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The Turnpike Cruiser, better known as Wilma’s ’31 Model 42 is in the shop (my garage) for an engine job. We’ve been nursing it along since the Williamstown meet and we plan to drive it next to Warwick in order to get a 1000 mile award for it.
I removed the rods last night. Guess how many of the rod bearings fell apart when I removed the bearing caps. ALL OF THEM! We drove to Fairfield and back (as well as Kalamazoo) on those bearings.
I’m often amazed at how these engines will run without the classic rod knock sound when they are on their last legs. Considering that Model 42 blocks are made of unobtanium, I’m extremely grateful that we caught the problem before something “really bad”” happened to the engine.
I’ll report back as we get deeper into the engine.
Bill”
The big question, is what is the condition of the cylinder that was pumping oil and fouling it’s spark plug? Stuck rings? scored bore? broken piston?
For as much oil that that cylinder consumed, there must be a pretty obvious ‘smoking gun’.
Greg
Did you take a few photos of the cracked, falling apart rod bearings, to share with us??
Greg
I’ll get the photos tonight.
Number 4 was the oil thrower. No broken ring, no gouge in the bore unless it’s way down in the bottom and I didn’t spot it. These were definitely old but not OEM pistons. They were knurlized (all eight of them) so you know that someone was in there trying to tighten things up.
The ring lands on number 4 were whole as well. I can only surmise that the oil control ring got fatigued and allowed the oil pumping. I’ll take some photos of number 4 piston next to number 5 for comparison.
Stay tuned.
Bill
This will be a series of posts.
First up is four of the rods.
Next is the other four rods.
Next is piston #4 on the right and #5 on the left. Number four was the oil thrower. This is the thrust side.
Here are the tops.
Here are the non-thrust sides.
Here is bore #4. I really don’t see anything obvious. Maybe it’s warn so out of round that the rings can’t cope.
Thanks for posting Bill! I take it you’re not driving a PA to NV 
Good thinking! We won’t be able to drive to a western meet until I retire. It just takes too long to get there. Not to speak of things like DESERT driving which scares me greatly.
Bill
Hi Bill, take the oil ring off the piston, and insert the ring in the cylinder, I’ll bet it has 1/8″ or more end gap, and if the cylinder is out of round, the ring will show that as well.
Greg L
Just keep inserting 100 dollar bills in the motor…… it will fix all the problems. Only problem is it’s a large engine! I am sure Bill will have it running again soon. Ed
I’ve heard this ‘story’ many times over many years: if an engine has worn rod bearings, and a good oil pump, the rod bearings will have excess oil coming through the bearing and being splashed/sprayed on the cylinder walls,
The story claims that the rings cannot control the excess oil on the cylinders, and the engine will burn oil..
So,, I’m curious, for #4 that was burning so much oil, did the rod have a really bad bearing, maybe missing a big piece of bearing that would cause excess oil on the cylinder??
And a follow up on the ring and cylinder wear: did you remove the oil ring and install it in the cylinder to see what the gap was??
Greg L
I did that tonight. Let’s see if this will load.
Number 4 bearing was intact when I unbolted the journal cap. I had pieces fall out of it because it was cracked but it was not eroded, so it would not have been leaking an unusual amount of oil. The photo is at the top of the bore and it still shows a big gap on the oil control ring.
It’s gonna be a full boat job. Mains, crank, cam bearings as well as the rod bearings and boring out to .040 over.
Will post more in a couple weeks.
Bill
Thanks for showing us the progress and keeping us up to date.
Bill, 40 over on the engine is about max. If you have severe pitting in the casting you may get a leak or hole in the bore. I have seen this several times. Be sure to sand blast the block to inspect for this condition. John just did a do over motor for a customer that was done in another shop and it was leaking coolent due to severe pitting. Ed
PS Use Aries or Ross pistons, NOT EGGE. Also, use a modern ring package and you will never burn oil again. My 36 uses no oil at all. Ed
You may wish to consider sleeving the cylinders in the block to alleviate any structural integrity concerns. Assuming magnafluxing dictates such. Best of luck