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the '38 is comin' home this weekend, advice for checkup?


ZondaC12
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yup its registered and ill be bringing it home friday afternoon.

for one thing if anyone remembers ill be checking all of my bearing caps. recap--last year, light tapping sounding like valvetrain/lifter noise under load at lower rpms.

IF the bearings check out--what else could it be? I had a friend's father recently tell me hes "been inside those old things with the tiny pistons before" and they often "had problems with the wrist pins". is this at all likely?

also: when i tore down my 87 cougar's 302 v8 for some hopups this winter, the timing chain had at LEAST 1/2" of slack. 118000 mile engine, running very smooth no oil burning etc...

could this make a tapping noise in my buick? just checking all grounds.

back to wrist pins--how big of a job, also how expensive is it to replace them? is that all that's necessary? could i drive it around this year if they are going bad? ESSENTIALLY: if i check out my rod bearings and theyre all fine, can I drive my buick carefree all this summer? the nature of the driving would be like last year, VERY light throttle all the time, babying the heck out of it.

heres the second issue: every grease fitting on the driver side front suspension takes grease fine. one of the joints where grease oozes out from on the lower a-arm's connection to the spindle on the wheel hub does NOT ooze grease. there are two such joints, the rear one (furthest away from the actual grease fitting) doesnt ooze grease.

i think this is why i cannot push down the driver's side at all and i can easily with the pass side. i think this part is bound up. i dont want to drive this thing, forcing the components to flex with this thing bound up, killing this part. i was thinking id take it apart and clean it. can i rent/loan a compressor for the spring at Advance Auto/autozone/whatever? should i not even worry about this at all?

ive also never checked on my steering box. can i just put grease in there? if not what should i put in? i know this all may sound a little crazy to be doing all at once right now but on may 6th our chapter is caravanning to rhinebeck, about 2 hrs away and i want this thing to be ready for that, so it does not get ruined by it, and furthermore gotta have it for the rest of the summer!

Pauly

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To check your rod bearings, I would recommend the plastigage approach. I had an old timer friend who would use a small ball-peen hammer and tap the rod bearing cap side to side, listening for a particular tone. (it would move side to side, but not too easily - tight ones or loose ones sound different. Try it! That's how it was done.) When I went back in a second time however, I used plastigage and got better results.

I am assuming you have already checked your valve adjustment.

A bit of piston slap or wrist pin noise may be ok, if its very minimal. Hard to say without listening. What weight oil are you running? Might go to a heavier weight oil. If it reduces the noise, I would say the issue is minimal.

That lower bushing is no big deal to fix. Pull the drum, but leave the brake assembly together. Remove the backing plate and hang it from the shock with a coat hanger. Then you can assess the bushings. A little heat may free it up to remove, clean and inspect. Also check the zerk fitting itself. They plug up sometimes - just remove it and soak in some gas, then see if you can free up the check ball with a piece of wire. Come to think of it, check the zerk fitting first - if you can get some grease in there and get some little bit of movement, you may be able to just work it back in shape without disassembly.

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i have adjusted the valve lash. in fact i played around with that ALOT last year early on and got it just right, because even at idle it would make quite a bit of noise. its very nice now. i just run non-detergent 30 weight oil. thats what i was told to do. but after reading some heated discussions here recently it sounds like maybe i could switch to detergent so i could use different viscosities. so i think ill do that, and use a heavier one. any particular one you'd reccommend?

i attached a picture of what i think the setup of the control arm looks like, fuzzy memory of the specific setup but its gotta be something like that right? i marked where the grease does come out and doesnt. the zerk is not clogged up. just that one gap where the grease doesnt come out.

post-39688-143137932765_thumb.jpg

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You may have to order it but 40 weight is still available. A friend of mine gets it every year in two and a half gallon jugs for his antique engine display at the Rhinebeck Fair in August. Most of those early one lung engines just drip oil on the ground as everything is exposed. Also 50 weight racing oil is available in most part stores but I would not use it in cold weather. I would pull the oil plug, drain the motor, and then feel around the inside of the bottom of the pan to get an idea of how much sluge is in it. If it feels fairly clean then go ahead and use Detergent oil. If it is real nasty and thick then pull the pan and clean it before using detergent oil. Some of the old tractor engines that I have done work on have had inch of gunk in the bottom of the pan almost burying the oil pump screen. If the engines were not knocking I have just cleaned them out and also the valve cover and lifter cover and those internal parts. I have had some very good results useing Detergent oil in engines after doing this. There is a fellow on the Brass Buicks site, Harold Sharron, <img src="http://forums.aaca.org/images/graemlins/smile.gif" alt="" /> and he wrote a book " Understanding your Brass Car" <img src="http://forums.aaca.org/images/graemlins/ooo.gif" alt="" /> There is a very good chapter on the subject of oil. I have worked on stuff for more that 30 years and still learned things in that book. Much of the information is true with any automobile not just Brass era. Get a copy, The education is well worth the twenty something dollars he gets for it. <img src="http://forums.aaca.org/images/graemlins/smile.gif" alt="" /> Dave!

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Regarding the knock - if you haven't dropped the pan yet, go ahead and do it. You will need to lower (not remove) the front sway bar. Then drop the pan for a good cleaning. This was practically routine maintenance in the day. As Dave mentioned, you can find an amazing amount of sludge in the pan, often beginning to obstruct the oil pump pickup. With the pan off, you can adjust the rod bearings - another "practically" routine maintenance item. Once you remove the cap, you will find that there is a shim pack between cap and rod. If your plastigage check says you are too loose, remove a layer of shim. Take your pocket knife to the edge of the shim pack - you'll see its made up of 4 - 5 layers of perhaps 0.0005 or 0.001 thickness. Peel one off (one from each side), reassemble, and try the plastigage again. I don't recall the clearance you are after - is it 0.0015??? Check to be sure the babbitted bearing surfaces are in reasonable shape - they should not be crumbling away, but a minor flaw or two may be ok.

Regarding the oil, I have used 20W-50 on a trial basis, even starting it up in the winter (garage at about 45F). But 40W is a good recommendation also.

If you want to try to avoid taking apart the lower A arm bushings, try taking out the zerk fitting, then throw a little heat (just propane) on the bushing and pin, near where you have no grease coming out. Hopefully, you will soften and maybe liquify the caked up grease and some will flow out where the zerk fitting goes. Once it cools a bit, shoot some WD40 in there and let it sit. Maybe bounce up and down on the front bumper a bit. Then re-install the zerk and shoot some new grease in. If this doesn't work - disassemble.

By the way, please invest in a fire extinguisher (should keep one in the car anyway) and keep it nearby when you use the torch.

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first of all (should have mentioned this) i dropped and cleaned the pan before i ever started driving this car. yes there was about 3/4" of sludge. gave it a real thorough scrub-down, looked so much better afterward! before that i drained the oil, put new in and started it for the first time. i drained it again and it came out black. all summer i think i only changed it once after cleaning the pan, it stayed clean for a while, and is now. i also had to take out and clean th rocker shaft, was very full of sludge also. now the valvetrain area is very nice looking too.

if i find 40w ill go with it, if not 20w-50 it is. also ill have to get a "plastigauge" as im not sure we have one here.

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When I first picked up my 38-41 the engine had less than 70 lbs compression and smoked so bad that at a stop it would seep up into the interior from the vent at the lower left side of the block. I drove it this way for a year or so, over 500 miles and other than some overheating due to a clogged radiator it never left me stranded.

When I tore the engine down the pistons were so damaged that there were no compression rings in half the pistons (they were pulverized) and deep trenches in the top edges that corresponded to 1/8" wide burns on the cylinder walls. The oil pressure dropped to about 5 pounds at 50MPH when hot (I threw in a few cans of STP to get the pressure up). Even with all this the car ran reasonably well. So I would not worry about driving the car for a season with loose wrist pins.

Link to some engine photos:

http://demandred.dyndns.org/540i/gallery/album01

Steve D

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haha! thanks, thats good news! in fact my compression, when i tested it once i got it running, was about 105 lbs i think, and every cylinder had exactly that much.

some interesting pictures! tells you something about these engines, doesnt it, "still ran". <img src="http://forums.aaca.org/images/graemlins/cool.gif" alt="" />

and of course the happy pictures, of the restored engine. looks great! nothing like a clean new-looking engine bay!

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Plastigage is available at any auto parts store. It comes in different size ranges. If you want to measure 0.0005 to 0.003 for example, you buy the blue package (or whatever).

The gauge is really a thread of waxy plastic stuff. You lay a single strand in the bearing cap, then reassemble the cap to the rod. Take the bolt torque up to a reasonably high level (maybe 80% of spec) then disassemble again. The string is now squashed, and there is a scale on the package to read its width (widest point). This correlates to a clearance. Next rod, new piece of plastigage. The stuff is pretty accurate.

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plates came in the mail today, just in time for me to come home for the weekend. went over and brought her home. what a fun drive!!! it was a rush to be behind the wheel again.

got her up on jackstands, pan off this evening. surprise! about 1/4 inch of sludge at the lower area of it!!! <img src="http://forums.aaca.org/images/graemlins/mad.gif" alt="" />. i shouted something i wont repeat here. well maybe that was up inside the engine? well whatever the case im officially chaning the oil like every two weeks this year. i do NOT want SLUDGE in this thing! i dont CARE about the cost, its not that bad. everyone says dont judge by the oil darkness. well screw that. it cant hurt the engine can it? (can it? i will do NOTHING that will cause harm) but if it only hurts my wallet that little bit more, then its every two weeks. real easy, pull the plug, wait, put plug in, pour in new stuff.

ANYWAY. i waited too long, so advance was closed when it occured to me that i needed a plastigage. oops. but i took off the rod cap from rod #2 (from the firewall). looked perfect. put some oil on it, ran my finger over it, very slippery. same with the journal. cant get the rod off though, even with the spark plug out. wont budge. please tell me all i gotta look at is the caps!!! <img src="http://forums.aaca.org/images/graemlins/laugh.gif" alt="" />

so plan is tomorrow morning ima get my plastigage and go right on through checking each rod. ill report. oh yeah camshaft looked good too. touched a couple lobes, felt smooth and slippery like the rod and journal.

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ok sorry for the delay just didnt get around to posting this!

first of all the sludge wasnt that bad i just didnt see it right, partly because some oil that didnt drain out was sitting on top. but i still cleaned it out like before, and im still going to change the oil like every three weeks.

now onto the rods: numbers 3,4 and 6 were the only ones that werent so good. ("1" being right at the firewall) the rest--the cap looked a dull gray, entire surface was even, kind of felt like a sharpening stone, but smearing some oil on and running my finger over it it felt very slippery. the corresponding journals were nice and shiny and smooth.

3,4, and 6 had a small groove exactly in the middle, kind of like something i saw on an insert bearing once, i think they have a groove machined in to carry oil right? thats what this looked like. 6's groove was about half as wide as the other two and they were about 1/16 of an inch wide. the rest of the surface looked like all the other ones though. the corresponding journals also had something in the middle--a brown stripe that looked to be just as wide. ive got no idea what this means. i attached a photo of the stripe.

once reassembled, there was no result. driving the car it sounded exactly the same. but, i did some careful observation, and standing next to the car with the hood up, and wacking the throttle a little, there was a tap or two right after i did it. kind of sporadic and spontaneous. sounding like someone hit the valve cover with a hammer. i listened close with my ear right near the cover and i swear it was right there. its a hollow cover, so i would guess noise would resonate in there. driving the car, i heard the exact same noise under load at lower rpms. if anyone still thinks ive got a bigger problem please speak up but all i know is what i heard and im going to try adjusting the valve lash on all of em.

im back at school now but on wednesday i have my last classes of this year, and ill be saying hello to a 4 month summer! so ill update then or the next day after i play around with the valve adjustment.

post-39688-143137932768_thumb.jpg

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Your main concern with the bearing surfaces are things that run across the bearing (like front to rear on the vehicle). Anything that's radial is less of a concern, as it won't contribute to loss of pressure. The grooves may be intentional, I don't recall. Its possible that your car has a mix of original and later rods and caps. That brown stripe looks like it simply corresponds to the groove in the bearing, if so its probably just some baked on oil residue.

How much shim was left in the shim pack between rod and cap (for each rod)? This is an indication of how much babbited bearing material you have left. What did your Plastigage results show?

Jeff

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well i probably should have written each reading down...sorry. but in all of them there were two shims on each side. maybe in one of them there was only one shim per side. gaaah see like i said i dont totally remember i should have taken note of it but i think there were two on each side for every rod.

most of them i had to remove one set of shims to get the clearance right, so that would mean the typical reading was 2 mils of clearance. i think one or two had 3 mils.

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Hi Paul. Just a quick compliment on your car - I had a chance to see it Sunday at Rhinebeck, and visit for a moment with your grandfather. It looks great - esp. under the hood. The color sets it off as well. Hope you had a smooth run down and back.

We had a slight issue with one of our dogs, turned out OK but Friday she decided to destroy a glass cake pan and we were not sure if she ate any glass with the cake.. So I did not have time to prep the car for a two hour drive each way since we have only driven it around the neighborhood so far this spring - but the show was pretty good anyway!

Steve

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well thank you very much! i cant believe i forgot to come look at your car! i actually had a whole bunch of people i was hoping to run into, and i found some windsheild wipers in the swap meet, boy i was all over the place!

though, as you said, the car didnt make it anyway! hope your doggy is okay!!! <img src="http://forums.aaca.org/images/graemlins/crazy.gif" alt="" /> what're you gonna do? pets seem to do that best--make messes!

and yes she ran great both ways! definitely was a smart move to put actual rubber fuel line in to replace that old thin plastic stuff, and route it away from heat sources! this time it wasnt a bucking bronco all the way home like last year

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Zonda, Good to see you at Rhinebeck with the 38. You should really consider keeping some of your dads micrometers and learn how to read them. They are very useful when doing crankshaft and bearing work as you can see how much a crank is worn, or see if it has been turned undersize at some point in its life. I use mine all the time when doing engine work. Shims come in different thickness and there is nothing like a mic to see exactly what you are dealing with. Great for checking valve stems and wrist pins and a whole variety of stuff. After hearing the car and that tapping noise I do belive that it is a wrist pin also. When you had the pan down you could have rocked the crank while looking up in the pistons to see which one seems to be looser than the others. Good talking with you over the weekend, <img src="http://forums.aaca.org/images/graemlins/smile.gif" alt="" /> Dave!

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