Daves1940Buick56S Posted June 2, 2014 Share Posted June 2, 2014 All, but especially for Mark Shaw:I am doing the rings and checking the conn rod bearing clearances with plastigauge as I go along. The bearings all had either 2 or 3 shims per side on disassembly, and I am thinking I am the first one to look at these since 1940 with the other evidence I am seeing. With the shims in they were way over, about 0.003" or more. So on #5 I pulled all of the shims off and I get abt 0.0015" on the plastigauge. #4 was a bit tighter, more towards less than 0.001" so I left 1 shim in on each side. I intend to do them all this way, checking as I go and more than likely pulling all or most of the shims. Am I doing this correctly? Certainly don't want a thrown rod after all of this work...Cheers, Dave Link to comment Share on other sites More sharing options...
carlisle1926 Posted June 3, 2014 Share Posted June 3, 2014 Add/ remove shims until you get the correct tolerances. It is not uncommon to have more shims on one side of a rod than the other, but it is best to try to keep the number of shims per side as close to equal as possible. It is usually not good to have 5 shims on the left and 0 on the right. Each time you add or remove a shim, a piece of plastigauge has to be inserted under the rod cap and then the rod cap has to be torqued back down. Then remove the rod cap again to see how much the plastigauge crushed down. Adjust the number of shims again and repeat the process until the gap is correct. Link to comment Share on other sites More sharing options...
Mark Shaw Posted June 3, 2014 Share Posted June 3, 2014 0.002 is acceptable.... Check to make sure the crank journal is still smooth & round and the Babbitt is smooth & not scored or chipped. Try to keep the same shim thickness on both sides of the bearing caps as advised above. Don't forget to add some assembly lube before you finish each bearing. Link to comment Share on other sites More sharing options...
Tom_S Posted June 3, 2014 Share Posted June 3, 2014 Dave,You doing this with engine out of the car?Thanks,Tom Link to comment Share on other sites More sharing options...
Daves1940Buick56S Posted June 3, 2014 Author Share Posted June 3, 2014 Jason and Mark: Thanks! My target of "good enough" is abt 0.0015" on the plastigauge but if it's closer to 0.002" I'll take it. So far all have been smooth but one - it had a shallow score but the journal was clean - must have been something that got caught in there at one point. Anyhow, since I don't have any room to remove any surface I left it be. And I am definitely using the assembly goo on each one.Tom: Unfortunately, engine in the car. Not fun.Cheers, Dave Link to comment Share on other sites More sharing options...
DonMicheletti Posted June 3, 2014 Share Posted June 3, 2014 It is a good idea to rotate the engine at least 1 turn as you set the clearances on each bearing. Sometimes the journal could be out of round enough to cause binding. If you rotate each time you'll know if you have a problem. If you do the whole engine and then have binding, you wont know which one might be a problem.Obviously you have to rotate the crank some to get the throws in the right place to do the job, but going through a whole rotation insures all is OK.Cheap insurance.Don Link to comment Share on other sites More sharing options...
jeff Posted June 3, 2014 Share Posted June 3, 2014 It is a good idea to rotate the engine at least 1 turn as you set the clearances on each bearing. Sometimes the journal could be out of round enough to cause binding. If you rotate each time you'll know if you have a problem. If you do the whole engine and then have binding, you wont know which one might be a problem.Obviously you have to rotate the crank some to get the throws in the right place to do the job, but going through a whole rotation insures all is OK.Cheap insurance.DonI agree with Don. The other suggestion that may keep you out of trouble is to "shim to the high spot". In other words, if your journal is not consistent you will end up with Plastigage that is not evenly crushed. You need to go with the widest reading of the Plastigage. Jeff Link to comment Share on other sites More sharing options...
herm111 Posted June 8, 2014 Share Posted June 8, 2014 (edited) Clearance on bearings should be set an .001 thousandths per inch of crank. You didn't say what size your crank was, but, a two inch crank pin should have .002 thousandths, no matter what engine, and that would be Minimum, or Plus .000-50 thousandths Maximum!Don't forget to oil the Plastigage, and always Mic the crank Pin so you know adjustment would be even plausible.Herm. Edited June 8, 2014 by herm111 (see edit history) Link to comment Share on other sites More sharing options...
Daves1940Buick56S Posted June 8, 2014 Author Share Posted June 8, 2014 Herm:Thanks! I ended up adjusting to the loose side of the tolerance on the high spot. IOW the spec is 0.0008" to about 0.002". I am leaving it close to 0.002", which is 1 shim per side on all but cyl 8, that one is 2 shims/side. All of this was done with the cranks abt 30 degrees BTDC as suggested in the shop manl. Originally they had either 2 or 3 shims/side, and I am pretty convinced that was the factory adjustment. I turned over the engine a couple of revs by hand and there are no apparent sticking parts, although the effort is greater since we replaced the rings. After we get the pan back on, will do a spinnup with the starter to make sure I get good oil pressure before we take it off the blocks and put the head back on.Cheers, Dave Link to comment Share on other sites More sharing options...
herm111 Posted June 9, 2014 Share Posted June 9, 2014 Herm:Thanks! I ended up adjusting to the loose side of the tolerance on the high spot. IOW the spec is 0.0008" to about 0.002". I am leaving it close to 0.002", which is 1 shim per side on all but cyl 8, that one is 2 shims/side. All of this was done with the cranks abt 30 degrees BTDC as suggested in the shop manl. Originally they had either 2 or 3 shims/side, and I am pretty convinced that was the factory adjustment. I turned over the engine a couple of revs by hand and there are no apparent sticking parts, although the effort is greater since we replaced the rings. After we get the pan back on, will do a spinnup with the starter to make sure I get good oil pressure before we take it off the blocks and put the head back on.Cheers, DaveYour Rods did have .006 thousandths shim on either side, 3 pieces of .002.All bearing books have a low, and a high number to work with.They will say from .000-50 to .003-50, and others, on different types of bearings, but that is because there are many different situations under which a bearing has to be, or can be, fit.Herm.Here are some 1936 Buick 40 series, 233 C.I.D. Rods, and Mains we Rebuilt. Link to comment Share on other sites More sharing options...
Daves1940Buick56S Posted June 9, 2014 Author Share Posted June 9, 2014 Herm:Interesting. So someone at some point pulled out a shim on each (they all had 5; 2 on one side, 3 on the other). It had to have been at least 30 or 40 years ago from the condition of the crankcase bottom. Now there are 2 on each except cyl 8.BTW, nice work. If I were doing a total ground up restore I would have had you rebabbitt the rods and gotten new mains. Maybe the next owner.Cheers, Dave Link to comment Share on other sites More sharing options...
trp3141592 Posted June 9, 2014 Share Posted June 9, 2014 Hi,I thought Buick rod bearings were cast-in place Babbitt? Apparently not. So what's the switch to "insert" rod bearings in about 1948? What's the difference in before-insert and after-insert?--Tom Link to comment Share on other sites More sharing options...
herm111 Posted June 9, 2014 Share Posted June 9, 2014 Hi,Tom, yes, Buick rods were cast in Babbitt untill some time in 1947 when they changed over to inserts.The motor Number was 4918702, and up to engine 4919898, in 1947.So what's the switch to "insert" rod bearings in about 1948? What's the difference in before-insert and after-insert? "END QUOTE"Tom, I am not sure what your asking here? Link to comment Share on other sites More sharing options...
trp3141592 Posted June 9, 2014 Share Posted June 9, 2014 Hi,I was confused about the cast babbitt bearings and inserts that are lined with babbitt. Your response cleared it up for me. Thank you.--Tom Link to comment Share on other sites More sharing options...
MrEarl Posted June 24, 2014 Share Posted June 24, 2014 Any further progress on this Dave. Please keep us posted. Link to comment Share on other sites More sharing options...
Daves1940Buick56S Posted June 25, 2014 Author Share Posted June 25, 2014 Yep - pan back on last week. Put oil in and 2 days ago I pulled the distributor and put a screwdriver attachment on a drill (you need abt 6" out of the chuck to fit down there comfortably). Spun it up to abt 100 rpm and got abt 10 lbs pressure. Spun to abt 250 rpm and got about 20 lbs. Called it good. Yesterday I put the cylinder head and manifold back on. Cylinder head was a bit of a pain due to lack of locator pins on these old engines. After maneuvering the head in place we used 2 - 2x4s across the fenders and ropes and lifted the head up abt an inch - enough to get the head gasket in place and start the bolts. After torquing down the head we put on my "new" manifold as per Ken Sogge's procedure. Tomorrow I put the rest of the engine together, hopefully to start on Friday.Cheers, Dave Link to comment Share on other sites More sharing options...
DonMicheletti Posted June 25, 2014 Share Posted June 25, 2014 I use 2 extra headbolts with the heads cut off and screwdriver slots sawed into the top as alignment pins. Once these "alignment pins" are screwed into the block You can safely put the head gasket and head on without much trouble. Once a few head bolts are started you can use a screwdriver to take the "alignment pins" out. 1 Link to comment Share on other sites More sharing options...
trp3141592 Posted June 25, 2014 Share Posted June 25, 2014 HI,I use 2 extra headbolts with the heads cut off and screwdriver slots sawed into the top as alignment pins. Once these "alignment pins" are screwed into the block You can safely put the head gasket and head on without much trouble. Once a few head bolts are started you can use a screwdriver to take the "alignment pins" out.I have done the same thing with cut-off bolts to act as guides when installing the wheels on the Cord and the Buick. Both cars use lug bolts and do not have studs to support the wheel when installing it.Man, does it make it easier to have two guide pins! I keep a set stored with the spare tire.--Tom Link to comment Share on other sites More sharing options...
Daves1940Buick56S Posted June 25, 2014 Author Share Posted June 25, 2014 Don and Tom: Yeah, I should have made and used guide pins, but 1) no bolt stock available to use and 2) that would make too much sense! So I had to do it the hard way. Notice how I am making use of my Engineering books since I retired!Cheers, Dave Link to comment Share on other sites More sharing options...
Daves1940Buick56S Posted June 29, 2014 Author Share Posted June 29, 2014 Update: As I said in the motor thread, I got it running yesterday afternoon. The valves need tightening but right now it absolutely purrs, and the vac gauge shows rock steady at 20 inches at abt 400 rpm. Oil pressure still seems low even after the work I did on the pump and tightening up on the connecting rod bearings. I have 10W-40 in there now, I might have to go back to 20W-50. I will put a more accurate gauge on there today and see where I am.Cheers, Dave Link to comment Share on other sites More sharing options...
DonMicheletti Posted June 29, 2014 Share Posted June 29, 2014 If you have 20 psi at idle I wouldnt worry. Buicks are nortorious for low idle oil pressure. I have seen some old Buicks that run fine with almost nothing showing on the gage at idle when warm. It will be interesting to know what you have with warm oil at driving speeds. Another possible contributor to low oil pressure is worn cam bearings - not as easy to fix.Did you check the main bearing clearances too? They have to be right also - kind of water under the bridge now at this point. Link to comment Share on other sites More sharing options...
dibarlaw Posted June 30, 2014 Share Posted June 30, 2014 Dave: I did "plastigage" my mains and rod bearings on my 37 248 cu. Took out 2 shims at most to bring it back to spec. Also rebuilt the oil pump with new gears. My pressure runs around 45lbs. I am running 10W-40. The only time it dropped below 20lbs was when I was on the return leg from South Bend last year and drove continuously for about 7 hours in 90 plus heat. After a 120 mile trip yesterday it was the same at around 40lbs. Has 106,242 miles now. Larry Link to comment Share on other sites More sharing options...
Daves1940Buick56S Posted June 30, 2014 Author Share Posted June 30, 2014 Larry, Don: I put a more accurate oil gauge on it today. Cold: 20 lbs idle, abt 40 lbs at 1500 rpmHot: 12 to 15 lbs idle, 25 to 30 lbs at 1500 rpmI was hoping for better, especially after carefully sealing the oil pump cover. The gears had only about 0.001" clearance so that was very good, spec is 0.004" or less. I also put in a small spacer on the reg spring. So my guess is loose mains. Rats! If I go back to 20W-50 that should bring it up a few lbs.Cheers, Dave Link to comment Share on other sites More sharing options...
DonMicheletti Posted June 30, 2014 Share Posted June 30, 2014 It will be interesting to see what the heavier oil will do.Will the oil pressure get above 30 psi at all when warm and at higher speeds? Link to comment Share on other sites More sharing options...
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