Cape Codder
Well-known member
BRENT - Is that a typo on the price of a short block? My guy said he balanced the motor but it cost me two more grand then what you stated.
Dave Lopes Fordor Model A
- Thread starter TerryH
- Start date
BRENT in 10-uh-C
Well-known member
Can't answer the 'why'. Even the modern V-8 piston the popular rebuilder out of Illinois retrofits is a heavier piston than what Ford's piston was.
My point is that these bargain engine rebuilders that many restorers use do not go to the level of balancing and fitting everything like Ford did. There is a large difference between 'restoring' and just 'rebuilding' in all facets of Model-A work. The same applies with the engine work.
Chris in WNC
Well-known member
Not all original engines ran better than today's rebuilds.
I owned an unrestored '31 Coupe, purchased from the late Steve Ciccalone, for nine years.
It had less than 16,000 miles when it arrived at our house and about 21,000 when it departed.
The engine never ran as smooth as some of our other Model As, no matter what was done to it.
The exception that proves the rule?
I owned an unrestored '31 Coupe, purchased from the late Steve Ciccalone, for nine years.
It had less than 16,000 miles when it arrived at our house and about 21,000 when it departed.
The engine never ran as smooth as some of our other Model As, no matter what was done to it.
The exception that proves the rule?
ryanheacox
Well-known member
Is there any way to remove material to bring it into Ford’s spec? Not being an engine builder or professional machinist I’m not sure where you could remove material and get away with it.
My thought has always been we are no longer using original parts on our rebuilds. I would have to think leaving the valve train out would not be a issue. I have had engines balanced electronically the crank, rods,pistons, flywheel and pressure plate. After balancing separately the crank along with flywheel and pressure plate were then balanced as a unit. The end results were the same....nothing changed. My thoughts always was we are not using original parts with original weights. I have been toying with looking for a standard crank, rods and pistons with pin and rings and building a engine but like you said this can get costly.
History
Well-known member
That's exactly what ran through my mind. Years ago I was at Richard Childress shop. It was late afternoon and Richard took my dad and myself into the engine room. I can't remember if this was his old shop or new one but anyway I asked Lou Larosa what he'd been up to. He said something about grinding rings all day and the way he said it made me laugh. He said "it's not funny, I've literally been grinding ******* piston rings all day". So there is a way to match (everything) better than Henry did it, but it'd be expensive.
BRENT in 10-uh-C
Well-known member
Yes, matching piston ring end gap is one thing that helps match parasitic drag or wall friction. Ryan, we use a piston vise to hold the piston on the Bridgeport milling machine to remove material from under the pin boss to lighten and ultimately match piston weights on a gram scale. While our target is 0.00 grams between all four piston differentials, I accept anything under 0.2 grams total differential. Weight matching connecting rods on the big end, and total are another.
Balancing engine pieces is much like mowing the front yard. Some do it where the rows are all straight and the lines are perfectly striped, -and others blow grass all over everything and miss a few spots here & there. Both people mowing can make the claim that they mowed the yard, but one did a better job. One definitely takes more skill and more time to do over the other one. The same thing applies for balancing. Maybe they balanced the parts but they missed a few weights here and there.
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Balancing engine pieces is much like mowing the front yard. Some do it where the rows are all straight and the lines are perfectly striped, -and others blow grass all over everything and miss a few spots here & there. Both people mowing can make the claim that they mowed the yard, but one did a better job. One definitely takes more skill and more time to do over the other one. The same thing applies for balancing. Maybe they balanced the parts but they missed a few weights here and there.
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Terry Burtz Calif
Senior Member
When a new Model A cylinder block was machined, the first machine operation was to machine the pan rail and main bearing bolt holes. During this first machine operation the front main bolt and rear main bolt holes on the side opposite to the camshaft were reamed for future machine operations. The drawing note for these two holes reads ".505 ream 1/2 deep for locating machining".
What this does is to establish a plane and 2 locating holes for subsequent machine operations.
The other 5 planes of the cylinder block were machined on at least 5 other special machines.
When a cylinder block was loaded into one of these other machines, the first plane and 2 reamed main bolt holes is where the cylinder block was mated to the machine.
The result was a cylinder block with all machined surfaces flat, square, perpendicular to each other, and in the same location for all cylinder blocks.
Over time (90 years), most engines have been rebuilt several times, and worn surfaces have been machined to make them flat.
The problem with rebuilt engines is that the machinery used to rebuild them does not index on the first plane and 2 reamed main bolt holes, but instead indexes on other features that may be out of location due to previous rebuilds.
A cylinder boring machine is a good example. Most cylinder boring machines use the top surface of the cylinder block as a plane, and determine location of where to bore from indexing low in the cylinder where the rings don't ride. If the top surface is not parallel to the pan rail and/or the cylinders were miss located in a previous rebuild, the engine will not be right.
What this does is to establish a plane and 2 locating holes for subsequent machine operations.
The other 5 planes of the cylinder block were machined on at least 5 other special machines.
When a cylinder block was loaded into one of these other machines, the first plane and 2 reamed main bolt holes is where the cylinder block was mated to the machine.
The result was a cylinder block with all machined surfaces flat, square, perpendicular to each other, and in the same location for all cylinder blocks.
Over time (90 years), most engines have been rebuilt several times, and worn surfaces have been machined to make them flat.
The problem with rebuilt engines is that the machinery used to rebuild them does not index on the first plane and 2 reamed main bolt holes, but instead indexes on other features that may be out of location due to previous rebuilds.
A cylinder boring machine is a good example. Most cylinder boring machines use the top surface of the cylinder block as a plane, and determine location of where to bore from indexing low in the cylinder where the rings don't ride. If the top surface is not parallel to the pan rail and/or the cylinders were miss located in a previous rebuild, the engine will not be right.