I am putting back together an engine that has a Model A crank in it. I did not build this from scratch but bought it already converted. The issue I have encountered is that the dippers I bought donít fit because the cap is larger than a standard T cap. I can modify the dippers by cutting and welding if necessary. However, before I spend the time to do that I was wondering what the opinions are on running drilled caps without dippers. The rod caps are not only drilled but the babbit has also been Xíed. I have been told that the rods are compressor rods. The engine doesnít have a pressurized oil system but will just rely on the standard splash method. Any advice would be greatly appreciated. The babbit is in great condition so replacing the caps is not an option that I would want to do.
I would want the oil dippers I don't know but I would call the vendors and see if there is a difference in the size for model A vs Model T might save you some work
Make your own. Drill for pipe thread and install a short brass nipple. Install the nipples before you cut the slot so you get them lined up. Use locktite on final assembly. Open one side and close the end some to act as a scoop. Model A rods have forged in scoops. Look close at the cap, did it have the scoop ground off? They might have done that because they came to close to the inspection plate if the spacer is not installed. You may need to install the spacer that goes between the pan and inspection plate.
Why not just get a set of Model A rods that the dippers are made into the caps. Sell the "compressor rods". Sounds like you are going around your elbow to get to your nose.
Jim - the Model A rods are a different length than the compressor rods and wonít work with the pistons that I have. Everyone is favoring the dippers which is the way I was leaning too. I will either modify the ones I have or make my own as Mark suggested. Thanks for your replies.
Maybe can modify 1950 Chevy dippers, if you can find some, shouldn't be too hard. Dave in Bellingham, WA
Thomas I would have an interest in the compressor rods if you decide to change them. Thanks
Having built several A cranked engines, I wouldnít worry about it, unless you are going for high performance.
I wonder what the rods are from?
At one time you could buy cast aluminum connecting rods to use with the A crank conversion
How has the crank length issue been dealt with on your engine? Various ideas have been tried. Some more successful than others!!
Les, I've asked the same question about where the compressor rods are from. I have a T engine with a "B" crank in it that uses rods from an air compressor. They have the length of a Model T rod and the journal diameter of the Model A.
I called Ron Millerís machine in Ohio just last week about this dipper or no dipper question.
I just got a set of rebabbitted rods for a T that were all done differently.
One was undrilled but xíd.
One was drilled through the rod but not the Babbitt.
One was drilled through the rod and Babbitt.
All four were xíd.
The guy at Ronís didnít think it made much difference.
He said they use dippers on their cars but there are none on their Montana 500 car.
Some of the most used cars do not have dippers and some are drilled with no dippers.
Doesnít seem to make a difference.
I bolted it together without the dippers as the bolts were too short anyway.
I did file the nuts a little so I could put cotter pins in all of the nuts
Self locking nuts would work too, as well as locktite.
David - I found the Chevy dippers and they were only $5 each so I ordered them. Thanks for the info on them as I didnít know that they even existed. I will see soon if they fit.
Les - the crank has been shortened but I couldnít tell if it was welded or squashed. We will see how much longevity it will have.
Mark - the A crank definitely needs the inspection cover spacer as well as a few other modifications in order to get the proper clearances to the pan.
The rods are about 7Ē measured center to center. I donít have a T rod readily accessible so am not sure how they compare in length. The pistons are Ford 292 V8. I am not going for a high performance engine but just want it to be a good driver. I would have been very happy with a T crank but the engine was just too good of a deal to pass up so I had to buy it. Canít wait till I can actually fire it up but that will take some more time as I still need to rebuild the carburetor, starter, generator , coils as well as finish up the transmission. It has been said many times that a running car is so much easier to start with than a bunch of pieces like I am doing. However, I think the experience that I am receiving as well as the satisfaction is more than worth the effort.
Sounds good. You will be ahead knowing what is inside and how it was put together.