1947 Flathead Oil Pressure

[Jeff Trahan]

I talked with the shop that rebuilt the engine and they assured me that the tolerances were correct when it was rebuilt.  I used Lucas SAE 20 break-in oil when starting the engine for the first time and when I drained it after maybe 45 minutes of running, it appeared to me there was more metal in the oil than I would have expected.  Is there anywhere I can send a sample of the oil to have it analyzed to confirm my suspicion?  Except for the lifter ticking, however, the engine seems to run very smoothly at idle speed of about 400 RPM.  If there were anything terribly wrong, I wouldn't expect it to be so smooth.  Is lifter ticking just annoying or is it damaging to the engine?  Thanks for the advice.  I included a link to a video of the engine idling at ~375 RPM.  You can hear the lifter tick more on the right side of the engine.

https://www.facebook.com/video.php?v=323194541206723&l=5503367588790609161

Jeff Trahan

[Bobby B]

Jeff,
   Hi. Can you shoot a pic of the oil that was drained. Fine Gold flake mixed with the oil? Silver Flake? Fine or coarse?
                                                                                                                                Bobby

[Jeff Trahan]

Unfortunately, I disposed of the oil. I would say it was fine silver flake, just from memory.  I'm hoping it was just leftover metal from the rebuild.

What do you think from looking at the video?  Is lifter tick bad for the engine?

[Jeff Trahan]

I changed the oil again after running the engine for longer and there are no more metal shavings.  I'm hoping they were just left over from the engine machining and came out with the first oil change.  Unfortunately, the lifters are still ticking when the engine warms up, but not ticking much when the engine is cold.  Does lifter tick hurt the engine or is it just annoying?  Thanks.

Jeff

[Jeff Trahan]

I'm still trying to figure out the problem of the noisy lifters. The manual says "Improper Oil Pressure" causes the lifters to be noisy when the oil is hot, which is exactly my problem. The lifters don't tick at all for several minutes after the engine is started. That makes me think the lifters are getting enough oil at start-up but somehow not getting enough oil when it warms up. The oil pressure gauge reads 25-30 psi even when hot. How can there be enough oil pressure at the valley when the engine is cold but not when it is hot? It doesn't seem like there could be a blockage or else the lifters would tick all the time, not just when hot.

These two videos show the difference between noise when cold and noise when hot. The first is about 3 1/2 minutes with no lifter noise. The second is about 15 minutes.

https://youtu.be/iTCwdi3KmYM

https://youtu.be/d62mjh0P4dY

Let me know what you think. Thanks.

Jeff T

[Jeff Rosansky CLC #28373]

I will follow this thread with interest. You can read my thread 472 with a tick.
I have the same exact problem......... I know our engines are different but the problem is the same.
My low pressure and tick start after about 20 miles of driving....... When it is good and hot, not just warm.
May I suggest you check your pressure when the oil is very hot.
Jeff

[Bobby B]

Jeff,
Hey, Welcome back! Thought your problems would've been solved by now. I'll throw the following out there.....Lifter blocks worn/too much clearance, Lifters NG/pumping down, Possible bad rod bearing. When it's running, pull a plug wire at a time to see if the ticking goes away. If it does, it's a possible rod bearing. If it's the Lifters, the sound won't change when you take that cylinder out of the picture. I still hope that you have the exact 3" clearance that is specified for the lifters to operate properly. Maybe try flushing the oil and adding a way thicker oil just to see if the ticking goes away slightly after warm-up. If it does, you know you have some excessive clearances going on. Is the oil temp and water temp normal when the ticking starts? Maybe the next thing in order is to open up the Valley covers and have a look.
                                                                                                                                                                        Bobby

[Jeff Trahan]

I took the front valley cover off and disconnected the tee fitting. Oil flows freely (squirts out a few inches) when cranked. With the tee fitting attached and the engine running, there really doesn't seem to be much oil in that area when either hot or cold. Is that the way it is supposed to be or should I be seeing steady oil flow around the lifters?

[Steve Passmore]

Theres a steady rate the lifters have to 'Leak down' if you could see the oil flowing the lifters would not be working. had an engine recently with this problem and t2 of the lifters were frozen.

[Bobby B]

I took the front valley cover off and disconnected the tee fitting. Oil flows freely (squirts out a few inches) when cranked. With the tee fitting attached and the engine running, there really doesn't seem to be much oil in that area when either hot or cold. Is that the way it is supposed to be or should I be seeing steady oil flow around the lifters?

Jeff
Hi. OK with flow through the lines..Fine.  How about the brass 90 degree fittings? Those are usually the culprits and caked up. Before you button it up, unscrew them while you have the lines already off. They don't usually clog up in the female flare side, they clog up closer to the male threaded NPT fitting that goes into the block/blocks because the opening is slightly restricted. Hard to see when they're threaded in if they're clogged.       
                        Bobby

[Jeff Trahan]

Thanks for the advice. The tee lines appear to be clear. The oil spurted out a few inches when the tee was removed and the engine was cranked and when I connected the tee feed but left the two downstream connections on the tee loose, oil was plentiful at those points too. The only thing I haven't checked yet is clogged passages inside the lifter blocks. I don't relish removing them, but it appears I will have to. The funny thing is the engine is really quiet when cold and the lifter ticks only show up when the oil is hot.

Jeff T.

[Bobby B]

Jeff,
Are they "new" lifters or did you rebuild those lifters, take them apart, and at least clean them? Was it a new cam? If you're taking the blocks out, now's the time to check your 3" clearance off the heel of the cam. Do you have a 3" standard or a snap gauge you could set to 3"?
             Bobby

[Bill Ingler #7799]

Jeff: As Bobby has asked- are these the old lifters and if so did they take each apart for cleaning? The tolerance between the plunger with spring and the plunger cylinder is probably the closest tolerance you will find in your engine. This close tolerance is necessary to maintain a certain leak down rate of oil that is trapped in the plunger cylinder. The tolerance between the plunger and the plunger cylinder wall establishes the rate of leak down or bleed off. Too much tolerance causes oil to escape to fast causing valves to open or close too late. Also, too much tolerance allows to fast a bleed off and now you have valve lash. Valve lash is the clearance between mechanical parts in the valve train. The hydraulic lifters maintain a zero lash in the valve train so we have a quite engine. So if you have a lifter with too high of a leak down then you have too much lash so you hear a click, click and a noisy engine.
Now when the engine is cold the viscosity of the oil is thicker which allows slower leak down of oil trapped in the plunger and you have a quite engine. As the engine gets hotter, oil gets thinner which could lead to too much leak down if the tolerance of the lifter is out of limits, then valve lash and click, click. So if you do take old lifters apart for cleaning don`t mix up the plungers with spring and plunger cylinders. As I understand in the manufacturing of the lifters, each plunger with spring is fitted with the plunger cylinder for the correct tolerance between the two pieces and you should always keep the same two pieces together otherwise the correct bleed down rate might not be maintained.  Jeff this might be the reason for the tick, tick noise in your engine.  Bill

[Jeff Trahan]

I had the engine rebuilt by a local shop and they installed new lifters from Terrill. The shop says they followed the directions (I gave them a copy of the military manual and the shop manual) on the 3" spec. Would new lifters have to break-in a little before they stop ticking? My next step is to try some Valvoline 20W-50 Racing Oil to see if that makes a difference.

[Jeff Trahan]

By the way, to circle back on an earlier topic in this thread, there is a "restrictor" in the oil line in my engine block. I have a spare engine, and it also had the restrictor but it looks like it was deliberately broken off to make the hole larger. I can't think of any way it could have broken on its own.

[Bobby B]

By the way, to circle back on an earlier topic in this thread, there is a "restrictor" in the oil line in my engine block. I have a spare engine, and it also had the restrictor but it looks like it was deliberately broken off to make the hole larger. I can't think of any way it could have broken on its own.

Jeff,
Hi. My lifters are quiet with the restrictor. Before you pull the blocks out, measure your full lift on each valve with a dial gauge, while turning over by hand. Do a comparison and see if it varies. You said new lifters, but is it a new cam, with new followers on the lifter bases?
             Bobby

[Tom Beaver]

Jeff,

If the camshaft is worn or reground and or the mushroom cam followers have been reground then the 3" clearance Bobby has mentioned may not be totally accurate.  The 37/38 Cadillac service manual states that the clearance be measured between the valve stem and a completely collapsed lifter.  The proper clearance is specified to be between 0.030" and 0.070".  I use a spare hydraulic lifter with the return spring removed to help make the process a little easier.  It's still a fairly tedious process but it guarantees that any variations in the individual cam lobes and cam followers are accounted for. 

However, your problem may be a combination of parts made in China and insufficient oil viscosity.  It's not clear to me that clearance between the lifter body and piston on the new lifters that are available today always meets the tolerance of the original parts.  You might try 20 W50 oil and see what happens.  An engine I have with the new lifters in it certainly quieted down when I switched oil.

Tom Beaver

[Jeff Trahan]

The camshaft is new and the entire lifter assemblies are all new (all from Terrill Machine). The shop said the valves were fine. I guess they probably just re-ground the valves and seats.

[Bobby B]

And I assume it was broken in properly with break-in oil, for the correct amount of time, and RPM? Go back to my previous post and before you take the lifter blocks out (if that's your next move), do a height check on the lift of every valve off it's seat with a dial gauge and compare. It won't be up to spec because the lifters have no oil to pump up/down, but they should all be consistent. That's what you need to find out. It's just for comparison. Like doing a compression check, it will all be consistent due to the circumstances of the temperature, equipment, etc. This will tell you if the culprit is in the mix there somewhere lurking and masquerading as a bad lobe, wiped lobe, bad lifter, loose valve guide, etc. If that doesn't work, start from scratch with the lifter blocks out, and please double check the 3" clearance. That would be your tapping noise right there in front of you. If you can't find anything once you get all the way down to the lifter blocks being out, you might have to remove the valve springs to see if you have excessive clearance in the guides and possible loose valves. Are you sure they put the springs back in with the correct upper seats against the block? We will help you figure it out. Lots of knowledgeable Flathead guys here.
                                                   Bobby

[Jeff Trahan]

Yes, I used Lucas SAE20 break-in oil (with zinc) and followed the instructions on Walt's Work Bench for breaking in a Cadillac flathead. Thanks for all the advice. I'll post again when I've made some progress.