This was a "running" '73 455 that I bought and put in my Skylark after throwing a rod in the old race engine so I could still drive the car while I save up to build the next engine. I barely even drive it since I put it in but it did seem to run well. Recently, it started smoking for the first several minutes after sitting for more then a few hours. Pulled plugs to do a compression check (cold) and it shot water out of #3. I removed the rockers and radiator cap, pressurized each cylinder and when I did #3 it overflowed the radiator. All other cylinders were ok. I don't see any mixing of oil and coolant at all. I pulled the head last night and did not see any evidence of a head gasket failure but the cylinder does show a good amount of pitting so it's had an issue at some point in the past. I'm guessing someone must have overheated it and it developed a small crack in ether the head or block that just got worse. Where should I be looking on the head for a crack? I'm hoping it's the head and I can just replace it for now to get it moving again because I really don't want to put any real money into this engine. If it's the cylinder it's just going to sit until I build the engine I want. Thanks, Ken
Heads tend to crack between the valves or around the coolant passages. I had a motor that got a pinhole in the sleeve. Basically it ate away from the inside and when the piston was down and cooling system pressurized I could see a misty stream in the cylinder with my scope Yours sounds to have much bigger leak if the system bubbled so much to overflow.
A crack can be almost impossible to see, but if the engine has never been rebuilt, it’s most likely in the head , but I would say it’s the gasket and if it’s been overheated it’s also maybe a head warping and not a crack. I would take the head in for an inspection.
You can have the head pressure tested. If it was bubbling that badly the failure should be fairly obvious. Was the fire ring in the head gasket intact?
The fire ring looks fine. I pulled the valves out and don't see anything obvious except a small amount of what looks like coolant on the back side of the exhaust valve. I'm suspecting the block at this point. I wiped that cylinder clean and it is VERY pitted. At this point, even if it is the head I don't think I'll bother with it as it is. My wife just gave me her blessing to go ahead and build another engine, lol. I've had the car since 1988 and met her 2 weeks after getting it and she loves it as much as I do. I know it's going to take a long time because of parts availability. The machine shop has had one of my Edelbrock heads for almost 5 months now waiting on 2 valves from Edelbrock. I have a few blocks to work with so I'll dig them out and get them checked out. I have a few projects I have to take care of around the house first though. Oh well, I've always wanted a Stage 2 anyway! Thanks for the help and advice. Ken
The pitting is not good but I think thats probably a symptom and not the main issue. Any signs of water/rust in that intake runner or port? If they are clean that indicates that the water came internally instead of through the carb. Also it would be cheap to sleeve that single cylinder and save the block. Quality fix too
No signs of rust in the head. I will keep the block just not using it for the next build, I have a few in better shape since I will be starting from scratch.
Out of curiosity...what's the deal w/availability on the valves? Did they make a unicorn with the 11/32" stem and the rest of the dimensions unique to BB Buick? Devon
Edelbrock has been in the process of moving their headquarters this year and as a result most parts show as out of stock. I've sent emails with no response. Machine shop has had trouble even getting them on the phone. First they told them a 2 month wait, then they were about to ship but never did. Most of the time they don't answer. I wasn't in a big hurry at the time and that's where he wanted to get them. I call every Friday for the update..
