Hi, Any opinions or advice on spacer plate vs. non spacer plate versions of these engines? Thanks for any help, Dominion
The older counterbore engines are prone to cracking the ledge where the liners sit down in the block when that happens it will let the liner down and leak compression into the water jacket, often they need to machine out the counterbore and install a new insert. On the spacer plate engines the block is flat and the plate creates the counter bore. It is much easier if necessary to machine the top of the block than to repair the older counterbores. It is my experience the spacer engines are less prone to liner pertrusion problems however over tightening or a loose head can still cause problems with the top of the block.
hi there the spacer plate engine is far superior also when the aftercooler added to late model Ks the engine life extented due to a cooler exhaust thanks the BIG D
The Ks had a lot of head problems to start with an no real answers from Cat. There was an update in which the muffler was taken out of the engine compartment and mounted on top of the hood. As far as I know that pretty much solved most of the head problems. As I understand it the plate was part of pulling more horsepower from the engine. Increased firing pressure put more strain and movement in the liners. From what I saw though now you had to worry about holding down a plate as well as the liners and heads. Changing heads in the field required a whole lot closer attention to getting the block and plate clean. The plate did not totally solve the problem of sunken liners. Now they just sank into the top of the block instead of the counterbore. I don't know if there was a field fix for the top of the block when a liner wiggled its way in. I've had several counterbored engines with shims and Z sleeves to keep an old dog running another year.
The spacer plate engine is better. If you look at the whole line of Cat engines, most of the ones built after the old 300 series used the spacer plate. Either way, they can be counterbored eaisily with the engine inframe to get the liners back to the right height. The problem of sunken liners still exists even in todays modern engines. I cant count the number of 3406A and B engines that I have counterbored. When the came out with the stainless steel shim, it improved the repair process even more.:guns
I'm not sure when Cat changed from head studs to bolts, both my K's had spacer engines with head bolts and my H had studs. The older D342 engines with studs would sometimes be very hard to remove the head from the studs. If the engine had been together for a long time the head would be stuck to the studs. With the head bolt engine once you remove the bolts the head is just sitting on the block waiting for the hoist.
I can relate to that. I had a D7 with the D339 that took an act of congress to get the head off.
Cat had two spacer plate blocks. The first was not as thick. When they had the Cat certified rebuild program going, a counter bore block was accepted into the program, but not the first series spacer plate block. the second series was quite a bit thicker. That block was accepted into the program. I am trying to remember the part #. Might have been 6N and 8N. My 8K was 77v11823, it came with the first series block. I bought the later one for it. Never had a problem with it. That is till a cat dealer siezed the engine on the dyno. It crushed the #5 hole deck. Then we Z inserted it.
ya, somehow dirt gets between the studs and the head together with several years of moisture and vibration it locks the head on. I never could see how the dirt gets in there with the flat washer an nut on top but it does. I've seen some come right apart and others take every bar and pipe in the shop to budge and fight all the way up.
So for the uninitiated which one is this??