanic was high, but not out of bounds. 12 hours of labor plus parts and machine shop costs. I wish I could hire Adam to give the entire engine bay the Smartin treatment! Probably wouldn't cost that much more!

[buick5563]

He isn't THAT far away!

[NTX5467]

I'd do the "bronze heli-coil" valve guide inserts. Gives you a wear surface rather than the base guide itself. EASY to do, too! Do them before you grind the valve seats. Not sure how they interface with the recommended stainless steel valves, but it's supposed to be the best wear interface with a chrome stem valve.

I wouldn't worry about a specific vacuum value, as it can vary with altitude AND the quality of the gauge you have. I've not had very much luck getting specific vacuum values on engines I have, BUT how the needle acts is (I feel) more important than the specific value on the gauge.

With the "good" compresion figures you got BEFORE you sent the car to the repair shop, it sounds like it's just "normal wear" on the engine. With ANY engine with a points distributor ignition system . . . I suspect you'll find wear on the distributor's breaker cam. What you can't see is how uneven the "peaks" on the cam lobe might be, relative to each other. I didn't realize that until I used a dial indicator to try to set the points in a distributor, once. I was amazed at the differences! These differences result in EACH cylinder having a different dwell period, period, which also relates to the specific timing of each spark relative to the other cylinders. After seeing the virtual imposibility of setting the points accurately, I became a strong believer in an electronic ignition conversion kit.

Harbor Freight has an "inspection light" device for looking into "dark places" (i.e., combustion chambers), with a screen. The higher-priced version has a memory card, or recorder, I believe. This might be better than pulling the heads! PLUS have other uses in the car area!

Given the basically good compression numbers, I'd question the real need to rebuild ANYTHING right now . . . especially as the real cause of the erratic running has NOT been definitely determined . . . just speculated . . . as of yet. UNTIL they can find and fix that, I'd say "NO engine disassembly". Sure, a complete teardown and look-see might be good, but it'll ALSO mean a full rebuild, too, to put everything back together "right".

I'd get them to rebuild the carb, or have somebody else do it, as irregular fuel distribution might cause lean mixtures (which will not fire-off as easily as the normal-strength mixtures will). If the erratic cylinders are all fed by one side of the carb, that could well be the determination of a "fuel" issue rather than ignition. What do the spark plugs center electrodes look like?

I'm not sure about the spark plug recommendation. "Single platinum" is the basic upgrade over normal plugs. "Double platinum" (if you can find the appropriate heat range) would be better, for a few dollars more, as would the newer Iridium plugs, which usually cost the same as the double plats. For now, though, "getting it running well" is the main orientation, so normal plugs would serve that purpose very well.

".045 plug gap"???? For a "low power" points ignition? Better use the factory spec for now!

Remember . . . for now, just get it running smoooooothly and reliably! IF you start pulling things apart, now, it'll only result in getting that "full rebuild" sooner than you might desire . . . or need.

I somewhat doubt your repair shop might desire to spend the time to fully diagnose the reason for the erratic running. But, usually, that does not get anywhere near a "full rebuild", or even a valve job (as the compression test has already ruled out any burnt valves . . . at least significantly "burnt").

I suspect the "rotating assembly" of the motor is still in pretty good shape, even for the miles on it. Not to say that there might not be a cam lobe(s) that might have some unusual wear OR it might need a timing chain replacement. All things considered, it might not be a bad idea to get the timing chain and sprockets replaced -- I consider this "an insurance issue", "insurance" that you know it's been replaced and is one less thing that might break and cause major engine damage if it did break. OEM quality or an upgrade to a Cloyes Plus-Roller timing set, if available ("LONG term insurance with the roller set . . . like 450K miles, in my case).

From the repair shop's perspective, they might desire to "fix everything that might need fixing" (resulting in the "complete rebuild" recommendation). They probably know that once you start "fixin' on it", nothing will be completely "right" until everything's been rebuilt. That old "one thing is fixed, but now something else is causing a problem . . ." syndrome. So, "bypass that" by not going there. Just get the fuel system and ignition systems working "as designed" and I suspect it'll mostly fix the driveability issue, plus the timing chain deal.

Just some thoughts . . .

NTX5467

[Smartin]

Estimate from the mechanic was high, but not out of bounds. 12 hours of labor plus parts and machine shop costs. I wish I could hire Adam to give the entire engine bay the Smartin treatment! Probably wouldn't cost that much more!

I'd probably spend a little more than 12 hours on it

[bhclark]

Well now I'm torn....I'll sleep on it and maybe call him in the morning and tell him to hold off. He's got it running, roughly, so I could bring it home or take it for a second opinion.

I've got the time, just not the room, knowledge or the strong back to work on it myself.

The carb is a fresh (2 years old) rebuild from the carburetor shop.

The spark plug recommendation was from Tom Telesco, I believe, as I found during a search. I think I'm running 43s now. They weren't looking new, but they weren't wet either. They were dark IIRC.

[60FlatTop]

I have a high voltage clamp on pickup for secondary ignition wires with an analog meter, an oscilloscope will work as well. I check the secondary voltage on each wire and record it.

Typical is about 6,000 volts. The reading is influenced by the air fuel ratio. Its that old E=IR thing where R varies with the condition of the electrical components and the richness or leanness of the mixture at the spark gap.

A lean cylinder might show 9,000 volts or so if the valve stem is worn and leaking air into the cylinder. Spray a little starter fluid around the valve springs to see if you can enrich the charge and drop the voltage. This kind of test helps you pinpoint internal problems.

A 55 year old car with 100,000 miles had to be sitting around a lot. With average use it should be over half a million miles. Concentrate on "sitting around" problems. Watch the valve action with a timing light for anomalies. Consider a dead spider body partly blocking a carburetor jet. Look at the four questioned cylinders an figure out if they were all at the bottom of the stroke at the same time while sitting. The bottom of the stroke has the least wear and those four sets of rings could have been compressed and are sticking; leaning out the cylinder from the crankcase.

Cars that sit around have special problems that mechanics don't anticipate. And you can buy some pretty neat tools with the money an inexperienced mechanic might charge to learn about your car.

Bernie

[old-tank]

Road trip! Change the oil and then run it 70 mph for a couple of tanks of gas. If that does not help, try adding Risolone to the oil and 44-K to the gas and repeat the trip. Or, if you don't like driving it that much use the additives on the first trip.

Willie

[bhclark]

I pick it up in the morning. We'll see how well he's got it running. Before I took it in, I don't think it would have made 70....The last tank had a decent amount of Seafoam in it.

[bhclark]

It's barely running. Idling, but exhaust is hot and sounds choppy. Idles, but when put into gear it starts to bog down. Very little power, takes a while to get it up to speed. When at speed and pedal is floored, I get a howl, but can't tell where it's coming from as it only happens under load, not revving in park. I took her up to about 50 on the way home. Died at a few stoplights.

Got home and checked a few things. Vacuum advance is moving. Used some heater hose to isolate plug wires to ensure there is no cross firing. No change.

Tried the starter fluid around the carb base and intake. Got some rise in rpm, but I got a rise in rpm when I sprayed it on the heater fan too. Very sensitive apparently. I double checked and the manifold is tight to 25 ft/lbs and the carb is tight at about 15 ft/lbs.

I'm looking for a new mechanic....

I don't doubt the car needs a valve job/heads rebuilt, but I am doubting that that is the cause of the car all of sudden losing all power.

Bernie, I'm not sure what you mean by secondary voltage? I'm going to pick up a clamp on meter, but will a digital one work?

Also, how do I watch the valve action with a timing light for anomalies?

Front 2 carb jets spray freely. I tied spraying some starting fluid in the carb while running, the passenger side seems to bog down a bit, then pick up, the driver's side increases rpm immediately.

Cylinders they reported as not firing were 2, 3, 5 and 8.

I appreciate all the advice, but please keep in mind that while I can change oil, shocks and brakes, engines, ignition and anything electrical are rather foreign to me. My wife will tell you that I also have zero patience.

Edited May 9, 2013 by bhclark (see edit history)

[60FlatTop]

Spraying the base of the carb will suck a little fluid in around the throttle shafts. Better to take the valve covers off and spray a little at the base of the valve springs. Then you are open to watch the valve action with a timing light strobe, too. On a "new to me" car I would pop the rocker arms off and press my finger on the top of the valve stem to see how much they wiggle. That shows worn guides. If only one wiggles a lot just fix that one.

The meter you need is an inductive KV meter, not easy to find. A local geek with an oscilloscope can help.

Did the mechanic take the airhorn off the carb and peek around? Did he check the rubber fuel hoses at the frame rail and at the tank to make sure they didn't suck air with the fuel? How much younger than the car was he?

I had an impatient friend that I did a lot of work for in the 1990's. His wife commented on that once. I told her "With my patience and *****'s money we can do anything." Guess how she responded to that!

Bernie

[avgwarhawk]

If 2,3,5 and 8 are not firing according to the mechanic I would think the engine would not have enough guts to move the car much less get you down the highway at 50 MPH. Firing pattern confirmed correct? Back firing? I would take the valve covers off and check to see if the rockers on each cylinder are moving. I have experienced poor running engines that are pulling gas down the throat of the carb and having good compression only to find a valve bent and stuck closed in the head.

[60FlatTop]

2,3,5,8; that is the two center cylinders on the right side and the front and rear on the left side. Look at the casting of the intake manifold and see how the runners use that configuration to maintain an equal length. one jet does 2,3,5, and 8. The other does 1, 4, 6, and 7, just the reverse.

Sounds more like a dead spider body in one jet to me and starving that runner for fuel. Time to gently lift that airhorn off.

Bernie

[bhclark]

2,3,5,8; that is the two center cylinders on the right side and the front and rear on the left side. Look at the casting of the intake manifold and see how the runners use that configuration to maintain an equal length. one jet does 2,3,5, and 8. The other does 1, 4, 6, and 7, just the reverse.

Sounds more like a dead spider body in one jet to me and starving that runner for fuel. Time to gently lift that airhorn off.

Bernie

Ding ding ding! We have a winner! Bernie you are a genius!

I can't say it was a spider body, but it definitely was clogged with gunk down in that jet.

I can't say she runs perfectly, but she's back to running like she was before, but rich. I'll need to tweak the carb back to how it was before the shop adjusted the mixture and idle, but she has power again!

Just tell me where to send the check Bernie!

Seriously, if you'll be in South Bend, I owe you a drink at least!

Now to decide whether to tell the shop what the "simple" fix was?

[buick5563]

Spider bodies.

Ethanol gunk. (My guess)

Whatever it turned out to be, it is certainly cheaper than a full rebuild, eh?

At the very least, run some gas with Techron in it for a while.

[60FlatTop]

Just a check for whatever the guy who couldn't fix it charged will be fine. Well, that's what you tell the mechanic the charge was.

On the richness, the low vacuum from no advance might be opening the power valve slightly. Give it a little more advance and see it the richness clears up.

Glad to help, that's why I joined the BCA in 1978.

Bernie

Edited May 10, 2013 by 60FlatTop (see edit history)

[TexasJohn55]

Ding ding ding! We have a winner! Bernie you are a genius!

I can't say it was a spider body, but it definitely was clogged with gunk down in that jet.

Now to decide whether to tell the shop what the "simple" fix was?

I vote to tell the shop, could be a great lesson learned for that mechanic. You can't learn unless you know your mistakes. TexasJohn

[Roadmaster75]

I vote to tell the shop, could be a great lesson learned for that mechanic. You can't learn unless you know your mistakes. TexasJohn

I agree,

If the guy is otherwise a good "wrench", but needs his troubleshooting skills to be improved

(esp. on old cars), then I'd go ahead and lay it out for him. I find that engaging and indoctrinating

mechanics, either breeds mutual respect or, at least, exposes them ...... Maybe they'll dig

a bit deeper the next time they are tempted to

say ..." you need a new motor " ....

mike