I was reading the other thread, “New rods with insert bearings for Model T's”, which reminded me of some engine rebuilding questions I’ve had for a while. And I did not want to hijack that thread. First, I will mention that I know only the basics about engine rebuilding. I’ve never done it myself, but I have helped my dad do it a couple of times. So, please don’t laugh if these questions seem rather elementary. If I don't ask, I'll probably never know.
I have a 1914 block that I want to rebuild. I have not had it magnafluxed but there are no cracks or any problems visible to the eye. Several others have looked at it said that it almost looks like a new block. The cylinder walls are smooth with no wear rings. The only indication that it has ever been used is that there are some carbon deposits around the valve seats. I would like to do as much of the work as I can on my own and I don’t have big bucks to spend on the project right now.
This is just a bare block that did not come with a crankshaft. My main question: Is there a chance that I could buy a used crankshaft and fit it to the engine without getting the upper bearings re-poured? I am assuming that I could get the crank reground and purchase re-manufactured main bearing caps and rods from a parts vendor. Is there any way this could work or do I need to just get new babbitt for all the bearings?
It won't work, get it repoured, and shaft reground, or you will be spending money to do the same thing twice. You can have good, or cheap, but not at the same time!
You can only fit a crank that match's the bearing size, if still standard you can't fit a ground shaft with out a repour and line bore, if they are already an over size from a earlier rebuild and you find a good STD shaft you might get away with a line bore, do it right as you don't want to stuff a good 14 block, they are not that easy to find and not cheap.
If your babbit in the block is good and standard, then you might consider buying a new standard Bill Dubat's or a Scat crank. It to me would be a better investment than a used crank and new babbit work.
A word of caution, some blocks came from the factory with 0.010 undersize cranks. You will need to measure very carefully.
The best is when you have a block with .030" undersized mains. Then all you have to do is buy a crank that is closer to standard and have the mains line bored to fit the crank.
That saves the cost of pouring new mains.
Rick
You don't say if you have the main caps that belong to this block. If you do and especially if you have the shims, then bolt the caps down and do a good measuring job. Measure the bearing bores in 3 or 4 locations and directions in each bearing. Contact me off list and I will help you interpret the results. I have done exactly what you are talking about with good results.
No, I don't have the main caps. Is it possible to measure without the cap? Maybe by holding a straight edge across the bearing, measure, and double the value?
Anyway, I'm not going to rush into anything. I need to get someone local, that is knowledgeable about engines, to take a look at it sometime. I recently moved to the Springfield, MO, area and don't really know any Model T folks here, yet.
You might try a rod or socket that measures exactly 1.250,(1.248 is actually correct). If it fits perfectly, then you are standard. If it rides up then you are undersize.
Beings you do not have the main caps.....save your nickels and do it right. You need to take in account cam shaft gear mesh....crank shaft end play which are major players beside bearing fit.
Have someone like Kohnke Rebabbiting who knows what they are doing do your babbit and machine work. Also, strongly suggest buying a SCAT crank...all the money spent on rebuilding a T engine can fly out the window if the crank breaks and busts out the block rear web.
I have a 16 engine block that had the rear web break due to a broken crank.