Need information on rebuilding A Engine

50Trucking

50Trucking

Member
Recently purchased a 28 Tudor that had been setting for 25 years. I rebuilt the carburetor, distributor, belts etc and it cranked and ran fine. It burns no oil, does not smoke or run hot. I took it on a 50 mile trip and it started knocking. I live near St. Augustine Florida. I need information on sourcing parts for the rebuild and where to get the rods and block re-babbitted or inserts put in. Possibly someone to do the complete build.
 
Knocking can come from a variety of sources. First thing to check are the bearings. Take the engine out of the car after draining the oil. You can rent or borrow a hoist or rig a come-a-long from a rafter or overhead A frame. Put the engine on an engine stand and turn it over. Remove the pan. Mark the rod and main bearings so that they can go back in the same location. Remove one bearing cap at a time and look at the Babbett. If it is not cracked or missing pieces and looks good you can remove one shim at a time, alternating sides, until the crank is hard to turn and then put one shim back. The shims are laminated so that you can peal off a thin shim one at a time.

There are many ways to measure the clearance in the bearing beside the method above. You can use a thin piece of paper in the bearing and if the crank is hard to turn with the paper in and not with it out, then you have the right number of shims. You can also use Plastigauge. The vendors have that and also all the parts for your engine that you may need. I use Snyders.

A knock can also come from a loose or broken cam timing gear. When you have the pan off check to see if the fiber gear is loose or missing teeth or is very worn. Most people replace the fiber gear with an aluminum one.

If the engine is kissed and not worth rebuilding, you can buy a Burtz block. It comes with the crankshaft and rods. This is a good choice if you will be driving your car a lot. Another option is to look around for a used engine that is in good shape.
 
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DON'T jump to conclusions. A knock does NOT necessarily mean a rebuild. No reason to pull the engine. Pull off the timing gear cover, then valve cover, then the oil pan. Check as you go. Most the answers you get here are going to be jumping to worse case. Methodical troubleshooting is always the best deal. Are you sure you lubed everything? 25 years is a long time to sit dry. Also, is the timing gear ok? Verify, verify, verify.
 
Generally I've found that a severely worn engine has a sort of "whuppa-whuppa" sound. Still very driveable and actually less noisy at speed.

My singular experience with a "knock" was my previously mentioned loss of one of the connecting rod nuts - which occurred primarily because the crankpin was so "egg-shaped" - and I had pushed the envelope trying to tighten the engine.

Loss of the cotter pin didn't help.

This while I was traveling about 50 on Cape Cod's "Mid Cape Highway" in the middle of weekend vacation traffic. Pull over to the edge and motor the break-down lane until I came to the next exit - then baby the car home on the backroads. Below about 30 it was very driveable, but noisy. I found the nut and the broken cotter pin in the bottom of the oil pan.

I would drop the oil pan and take a look.

Replacing about four oil pan bolts with allen head bolts make diagnostic drops easier with a hex extension.

Joe K
 
Eagle has some very good advice.
Get a mechanics stethoscope and do some listening to see if you can narrow down where the knock is coming from. A loose timing gear can make it sound like the engine is on its last leg when it is actually not.
 
If it turns out that your engine needs rebuilding, get it done by a professional shop, and have the engine equipped with insert bearings instead of Babbitt.
 
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