Is your Bantam in need of a new heart?

$4,000 is a lot of money, there is no question about that.  So when confronted with a price tag calling for that much money, it’s best to be an intelligent buyer.  This engine has been listed for auction by a seller who has been listing a lot of Bantam and Austin parts over the past few months.  This engine is probably one of the greatest finds in the collection because of the potential it may offer.

I don’t have an awful lot to say about this engine, as people have their different views on rebuilt engines and engines that are rebuilt but lay dormant.  While some may recommend tearing it down to go through the engine, others may be willing to run it as is.  If you’re willing to accept this as being equal to a modern rebuild where all of the parts have been wet magnafluxed, rebabitted, and assembled with the highest quality materials; this could be a bargain.

In theory, I believe it should be torn down and inspected before being run; but then again I am usually a “get the ether and a jumper pack” kind of guy because I just want to hear the engine come to life (which is a terrible idea).  I’ll let you be the judge, but I’ll give you a few things to consider:

  1. In the 1980’s, parts may have not been magnafluxed or at least not wet magnafluxed (which is a far superior method of crack detection).
  2. Original Bantam rod bolts are notoriously weak, we do not see a bill of materials indicating what was used.
  3. New main bearings were cited in the ad. Does that mean the rebuilder used NOS front and rear bearing retainers with their original poured babbit, were original retainers rebabbitted, or were some sort of inserts used?
  4. We don’t know if the new rods were the NOS 38 style rods which were available with original babbit or something else.  In any event, how were they modified to accommodate the undersized crankshaft?
  5. The engine does not appear to have any of its openings sealed.
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This is what a NEW or never run rebuilt Brennan IMP looked like in the exhaust ports after laying dormant for years.

 

 

 

This engine could be great or it could be a very expensive (but pretty) collection of parts.

What are your thoughts? (A few people have already chimed in and have inspired some additions to this post).

 

Click here to see the American Bantam Engine

 

Autopsy of an American Bantam Engine, Part II

This is the second installment in the tear down procedure.  I left off with needing pullers to get the rest of the engine ready in order for me to pull the crank out.

If you do not have a three jaw puller, you can usually borrow them from Autozone or Advanced Auto Parts.  They charge you the full price of the tool, and refund it upon return.  It’s a great service, however the tools are generally about the same quality you would find at a Harbor Freight.  So, if you decide you’re in love with the tool or it is something you will need repeatedly, it would be cheaper to buy it almost anywhere else than to keep the one from the auto parts store.

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I left off with the crank pulley still attached to the crank.  Since the cover behind it is aluminum, there is no way I want to pry against it, even though it’s already broken.  The piece that is broken is very repairable.  The pulley however, is already broken, with a large chip out of it.  I believe they make special pulley pullers, but I didn’t really think about it at the time I was renting this one.

Keeping the crank engagement bolt in place, I attached the puller as you can see below.  When you do this, make sure to thread the bolt into the crank so you don’t foul up the threads, but leave room so you have where to move the pulley.  Removing the washer will help.  If you don’t provide ample room, you may not realize that the pulley is infact moving, but you are just pulling against the bolt.  This will result in breaking the cast pulley even more.  I’ll let you guess how I found that one out.

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The pulley is kept in place with a key, but it pulls off nicely.  Once it is off, removing the perimeter bolts of the cover allow it to free itself and you are then faced with the next challenge, the timing gears.  At first glance, it looks as though the right way to do this is to remove the nut from the cam to take those gears off.  This nut has been marred in an effort to keep the assembly attached.  Attempting to take the nut off ended up yielding the entire cam assembly.  This is okay for me for now.

The last challenge on the front end of the crank case is the timing gear attached to the front of the crank.  The puller and the crank engagement bolt will come in handy here.  Make sure you have the jaws engaged so you don’t damage the teeth.  (This one I didn’t learn the hard way).  You may want to soak this in your favorite penetrating fluid.  Now all of the front end impediments to pulling the crankshaft out have been dealt with.  If you look carefully, you can see more damage to this crank case, the lower two bolt holes are broken.

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The next challenge will be dealt with tomorrow.  This final step in pulling the crank out is by far the most important.  Once you pull off the flywheel, you will see 6 fasteners holding in the rear bearing carrier.  You will also see two holes that have nothing in them.  These holes are threaded and are going to be very important in getting the crank out.

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For part three, make sure you have two bolts that thread into those holes that are over an inch long and a space heater.  In part III, you see what to do with them.  Don’t touch your engine until you read the rest.

Also, this is the perfect time to say, if you haven’t joined the clubs, DO IT.  If you’re not interested in the club scene or the great people you’ll meet, at least do it for the tech information. The Austin Bantam society has a wonderful CD indexing all of the tech articles that both clubs have put out during their existence.  Among those articles is most of a great engine rebuilding manual.  The guidance of that manual and the club members have helped me greatly in this process.

Remember, when it comes to Bantam parts; don’t break them, please.