1964 300 engine question

[Pete Phillips]

Am working on the 300 two-barrel engine in my '64 LeSabre two-door hardtop. For those who have followed these forums for several years, this is the engine and 3-speed standard transmission that was in a very, very rusty '64 LeSabre that I rescued from western New York a few years ago. The car's body was too far gone to restore, after seeing it in person, so I removed the running engine and transmission and steering column, and found another '64 LeSabre with a decent body and no engine or transmission, and performed a transplant. The 300 V-8 has, as best I can tell, somewhere between 120,000 and 130,000 miles. It does not smoke, has good compression, always starts on first or second try, but has a lot of valve clatter and valve train noise.

I decided to replace the hydraulic lifters to see if that would help reduce the noise. Opened the engine up today, and it was surprisingly clean inside, but the bottoms of the lifters do show wear. What concerns me more, however, is there is between 1/8th and 1/4 of an inch of back and forth movement of the camshaft. It moves from the front to the back of the engine, and makes a clicking noise when it does this. This movement also affects the distributor shaft and makes it move some, too. Not good. I'm thinking there is wear either in the timing cover or at the back of the engine where the camshaft turns. Have any of you experienced this with a 300 or 340 V8?

Removed the two cylinder heads to inspect some more, and with no heads on the engine, the crankshaft binds up when you get about half a turn in either direction. That really has me puzzled. Pistons and cylinder walls look good. This seems to leave the timing chain and cam gears as a possible problem. I guess I will remove the timing cover tomorrow and see what the chain looks like. Any other suggestions?

Pete Phillips, BCA #7338

[Pete Phillips]

Well, I removed the timing cover and answered my own question. The chain was loose and was therefore binding up on the gear teeth as it was turned. Removed the timing chain and no more binding up. So, a new timing chain and gears will be installed.

Pete

[ol' yeller]

Pete, if original, the '64 300 used a phoenelic coated cam gear for the timing chain. Given time and miles this coating would break up and fall off the gear messing with the timing. If you find this type of gear, I'd definitely recommend changing it out as well as the smaller crank gear and chain. Buick used this coating on the timing chain gear to reduce noise but I never heard a marked increase in noise after changing to metal gears. As for the movement of the cam, I don't remember specifically ever noticing that. If you're pulling the timing cover, you may as well pull the camshaft and inspect the bearings and where it meets in front and back.

 

Many years ago I bought a '64 Skylark convertible project. The best thing about the car was that the engine was rebuilt in the not too distant past. As I was doing a frame off restoration, I pulled the engine and put it on an engine stand to "pretty it up".  I bought a complete gasket set  as it was cheaper than piece-mealing together the gaskets that were installed incorrectly and leaking. As I reassembled the engine, I had the engine upside down on the stand and debated with myself whether or not to pull the crank and install a new rear crank seal.  I decided to pull the crank and it was a good thing I did.  All the main and connecting rods were trashed as was the crank surface.  Evidently whoever "rebuilt" the engine installed all the pistons backwards which had the oil spurt holes oiling the inside of the block instead of the crankshaft.  I had to completely rebuild the entire motor correctly this time. 

[NTX5467]

In most flat tappet engines, camshaft location (on the front) is the camshaft sproket's backside's wear surface against the front of the cylinder block and any "plugs" at the rear of the cylinder block.  The camshaft lobes have a front to rear taper on them too, so they are not exactly parallel to the length of the camshaft.  The bottom surface of the valve lifter (tappet) has a slight convex (outwardly curved) surface to allow for some "spin" as the lifters work against the cam lobes.  As the lifters are held against the camshaft lobes by valve spring pressure, there is a downward-locating force acting on the camshaft.  Between the rear of the camshaft sproket's thrust surface and the pressure of the valve springs, the camshaft is kept "in place" such that it doesn't move far enough to seek to push the rear core plug out.

 

When installing a roller-lifter camshaft in a block where a normal flat tappet camshaft used to be, there are a few other positive location scenarios for the camshaft.  As the roller lifters have to remain in a particular location all of the time (i.e., they can't rotate in their lifter bores, for obvious reasons), the camshaft lobes are parallel with the camshaft's length.  The lifters can use various methods to ensure they don't turn in their lifter bores.  At the front of the camshaft, there is a machined "hole" which a "cam button" will reside in.  This is the travel limiter for camshaft movement toward the front of the engine.  In a small block Chevy V-8, for example, it "locates" against the timing cover's inner surface.  As the rear thrust surface of the camshaft sprocket can wear, a different camshaft sprocket is used which requires a Torrington bearing between the cam sprocket and the cylinder block for positive sprocket location that will not change with use.

 

When I upgraded the cam in my '77 Camaro, I also installed a Cloyes Plus-Roller timing chain set.  As the timing chain is oiled by "splash", I used the moly paste that I put on the camshaft lobes prior to installing the cam in the block, on the rear surface of the camshaft sprocket.  I also poured some GM EOS over the installed timing chain set for good measure.  Even with the moly paste on the cam lobes and lifter bottoms, I poured a can of GM EOS into the lifter valley holes for additional camshaft initial start-up lube.  In more recent times, the old EOS has been replaced by GM Cam and Lifter Assembly Lube (in a small squeeze bottle, as many other similar lubes sold by cam companies have been for a while).  It's much more efficient to use.

 

Sounds like you've got a good engine there, Pete.

 

NTX5467

[NTX5467]

Ol Yeller, you mean there was ONLY "splash" oil from the pistons oiling the crank journals???  Nothing from the oil pump?

 

Reason I inquire is that most pistons have the centerline of the piston pin offset about .030" toward the thrust side of the piston for piston noise concerns.  In many cases, reversing the pistons can unleash some additional horsepower, but can also result in some piston noise. 

 

Might there have been another reason for the bearing journals to run a little too dry?  Restricted main oil galley in the block, which feeds the main bearings?

 

I concur that purchasing an engine overhaul gasket set (or the separate gasket sets to make the complete set) are always less expensive than "by the piece".  Plus you usually get some gaskets you didn't know about, which you'll also need to do the job.

 

Respectfully,

NTX5467

[TexasJohn55]

"All the main and connecting rods were trashed as was the crank surface.  Evidently whoever "rebuilt" the engine installed all the pistons backwards which had the oil spurt holes oiling the inside of the block instead of the crankshaft.  I had to completely rebuild the entire motor correctly this time."

 

     Me thinks that the oil spurt holes are on the rods, usually to oil the wrist pins. Reversing the rods or pistons should have no ill effect on the rod and main bearings.........But I could be wrong, I am not intimate with that particular engine. 

     Trashed bearings are usually caused by "trash", as in filtering failure or severe low oil level,etc.

 

I probably should have stayed out of this because it may not be relevant as to what caused your failure or to Pete's issues.

Edited August 26, 2015 by TexasJohn55 (see edit history)

[ol' yeller]

Sorry I didn't mean to HiJack Pete's thread.  To close the issue, This happened about 20 years ago so I am going on my faulty memory so please discount for that. There may have been other oiling issues that I didn't explore.  I do remember that both the main bearings and the rod bearings were scored very badly and the pistons and rods were installed backwards.  I just equated the 2 together. As a disclaimer, please see my signature, " I am not a mechanic although I do play one in my garage". 

[60FlatTop]

Back to the lifter diagnosis, check the rocker arm shafts for wear on the bottom side. A lot of Buicks have had new lifters installed when the problem was worn rocker arm shafts. I have stripped the shafts down and held them at a 45 degrre angle; they look just like a set of steps.

Bernie

[NTX5467]

Thanks for that additional information, Ol Yeller.

 

As for the rocker shafts, the bottom is the main wear surface, although it's generally hidden from view.  Thanks for that reminder, Bernie.

 

NTX5467