VCCA Home Forums TECHNICAL - GENERAL Mechanical - Engine, Trans, etc 1954 cylinder head

I had my 54 cylinder head checked and even though it looked good they tell me it has several cracks. When I removed the head there was no sign of leakage. All cylinders were the same color with all valves good and plenty left for refacing. If it has stress cracks that are not leaking I am wondering if is it re-usable without repairing the cracks. The shop said they see a lot of that on early 50's heads and having driven many miles with 53-and 54's I have never had a cracked head. Is it now common for those heads to be failing due to their age? Most of the miles I put on my 53-54's were when the cars were8-12 years old. I do have another 235 but it's a PG not standard and I believe the head is the same except for the valve seats. Will that head fit if the seats are changed?

There is no difference between the PG and stick heads....and valve seats???
The PG engine had a better quality exhaust valve and stronger valve springs due to the PG engine having a higher valve lift. If it were mine I would use the stronger springs either way because each time the valve seats are ground the valves go deeper into the head, thus causing loss of spring tension.
Those heads didn't tend to crack that easily but someone may have added cold water when the engine was hot and cracked the head.

Some 235 engine exhaust valve history. From 1941-1949 the heavy duty truck used a 235 engine. It had the same head as a 216 and the same poor quality exhaust valves. Was commonn to grind the valve in the truck head at 20,000 miles or less. Some replaced the valves with the much better Stelite valves and rotators.
In 1950 the 235 track and PG cars used the low quality valves. In the 1950-1952 PG cars the ex. valves could burn in 15,000 miles. This was partly due to the valve lifters over pumping up at high speed, holding the valve from closing tight and causing it to burn. The lifter problem was due to the poor quality oil. (I added Almite CDT Detergent to the oil in my original 1950 and never had a problem). In 1953 the valves were a little better and in 1954 the PG engine got the good XCR better exhaust vlaves. Also oil had gotten better and the problem was solved. (the XCR valves can be used in the stick engines)
If I were replacing exhaust valves today in a 1950 and up 216 OR 235 I would use small block V-8 exhaust valves. A direct fit and much better quality OR STAINLESS STEEL VALVES.
I would not have hard seats installed because you don't need them and more material is ground out og the head making cracking easier.

Thanks Gene you have made my day. I emailed myself this post for future reference.

I just got back from the machine shop and the head I brought them does have cracks. Unknown how deep they may be or whether it would leak in to the cylinder or possibly the exhaust ports. The 3835913 is listed by Patricks as fitting 54-62 both 235,261 but hey suggest using a head that with a casting number 3836848 which shows in their catalog as for a 56 235. The reason being is that it will raise the compression ratio by .5. There is also another head 3864848 for 58-62 that is also listed as fitting the 235. When searching for a replacement what would be the ideal head? I only have parts books that cover up to 1955.

The "848" head can have a 8.0 to 1 C.R. in 1956 and 1957.
8.25 from 1958-1962.
Chevrolet sold it as a replacement for 1953 and up.
You will need an adapter to attach the temp. gauge sender. No problem there.

Again I thank you. I am hoping to find a good head without having to take apart an engine. I did see one on Ebay for around $200 so will check the numbers. Might as well have the latest and best if I can as long as I don't break the bank. Have seen some for 1200-2000 and not looking to go that route.

Gene, will all rocker assembly parts fit? I am looking at a head that is the 3836848 complete with valves so if my other parts will fit most likely will buy it. Just placed order-will await your reply.

You use the 1954 rocker assembly. The 1959-1962 rocker arms are different as the oiling grove is off-set. This is to reduce the oil overflow because higher pressure is sent to the rocker arms.
If the head and arms are from a 1955-1958 they are the same so you can use the best of the batch.

The head has valves but no rocker assemblies. I tried to get the date casting # but to no avail. When it gets here I will check it further as the seller said he could not find it. It will be a while as it is being shipped from Ca. The good part is the freight is included in the price of the head and when I calculated the cost of finding and rebuilding a core it was probably about the same. As they say a bird in the hand is worth two in the bush.

The date code will be on the top of the head along with the casting number ending in 848

I did see the casting number in the photo on Ebay but no casting date code. Not my most favorite place or way to buy that type of item so I have my fingers crossed. The seller is an automotive machine shop so I think the chances of getting a good product is better than dealing with an individual. Plus it does have the Ebay warranty of being as advertised and on a big dollar item I think that is important.

Steve,
I have two '51's, both have 235's, with 848 heads.
Casting numbers on both heads, including date codes, are just above the spark plug hole, on # 3 cylinder.

Perhaps we should mention that your 1951's have later model 235 engines. An 848 head wil not fit on a 1951 235.

Thanks Bob. With Gene's information and your cars for reference it should make the job go a lot easier. I worked on getting the crank cleaned today but gave up as it has too much baked on crap. My goal is to get the engine back together by the end of March.

Will it be in Mich. in Sept?

That is highly doubtful as the body is off the frame and once the chassis is done then the body work begins. Still have the front axle to do also. I am doing most of the work myself with help from a friend so only the machine work is being farmed out. I do have the frame, rear axle and rear suspension and tranny completed but 2014 was not a good year for me and I did very little work on the car.

That is correct, one engine is a 1955 235, the other engine is a 1961 235.

I made mention of the "848" heads, to pinpoint the location of the date codes, on mine.

The head I ordered was shipped via Fedx ground a week ago today and was scheduled to be delivered today but that did not happen. I spoke with four customer service reps and finally convinced them it does not take over 24 hours to go from Willington Ct. where it left from yesterday to go to Londonderry N.H., the delivering terminal. In todays computer world most sense of logic is lost as they can only advise what they see on the screen in front of them. The search is on as they are now trying to locate that trailer.

Steve, it has become a fact of life that any thing we do (my wife and I), nothing go smoothly, nothing goes without a hitch, whether it be buying a hamburger or a new house, or anything in between.

One phrase sums it all, in todays world ..... common sense is very uncommon.

I hope they find the trailer with your 848 head.

Having spent over 40 years servicing the trucking industry I found it amazing that they could not (or would not) know where their trailer was. With todays technology they can not only know where it is but the speed it is traveling, the pressure in the tires and almost any other mechanical information that is pertinent. This AM it shows out for delivery so I will keep my fingers crossed.

Your post is very accurate. Even with all the experience I have in the business getting things to go smoothly is impossible. My parts supplier (Patricks) who was going to get the shipment "right out" now advises he may have all of it next week. The machine shop (one of the few left) was going to wait for the pistons and fit them but yesterday they called to say the block was ready and I have yet to deliver the pistons! I am also trying to rebuild the transmission mount with the Mickey Mouse kit from COF. Using the insulators they supplied I plan on using a mold to recreate the original dimensions with a polyurethane product. My one tube that I had (apparently too long) had hardened so I went to get a new one. When I got there there was a sign on the door " Closed for Winter Inventory". My goal is to have the engine done by the end of March. Luckily I have not chosen a year.

The head arrived today and I am still trying to determine if it was "remanufactured" or "repainted". It does have all new valves and the surface has been ground including the manifold surface. That's the good. The bad is the temp sensor was never removed and after removing there are some signs of rust inside-not heavy but certainly not the cleanest. It is painted black-everywhere except the top and bottom surface-including inside the intakes and spark plug holes. Probably I should pull a couple valves to check the seat fit. As far as date code could only find 1c8. Thats the best I could make out of the cast number.

Based on your comments, will it now be your plan to magniflux the head?

Was it an eletrical temp, sender?

Yes it was. I spoke with the shop owner today who assured me that the head was OK to use and had been completely checked and rebuilt. He did acknowledge that it should have had the sender removed and been properly painted and seemed genuinely concerned as he has a 100% favorable rating on Ebay and wished to maintain it. I will remove all the valves etc. and check the machine work and if all is OK will then remove the paint and flush it out. He did offer or at least ask what I thought it would cost to make it right. Once I check the machine work and clean it up inside and out then I will let him know. His price was far less than others on line so if it's ok to use I will go ahead with it. Getting the paint out of the intake will be my biggest challenge.

Magnifluxing may be a good idea. It does have all new valves and guides so I doubt they would have done that if it had been cracked. Before buying I posted a question on Ebay and was assured it had never been cracked or welded and the owner reiterated that again today when I spoke with him.

Well, it's much like flipping a coin, isn't it, whether to accept statements or not. Guess one has to go with his gut feelings.
One item worth mentioning, I think, is the fact that "modern engine builders" tend to use the same guide to stem clearances / tolerances for the 235 valves, which may be too tight.

Gut feelings and verification. My friend that is helping has been a mechanical and electronic technician for over forty years. His last job was the mechanical rebuilding of a 31 Chevy before retiring from a restoration shop. One job was assembling an early Buick engine from two used ones and another a complete mechanical rebuild on a 36 Ford Phaeton. I will pass on the info on the valve guide clearance as there is no such thing as too much knowledge.

The 235 engine called for .001"-.003" for the intakes and .002"-.004" for the exhausts. I would stay at the greater clearences.

Thank you for that info. I have emailed it to my friend.

I decided that it's best to have it magnafluxed so today i started removing the valves. It has seals on all of the guides and I need to know how to remove them without damaging them. The oil on the springs and valve stems is black, but I don't know if its paint or just dirty oil. While it's at the machine shop for magnafluxing it will be cleaned of ALL paint. I spoke with the seller and he says he will pay for any work that needs doing, but he is a long way off. We'll see how that goes.

If the O ring seals on the valve stems are installed (correctly) the external seals are not necessary.
The 235's don't get that much oil upstairs compared to a small block.

That is the same advise I just got from my friend who is helping me. He was not around when I started taking it apart. Good to know you are both have the same opinion.

Magnafluxing the head is good to do, discovering the actual head condition and for your own peace of mind.

By installed correctly Gene I believe that means the oring (actually a quad ring) is seated in the lower groove and not twisted. If there are any other tips I welcome the information.

Important to first compress the valve spring and retainer cap. Then install the O ring and keepers, carefully releasing the spring and cap. Some install the O ring and then compress. This can pull the O ring out of the grove in the valve.

I had the head tested and cleaned and now have it back. The shop that did it said it is excellent condition with all new valves and springs and other than the paint where it should not have been all machining was good. They also vacuum tested it so it is good to go. Now I will see if the seller lives up to his end of the bargain and pays for the additional work which was $216.06.

Magnafluxed or not ?

Magnafluxed and pressure tested in addition to vacuum tested for valve seat seal condition. Photos to be posted in members photos. ( If I had the setting correct). More on that later.

Just thought I would update that I received a check today from the seller. It was very quick and without any third degree conversations. I am very pleased with the head and am now hoping my engine parts will arrive soon so I can get the engine together .

It sure is heartening when people stand behind what they say and do. Fortunately many of the old Chevy folks are that way.

I can say I was honestly impressed with the owners handling of the situation. When I told him of my concerns he apologized and immediately offered to remedy the situation. Also when I phoned his shop he did not avoid me and even gave me his cell phone number and said to call him when I knew what the cost was going to be. I did that last Weds. and got his check today. Certainly is much better service than I am getting from another vendor who had no problem charging my credit card three weeks ago and has yet to ship a single part. They will likely be the subject of another post but not till I receive my parts.

Did you install valve stem seals when reassembling?

The shop that checked it out did the re-assembly and put all new oring seals on the valve stems and left off the seals on the guides.

Words like yours re-establish our faith in others.