Rusty,
Three times I considered writing this response and twice I decided not to do it. Guess that makes this the third time. I was not sure that I could write it so it would not be taken as a personal attack. I don't know you except for this forum and don't know if your suggestions is your personal feeling or just a possible option or a tongue in cheek situation.

I hope you don't take this response as directed to you personally. It is intended only to point out what has almost become an acceptible practice.

I personally have a problem with your suggested approach. First since the numbers do not show when the manifold is attached why change the numbers? Just to fool someone into thinking that it was the numbers matching head? If the numbers are changed what has been accomplished? Is there a sense of accomplishment equal to that when you have saved the genuine part? Which is perservation or restoration of an old Chevrolet? Or both?

Unfortunately my opinion is that the changing of numbers has become more acceptable. I hope that the trend does not continue or I am wrong and it is not becoming more acceptable. I also hope that I have not insulted anyone but in a little way pointed out the possible sense of accomplishment in saving Chevrolet history.

Hi Chip, my post was written with tongue in cheek but I'm sure there are those who seriously considered this solution. (maybe wont admit it). In my opinion, I don't care if the numbers don't match but it would be wrong to change them.

I don't want this thread to degenerate into a holy war about right/wrong practices, we can start a new thread about that one. I look forward to the teacher's next session.

Thanks,
-R

If you want to use another head why do anything to it, who besides your self will know, so if it don't bother you and your vanity, just find another head put it on and when you sell the car (unlikely?) tell the new owner you put on a new head and charge extra for the new head!
Then I would try to fix the old head, anyway just so My vanity could say "Yeah I fixed it!"

Hi All

I would fix the head and NOT change the numbers. I am also a member of the National Corvette Restorers Society (a Chev Club!!) and this is the topic of many a discussion. Guys are restamping engine pads and then presenting the car as an all Original car. WRONG!! I am against restamping of ANY kind. Big problems will result. Just my $.02.
great class....keep it up teach!

mromano

mr Ray. a note for you to think about? i looked at my serial number and they did in fact stamp matching ### on head and block on truck engine's as noted on car's! not sure of assembly plant? but the engine is a 1928 coded ( t ) at least our two engine's, one being a car the other a truck are. thank you for teaching us new thing's and thought's.

Did not expect this project to get into a discussion on ethics. However, now that the subject has been thrust out into the open I’ll give you my take on it. As I mentioned in an earlier post it was important to me to keep this head married to the block in the car as they had matching numbers. To do that it became a challenge to find a way to repair the head and salvage it. As mentioned, I have other heads available, which could have been used either without changing the numbers or by replacing the numbers. Honestly, those options did not even occur to me, as there was a viable method of repairing the head.

I guess I have a ‘thing’ about restoring these old fellows. My ‘25 Roadster had a section approximately 3 X 3 inches in the center of the block that was cracked all around as a result of freezing many years ago. It would have been much cheaper to replace the complete engine, but the head and block had matching numbers, WHICH APPEARED ON THE ORIGINAL TITLE THAT CAME WITH THE CAR. Without hesitation I stripped the block, loaded it up and drove the 2700 miles to Oklahoma to the fellow who was the master of block/head repair. I defy you to examine my Roadster now and discover that the block has even been worked on. It is a perfect job and now the car is restored with the ORIGINAL engine whose numbers match the ORIGINAL title.

Every job I tackle is done with the thought that someday, someone, will disassemble this project and critique my workmanship.

Running behind a bit on keeping the pictures up with the actual project. So, a complete change of pace.



This is how the head looked when it was removed. You can see considerable carbon build up. Too much build up can cause problems, such as pre-ignition, caused by the carbon getting hot enough to ignite the fuel mixture before the plug fires. Pieces of the carbon can break loose and get under the exhaust valve. This can cause the valve to burn or be damaged. Too much carbon build up can also cause ‘pounding’ on acceleration, and can lead to overheating.

HOMEWORK: How do we remove this carbon build up?

Well, I think we should remove the carbon like the repair manual says to do, whenever the valves are ground. unless someone wants to do it the modern way.

I've used a small, stiff rotary brush with a ¼" electric variable speed drill motor to remove the carbon and it seemed to work well. The heavier pieces can be carefully "chipped" out with small dental picks, that I con my dentist out of. The operative word in removing the carbon deposits is "CAREFULLY", so as not to damage the combustion chamber surfaces in the process.

I'm not aware of any chemical means of removal, but would be very interested in trying one (or several), if anyone would like to share their ideas here. -Bob

That is one of the ways I have done the carbon removal, except I don't use dental burrs, I usually do a good cleaning job with my hot water pressure washer and dry with compressed air, then immediately spray everything down with a mixture of 1 part WD 40, 1 part 20 wt motor oil and 1 part MMO (Chip can subsitute ATF if he wants) and work the valves up and down then let it set for a couple of days, then wash in solvent and most of the carbon is gone. Then a round of the metal brushes on a drill or die grinder produces results I like. I don't normally send the head off for new seats and guides unless it is one that I haven't seen run, or after inspection I decide the expense is justified, I will usually do a valve grinding operation by hand, the old fashioned way). That is a perk of being retired, I have a lot of time to do things without being in a real rush.

Teacher was not clear on this homework assignment. Let's assume the head is still on the engine. How can we prevent or remove some of this carbon without removing the head. Or can it be done?

That sounds better.Carbon accumalation can be "controlled" by having correct air/fuel mixture and spark setting.May be removed by running a carbon solvent thru the carburetor with engine running.(notice I said MAY).I won't even suggest the pouring water thru carb. with engine running as a more serious problem than carbon can result.

Carbon is a fact of life with the low compression Chevrolet four with the fixed jet carb. and the choke. also any stop and go driveing, however it can be minimized by proper service , tuneups, correct sparkplugs and sparing use of the choke and proper driveing techniques. (i think that a correctly operating thermostat that maintains a coolant temp above 160* F helps.

Carbon build up can be controlled to a certain degree, but eventually will become an issue to deal with. My experience has been that if there's enough build up to initiate pre-ignition, the head should be removed and the job done right to prevent any little pieces from interferring with the valves or scoring the cylinder walls. Every time (or so it seems) I try to take a short cut, I seem to wind up with more work and greater expense than I would have had by doing the job the right way in the first place. There must be a Murphy's law on that issue, isn't there??
Anyway, just my 2¢ worth.

-Bob

Teacher, short 6cyl kid from the back of the room. There use to be a product called Carbosolve it was a chemical fluid that dissolved the tarry binder which held the carbon particles togather. When this tarry binder is dried out by running the motor, the loose carbon particles are blown out thorugh the exaust. They use to sell an injector kit which mounted to the dash and a small copper tube attached to the center of the intake manifold. you attached a can of the Carbosolve to the injector under the dash and pulled the handle once to inject just the right amount of cleaning fluid into the cylinders with the engine running and then turned off the engine for the night and in the morning the dried carbon was blown out through the exaust.

This type of solvent was offered by numerous automotive suppliers such as Faeth Company of Kansas City (1930's) and also Chanslor & Lyon Co. of Los Angeles in their 1917 Catalog.

A water mist injection system was also used in the late 40's and 50's to accomplish this task.

maybe we could rig up one of those injectors and fill it up with Jack Daniels. It should loosen up those pesky carbon particles, it surely loosens up the tongue! and if things get too bad just divert the flow and take a snort!

Your local Chevrolet dealer sold a carbon remover chemical as late as the 80s maybe later. It was a solvent that was poured down the carbutetor with the engine running at moderate speed. The idea was to get about 1/2 the quart can into the engine slowly enough so it did not die. Then the last half was poured quickly so the engine died. You waited several hours for the solvent to penetrate the carbon deposits. Then started the engine. The process produced lots of white smoke. Since the solvent also washed the oil from the cylinder walls and penetrated into the rings and probably the pan draining the oil soon after the treatment was recommended. It was also not recommended to use the stuff more than once.

The effectiveness of the above treatment is unknown to the author (this student). The only truly effective way to remove carbon is mechanically!

The carbon cleaner sold by GM originally was called Cleens and was great.In the 70s the name was changed to "Top Engine Cleaner" and is still available but seldom used as its impossible to pour in to a fuel injected car.It does come in an aresol can also.The modern method for cleaning carbon is a device that blasts the combustion chambers and valves with walnut shells( rice was also used at on time-un-cooked),It is sucked back out and any remaining is harmlesly blown out or burned.On some older Toyotas the engines got to the point where there refused to run due to intake valve deposits and this process would work without removing the head.

Hey Chipper! that is exactly the process of "Fogging" with Marvel Mystery Oil! Except it was oily enough that it didn't wash the oil out of the cylinders, in fact it worked as a Mystery lube, and the bif cloud of white smoke smells heavenly! Yeah! (TIC)

Hey Gene,
Is that how the Japanese cars got the name 'rice burner'.

Thanks to all the students who took time to address the homework assignment.

After an engine has ran for several miles/years it is not a bad idea to remove the head for cleaning and inspection. This is the best time to make an effort to remove any carbon buildup.

Any attempt to remove the carbon without disassembly is a hit and miss proposition. A few years ago (Late ‘40s early ‘50s) when I worked at a service station, it was common to use SHALOR RISLONE. Approximately ½ of the contents were run through the engine by way of the carburetor. Then the oil was drained and the other ½ of the container added to the new oil. Automatic transmission fluid works just as well and is cheaper. As suggested brake fluid and water were sometimes used for a quick tune-up and cleansing of the engine.

As a sidelight, the station where I worked sold GULF gasoline in three mixtures, regular, Ethyl, and white gas. The white gas was used in gasoline lanterns, gasoline irons, and any appliance that required a fuel that had a minimum of residue. The pumps were the 10-gallon visible with the pump handle. And yes, we sold “White Lightening” in the back room and NO; I do not know where the pumps went. The "White Lightening" would have been an excellent carbon remover, however the cost was prohibitive.

We left unanswered the selected method to attack the broken bosses on the front of the head. Someone was astute enough to observe the 6 small holes drilled in the outer edge of the opening. This was the solution of the prior engine rebuild. These holes were tapped to accept screws to attach a fabricated plate.



This plate was ¼ inches thick and was counter sunk at the locations for the 6 mounting screws. Eight large holes were drilled to allow water passage. A gasket was used to mount this plate to the front of the head.



Two holes were drilled and tapped to receive the two mounting bolts. A smart decision was made to select brass bolts to mount the water outlet. As mentioned earlier, this was a weak point in the design of the engine in that the shafts of the original bolts were exposed to the water and quickly rusted away. Another gasket was required to mount the water outlet. Crushable gaskets were used on the shoulder of the bolts to seal that area.



My solution to the problem was to take the head to an expert cast iron worker. The old cracked and broken remains of the bosses were ground away to expose good solid metal. The head then was heated to a very high temperature; new metal was built up similar to the original bosses. The head was then allowed to cool over a long period of time. The front mounting area was machined flat and holes bored and tapped to accept the mounting bolts. Either brass or stainless steel bolts are recommended to attach the water outlet. Crushable brass washers are used to seal the shoulders.



Exploded view of the water outlet. Nineteen-twenty-eight was the first year that Chevrolet provided for a thermostat. A quick look at a ’28 engine and you immediately see the bulged water inlet. Inside is the thermostat held in place by a “C” shaped device held in position by two BRASS bolts.



Thermostat held in position and water outlet ready to install. Seventy-five years later and a current day thermostat fits very nicely.



Casting date of November 10, 1927 for the head. November 16, 1927 was the date on the block. Both the head and the block have matching serial numbers and the casting dates fall into place for this to all be a successful marriage.

You did so well on the last homework assignment you get a break till next class.

Hi Teach

Sorry for taking so long to do the homework.... How about crushed walnut shells?? An old timer told me they would raise the rpm and introduce some crushed walnut shells via the air opening of the carb. Any shells that might get caught will eventually burn. What do you think??

My compliments to you for maintaining the use of original parts in your restoration projects.

I completed a spare 28 engine restoration just before christmas and I cut the valves and head at the local shop owned by a friend that had the right equipment. Put a 45 degree on the valves and a 45and 60 on the head for secure seating and then used the seat dressing making sure not to go in a complete circle and used the "slot" in the valve for a large screwdriver. You can actually "FEEL" when it eventually seats. What a fun project it was!!! There is minimal "blow-by" via the valve stems but then we must remember the technology back in 1928!!!
OK I am done talking I'll sit down and pay attention!!!

mromano

Teacher,
could you tell us how the metal was bulit up in the head repair. Would this be gas welding or MIG welding ?

Student in the back row.

Question for the teacher. How does one go about looking for an 'expert' cast iron worker qualified for such a job. Likewise, how does one find a qualified shop for any type of machine work? I have been burned twice in the past by shops that were recommended as reputable and either did lousy work (caused more damage) or else sat on the project so long they lost the parts.

Thanks,
-R

mromano ,

Interesting recommendation on the crushed walnut shells. As they are also used to do blasting, such as paint removal, who knows, it may work.

Not sure what you meant by “blow-by” in reference to the valve stems. Valves will be a subject for discussion and probably homework later.

Old216 ,

Sure, here is some more input on the head repair. The shop that did the work has a very elderly gentleman who still practices procedures that have been used for years and have survived the passing of time. First the head is brought up to around 800 degrees by use of a rosebud(s). When it has achieved an even temperature it is placed in an electric blanket to maintain the heat. With the use of a special cast iron gas welding rod and a borax based flux, the area is built up to the desired level. With the use of the electric blanket the head is slowly brought back to room temperature. The next step is the milling machine where it is decked, drilled and tapped. As you can see this procedure is not inexpensive.

RustyFender ,

Very good question and something I pride myself at. In addition to knowing your own limits it is important to know sources of parts, services, and other means of doing outsourcing. Each Friday some 15 to 20 fellows gather at a local cafeteria for lunch. The group includes three owners of restoration shops, a master machinist, a parts man, a painter, and several fellows who own one or more antique cars/equipment/trucks. Antique cars are usually driven to the cafeteria and a special area is provided for us to park. If the city and parking lot owner would allow it one of the members would fly in in his helicopter. (Most of the owners have way too much money). In addition to feeding our face a wealth of information is exchanged.

I do not consider myself bashful. If I need something done it does not bother me to enter a shop, ask for the manager, state my need, and then ask to see a sample of the work so I can judge for myself. My experience is that almost every shop knows the capabilities of the other shops in town and are not hesitant to recommend someone if you have a special problem.

If nothing else, I would think that if you have been following my “School is in Session”, you have at least been exposed to some of the methods employed in engine rebuilding and can arm yourself with much more intelligent questions in solving your projects.





This subject should have been covered when we were hot-tanking and cleaning the block. There are eight bolt holes used to attach the head. For years the 4-cylinder people have been hindered by the lack of NEW head bolts for reassembly. The old head bolts have been stretched or will stretch more when we reuse them. Due to the non-standard size of the bolts we can’t buy new ones. You can have new ones “made” at a machine shop, however that is expensive. Inspect the threads in the 8 holes in the head for condition. If they are already showing signs of wear and damage one solution is to replace the threads. For about $50.00 you can purchase a Helicoil kit to replace all 8 holes. The kit will include a special size drill to clean the holes, a tool to retap the threads, enough inserts to do the 8 holes, and a special tool to install the inserts. This will change the number of threads per inch and allow you to purchase new head bolts.

When you have finished inspecting the holes or making the repairs it is EXTREMELY important that each hole be cleaned out thoroughly. This is to prevent false torque readings and possibly breaking the boss that contains the hole.

It is time to install the head. If the head gasket removed from the engine is inspected and found to be in good shape it may be reused. I have used the same head gasket as many as 4 times with good success. If you have a new copper or metal head gasket, by all means use it. The repair manuals suggest the gasket be coated with grease on both sides. I prefer to use the Permatex copper spray-a-gasket. Place a good coating at each of the water passages. While you are looking in the repair manual notice the pattern recommended for the sequence of tightening the bolts. Recommendation is that you start at the ENDS . How much torque for the bolts? This subject has been broached several times in this forum. Can you remember the steps and pounds of torque?

Homework :

Describe the steps used to torque the head bolts on this engine. Give the torque for new bolts and used bolts.

This is the first time I have heard of reusing a head gasket. Is this head gasket a composite one or a pure metal one ? I am asking because I want to know if your advice is only for one type of gasket.