philipj Posted May 25, 2022 Share Posted May 25, 2022 (edited) After replacing the pan gasket due to a leak, I started noticing a light noise at start-up when cold, a noise that goes away as soon as you rev the engine a little... Then when the engine is warm the noise is gone, yet you only hear a slight tap as you shut the engine off... I pulled the pan and to my surprise, I found quite a bit of sludge and some dirt... This engine had not run for at least 10 years and was put together by somebody else... It does not smoke which is great, but I would like to address what seems to be a connecting rod knock... I have some instructions from a 1954 publication, which leave some questions... I really do not want to ruin this engine... The steps are listed are: Drain and remove pan... Remove ROD bearing cap and remove an equal number of shims until the rod cannot be snapped by hand, but can be snapped back and forth with an 8 oz hammer... I understand that the shims should be silver (.001) and copper (.002) and if untouched, it should have 4 shims each from the factory on each side of the connecting rod... That being the case, if I find that a cap is loose, I should start by removing one shim from each side and then torque the cap to 40 or 45 lbs? in theory, I should be able to slide the bearing cap with one hand? Instructions are confusing, since they mention using an 8 oz hammer, but then ... 3. Replace (add) one .002 shim on one side, being able to keep an equal number of shims if possible... Should this step read: " If after removing an equal number of shims (from step 2) and cap cannot be moved by hand add one .002 shim” 4. When bearing is properly fitted it should be able to snap back and forth on the crank pin with one hand... But this contradicts step #2. And what about the 8 oz. hammer test?? As I understand, every time you add or remove any shims you must torque the rod down... The contradiction is in the hammer vs. slide with one hand check... 5. If it is not possible to keep the same number of shims equal on each side, it is preferable to have more shims on the CRANSHAFT side... Reading similar topics online, I found that it is better to have more shims on the CAMSHAFT side... Which leaves me in doubt as to which is correct??... 6. Check connecting rod clearance between the upper half of the connecting rod and the side of the crankpin. Clearance should not be less than .004 nor more than .011... No questions here, but I wonder what to do if I have more than .011?? 7. Tighten connecting rod bolt nuts to 40–50-foot pounds and install pal nuts with open side of the nut toward the open end of the bolt... Turn finger tight, and then ½ a turn more… 8. As a final check, be sure that the piston and rod assembly will travel true with the bore... Chack the clearance between the PISTON PIN end of the connecting rod and the piston pin bosses on the piston. The clearance should not be less than .025... I am not very clear on this and not sure how to reach the piston pin end when everything is together... I should also mention that oil pressure on this engine does not seem great, 5 lbs. cold at idle (but can it be the gauge? I also can go into checking the oil tubes on the pan, but I do not have the special tools to do it... Additionally, I am more concerned about the fact that someone has made a partial straight cut into the small tube (fitted on the block) that slides into the pan (where it connects to the feeding pipes) and hope that this does not mean a reduction in oil pressure… The tube is pressed fitted into the block, and I cannot find a part number for it anywhere, nor can I find a part number for the dippers fitted to the rods, as I see that some might be bent from carelessness over the years... Maybe someone can shed some light here, and save me from a major disaster which I would like to avoid... I would like to keep this vehicle running, which I just put together... Edited May 25, 2022 by philipj (see edit history) Link to comment Share on other sites More sharing options...
Rusty_OToole Posted May 25, 2022 Share Posted May 25, 2022 (edited) I wonder if you could check bearing clearance with Plastigauge which I don't believe was available when your manual was written? It would make the job easier and more accurate. 5PSI may be all the pressure you get. It is a low pressure oiling system that depends on spraying a high volume of oil at low pressure. Since the bearings are not pressure fed they have no effect on oil pressure. Does your manual say how much pressure you should have? #6 the only way to reduce this clearance is to replace the connecting rod. You used to be able to buy reconditioned rods with new babbitt from any parts store, but I don't know where you could get such a thing now. This spec was important when replacing rods, I wouldn't worry about it now. #8 the only way to do this with the engine together is from underneath with a strong light and a feeler gauge. Check with the piston all the way down in the bore then observe as someone slowly turns the engine, if the clearance does not appear to change you are ok, if it does change you may have a bent connecting rod or something off kilter someplace. You probably know that the oiling of the rods depends on the dippers lining up with the sprayers. If there is any doubt about this, it is recommended to assemble the oilers without the pan, connect to water pressure and bend the sprayers so the streams of water hit the dippers.This should be covered in your manual. I would be checking the journals and bearings for wear and give them a light polish with crocus cloth then adjust using Plastigauge. The dippers and sprayers are critical, straighten and replace as necessary. One lucky thing, they made millions of those Chevy engines and parts are easy to get. Should also add, they were very reliable and long lived when used within their limitations. In a car that means keep the speed to 50 MPH or less and they will run forever. They are NOT a high speed or high revving engine. In your low geared truck this may mean keeping it below 40, you will have to check your RPMs or find out from other owners what is a safe speed. Edited May 25, 2022 by Rusty_OToole (see edit history) 1 Link to comment Share on other sites More sharing options...
Bloo Posted May 25, 2022 Share Posted May 25, 2022 (edited) Rusty_OToole's post is right on point. I would add that the guys on the VCCA forums use the hammer method on 4 cylinder Chevys, and do not trust plastigage for this particular operation, as the bearings tend to wind up too loose. I don't know if this applies to the 216 6 cylinder also, but it wouldn't surprise me. I believe the point is to find zero clearance and then add a tiny shim. .002 sounds like a lot? I would go over there and ask for clarification because I know they post about using the hammer method. There's hardly any oil pressure in these engines, and as Rusty_OToole already mentioned the squirter aiming is critical. It is also important to use a light oil so the squirters will reach the dippers when the engine is cold. Never thicker than 20W in the old days unless it is 100F+ outside, and never thicker than 10w30 now. Edited May 25, 2022 by Bloo (see edit history) Link to comment Share on other sites More sharing options...
Oldtech Posted May 26, 2022 Share Posted May 26, 2022 Agree on above points. Lose the 8 oz hammer. If you remove shims until you can just "click" the rod sideways by squeezing by hand, then add one just to make it free - it'll be a 001 0r 002. These splashers like em snug as there's no pressure for 3/4 of the rotation to take up any slack. and yes, a garden hose is the special tool for aligning the spray nozzles. it's obvious when they are spraying down the center of the trays all nice and even. The split pipe is nothing, Doesn't affect pressure. Oil pressure may hit 30 lbs when cold and will drop to not much when hot. They don't need pressure, they need circulation. I worked on many of these but it's been decades. Fun Memories. 1 Link to comment Share on other sites More sharing options...
philipj Posted May 26, 2022 Author Share Posted May 26, 2022 Hello there, I went through all the bearings and found that # 4 rod had no shims, and had the most axial play, so nothing I could do, short of finding a new babitted rod to match my crankshaft (which may be STD) and pull the head... Annoyed about the situation, I did not measure the crank... Finding a replacement babbited rod to fit my crankshaft would be next to impossible, so I decided to put it together! So It makes a little noise at start up, who cares, is a damn tractor! Oil pressure is about 5 psi cold and about 15 - 18 at higher RPM... Along with the dirt in the motor I found a thin piece of foil paper that may have been used by the previous "builder" to mask this problem... I just have to think of this as a temporary engine for this truck until I can afford to rebuild a spare 216 I have... By the way, I am using non-detergent Valvoline 30W oil in this motor since I am in Florida and it is bloody hot here all the time... Link to comment Share on other sites More sharing options...
Rusty_OToole Posted May 26, 2022 Share Posted May 26, 2022 You can tighten up that bearing by filing the rod cap. 2 Link to comment Share on other sites More sharing options...
Oldtech Posted May 27, 2022 Share Posted May 27, 2022 Your oil pressure is normal. and, being the splash system is unaffected by rod bearing clearance. 2 Link to comment Share on other sites More sharing options...
philipj Posted May 27, 2022 Author Share Posted May 27, 2022 You're absolutely right, but I was so annoyed at the time (finding chewing gum wrapper on the pan) that I remembered about filling the cap afterwards...;( I suppose I could pull the pan down again (now that I am an expert) and file that cap down with a flat stone... What I am not finding is a source for the .001 silver shims, only the .002 for ridiculous money... Link to comment Share on other sites More sharing options...
Rusty_OToole Posted May 27, 2022 Share Posted May 27, 2022 If you need shims you can cut them from shim stock. A beer can will do. If you file the cap carefully and test fit frequently you should not need any shims. 1 1 Link to comment Share on other sites More sharing options...
Rusty_OToole Posted May 28, 2022 Share Posted May 28, 2022 Did you take any shims out of any of the bearings? Hope you saved them, they can be reused. 1 Link to comment Share on other sites More sharing options...
WPVT Posted June 2, 2022 Share Posted June 2, 2022 I rebuilt my 216 in 1974 in the kitchen of my apartment. Put all the dippers on backwards. After putting the engine back in the truck, I peaked through the oil drain hole and saw my mistake, avoiding a disaster. As I recall, there was a small oil line that was routed through the water jacket that caused me problems and turned the oil into sludge. I replaced many head gaskets before figuring that one out. At that time I was still able to buy standard size babitted rods. The rear seal always leaked so much that the engine took 2 quarts of oil with every tank of gas. I replaced it once and got it so tight the crankshaft wouldn't turn. Despite my hit or miss repairs, it was a very dependable engine and took me all over the U.S. at 40 MPH. It was a good learning experience, and I have fond memories of all the old guys who gave me advice and assistance. 1 Link to comment Share on other sites More sharing options...
philipj Posted June 5, 2022 Author Share Posted June 5, 2022 (edited) Hello Rusty, I still have a little noise from #4 (loose cap) which I will file... Any recommendations? I should probably do it on a perfectly flat surface with a sheet of fine sandpaper as opposed to using a file? Funny, but the minute a cap is too tight, you are unable to turn the crankshaft by hand, It locks right up… I have only one brass shim saved... Worse case scenario, I will try the beer can for a source of a shim... Edited June 5, 2022 by philipj (see edit history) Link to comment Share on other sites More sharing options...
Oldtech Posted June 5, 2022 Share Posted June 5, 2022 If you have plastigage it would be good to know the clearance. Sandpaper on a flat surface is great but will take forever if you have to take off 2-3- thous. A good file and file straight, then an X pattern will remove relatively much more metal, then you can finish with the sandpaper on glass. be careful and test often. ( yes, I used to do this often when I couldn't afford to fix it properly) Link to comment Share on other sites More sharing options...
Rusty_OToole Posted June 6, 2022 Share Posted June 6, 2022 Do auto parts stores still have shim stock? What about McMaster Carr or the antique parts specialists? Link to comment Share on other sites More sharing options...
Oldtech Posted June 6, 2022 Share Posted June 6, 2022 Napa stores had it not that long ago. Link to comment Share on other sites More sharing options...
philipj Posted June 7, 2022 Author Share Posted June 7, 2022 Nothing from the local Napa store, I will have to check other sources... Link to comment Share on other sites More sharing options...
WPVT Posted June 7, 2022 Share Posted June 7, 2022 Keep in mind that if you have a bearing that has an oversize and theoretically cylindrical opening, when you remove shims or file the caps, the opening dimension is reduced in one direction but not in the other. In reality, the bearing has probably worn somewhat oval anyway, and removing a shim may return it to more of a cylindrical shape. I mention this only so that efforts to be absolutely precise can be put into perspective. Link to comment Share on other sites More sharing options...
philipj Posted June 8, 2022 Author Share Posted June 8, 2022 I appreciate your input here... I understand the complications and hope that the Babbitt design will work in my favor when dealing with these minor differences/adjustments... Another thought I had was to purchase another babbitted rod of the same size and just use the cap, thus compensating for some of the existing wear in the cap and hopefully remedying the situation... Quite frankly, I like that idea better than shaving the existing cap… Link to comment Share on other sites More sharing options...
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