MTFCA Forum

So, I lost the brass shims for one of my connecting rods while taking apart my motor several months ago. I ordered a set of new ones, but they are way too thick and the clearance is much more than it should be. The plastigauge was hardly phased after I tightened down my cap when I was checking it. I also tried putting the cap on with no shim to see if it would be within spec. It didn't look good either.

Here's a picture after I put the cap on with no shims The shims that were in my motor (and still are on the rest of the rods) are clearly much thinner than the repros I bought from langs. The repro ones are .003

Is there a way I could file the shims down to fit, or another way I could fix this? Thanks in advance

Some shims are "peelable", that is, they are made of several very thin shims glued together. You can carefully peel off layers to get the correct fit. You have to be careful not to bend the shims. They need to stay flat.

I don't think you could get good results trying to file or sand down a shim.

I agree with Pat. Also I like to keep the old shims from my engines when I work on them. Usually if you have done a number of engines several times, you will acquire a collection of shims in various thicknesses so you can stack them to give the correct fit.
Norm

Carson - do you always use the metric system of measurement ? You are attempting to get the clearance between .001 - .0015 thousands. I have an envelope of used shims from other engines - be glad to send you an assortment in an envelope !

Heat the shim stack with a lighter. The layers will separate for easy removal. It is not a solid piece.

RajoRacer wrote: ↑

Tue Aug 01, 2023 10:06 pm

Carson - do you always use the metric system of measurement ? You are attempting to get the clearance between .001 - .0015 thousands. I have an envelope of used shims from other engines - be glad to send you an assortment in an envelope !

Turn the paper sleeve over for English readings.

I've been making my own shims for years, because what's available doesn't do the job. The .003" shims are fine, but I've had to make .002" and .001" shims to get the job done. I've also had to do the same thing for the mains.

Thank you guys. I decided I'd try to find something that would work to make my own shim before I get some used ones.

I figured out this aluminum can that held my soda was almost the perfect thickness when I doubled the thickness, so I cut a model of a shim. Do you guys think this will work? Or should the shim be made of brass?

Aluminum is fine..

Soda Can... Beer Can.. Aluminum Foil.. Used all of them..

Cap

I found news paper in one once? I don't recomend it but it worked.
Craig.

Craig Leach wrote: ↑

Tue Aug 08, 2023 10:58 am

I found news paper in one once? I don't recomend it but it worked.
Craig.

It must have been "hard news", not that fluff on the back pages

T Fords never left the factory with metal shims in the rods, parts supplied rods had a paper shim called a broaching shim and was .003" thick that could be removed, then the filing of the cap was the way for adjustment.

I just checked McMaster Carr. They have what you need in steel or brass. .001"-.003".