346 engine tick (next steps..)

[wustjaap]

Hello Cadillac friends,

This concerns my 346 from 1948.
Runs well and oil pressure of 30+ on dashboard.
Annoying engine tick when the engine is warm is the issue I want to solve.
I have read many Posts about this topic which is very usefull.

Several months ago you gave me suggestions on how to solve the engine tap problem (only when it is warm does it tap). With your help I have made a checklist that I follow to solve the problem. I've done the following:
-Muck removed from engine pan (2cm thick) and engine cleaned (Cleaning oil and adaptive).
-Oil supply to valves checked -> oil gets to the valves
-lifter blocks removed, all 16 filters cleaned and installed.

Before I close the engine for testing, I have the following questions:
1. It is hard to turn the engine without spark plugs. I expected this to be easier. Is this correct or should it spin smoothly?
2. I see that some lifters are not turning when I run the engine (via the starter motor). Is that because there is not yet oil everywhere after cleaning or could this also have another reason?
3. The engine had a external oil filter which I have now removed (input from main and output to crankcase). This is because it is a bypass, not all the oil is filtered. Isn't wise to get the oil to the lifters through a filter? (Do anyone have experiences, also in terms of oil pressure loss?)

Please give your advice and experience.

Regards,
Jaap

[James Landi]

Jaap,

Having owned Cadillacs all of my six decades of driving "life," I suggest that your problem may "solve itself" once you get the engine running and under load. I have noticed that taking long highway trips with older Cadillacs actually improves their functioning and performance.  It may have something to do with the metallurgy or the way the valves seat, or perhaps carbon in the seats and/or valve stems in the combustion chamber; however, as I stated above, my older model Cadillac engines seemed to thrive on long road trips, and annoying mechanical noises and concerns simply disappeared. I realize that my response will not verify just what causes the ticking, but I've experienced this problem, and in my estimation based on what you've described, the ticking may simply disappear once you get the car on the road and drive it.  Hope this helps, James 

[Cadillac Jack 82]

I'd get an occasional tick with my 1937 Lasalle until I added some Marvels Mystery Oil during an oil change.  Went away and the engine sounded great!

[James Landi]

Tim,  I'm also a great fan of Marvel oil, and using it as a potential "cure" for Jaap's tick is a great idea.  I also have used it with terrific results with hard starting (when hot) Cadillacs in the gas tank during the summer months.  My theory is that the Marvel oil "ups" the boiling temperatures of modern gasoline and decidedly causes these older engines to start far more easily.    James

[harry s]

I'm not sure how far you have come with closing the engine up. Each lifter should be primed with oil before installing in the carrier. Once the lifters are in place hook the oil feed lines but do not tighten. You can then spin the engine with spark plugs out until you see oil coming out of the fittings then tighten them up. This procedure forces the air out of the system.      Harry

[Bobby B]

Jaap,
Hi....A, number one question in my book would be did you check the measurements between the heel of the cam lobes to the valve stem tips while you had the blocks out? That would be my first choice other than checking oil pressure at various locations by fabricating an in-line "Tee" fitting. To me, the oil filter is Waste of time if you just change it more often. When you said you "cleaned" the lifters, I assume you disassembled them completely, cleaned, and re-assembled. Hopefully they went back in their respective positions in the lifter blocks...
                                                 Bobby

[wustjaap]

Thanks for the suggestions guys.
Yesterday I closed the engine again and started it. It runs not stable and leaked a bit through the exhaust manifold. After a few minutes there was a screeching noise that looked like a rotating object that was not getting any oil. (or slipping V-belt) I turned it off immediately. It wasn't the generator or the fan. (disconnect both V-belts)
Oil level is just below max.

Do anyone have any idea what this could be?

@bobbie: I haven't checked the 3 "because nothing has been renewed at any of the valves and lifters. I want to do that, but I haven't read anywhere yet what to do to get it within the tolerance (not in my 1948 Shopmanual). I have also read your previous post on this topic and understand that this is an important element.

Yes, I have disassembled them completely, cleaned, and reassembled them, piece by piece. I oil them before reassembling in the Bracket. I oiled also the plunger in the body before reassembling. (I have Unit-tpe lifters see attachment)

[Cadillac Jack 82]

Screeching is a belt unless its internal. 

[Bobby B]

Jaap,
  Having nothing renewed has no bearing on that clearance spec because it changes as valve stem tips wear and valves pocket into the seats. When you had it open would've been an ideal time to measure. At least you could have eliminated another variable....
                                                                                                     Bobby

[79 Eldorado]

Screeching is a belt unless its internal.

I once installed a new water pump and one of the bearings on the new pump was bad. That made a terrible screeching noise instantly upon starting. I turned it off immediately and the snout of the pump was EXTREMELY hot. It wasn't on a 1948 346 though.

My point is a high pitched screech, which you feel is metal-on-metal, will make heat fast so one of the infrared pyrometers can be very useful in determining the source of the noise even after you shut it down immediately. I would be very reluctant to start it if you think a high pitch metal-on-metal was an internal issue.

Once you resolve the screech: If you think it's in the valve train one trick is to remove one spark plug wire at a time until you notice a difference in the sound. You can at least narrow down where it's coming from. If you go through every plug, only 1 wire off at a time, and it doesn't change it's also evidence the issue may be somewhere else. That can also work with a rod knock.

Good luck.

Scott

[wustjaap]

Jaap,
  Having nothing renewed has no bearing on that clearance spec because it changes as valve stem tips wear and valves pocket into the seats. When you had it open would've been an ideal time to measure. At least you could have eliminated another variable....
                                                                                                     Bobby

Hi Bobby,
You are right and I need to open the motor again for the screeching noice, I want to be sure everything is normal at the valves. (I hope it's). My question is how do I change the 3" space, I can't find any documentation on this. If you can help me on this, I would be grateful.

[wustjaap]

My point is a high pitched screech, which you feel is metal-on-metal, will make heat fast so one of the infrared pyrometers can be very useful in determining the source of the noise even after you shut it down immediately. I would be very reluctant to start it if you think a high pitch metal-on-metal was an internal issue.

Thanks for the tip Scott. My main concern now is to locate the source of this. Nothing els (exept the lifter disassembly; cleaning; assemble) is changed on the engine. I disconnect both belt to eliminate the belt screeching. With this the waterpump and generator are also disconnect so that will not cource the problem I gues.

I'm open for other suggestions.

[James Landi]

Jaap--

This is truly suggestion, and I'm hoping others will join in--- I have heard of distributor shafts that, for lack for lubrication will squeal and seize... the problem, I think having to do with  its placement and the possibility that the oil gallery to the bearing is clogged. Again, just a "thought," and I'm hoping others will continue the conversation.  Clearly, if you can avoid dismantling the entire engine, that would be great.   Happy holiday.   James

[Bobby B]

My question is how do I change the 3" space, I can't find any documentation on this. If you can help me on this, I would be grateful.

Jaap,
Hi. You can't. It's a time consuming task and usually done when a "Valve job" is in order, which on a flathead, is basically a teardown. Once the seats are changed (or re-cut) and new (or existing re-cut) valves are installed, every valve/spring has to be put back together, minus the lifters, and that distance must be checked on each and every valve. For checking purposes, I use lighter springs to make it easier. As long as they have enough tension to hold the valve fully closed, any spring works. It usually involves removing the valves again after measuring and grinding the valve stem tips down to get the proper 3" clearance needed. New valves are cheap and there's usually enough meat on them to cut down to get the proper clearance. It's a tedious and time consuming job to get it right, and I can't tell you how many horror stories I've heard regarding Flathead rebuilds where the machinist/ assembler never performed this critical step and the engine had to be taken apart again. If it's an existing situation and it's not WAY out, I would let it fly, but it should be checked first before tearing stuff apart just because it'll eliminate that as a culprit regarding your ticking problem. An older Flathead has some ticking noises anyway, so if your oil pressure seems OK and it runs good with decent power, I would either live with it or be prepared to have it rebuilt.
                           Bobby

[fishnjim]

One of the tenets of "systematic troubleshooting" asks is there any recent work on or about where the defect resides before the defect occurred.   Usually, that work's related to the cause, something done or left undone.   So probabilistically, the squeal is "most likely" related to your recent efforts, not something "new".   Yes, it's possible you got oil on a belt, pulley, or something minor but that's related to the work too.
Might help to know what the age / mileage is on this motor and what the overall condition of it is.  Tell:2cm is nearly an inch of sludge, so not exactly clean block and lube system and smacks of a life of poor maintenance and sitting.   Can't reverse that with an additive, unfortunately.
Sometimes, one just has to bite the overhaul bullet, if the desire is perfection.  That's even not a guarantee as we've seen with some post lube rebuild issues. 
I think you're bettor of WITH the partial filter since the sediment was disturbed.   Suggest you  change the oil again right after you get it back running after it warms up.  Any dislodged sludge will find a resting spot in some passage and wreck havoc.   If it's had a life of non-detergent oil and you introduce modern detergent oil, it's a recipe for these problems.
As mentioned, sometimes, those little imperfections will go away, and better left untouched, but which ones to treat is a conundrum.   

[79 Eldorado]

One other thing which came to mind when  someone mentioned detergent vs non detergent oil is everything they've taken out of the modern oil in the past 2 years. I would need to verify API standard per allowable additive level but the oil standard as updated in either 2018 or 2019 resulted in a further reduction of some of the additives which act as high pressure point lubricants. At the time I heard Ford was filing against one of the large oil companies because the tip pressure on some of the rockers was high enough that failures started to occur which Ford believed were as a result of these reductions. In general there has been a lot of discussion around the issue with rebuilding any engine but especially anything which uses a flat tappet cam. I'm now using a 1/2 bottle of STP additive when I do a standard maintenance oil change and any significant rebuild should probably use break-in oil which has a higher Zn and Phosphorus content. I didn't do a lot of research regarding which additive is the best but I've been using "STP NCB65148 Zn additive" from NAPA.

As Jim mentioned normally when a new issue occurs after a repair it was something touched during the repair; even if it wasn't something conscientiously touched. I was also thinking the same but I didn't mention it because we really didn't know well how long things were sitting and the overall condition other than the 2cm of sludge... anyway the rule is more times true than not in my experience.

Removing the belts for a quick check was a good idea.

Scott

[wustjaap]

All, thanks you for you response
First I will celebrate Christmas 🎄  (on covid-19 distance)

All,  happy holidays!!!

[LaSalle5019]

Merry Christmas. I sent you a PM in case you want some good documentation.
Scott

[wustjaap]

Thanks guys for the suggestion and Best wishes for 2021.

At one point I thought the screeching noise was the starter, but when I reassembled the engine screeching noise does not appear and it started fine and ran well.
The result of my actions is a clean engine of which I know the lubrication system is working properly.

BUT: The tap/tick is still there but is therefore not caused by a dirty engine or mallfunction of the oil system.

Easy first step is to change the oil and add some Marvels Mystery Oil.
First I want to rebuild my Carter carburetor and fuel pump. (ordered 2 rebuild kids for it.)

@Bobby: I measured the 3" distance and found it to be a little less than 3" on all lifters. That would mean that I have to remove something from all valve stamps and the head has to be removed for that. I first want to prepare myself well for such a job  . I am afraid that more pieces will break (mallfunction) when I remove the head.

Thanks for helping..
Jaap

[Brad Ipsen CLC #737]

The 3" check gauge is just a check.  The actual clearance required is 0.030 to 0.070.  Most likely you are fine.  To check the clearance you have to get the oil out of the lifter.