plastigauge

[ElGranadaT]

Its the weekend, time to get greasy...

I have an engine knock on my 22T- so I pulled each plug wires individually and seems like its coming from No. 1. So, I pulled the pan and I'm using plastigague to check the clearance. First pass came with no deformation at all, so I know the gap is greater than 0.003 in.

I measured the shims and they were 0.140 in. on the left side bolt and 0.120 in. on the right side. Stupid question, but It seems like both sides should be of equal thickness but I am not sure - is this a common thing? I did buy new peelable shims and plan to use those along with the original - as I work my way to number 4.

As for clearance; I searched the site but couldn't seem to find a spec for the best fit. Is it 0.001 in? Some say just see if the engine cranks at all... and tweak as necessary...

Thanks again and hope you're having a good weekend

[Rich P. Bingham]

Rod clearance should be .0015”. In my experience, plastigage is of minimal utility when re-fitting worn parts. Old timers (I’m one) liked to fit up with newspaper, to where the rod binds with a wrap of paper. Brass shim stock is a better choice. We OCD types would like to see equal shims on both sides of the cap, but a very few thousandths difference is of no importance. What counts is the bearing fit !

If #1 rod is wearing, now is a good time to make sure you have positive oil return to the front end. Perhaps need to blow out the oil return pipe by removing the timing cover.

[Mr man]

The model T restorers book from the MTFCA says clearance for connecting rod caps should be .001 to .0015. Seems odd that your shims are different. Maybe it was supposed to be a temporary fix?

[ElGranadaT]

Perfect! THANK YOU !

0.0015 it shall be-

and 100% agree on the oil tube - I live on a steep hill and it takes a good 5 minutes in low gear at maybe 5 mph to get home, so I also bought the Model T Crankcase Outside Oil Line Kit from Ecklers. that's next.

[Dan Hatch]

The Service Manual tells how to adjust the rods and the mains too.
If you don’t have one you need to get one.

[Kerry]

No set rule on what thickness shim to have in a rebuilt rod (Ford never used rod shims in new engines) it was as simple as crabbing 2 shims and machining the babbitt. I have a few boxes of aftermarket shims dating back to 1910 for replacing what might have been filed of the cap, the shims vary in a few thou in thickness.

[Norman Kling]

Be sure to measure the crankshaft. It must be round or the bearing will still knock.
Norm

[BobUkPipedream]

Those peelable shims, I had no idea they were. I received them and thought ‘what the hell is the point of these, they are way to thick…’ Took me some time to realise.

I did mine all to 0.0015, but that was whilst rebuilding. I guess when taking up a rod, you need to go tighter and then it will wear to a round clearance? I hoping not to need to know the answer to this for many years…

[ABoer]

Rich P.
The news paper , must that be all around , or just the cap .
Toon

[Rich P. Bingham]

Toon, just the cap. If you have a dial caliper, it’s a good idea to measure the paper to be sure ! Brass shim stock is better, but paper is amazingly regular. If you “paper” the circumference of the journal, you have .003” clearance. (that’s on the outside of permissible tolerance).

Bob UK, it’s best to set up at .0015” in every case. Don’t set clearance too tight !

[ElGranadaT]

Good feedback and ideas!

[ElGranadaT]

Closing up this case -

Thanks to all for the help with plastigauge- By no. 4 connecting rod it I think I finally got the rhythm down... but overall It's a good day's job.

The engine knocking ended up being worn no. 1 and 2 connecting rod bearings, probably due to oil starvation while climbing our hill.
No. 1 was a bit over 0.003 in - no 2 about 0.002 - 3 and 4 were also a bit off- but less than 0.002 to start-
Took all down to 0.0015 - A bit stiff on turning but should break in - Didn't really want to dive into the mains until I first tried the
connecting rods.

While there I added an auxiliary oil feed line. Fingers crossed - but hard to know if it really makes a difference without somehow
seeing evidence of a flow - but others swear by it - and it was a snap to install. Regrettably, I couldn't check the flywheel pick up scupper
without pulling the hogshead -and I'm pretty lazy -

Does anyone have an easy way to either blow that out or get to it?

[Dan Hatch]

Once again the service manual has the answer to the oil line.

[Norman Kling]

`Depending on what kind of outside oil line you placed, if it goes right to the front of the crankcase, you can remove one of the front bolts from the inspection plate underneath nearest the oil line and with the engine running, some oil should come out. When done with this test, be sure to replace and tighten the bolt.
Norm

[BobUkPipedream]

I made my own outside oil line - the high capacity one from hogshead to front of sump. It’s 3/8 stainless steel I used for the fittings and some clear tube for the hose. It does send a lot of oil down there… anyway one way to verify is have a bit of clear tube. I am tempted to put a filter in line.

[ElGranadaT]

I used the ECKLERS Model T Crankcase Outside Oil Line Kit Accessory, 1909-1925 - $49.99. Looks like the same one from the other suppliers but half the cost.