So once again the is a 228 gmc (1949). I dont think it has ever been opened up before. The number 3 pison had a broken top ring and the number 4 was rusted in place. The crankshaft and camshaft look excellent, the bearings on the crank were tight with no scoring visible. Nate, I still didnt check to see if the Distro drive gear is aluminum. I will soon! By the way, can I pull the oil pump? should I? I did pull all the lifters and have them hermeticaaly sealed and numbered in their own little marked baggies (they all looked good also). I cleaned the cylinders a little and have enclosed the pictures. The hard part was lifting it up onto my work table! There is a definite ridge on all the cylinders near the top of the bore. The number 3 cylinder is damaged from the broken ring. Part of me wants to hone them a little but I assume the number 3 will need bored and the rest to match. The block and pistons are stamped 6 (size)? The pictures are in cylinder pairs 1-2, 3-4, 5-6 (5&6 look the best) As always any suggestions are appreciated. v/r john m.
I'm a complete novice, so take it for what it's worth... While you have the engine tore down this far, I'd do anything and everything to it to ensure you have a tip-top machine ready for years of service... oil pump included. I'd also take the block to a machine shop to check the cylinders, and have any and all necessary machine work done to make the engine right. That's what I did with the Chevy 235 I'm building for my project. I just don't want to get the truck built, then have something go wrong with the engine making me say, "Man, I wish I would've done that the first time..." Playing devil's advocate, one can always say even a freshly built engine can always take a dive on ya. But I think the peace of mind doing a fresh build would be priceless. Just my cheap two cents. Good luck, and I enjoy following your photos and progress! Damon
Thanks Damon, I like the pictures of your shop and your ongoing build. I am sure I have to go to the machine shop. Just looking for any and all advice so I do a good job. (hopefully) only once! v/r john m.
Would you mind checking to see if the space between #3 and #4 cylinders is the same as the spacing between the other cylinders. The head gasket would also show this. Thank you; Evan
Evan, I will measure it tommorow. They cylinder are kind of in pairs as the block is divided by the crankshaft bearings (4). One on each end and one between the 2nd/3rd and 4th/5th cylinder. Otherwise it appears symetrical and even from the top of the block.
From what I remember from 50 years ago, when you re-ring, with the requisite honing, there's a tool called a ridge reamer that gets rid of this ridge so the new rings don't hit it. They really look nice other than the damage from the broken ring. My uninformed opinion says you will probably need at least a slight over bore with pistons and rings to match. Since you need a new set of pistons anyway, the price difference should be negligible. nice pics...
Have the machine shop clean it up, whatever that requires. Also balance the rotating assembly. I usually have them do the assembly to a closed up block, that way I don't have to open it up and if there are any problems I can't be blamed and won't have warranty issues.
3 & 4 cylinder walls are damaged As far as the eye can see the number 3 & 4 are damaged most likely becausse of the damaged piston rings. There should be more numbers then 6 on top of each piston or use a digital meter to measure out.
Evan, I am posting a couple of pics for you also. The measurements I got (eyeball) were about 15/16ths of an inch or 22/23 mm. I does appear as if the measurements between the 3-4 cylinder are slightly closer together compared to 1-2 and 5-6. I dont have a micrometer and was just eyeballing this so I could be slightly off. The difference to me appeared to be about 1mm. Maybe this is due to cylinder wear? Otherwise the disance between cylinders looks the same other than the thicker block to the front of the 1 cylinder and rear of the number 6. Hope this helps you. Eveyone else, I am looking for a machine shop here in the Colorado Springs, Colorado area unless anyone knows of someone else within a couple hundred miles. Thanks again as always, v/r john m.
Martinius, The 6 "stamp" is visible on the block. I can also see this on the pistons but havent cleaned them to see anything else on the top. It does say zollander on the sides,etc
measuring not presize anaugh! The machine workshop uses other tools then the one you have here. Wait until they have done a full checkup with your engine and let them have measure up inside , the cyl. top and your block horisontal levels. Remember to have it X raid first of all so you dont spend money on an engined that has not visable cracks.
Bench Work John ; THANK YOU for sharing ! I wish I were there to get my hands dirty.... Anyways , you may well have to bore this one out , I can't tell but it looks kinda rough to me . It appears you've done some honing or de glazing already ? . Yes , the # 6 denotes the selective fit of the pistons . I'd not worry about the oil pump but the Machine Shop will want it removed . Don't sweat the cam's drive gear unless it's fibre , then replace BOTH with the same brand or it'll sing forevermore . Expect to find many tiny cracks around the exhaust port or valve seats , this is normal odd as it sounds . I recently got my hands on an old 292 L6 GMC engine and have hopes to overhaul it for a lark before I croak .
Thank you very much, John. I tried twice to make a 12 port crossflow DOHC head for my 302 GMC engine and messed up a very expensive billet both times. I know the bore spacing on it but not the 270,248, or 228 engine. It will give Neil (Brit 50) much fodder to harass me with but am now exploring adapting a 4.2 (256ci) I6 Jaguar head to a GMC block. It is a DOHC 12 port cross flow head. This is very close to a 261 chevy but the spacing between the 3 and 4 cylinders on the chevy is a big problem. This approach is not my brainstorm but is being done by a fellow on the west coast on which Hot Rod mag had a good article on. He uses Porsche heads on big block chevies and Nissan ones on a sbc. It basically involves plugging all the holes in the deck of the block and then drilling new water, oil, and head bolt ones to match up to the new head.
Evan, Glad to be of any help. When I get a caliper on it I will send you a definitive measurement. I have read where some people take v-8 heads and cut them down also to make one head. Nate, Thanks as always. Good luck with your 292. I had that engine in the first truck I ever owned (66 chevy). I have a new engine I picked up yesterday and wanted to see what you think. I will post in a new thread. thanks to all for the advice v/r john m.
