kobayashimaru

Learning to rebuild an engine

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Greetings!

 

I am just starting out working on my 401 nailhead and I realized something. While I know how its put together, and we all know that its easier to take something apart than to put it together again, there is still a lot I don't know. Once the cylinder head is off, my knowledge ends. When it comes to machining things, grinding crankshafts and doing performance upgrades, I am lost.

I am wondering if anyone here can recommend a book or a website that I can read and learn about this stuff.

Thanks in advance

 

Joe

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I don't know a lot about rebuilding engines. It's been thirty years and I've forgotten most of what I knew.

But, I do remember that Buick engines should be put together at specifications (tight) 

Not like Chevy, put together loose and adjusted after it's running

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^^^^^How do you "adjust" tolerances after an engine is running???^^^^^^

All engines should be assembled at factory established tolerances. If it calls for a certain rod and main bearing fit or piston to wall clearance, then that's it. You cant go back and loosen or tighten thing up a bit unless, maybe, it's valve clearance

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^^^^^How do you "adjust" tolerances after an engine is running???^^^^^^

All engines should be assembled at factory established tolerances. If it calls for a certain rod and main bearing fit or piston to wall clearance, then that's it. You cant go back and loosen or tighten thing up a bit unless, maybe, it's valve clearance

 

That's what I thought he meant too.  Valve clearances can be adjusted on a running Small Block Chevy engine.  I hear it's the same for the big blocks, but I've never messed with those.  As you pointed out, other clearances are adjusted as the engine is assembled.

 

Cheers,

Grog

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As I recall there is NO adjustment in the Buick nail head design out of the factory. I am pretty sure the valve tips have to be ground to a specific height. The head was rebuilt and this was not done correctly and created a problem for us. The rockers had no adjustment and sit on a rocker shaft. The cure was simple but expensive, there are aftermarket adjustable push rods that I found and the problem was cured. They do get built tight 

Edited by John348 (see edit history)

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Really no adjustment?  How strange.  An early manifestation of bean-counteritis?

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There is no need to "adjust" or grind anything - the engine has hydraulic valve lifters. The parts are machined so the lifters do all the adjustment.

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^^^^^How do you "adjust" tolerances after an engine is running???^^^^^^

All engines should be assembled at factory established tolerances. If it calls for a certain rod and main bearing fit or piston to wall clearance, then that's it. You cant go back and loosen or tighten thing up a bit unless, maybe, it's valve clearance

right.

It's the valve clearance I that I had in mind

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There is no need to "adjust" or grind anything - the engine has hydraulic valve lifters. The parts are machined so the lifters do all the adjustment.

true

The lifters have to be matched to the head.

Any milling of the head will require a set of lifters of different length. 

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As I recall there is NO adjustment in the Buick nail head design out of the factory. I am pretty sure the valve tips have to be ground to a specific height. The head was rebuilt and this was not done correctly and created a problem for us. The rockers had no adjustment and sit on a rocker shaft. The cure was simple but expensive, there are aftermarket adjustable push rods that I found and the problem was cured. They do get built tight 

right.

This is a common mistake by builders uninitiated with nailheads

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Greetings!

 

I am just starting out working on my 401 nailhead and I realized something. While I know how its put together, and we all know that its easier to take something apart than to put it together again, there is still a lot I don't know. Once the cylinder head is off, my knowledge ends. When it comes to machining things, grinding crankshafts and doing performance upgrades, I am lost.

I am wondering if anyone here can recommend a book or a website that I can read and learn about this stuff.

Thanks in advance

 

Joe

Post your question in the Buick forum on this same site. "Buick Post War"

You're sure to get some folks familiar with the nailhead there

Edited by JamesBulldogMiller55Buick (see edit history)

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Post your question in the Buick forum on this same site. "Buick Post War"

You're sure to get some folks familiar with the nailhead there

 

true

The lifters have to be matched to the head.

Any milling of the head will require a set of lifters of different length. 

 

 

right.

It's the valve clearance I that I had in mind

 

 

right.

This is a common mistake by builders uninitiated with nailheads

 

 

Actually it was the  engineers having their way over the bean counters. 

 

 

Post your question in the Buick forum on this same site. "Buick Post War"

You're sure to get some folks familiar with the nailhead there

You should use the multiquote feature.

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true

The lifters have to be matched to the head.

Any milling of the head will require a set of lifters of different length. 

 

Like I mentioned in an earlier post I did not recall the exact reason for the problem, now that the milling of the heads was mentioned it came back to me. I came into the project after the engine was built but running like crap.  I think the adjustable push rods really did the trick, and with less margin for error, and they were the way to go. Just as an option to know they are available if needed.

 

I was told there was some sort of circle track class where the cars have to weigh over 4,000 lbs and have a non adjustable valve train. These push rods are able to give them the valve lift they need. It is cheating.

 

Anyway to the OP, have someone help you out with the rebuild who has is familiar with Buick engines, there are a few quirks like the valve train an experienced eye will help you overcome

 

http://nailheadbuick.com/nailhead-speed-secrets

Edited by John348 (see edit history)

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I'm screwing around with Motors all the time. No formal training - not a job, but just for fun.
 

1. Get the shop manual - MUST HAVE

2. Order the basic engine rebuilding video from Boxwrench - MUST HAVE

3. If there's a specific manual for overhauling your engine get it, but 1 and 2 are probably enuf. :D 
4. Find a reliable/experienced speed shop in your area.

5. Take photos of the motor from every angle.

6. Tear down the motor systematically (Boxwrench walks you right thru it) memorializing each step with more photos.
      * Wire tag bigger parts
      * Nuts, bolts,washers, screws go in a zip-lock plastic baggie. Mark each bag with a sharpie.
7. Once you've got a clean block and stripped down the heads send em off with the crankshaft to the speed shop and get em magnafluxed (checked for cracks)
8. You, like me, probably do not have your own machine shop. The speed shop will assess your engine and make recommendations about boring cylinders, porting heads, valve jobs, and balancing cranks.  
9. The will order valves, pistons, cams, etc.... to conform to your newly machined parts, OR, get the specs from them and order your own. I think some companies make stuff better than others and mix and match
10. Now its decision time. Do you get your block, heads, crankshaft back from the shop and reassemble everything with your brand new boxes of parts and gaskets, or do you let the speed shop assemble the short block - hang pistons on rods, install crank and rotating assemblies, cam bearings and cam.
      * I've done it both ways on a number of motors. 327's, 350's, 283's seem a little more forgiving with a corresponding lesser chance of screwing up. Anymore, I let the speedshop do the basic rebuild most of the time as the reassembly isn't that expensive.

11. Back in the day, I rebuilt carbs, starters, generators, water pupms and oil pumps. Kits were cheap and I fixed em whether they needed it or not. Now days, I usually clean up the starters and generators and have the old guy down at the fix-it shop put em back together, or exchange my core for a rebuild on Ebay or any number places on the net.
12. I've had real good luck with Eastwoods paint products.
13. If you don't have a lotta tools - Boxwrench gas an index that tells you everything you'll need and why.

Nuthin looks cooler than a freshly rebuilt motor and an appropriately painted block. I just finished a 62 390 Cadillac V8, and now I'm starting a 65 Corvette 300hp 327 and a 1953 straight 8 out of a Pontiac.




 

 


 

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A lot of early engines, I am finding had no "adjustment". The valve adjustment was to grind the lifter, and once you went to far, you bought new ones and started over. I agree completely with "get the manual". I found on my Ford, several different specs depending on what site you were on. I got the Ford book from that era and am using it. And be willing to talk to whomever you need to, it so happened I needed to talk to a Ford tractor guru about my oil pump. The guys on this site have and will be of great help to you, they have been for me. There's a wealth of knowledge here. Majordan is right in all his steps, either way you go, you may have to open your motor back up, I did, it happens. That's why the book is great, you're ready for whatever comes your way. 

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I have NEVER heard of grinding a lifter. Maybe machining a lifter, but it has to be hardened and I have never heard of that either.

Adjustable push rods are common. As are aftermarket rockers for some engines that will allow adjustment.

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Major Dan had hit it pretty much on the head, but one thing I would like to add that is very important. Certain things like bearing caps have to go back in the same location they came from and direction they were facing. Identify them as to where they belong with something that will not wash off, I use a small punch and place a "dot" on each cap to represent the location as to where they came off.

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I have NEVER heard of grinding a lifter. Maybe machining a lifter, but it has to be hardened and I have never heard of that either.

Adjustable push rods are common. As are aftermarket rockers for some engines that will allow adjustment.

 

I'm not all that experienced, but I agree with Jack M.  Lifters, as are all components that have to endure heavy loads, are surface hardened, and grinding (even machining) would remove that hardened surface.  I'm not sure the average amateur mechanic would have the knowledge or equipment to appropriately surface harden metal.

 

Just my opinion,

Grog

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Jack M, you are correct, the term is machining. My 6 cyl flattie had non adjustable lifters which the machine shop that did the rebuild said they could machine to accommodate the 0.040 that was machined off the block/head, we opted for the adjustable lifters instead.

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I have NEVER heard of grinding a lifter...

 

Me neither, but Model T Fords did not have adjustable lifters (of course most rebuilt T engines do now) and the valve stems were to be ground as necessary to get the factory-recommended clearance of "a thin dime" — roughly 0.030"

Edited by Chris Bamford (see edit history)

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Guys, lets get back on topic. The guy didn't ask about lifters, but learning to rebuild an engine.  I suggest looking at a community college.  Many offer a class in engine overhaul.  I took one and it was a great experience.  We had to tear down, measure, reassemble and start three engines to pass the class.  As you could imagine, most of the wear was in the bolt holes from repeated tear downs.  Good luck on your 401.

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I have heard of shortening valve stems.

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