1947 Cadillac flathead rebuild

[Glen]

I have one of those and it took me a while to figure out what it was.  I inherited it from my father.  Nobody at the local AACA club knew what it was either. Thanks for the instruction tag.  Now I know haw to use it on my car. 

[Steve Passmore]

Been studying your picture Harry, how does that work? I can see it pushes against the head of the spring but what does the other end rest on? there's a big hole into the cam valley when the lifters are removed.  4 values on the Flathead are the devil to get the collets in when the com presser is in there as well.

[Fred Pennington 25635]

Be careful, their is a spacer / locater washer at the top of each valve spring next to the block.
It sometimes sticks to the block and can be lost while doing other things like cleaning, transporting etc.
If it is not present when reassembled the spring tension will be to light.

Fred P.

[harry s]

Steve, The curved end of the tool sits on the lower part of the cam lobe and when the ratchet handle is turned it extends and compresses the valve spring. Since the tool doesn't take up too much space it is easy to remove or install the keepers. It is still a good idea to keep a rag or some sort of screen in the valley, just in case.

[Jeff Trahan]

Fred, thanks for the advice regarding the spacers.  When I removed the valves and springs, I didn't even know the spacers were there until I went back and looked after reading your post.  They were hiding amongst the sludge.

Now that the block is almost bare, I measured the cylinders with a bore gauge.  All of them are tapered.  I haven't honed the cylinders yet. On average, the bottom of the cylinders are 3.500, the centers are 3.525, and the top (1" down) are 3.540.  Is that normal?  I don't know how many miles are on the engine.  If I get new pistons, which measurement do I use?

One of the cylinders in particular seems out-of-round at the top (1" down).  I measured at 45 degree intervals.  The difference between the widest and narrowest measurements is about 0.027 inch.  If that difference holds up after honing, should I buy a piston for the smallest measurement?

Jeff T.

[pauldridge]

Jeff,
In my opinion, your wear is HUGE.. essentially you are saying that part of your cylinder is 40 thousandths over.  That's even beyond the standard max piston sizes (.030) There should be negligible taper to the cylinder according to the Caddy manual.  I believe the max allowable is .5 thou or less.. same for out-of-round which you didn't mention?

I can't imagine considering new pistons without a full-on cylinder bore, not just hone.

Today I'm pulling my newly overhauled engine back out of the car.. the machinist mucked up and bored the cylinder 1.5 thou too small  (I guess that's preferable to too large!).. the pistons were binding up after less than 1 minute of operation.

What I've learned the hard way... take nothing for granted from the machine shop, no matter what their reputation.. check every bore, ring gap, bearing clearance, new piston diameter, etc.

And, I highly recommend buying your parts from Terrill Machine.  I bought a complete overhaul kit (pistons, rings, bearings, valves, cam, lifters, etc) from an eBay company to save a couple hundred bucks.  The holes in the conrod bearings for the squirter hole didn't line up with holes in the rod.  Bearings from Terrill turned out to be a perfect fit!

Considering all the effort you're going through, it doesn't pay to try to skimp on the rebuild.  You'll thank yourself in the long run for doing it right.

[kkarrer]

Phil,
     Keep me posted on how it goes with your engine.  It's hard to believe you've had to go through so much trouble.  Try David Black next time at Travis Engine.
Later,
Ken Karrer 1941 6227D coupe

[Fred Pennington 25635]

You definitely need to bore this engine. If you go with the " I won't be driving it that much, why put out that much money?" thought you will find with that much taper the rings must flex each and every stroke, up and down. They will break from fatigue in a very short period of time. The original rings may not be broken because the worked up to that taper slowly and weakend over time. Check with Terrell or Egge to find out what oversized pistons and rings are available and have a good discussion with your machine shop to determain the best course for you and your engine. Sleeving is another option.

Good Luck,

Fred P.

[Paul Phillips]

I found a similar tapered wear pattern in my 47 flathead block when rebuilding a few months ago.  Not trying to suggest this is a '47' issue, but just to reinforce for others that they should check the bores carefully when servicing an engine, as it is not a unique problem.  I am thinking Terrill had pistons & rings in +0.040, so that may be what you need.  Otherwise, you can have the machine shop sleeve the worse bores.

Be sure as well to look for micro cracks between the valves and bore, possibly extending into the cylinder.  Both Phil and I encountered that in our recent builds, and resolve by having them stitch-welded.

Paul

[Jeff Trahan]

Thanks for the advice.  I decided to take the block to a local machine shop to see what they can do about the taper.

Now I'm trying to get the flywheel off.  I removed the six hex bolts from the face of the flywheel but it is still not budging.  Unfortunately, the manual says to remove the flywheel with the crankshaft.  I don't want to remove the crankshaft.  Is there a way to remove the flywheel without removing the crankshaft?  The block will be more transportable if I remove the flywheel before delivering to the machine shop.  Thanks.

Jeff T.

[Steve Passmore]

The flywheel is located on two very tight dowels, you have to turn the flywheel while gently tapping it using a piece of wood and a hammer. Its sometimes necessary to unbolt the bell housing and ease that off its dowels a tiny bit to allow the flywheel clearance to come off its dowels and clear the bellhousing.

[pauldridge]

The flywheel is located on two very tight dowels, you have to turn the flywheel while gently tapping it using a piece of wood and a hammer. Its sometimes necessary to unbolt the bell housing and ease that off its dowels a tiny bit to allow the flywheel clearance to come off its dowels and clear the bellhousing.

I confirm the above all the way.  I just had to remove the flywheel on my engine that I just assembled not 2 months ago.  I was beginning to think it would never come off.  Yes.. loosen the bell housing bolts a bit, then put a substantial pry bar on each side and just keep wiggling at it.  Eventually it will let go.  I spent the better part of an hour with mine!  finally, be careful as you get near the end.. make sure there is something close underneath to catch it, as this baby is REALLY heavy

[Steve Passmore]

You think that's heavy Phil? Iv just today removed the flywheel from a 1936 engine and that sucker out-weighs the later flywheels by a noticeable margin half as much again I fancy.

[Brad Ipsen CLC #737]

Removing the dowels first is the way to remove the flywheel.  Take off the four bolts that hold the dowel keepers on.  The dowels have a male 3/8 fine thread extension on them.  Come up with a tool to attach to the dowels and pull them out.  Attached is a tool I made to do the job.  A stack of washers added as the dowel comes out would work also.  Once they are out take off the last two bolts carefully.  The flywheel has about an 1/8" step in it.  Just pull back slightly and it will come right off putting all of that weight on you.

[Jeff Trahan]

I've been able to find rebuilt versions of most of the major outside components of the engine but I haven't seen anyone who rebuilds the hydraulic pump that works the windows, seat and top. Any referrals?  Thanks.

Jeff T

[harry s]

Jeff, Try these folks in Fla. They are the go to  people:  http://www.hydroe.com/    Harry