I tried to fire off the Nailhead in the RPU for the first time last week: ... and spewed oil all over the shop floor. I could even see it running down over the pressure plate. Today I pulled it apart and look what I found: The machine shop that assembled the engine forgot to button it up before bolting on the flywheel. You can see the oil pump drive thru the big hole at the upper right. And the lower hole is threaded for a plug. But what's this hole to the upper left: Also... I'm an amatuer when it comes to this stuff, but shouldn't there be some sort of seal behind the cam, too? Do the little right and left holes get soft plugs? Does the holes below the cam get some sort of flat-headed plug (that doesn't hit the flywheel)? The leak(s) also marinated the clutch disk. It was brand new, never run. Am I looking at a new one? Thanks in advance for any advise you can give.
Oh yes, a freeze plug behind the cam. Upper left looks like it's lined up with the lifter feed area, so it'll take a plug too. Look in there to see if it's threaded further in. Pontiacs are. If yes, it'll take a pipe plug BEFORE a smaller soft plug. I'd be scared what else those guys FORGOT. PS-i looked at your other pics. EVERYBODY gets a plug. Wipe all clean with acetone or laquer thinner and put sealer on threaded and soft plugs
Wow man, you may want to stay from that machine shop in the future. I will second what Groucho said about the plugs. It would be hard to miss the oil galley plugs, but how in hell can a machine shop miss the cam plug? If they forgot those HUGE plugs, I hope they didn't miss anything else in the machining process. I think that disc is toast man. I wouldn't use it. Good luck brother.
Sad to say that's common due to shop ignorance about nailheads and their quirks. Typical shop builds 8 bajillion SBC's and you toss a nailhead in the mix, they do the typical SBC crap to it and you get leaks. If memory serves, an article by Doc Frohmader on building a nailhead said to doublecheck that area, as most shops won't remember to plug it. More than likely you're SOL on that clutch as well. If it oiled it down as bad as you say, it's probably ruined. EDIT: Oh,also, I believe there's sposed to be a snapring in that groove behind the back of the cam. Not 100% sure on that, think it's to keep the cam from tryin to walk out the back of the block and thru the freezeplug.
Byooik may be right on that snap ring. I am pretty sure the article seires done by Street Rodder on Nailheads a few years ago said there was one at the front, and if you tried to remove the cam with the ring still in you could destroy the block. Sorry about the set-back. That's price of doing something different, isn't it? That's why so many of us are here, isn't it? Good luck. I have a 322 that needs a Model A or SOMETHING to ride around in.
These guys left some plugs out of the water jackets, too -- but they were in the side of the block and easy to get to. But we love doing this, right? Actually, it's a great machine shop and we're lucky to have 'em here in the neighborhood. I think this was a matter of some kind of distraction or something. You know, shit happens. Luckily they're hooked up with a good, independent parts house -- where I bought the clutch -- so I'm pretty sure I'll be treated okay.
i dont think throwing them a nailhead mixed em up, every motor ive ever worked on at my work has had frost plugs and oil galley plugs in the back, it just got missed, but damn thats a hard one to miss!! like Groucho said, the passenger side where you can see the oil drive, there will be a pipe threaded oil galley plug in there, dont forget that one, youll have to take the dist. out to get to it. it happens jeff
so does the cam just walk up to the back of the plug? how do they keep it in place? i think the early hemis all used real soft welch plugs made from lead or something that would stop the cam from rolling back. they had a plate on the front behind the timing gear to stop it from walking forward. just curious how the general did it.
how did the guy putting the flywheel and the gearbox on miss it to? oh well, at least you know its got oil pressure!
Next time, bring the oil pressure up before you ever put fire to it ... stick a gauge in the sensor or gauge takeoff & spin the pump with a drill. Doing this before you start bolting it together will save lots of grief.
Never, NEVER, trust your machinist. Always check everything he did. Your time as the final inspector will be worth it to you. Charlie
usually the cam sprocket has a thrust suface on the back of it in which it contacts the block, just like small block chevys, i think it has something to do with the dist location, anuthing with a front dist wants to thrust the cam forward, and thats why they have a front cam retainer, where as the rear dist. motors has a thrust on the cam sprocket. i wouldnt say dont trust your machinist, id say look over his work, i try and do everything the best i can but i can miss things too, i havent missed anything that i know about! jeff
This one has me a little confused. Does this plug go BEHIND the disti gear (toward the front of the car)? In the photo, to the upper right in that shadowed area, there's a galley that runs on the same axis as the cam, straight into the block (you can't really see it in this photo) -- but it's NOT threaded. Do I have to get and there and plu THAT hole, too? My Nailhead is a '54 322
not to the upper right, directly in the center of the frost plug hole, you can just see the edge of the whole between the dist gear and housing. also you might want to check and see if he put the front frost plugs in to, i think you could try and push a piece of thick rod through the oil gally and see if it come out and touches the timing cover. jeff
Jeff -- you're right, it is the hole you see just behind the edge of the gear. But it's not threaded. So it gets a freeze plug -- yes? If it does, how does this galley get its oil?
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yep, if its not threaded it takes a small frost plug. im sure it gets it oild some how, theres lots of paths for the oil to travel. like i said before, i hope the front ones are in the motor, you should be able to take some welding rod or something, push it through the oil gally and see how deep it goes, you should be able to gauge it by measuring the block. jeff
That area by the cam gear experiences only crankcase pressure, it is an oil drainback area, they had to put a hole there to get the sand out after casting the block, hence the core plug. "Freeze Plug" or "Frost Plug" are misnomers! Do not get the idea those things will push out and keep your block from cracking this winter! Just another tip from yer UNCLEE!
I my opinion this machine shop should be over checking all of this out and replacing what they missed and covering the costs of the clutch and whatever other damage they incurred. They shouldn't just say "oops" and leave it all to you. It wasn't your mistake.
Yep - I learned the hard way (and cost me a good bit of $). I will Always check a machine shops work from now on.
id be bringing that motor right back to the shop. there is no reason you should have to pull things apart to fix crap that you paid them to do. i would also push the issue of them tearing it all down and inspecting it. i would be so pissed. did it actually run? how long? i know it would be hard to bring it back as mean as it looks in their, probably want to slam it back in and get it runnig again.
They've already given me a new clutch disk, they're good people to work with. This is kind of a fluke. I've got some more poking around to do, but if I discover the freeze plugs behind the timing chain are missing, I'll have them tear it down and start over. It also means tearing the entire front end off my rpu.
In the left rear of the block there should be a 1/4" (maybe 3/8ths) pipe plug. Same with the hole on the right in front of the dist. gear. Behind the dist. gear is a freeze plug. There should be a snap ring behind the cam to keep it from pushing it's way out the rear of the block & also to keep from wearing the front of the block. Then install the correct size plug after the installing the snap ring. Tom T.
Also, sorry forgot to look at pic again. Should be a pipe plug also under cam. That is the main oil galley. All the oil came out that plug & didn't go anywhere else. This is the galley that feeds the rest of the engine. Since you started it already with NO oil pressure at all or oil going to anything I would at least drop the pan & check the bearings.
Let me tell you a story about a man named Jed, a poor mountaineer, barely kept his family fed...... Bad deal, did you call the motor shop?
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