CA knocking but it can't come in

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I'm in the process of setting my CA up for front snowblower and rear blade for the coming winter.I've had a come and go knock in the engine that worries me. 
The last time I had a knock and didn't let it worry me I threw a Rod through the block.
This knock is coming from the engine I rebuilt (or reassembled) to replace the one with the hole in the side of the block, oh, about 8 years ago.
The CA hasn't seen much use but every time I have used it I get a knock that comes and goes.  The knock will actually lessen as I put the tractor under load and almost disappear!
Anyway, I dropped the pan and looked for missing or loose rod nuts or anything else I could get some movement out of indicating excess clearance. I found nothing and remembered I had rebuilt this engine so there couldn't be anything wrong (cough, choke).
Just looking for any ideas and wondering if a governor weight or some thing else could be the cause.
Incidentally the only similarity between my CA and Mike Noonans is the extreme narrow track of the rear spin out wheels!

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SteveC(NS) Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 12 Oct 2009 Location: Nova Scotia Points: 663	Post Options Post Reply Quote SteveC(NS) Report Post Thanks(0) Quote Reply Topic: CA knocking but it can't come in Posted: 14 Sep 2011 at 1:15pm
	I'm in the process of setting my CA up for front snowblower and rear blade for the coming winter. I've had a come and go knock in the engine that worries me. The last time I had a knock and didn't let it worry me I threw a Rod through the block. This knock is coming from the engine I rebuilt (or reassembled) to replace the one with the hole in the side of the block, oh, about 8 years ago. The CA hasn't seen much use but every time I have used it I get a knock that comes and goes. The knock will actually lessen as I put the tractor under load and almost disappear! Anyway, I dropped the pan and looked for missing or loose rod nuts or anything else I could get some movement out of indicating excess clearance. I found nothing and remembered I had rebuilt this engine so there couldn't be anything wrong (cough, choke). Just looking for any ideas and wondering if a governor weight or some thing else could be the cause. Incidentally the only similarity between my CA and Mike Noonans is the extreme narrow track of the rear spin out wheels!

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427435 Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 18 Nov 2010 Location: SE Minnesota Points: 18637	Post Options Post Reply Quote 427435 Report Post Thanks(0) Quote Reply Posted: 14 Sep 2011 at 1:19pm
	You might try using a mechanics stethoscope to try and pinpoint the location of the noise. I've also used a length of 1/4" ID hose, with one end in my ear, to isolate noise sources.
	Mark B10 Allis, 917 Allis, 7116 Simplicity, 7790 Simplicity Diesel, GTH-L Simplicity Ignorance is curable-----stupidity is not.

Dakota Dave Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 12 Sep 2009 Location: ND Points: 3968	Post Options Post Reply Quote Dakota Dave Report Post Thanks(0) Quote Reply Posted: 14 Sep 2011 at 1:25pm
	take it apart and look for a busted skirt up by the wristpin.

SteveC(NS) Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 12 Oct 2009 Location: Nova Scotia Points: 663	Post Options Post Reply Quote SteveC(NS) Report Post Thanks(0) Quote Reply Posted: 14 Sep 2011 at 2:33pm
	Dave, would such a crack be visible from below? I really don't want to tear this engine down, it looks gorgeous from underneath, doesn't lack power and starts like it's anxious to work. I have a running replacement waiting in the wings if it does blow but I'd rather not be breaking any more cast iron. Mark, when and if I put the pan back on I'll try the stethoscope. Any opinions on the worth of looking under the valve cover, it could have been a half speed knock.

Walker Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Access Joined: 12 Sep 2009 Location: oh Points: 8830	Post Options Post Reply Quote Walker Report Post Thanks(0) Quote Reply Posted: 14 Sep 2011 at 2:46pm
	Rod bearings will make the noise you describe. Under load they will quit knocking. I'd get in there with some Plasti Gage and check them very soon. Blocks ain't very pretty with rods sticking out the side of them.

GregLawlerMinn Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 11 Sep 2009 Location: Lawler, Mn Points: 1226	Post Options Post Reply Quote GregLawlerMinn Report Post Thanks(0) Quote Reply Posted: 14 Sep 2011 at 2:54pm
	You should also check out the thrust bearing. The front main has a "lip" that prevents the crank from moving back and forth; if it does, you will hear "knock" as the engine loads and unloads. Sounds like a loose main bearing, but not as steady.
	What this country needs is more unemployed politicians-and lawyers. Currently have: 1 D14 and a D15S2. With new owners: 2Bs,9CAs,1WD,2 D12s,5D14s,3D15S2s, 2D17SIVs,D17D,1D19D;1 Unstyled WC

SteveC(NS) Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 12 Oct 2009 Location: Nova Scotia Points: 663	Post Options Post Reply Quote SteveC(NS) Report Post Thanks(0) Quote Reply Posted: 14 Sep 2011 at 7:09pm
	Well, I guess it's gotta come out. Since I gotta remove the sheet metal and valve cover to get me some lift points I'll take a peek at the valve train. Walker, I don't wanna plastigage and de-shim etc. under the tractor (I'm too old) so , it'll be a bench rebuild. I have 2 reground cranks complete with inserts in "inventory" so I figure that's the way to go. Greg, I'll sure take a look at the thrust play when it's on the bench/engine stand. In the meantime, I'll stuff in the spare engine I have that seems pretty good and give it a test this winter. Thanks guys, I'll be back to you with progress. Steve

Walker Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Access Joined: 12 Sep 2009 Location: oh Points: 8830	Post Options Post Reply Quote Walker Report Post Thanks(0) Quote Reply Posted: 14 Sep 2011 at 7:17pm
	I'm old also, but never turn your back on me. I'll grab one of your reground cranks and disappear in an instant.

Leon B MO Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 12 Sep 2009 Location: Old Monroe, Mo Points: 2180	Post Options Post Reply Quote Leon B MO Report Post Thanks(0) Quote Reply Posted: 14 Sep 2011 at 7:42pm
	Couple years back I had a "small knock" too, the last time it started, it was just sitting there idiling, warming up. The #2 rod broke in half and made lots of noise. You know it's time for some work it just depends on how far do you let it go. Good luck. Leon B Mo
	Uncle always said "Fill the back of the shovel and the front will take care of itself".

CTuckerNWIL Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 11 Sep 2009 Location: NW Illinois Points: 22824	Post Options Post Reply Quote CTuckerNWIL Report Post Thanks(0) Quote Reply Posted: 14 Sep 2011 at 8:12pm
	My CA started with an on again off again Knock. It took me a while to figure it out cause I couldn't get the location using a big screw driver for a stethoscope. Anyway, someone on here suggested checking the front crank pulley because if the setscrew gets loose it will cause a knocking similar to a bottom end knock. When I checked the pulley it mover for and aft about .090 of an inch but the crank went with it. She's setting waiting for a rebuild now cause I don't have a reground crank on the shelf. LOL It needs sleeves and pistons too so when I get my spare crank ground, I will tear into it.
	http://www.ae-ta.com Lena 1935 WC12xxx, Willie 1951 CA6xx Dad bought new, 1954WD45 PS, 1960 D17 NF

SteveC(NS) Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 12 Oct 2009 Location: Nova Scotia Points: 663	Post Options Post Reply Quote SteveC(NS) Report Post Thanks(0) Quote Reply Posted: 15 Sep 2011 at 1:10pm
	OK, I guess I better Fess up. I have two reground cranks & bearings because I'm dumb. when I got the first crank ground I ordered the bearings from somebody else. The crank came back 30 thou under but the bearings I got were 20 thou. In the mean time I got the idea to get another crank i had stroked so I asked for 1/16 stroke at 20 thou under. When I picked the stroker the guy said "all I had was std. bearings so seeing I had to build up the throws I bulit up the mains too, so there all std, no extra charge. Now I've got 2 ground cranks and only the stroker has brgs. so I had another crank and decided to get it done 20 thou under and ordered 30 thou under inserts for it. Well, obviously the stroker went into the then project and the other cranks went on the shelf. Back to the stroker crank you ask?, it seems there was a bit of confusion as to 1/16 stroke. He understood 1/16 throw, so I ended up with a crank that gave me 1/8" stroke! I had to machine my head to accomodate the rise of the piston beyond the gasket. Starting seems hard, I don't know if it's all increased compression or poor amperage delivery. That project got stalled due to my move from Ont. to N.S. it's an IB conversion and I hope to get back to it soon.