The Stovebolt Site Forums The Shop Area Engine Shop Bad milk can lifters?

Since most of my antique racing was done with flathead Fords, I have a very limited amount of experience with 261's. One of our competitors back in the early 1960's in "Hobby Stock" class racing which was limited to flatheads and inline sixes gave us a little bit of a run for the money with a 261 (which he called a "Canadian Pontiac") but once we got the rules changed to allow 4" stroke Mercury crankshafts in Ford coupe bodies and almost caught up displacement-wise, (252 cubic inches instead of 239) he couldn't stay within half a lap of us.

Machining for the mains is simply a matter of cutting a slot at the parting line instead of drilling a dimple at the top center of the main bore, so the casting core could have gone either way, I suppose.
Jerry

Jerry,

The Canadian Pontiac 261 came with hydraulic lifters. Did you use them, or change to mechanical lifters?

How did a GMC 302 (or, 270) match-up against those 239->252 V-8 Fords?

Looking ahead, I'd like to clean out the oil passages with gun bore brushes. I don't own a gun, so I don't know where the best place to get them is..... also, are they sold by diameter/size? What size should I get? Do you recommend buying only one? Ten? Do they sell different shapes?

Pontiac of Canada used a version of the 261 as its base 6 cylinder. I have two of those blocks, one of which is in my 57. They are a little bit different. For example, a Chevy 59 261 generally is found with full flow oil filter and the larger oil filter lines, the Canadian Pontiac version still used a bypass filter and the small filter lines, even though the blocks were cast in 59 for use in a 59 car. So it is a little bit of a mash up. The Canadian Pontiac blocks also generally had the 55-57 front side motor mount arrangement cast in place, and some had both the front and side mount arrangement. I doo not have any later Canadian blocks but I have heard that those engines did not get the full flow treatment during the time they were used in the Pontiacs. Chevy truck 261s are somewhat all over the place. I just looked at a 60 block, no 55-57 mounts, and a couple of years ago I saw a 59 chevy with both. I have a chevy 261 block that I pulled from a oil truck 30 years ago buried in the back of the garage. I had a main cap split on me 25 years ago when I was putting it back together. Full flow lines and both sets of motor mounts so I think its hit or miss. I will look at that block because I am not sure whether that block is drilled for hydraulic lifters or not. My gut tells me yes only because the 55-58 steel line is not present and so there must be some provision made to feed the rockers. It would make sense to drill the galley, even though the motor originally came with solid lifters (and had the st874 style lifter in the motor when I originally took it apart in the 90s).

I used mechanical lifters on the new motor. Unless you have some real GM nos hydraulic lifters, or some hydraulic lifters that are like 20-25 years old or older, you may run into the lifter issue thar has been somewhat troublesome for a couple of years now, namely, brand new hydraulic lifters collapsing at break in or shortly thereafter. That and I was building a very modified motor with a fairly aggressive Schneider cam so mechanical was it. Also, while some guys like to garden, cut grass, put little white balls into a hole, as a form of relaxation, I myself find adjusting valves, performing a tune up, oil change, or whatever on my old stovebolt motors the ultimate in relaxation, lol.

A friend of mine owns a machine shop. He had rebuilt a 51 or 52 powerglide 235 for one of his customers. Used new lifters. Had issues with two different sets. I gave him a set of nos gm and what do you know, not a single issue.

Just to keep everyone on their toes, my engine has the old style front motor mount as well.

Wow...talk about water on the fire. Lol.

There were thousands of 270 GMC's available in the 1950's, surplus from salvaged military 6X6 trucks. They were bigger than all but the highly modified flatheads, and a lot of them found their way to dirt tracks. They did very well on long, high banked tracks where they could stay wound up. Coming off the turns on shorter, flatter tracks, they got so much wheelspin from low end torque that the the Fords were halfway down the straightaway before the Jimmys got hooked up!

Tadd, any good gun shop will have a big assortment of cleaning rods and brushes, or shop one of the online suppliers like Midway USA under "cleaning supplies". Another source for military surplus cleaning rods and brushes is the Numrich Arms website, AKA "Gun Parts Co."
Jerry

Thanks Jerry!

Alright, things just got interesting.....
I've found out that my block has indeed been drilled for hydraulic lifters. (Pic)
I've removed every lifter, and made note of what I found.

#6 Exhaust: Only groove near top. (Pic)
Intake: Hole through cup and body drilled near bottom. (Pics)
#5 Intake: Only groove near top.
Exhaust: Only groove near top.
#4 Exhaust: Only groove near top.
Intake: Only groove near top.
#3 Intake: Hole through cup and body drilled near bottom.
Exhaust: Hole through cup and body drilled near bottom.
#2 Exhaust: Only groove near top.
Intake: Only groove near top.
#1 Intake: Only groove near top.
Exhaust: Only groove near top.
It should be noted that every lifter had the groove near the top.

The groove is barely detectable with a fingernail, and if the exhaust lifter for #6 had a hole in the cup, and been drilled near the bottom, at least there would have been an identifiable pattern here. I'm thinking it might not have lasted much longer....thoughts?

Do you plan to replace the cam? If so, the condition of the lifters is a moot point- - - -new cam, new lifters, always! Check the bottom of the lifters- - - -if there's any concave wear at all (light visible under a straight edge) they're worn out, and the cam lobes they have been riding on are also suspect. New lifters can "break in" on an old cam, as long as it isn't badly worn- - - -old lifters on a new cam- - - -never!
Jerry

I'm definitely replacing the cam, lifters, and even the pushrods. I just figured my unusual situation could be something to learn from.

Do a little research on the oil passages before you decide which design of lifter to go with. If you've got the external line from the rear cam bearing, you could use either style. Without it the reduced diameter solid lifters that resemble hydraulics are most likely the ones to go with.
Jerry

Do you mean the oil line behind the side cover? If so, I actually do have it, I just removed it before I took this picture, it shows the spot the exhaust lifter for #6 goes, and just to the left of it is where the line attaches just above the rear cam bearing.

OK- - -that eliminates the concern about the milk can lifters cutting off oil flow to the rocker arms. That block will work with either style of lifter.
Jerry

Good to know!
Your knowledge is a great resource here....

Do you have a recommendation on how to install a new timing gear on the new camshaft?

Either use a hydraulic press, an arbor press, or if you're using an all-aluminum cam gear, heat it to about 400 degrees and it will tap on easily with a hardwood block and a hammer. Don't forget to install the thrust plate and the spacer washer before you put the gear on! Also be sure the timing mark is facing the front.
Jerry

Thanks, this will seem like a dumb question but, do I install the new gear while the cam is in the block, or out?

Install the gear before putting the cam into the block. There's not much of a way to secure the cam while you tap the gear on once it's in the engine. One trick we used when installing a timing gear with the cam in the block was to remove the fuel pump and have a helper hold the cam forward with a pry bar, and drive the new gear on with an air hammer. It's a lot less hazardous to do it outside the block with a press during a rebuild. Be VERY careful not to gouge the soft metal of the cam bearings with the sharp edges of the lobes while installing the cam- - - -that kills oil pressure.
Jerry

I read ya...
How about the crankshaft?

It's easier to install the timing gear on the crank AFTER it's in the block. The timing plate gets installed after the crank is in, then the gear is pushed into place. It's steel, so you can get it hot enough that it almost slides all the way onto the crank with a gentle push (wear a welding glove- - - -it's much less painful that way!). Wedge the crank forward with something to keep the load off the thrust bearing flanges as you tap the gear home. I use a large-diameter deep socket as a driver, and moderately firm taps with a BFH.
Jerry

Again, Thanks!!!

I use an old toaster oven, I set the heat for around 350 and bake it for about half an hour. I put the gear on with heavy gloves and give it a tap using a big pipe nipple. It encounters very little resistance going on, very amazing actually.

Great tip!