I just got my rebuilt 59 312 Y Block in my 55 Mercury fired up for the first time and I was expecting to see the rocker shafts oiling, but they don't seem to be. Since I did Tim McMasters pressurized rocker shaft mod, I cut open an old rocker cover and installed it on the passenger side to see how it was oiling during startup. I got it up to 1300rpm and only ran it for a couple of minutes and didn't see it oiling like I expected so I shut her down and ran for the HAMB so I could check before proceeding. A YouTube video by LHogas shows a fresh y-block startup and it took about 40 seconds on the driver's side. Perhaps it takes longer to reach the passenger side. Am I just being impatient and overly cautious? How long can I safely run it if it's not oiling up top? BTW, I used a priming tool and ran it with a drill on the pump, and it seems to get pressure after a bit of spinning. Thanks for any help on this.
Double check your rocker shafts for hole alignment(easy to miss: yes, I've done that one!) Use your priming tool & spin that oil pump until the rockers oil (possibly remove the rockers{you were going to check the hole alignment, weren't you?} & see if you're getting oil out of the holes for the rocker shaft oilers) if they do not you may have something as simple as a stuck pressure relief valve in the oil pump also you might want to make sure that ALL the oil gallery plugs are installed. Do the previous before you get radical & do a partial teardown to check the cam bearings for oil hole alignment(unlikely, but known to happen!) Final thought: what kind of assembly lube was used on this engine; if it was grease, it may take a while for the oil to push it all out of the oil passages. (That's why I like the modern assembly lubes or the '60s favorite straight STP, as they don't harden while sitting, & flow readily with the lube oil.)
One other thing. By chance did you assemble the rockers with the rocker shaft upside down?If you remove the rocker assemblies, push a rocker arm to the side and make sure the feed hole to the rocker arm is to the bottom.
"seemed to get pressure" What does that mean? when you spun the pump you should have seen oil from the rockers. what pressure did you get? ^ Double check your rocker shafts or you have a restriction in the passage from the center cam journal (most likely at the turn between the head and block)
Have you got the head gasket the right way up....did you put the skinny head bolt in the correct position..tight cam bearing (center) can spin and block align hole...(( never rev the engine when its cold))..I have done the bleed off modification on rockers and found too much oil up top causing weeping rocker seal problems.....standard system works great if its all new.....
That's the point of Tim McMaster's pressurized rocker oiling modification, the standard system does not work well and isn't reliable. There was a problem with the Y block rocker oiling from day one and many brand new engines had an external rocker oiling tube that the dealer had installed. Tim's Y block pressurized rockers mod works well and you should probably check some of the things mentioned here and possibly even run your problem by Tim himself.
Same old BS keeps coming up,No "Y"s don't need outside oiling if holes are all in line as designed an clear; Patch up kit out side oiling was the lazy way. Yes we had a lot shitty oil that slugged up if not kept clean. Yes it is a good idea to block off rocker bypass = a bent tube on top end of rocker shafts. Now if you think you screwed putting Y together,heres some EZ checks, #1 pull spark plugs out,take rockshaft off one side at a time an spin motor to see oil come up out of block/head<at hole under rocker stand*{ if nothing comes out of head? There can be if old motor slug blocking an that very offten can be cleaned out by spraying brakekleen down hole ,let it site an after a min. ,then blow air psi down hole,spin motor again tell oil apears/or repete. Now if it's a new rebuilt,its possible you have cambaering in wrong or head gastket wrong blocking hole,or even you milled the heads with out grinding out oil slot after. Now for rockers stands an shaft; stands have hole up through them that must be lined up with both head oil feed and the rocker shaft hole{ some have turn over the shaft tube*{ canbe done if you also drill hole to replace the one facing up vs down,with there idea being used ungauled side lets rocker ride better} Better to buy new shafts really.
Thanks morac41...more things for me to check if I don't readily find the problem. I kept the old parts in case the mod is a problem. It's been so long since I installed the heads, I can't remember the particulars. This would be my first build.
Thanks Blue One. I did send Tim an email...he really seems to know his Y Blocks. As I mentioned, the LHogas video showed dry rockers taking 40 seconds to oil on the driver's side...it may be that it takes a few seconds longer to start coming out the other side where I was watching. The pump is on the driver's side outside of the block. I ran it for less than a minute. I understand you really don't want to let it idle when you first start it up but, rather get right on with the break-in process. So I'm really trying to limit running it until I can get things right and move on to the next step.
Thanks Dana! Unfortunately, a Napa machine shop did the rebuild about 20 years ago for the guy's son (who I bought it from) and then it sat and never got touched til I bought it. The crank, rods, pistons, cam, and bearings were already installed, so I didn't see much of anything in the cam department. The heads didn't look resurfaced (to my recollection) but everything was clean as a whistle and assembly lube seemed soft enough still. I did rebuild my rocker assemblies (borrowed from the original Merc motor) and followed Tim McMasters' Y Block Ford Rocker Arm Rebuild video on YouTube . The rocker stands and shafts should be lined up (I say should) because You dogpoint the bolt that goes into where the oil tube was, and then the dog point tip of the bolt slips snugly into the same hole the tube came out of. So that should keep every other hole lined up (again, I say should). But thanks for the troubleshooting tips...that will help!
Thank you drtrcrV-8! I , as a first timer am really lucky that this forum exists. I'll be checking some of this out for sure tonight!
Use some molly lube on the rockers It will stay with you for 20 minutes that it takes to break in the cam
Do you know if I can put that on over the oil I can-squirted over the rockers? Or should I maybe clean 'em first?
If you didn't get oil to the rockers during the priming operation, then you've got an issue anywhere from the center cam bearing up to the rocker arm shafts. Head gaskets can go either way to get oil up to the shafts so you should be good there. Soft cam bearings and camshafts with an inadequate groove depth are at the top of the list for rocker arms not oiling on a fresh engine build. Ted Eaton.
Sure is a lot of good info in this thread. Curious on a rebuilt 272, gets oil to one bank and no oil on other. Could that still be cam bearings?
Hey, Kennewick Man, I'd love to hear a veteran Y-Block guy answer that. From my research, it seems like there are two separate oil passages to the two separate heads (please someone chime in if you know) and that the center cam bearing is where oil passes on to the passenger side rockers and that oil passes through a different cam bearing (front maybe) for the driver's side. I assume that the mechanics and structure of the 272 is the same as the 292/312 block, internally anyway. Three things stood out for me: 1: There may be assembly grease blocking one side and it may take time and pressure to break through (see drtrcrV-8's post). 2: The head surfaces may have been milled (resurfaced) and the recessed passage (turn) connecting the block hole and the head oil hole isn't deep enough anymore for the oil to pass (see dana barlow's post). In which case I'd pull that head and carve it deeper with my Dremel. And 3: You may have a stuck pressure relief valve in the oil pump (assuming drtrcrV-8 read that I had good oiling on the driver's side and that that doesn't matter). Finally, if all other easy solutions fail to fix the problem on a new CLEAN rebuilt engine, then here's what Tim McMasters says: "It should get oil very quickly. Did it have a grooved center journal on the cam or a cross drilled one? If you pour some oil or even STP over the rocker assemblies you can run it for a few minutes to see if it feeds the top. If there is no oil to the rockers after a minute or so it may have a cam bearing installed incorrectly. I always blow air through the hole in the block to make sure it comes out the hole in the cam bearing." I've heard that cam bearings can spin on these motors and one other mechanic said he "used to pin 'em". Worst case scenario: i have to pull the engine and open her up to see if the cam bearing is the problem :^ (
Ive torn down dozens of non rocker oiling Y blocks and not one ever had a spun cam bearing. The cam bearing clearance was worn too big or the passages where clogged. I radised the edges of the oil hole in the block and heads and cut the groove in the head deeper. Squirrel here on the Hamb reciently fixed a Y block in a Edsel. He mentioned something about finding a wider cam bearing. Ok you could attach a line to the return tubes on the rockers . fix up a container of oil to gravity feed the rockers and you can run it as long as you wish. Back 50 years ago I had a Y block that the rockers where bone dry. So I got a external oiling kit. The engine was terribly sludged . I cleaned up the rocker arms and heads. and I got oil to those rockers. The rocker arms and shafts where so worn the oil light stayed on. The top end was flooded with oil. So I removed the external lines. I installed a grease alemite fitting to the rockers. I would pump them full of 90 wt gear oil. I could run about twenty miles before they started getting hot. So I just got out and refilled them never even shutting off the engine. About the only good thing about that engine was the valve covers didn't leak. there wasn't even any gaskets. and they weren't even bolted down. I ran a 50-50 mixture of STP and any kind of engine oil. One cold day on start up the thick oil caused the hex pump drive to the oil pump to twist in two. I never noticed anything wrong until it overheated and locked up. I had lots of fun with that $15 car.
I am just wondering about the cam bearing possibility. When we search for a similar problem and a solution, others down the road will look at this thread and get some great info. My situation is, my uncle rebuilt a 272 for his 55 vicky, less then 300 miles on it while shaking the bugs out. He took the car back apart for paint and this one never got past primer and finished. 25 years later he sold the car and new owner had no interest and left the y block/3 speed od. So we now have a orphaned rebuilt y block that is known to only oil on one bank. Been sitting in the shed for 25 years, needs to be disassembled, cleaned painted inspected and re assembled. And if needed, new cam bearings installed at this time. And sometime over the years, the distributor disappeared, really would not want to prime it without disassemble / clean first. So this brings me to my question, if one bank is getting oil, would this automatically rule out the possibility of mis installed cam bearings on a fresh rebuild? Is there 1 oil passage for both heads, or 2 oil passages 1 for each head? I love the sound of a flathead, is the most sweetest music. A y block on straight pipes, they have this raspy nasty sound, reminds me of the preachers daughter gone wild.
If I had a engine that was oiling one bank and not the other. I likely would simply run a line from one side to the other.
When there is a cam bearing issue, the right bank stops oiling first. In all instances, the 3 holes in the center bearing are still aligned with their respective holes. Have never figured out the mechanics of why that happens but it's consistent in that regard; right bank simply stops oiling first. Those cam bearing issues have typically happened within the first few hundred miles of the engine being rebuilt and the cam bearings being replaced. As mentioned above, I've never seen either an oem or aftermarket cam bearing spin in a Y. The original (oem) FoMoCo bearings were much harder than the Durabond and Sealed Power bearings we get today. Several fixes are around for that cam bearing issue. Fix 1: Groove the center camshaft journal deeper, Fix 2: Install cam bearings with a outside groove on the center bearing (Schumann sells these), Fix 3: Machine a groove in the center cam hole of the block that allows the 3 holes to be interconnected (That's my fix!). If you end up with a surplus of oil to the top end, it's easily rectified by putting a drilled orifice in the bottoms of the second from the right rocker arm pedestals. Ted Eaton.
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