VCCA Home Forums TECHNICAL - GENERAL Radios, Tools, Accessories School is in session (Contd)

Well, it is obvious that the students drank way too much eggnog over the Christmas Holidays. Not only did no one identify the cover, we didn’t even have any guessers. So here is the picture again.



As you can see this is near the rear main bearing and up against the lower flywheel cover.



More hints. Now the area is exposed that was covered. There is of course one on each side of the engine. Suggest you go back and review some of the previous pictures and the text that goes with them and see if you can now identify what is going on. Remember the bonus points if you provide the part number(s).



This is the front of the engine and is the motor mount. You can also see the area where the pan connects across the main bearing cap and at the junction you can observe just a small “dollop” of the black RTV. On the opposite side is a through bolt with a lock washer and nut. This side has a through bolt that goes into the front timing gear cavity.

Home Work: What must we do specifically to the bolt and why?

Apply sealant to the threads to prevent leakage due to a "thru" hole :confused:

-Bob

Gosh......golly....... on Ray's idea of using a Coors can and the subsequent suggestion of the soft drink can! ......The only way I'd be able to help sombody do that is to drink the beer (or whatever) first. ROTFLOL.... Or......wait a sec, those elastic bands would crunch an empty can come to think of wouldn,t they? Oh well......I'd still think I'd be able to help out somehow. LOL. Hey.......I,m still friendly.

Little kid in the back with black felt cowboy hat (it's winter y'all) raises his hand. "Hey Teach, Hey Teach, I know!
The cover fits over the gap between the block and the flywheel housing. The part number is ??? can't find a number yet. Maybe when mind clears near midnite.

From the short kid in the back of the room, has been out sick alot. I think the part # is 345511 and the gasket is 345510. Not being a 4cyl kid and having just this old 6cyl to work with not sure of it's purpose.

Q&A

Bowtie Bob,

100% credit for that answer Bob. That bolt does in fact penetrate into the cavity that contains the cam and crank gear. If we did not seal the threads on the bolt, oil would eventually escape. This would appear as if the front main were leaking. If this problem exists on your car I suggest you remove the bolt, clean it, and coat liberally with the “yellow snot” and replace.

DdeuceMan,

Too bad. If you empty the can first it is subject to collapse from the rubber bands. After the job is finished then you could reward yourself with the contents.

ChevyChip,

Can only give you ½ credit. The two covers, one on each side, are to keep any liquid (oil, water, fuel) or dust/debris from entering the clutch housing and contaminating the clutch disc or causing premature wear to the graphite throw out bearing. It is obvious to me that this was a factory installation. The threaded holes are too perfect for in the field application and the uniform cut of the two covers tells the same story. However, if true, they should be in the parts book or in some special publication from Chevrolet. I have looked in every parts book I have and any other publication from Chevrolet for the period and find no mention of these parts. If someone runs into the answer please post it for us.

29chevy,

Great answer, but we do not have a question to credit it to. The two part numbers you list are the Gear Cover and Gear Cover Gasket. Those parts are on the front end of the engine. But, hang in there; and at least you were trying.

Now that the bottom part of the engine is finished it is time to set it aside and start work on the head. This is not the configuration the engine should be when it is painted, however due to space and time requirements I have elected to paint the engine as it sits and let it dry before tipping upright for the final assembly.





Now get ready for the real fun part. Information about the head, steps to be taken and the final assembly.

Here we have a picture of our illustrious teacher photographing today's session for the students. (Sorry, I couldn't resist!

Hello Ray, Sorry Im late to class, But just have not had time to follow the four cylinder engine rebuild. The junkyard dog keeps me to busy with the six cylinder engines. Ray did you use washers and lock washers on the pan bolts like the six cylinder engines? thanks :) :) :) :) :) :)

DONALDASAN, I WONDERED IF YOU SURVIVED THE BIG HOLIDAY!

Hi Mackie Wacky and Ray, Happy New Year TO You and Everyone. Ray I now have got very Interested In your thread on the rebuilding of your engine. You have without a doubt, Put on a great classroom session for everyone and have been very helpful about the rebuilding process of your engine. Now If I could get you to sell me one of those four cylinder buggies you have, Then I could go on the 4 cylinder tours????

The engine looks grey on my screen.Is that due to the glare of the lights???

Gene, it looks gray to me too, but I wasn't about to say anything ,...... We both might end up in D- hall!

Hey Teacher, I was wondering, Was those engine pan bolts supposed to be painted engine color? :confused: :confused: :confused: :confused:

My wife tells me that I am color blind particularly for grey, green colors. It must be my problem that it looks gray, or grey and not green.
Ray, I also checked all the parts books that I have and could not come up with any part number. But the '28 engines I checked all have the parts. I have two more that I can check. I agree that it is a factory installation. Why no number? I even checked some of my later (up to '32 effective date) and part is not in them either (or I can't find where the little sucker is hiding).

CHEVY

It is very important that you keep up with your lessons and continue to read the text. Go check this out here.

As to the paint color; permit me to delay the answer to this question until I post more pictures. However, consider this; the pictures were made with very bright florescent lights, with a flash used on the camera, the paint is extremely shiny and reflects my blue coveralls, and perhaps most important, the proficiency of the photographer is highly suspect, he even tried to slip in a "self-portrait".

Dear Mr. "self-portrait".........Neat anyway LOL

Ray, The engine Is looking good. Just thought that you might keep me In mind when you decide to sell one of your 4 cylinder cars. With the limited space you have to park them, I do have room for one of yours In my garage. By selling me one of yours, You may want to buy a firetruck or a wrecker. YA

Time to clear the desks and get out your books and turn to Chapter 9, Heads. Now that the bottom part is finished and painted lets work on the head. One of the most exciting things about this head is the matching numbers. To refresh your memory lets go back and take a look at the serial number that is stamped on the block.



This is the serial number of the block from the engine we are working on. It is located on the right (passenger) side of the engine near the rear on a boss provided for this purpose.



This is the serial number of the head. This number is stamped on the head under the rear exhaust manifold. When the manifold is installed this number is not visible. As you can see this number is the same as the number on the block. This proves we have a matched set (head/block) as installed at the factory. I do not know how extensive this method of numbering block/head is, however every engine I have disassembled that were obviously the original have had these matching numbers. I must admit that most of these engines were from #6 plant (Oakland). Would be interesting to hear from students on the other side of the states to see if this system was used at other eastern plants. Was the purpose to provide a means of identifying stolen heads? What was the purpose?

Now to show how important it is to me to keep these matched serial numbers together take a look at the front of the head where the water outlet bolts on.



If you look closely you will see that both bosses that are threaded and are used to mount the water outlet are destroyed. One is gone and the other is obviously split and not useable. Obviously if you have another head that was good you would use it. (And I do have several more ”˜28 heads). But, because of the numbers we must find a solution to fasten the water outlet and keep the set intact.

Those of you who have worked on the ”˜28 heads have seen this problem frequently along with broken bolts as a result of rust. The ”˜28 head is the only head that exposes the center part of the bolt. Because it is exposed to the water, which in many cases is not protected by antifreeze, these bolts will rust completely through. When you go to remove the water outlet the bolt breaks off flush with the front of the head. Removing and repairing this problem is difficult and time consuming. If the bolts used for this purpose were either brass or stainless steel it would reduce the cause of the problem.

HOMEWORK: Suggest how we can salvage this head and make it serviceable.

One suggestion would be to braze two studs into the head and tighten housing with nuts-won't look original but could save head.

That could work Gene or mill out a larger round hole and machine a couple of threaded bushings and either press them into the head and lock them with pins or braze them in. The trick will be to keep them in the correct alignment, a templet could be made from a really good housing.

It would appear that the head has been repaired earilier. The only reason I can give for the 6 extra 1/4" or 5/16" holes (can't really tell size from the photograph) would be for the installation of plate that the water outlet housing could then be attached to. The plate would have to be thick enough to accept counter bored hole(s) in order to recess the bolt heads or flat head machine screws. This repair also requires that the plate be thick enough to withstand the water housing attaching bolt stress. That's one method of repair.

The picture gives the impression that the water outlet housing right (as viewed) attaching bolt embossment is missing. Originally that portion of the casting was attached to the wall that forms the inlet valve chamber. Not sure how critical that might be.

If I were trying to not draw attention to the repair I might try something similar but different. I would square up the cylinder head opening removing the damaged bolt embossment areas. Then I would fabricate a plate with the similar inner opening shape as the original opening. I would add a second thickness of material on the back side where the water outlet housing bolts holes are required. The plate would be approximately 3/16" thick and 1/8 inch larger on all sides than the original shape of the cylinder head. Next I would chamfer a 45 degree edge at the outer egdes of the original sealing surface approximately 1/8 inch deep. The next step is the most difficult and risky. Weld the plate on the back side to the cylinder head at the chamfer area. (could be the total downfall of this process from heat warpage or poor welding or both). If successfull, I would then grind the outer edges of the plate down to something resembling the original contour. Install the water outlet housing and paint the unit. Hopefully, only the most knowledgable would even question the repair.

Teach,
Since the damages holes are on the edge of the casting there are several options. The easiest is to clean the area then weld or braze enough to drill and thread the holes. Tig or even wire welding can be used. If the area to be welded is heated then the stress cracking will be reduced. But cracking caused by the shrinkage of the filler versus the cast iron is much less because the weld can shrink in two dimensions and the third for most of its area. It is much different than welding a crack which can not relieve the stress in two dimensions. It is recommended to heat the area to 400-600 deg. if brazing and higher for welding and allow to cool gradually.

If you don't believe it can be welded with steel wire then try it on the edge of a piece of cast iron. You will be surprized.

mr ray, i have read and followed the sessions as they started from page one on! and have found your information greater, than one could ever compile from book's ? a question that i have for you sir: is the engine and head have matching ### that you have shown ! but the engine's that are coded with a truck ## , or ( t ) in the front of code, i wonder what difference does that really mean? when in fact i believed the car and truck were the same for 1/2 ton in 1927 / 1928 then? meaning the chassis and engine's are the same? or are they mr ray.

WOW, suggestions don’t get any better than this. All the work in putting this “Class is in Session” together is paid for in full with responses like those above.

Chev Nut,

Your suggestion is perhaps the best of all if you are working on a driver. Not only that, but your method is perhaps the least invasive.

MrMack,

Your suggestion is similar to Chev Nut with the added benefit of the ability to use the bolts and the end result would not reveal any work done. After bolting up the water outlet and a paint job this “fix” would not be noted. Keep in mind that in order to do the brazing some of the procedures presented by Oldie and ChevyChip must be followed.

Oldie

Good eye. You have noted another solution to the problem. At this point I will reserve comment on that procedure till later.

Your suggested solution would undoubtedly work. And work is the key word. Only a qualified machinist/welder would be capable of executing your plan, however it would accomplish both missions, that is to repair the head and attempt to conceal the original problem.

ChevyChip,

Your suggestion is also viable. You have also touched on a very critical step if any type welding/brazing is attempted on the head. The head must be stripped (all valves, rocker shafts, fittings, and rockers removed). The head must then be heated slowly to achieve sufficient heat and expansion to accommodate the invasive welding/brazing procedure. After the work is done then the head must be cooled very slowly to prevent stress.

I hope it is understood that the suggestions offered above are not intended to be accomplished by the owner. These suggestions are presented in order to give the owner an option in selecting the method of repair and then being able to describe his desires to the appropriate machine/welding shop. Of course the easy way to solve the problem is to take the head to a specialist that concentrates on solutions to problems associated with cracked heads/blocks and other cast iron devices.

n j horst,

Let me try to answer your question/concern and if someone wishes to jump in and assist, be my guest. As I noted in my discussion of the matching numbers I am not an expert in this area. I have solicited response from members as to their experience as to how widespread this procedure was. Perhaps it was only done at the Oakland assembly plant or could have been implemented at every assembly plant. I do not think there would be any difference in the procedures in the passenger car and truck engines. I still welcome member’s comments on this subject.

Your last comment needs some explanation. The easy part is that the truck frame (chassis) and the car frame was NOT the same. Now for the engine. Let’s start with a known quantity and work our way up to the end of the 4-cylinder area. The ”˜26 engine had the distributor in the block, a single exhaust and both intake and exhaust valves were the same size ½ inch. This configuration was correct for the start of ”˜27. The next step was single exhaust, distributor in the block and now the valves are 1 21/32 inch. And in 1928 the combination was 1 21/32 inch valve, distributor in the block and a dual exhaust. (Dual exhaust means the exhaust left the head at two places as opposed to a single port). So, although the truck and car engine were interchangeable, they were not the same. The parts book lists a separate number for the ”˜27 complete engines (car & truck) and the ”˜28 complete engines. The major difference is the valves.

Due to a glitch in the picture department you will not get to see the instructors solution to the problem till the next class. And best of all, no HOMEWORK .

Pragmatic Approach: Obtain another 28 Chevy cylinder head. Face down the exhaust port to remove the numbers. Stamp new numbers in the exhaust port. Problem solved. :p

-R