1949 8ba engine saga,,,

denson1932

denson1932

Senior Member
this is on the engine supposedly overhauled by a vo-tech school in the '80s i bought dirty filthy b/c no oil pan ect. the good news:
std bore 3 3/16 3,1875 no ridge has crosshatch pistons with new rings some carbon atop pistons...no sleeves, go figure...
has wide belt gen and water pumps. so:
Ford 8BA passenger car engines had the wide 5/8" belt for the generator and water pumps in 1949, while Mercury 8CM engines had it for 1949 (and some 1949–1950 applications depending on the specific passenger car or build rollout) before switching to narrow belts.
anyway todays issue is the valve train. all valves new intakes are steel no name flattop and exhaust are FORD USA-1 STAINLESS, but sone in closed position i can easily spin the valve spring and when i remove that valve assy there is 1/8-1/4" slop on the spring. th when i thought maybe the valves were sbc but no. then i read about this 'rotator option by the keeper...if i were to add that to all my valve assays perhaps that would provide the proper pre-inserted tension? for now i am experimenting with the longer 59ab springs.
so basically can i ...should i try ordering those rotators and installing them?
 
denson1932 said:
this is on the engine supposedly overhauled by a vo-tech school in the '80s i bought dirty filthy b/c no oil pan ect. the good news:
std bore 3 3/16 3,1875 no ridge has crosshatch pistons with new rings some carbon atop pistons...no sleeves, go figure...
has wide belt gen and water pumps. so:
Ford 8BA passenger car engines had the wide 5/8" belt for the generator and water pumps in 1949, while Mercury 8CM engines had it for 1949 (and some 1949–1950 applications depending on the specific passenger car or build rollout) before switching to narrow belts.
anyway todays issue is the valve train. all valves new intakes are steel no name flattop and exhaust are FORD USA-1 STAINLESS, but sone in closed position i can easily spin the valve spring and when i remove that valve assy there is 1/8-1/4" slop on the spring. th when i thought maybe the valves were sbc but no. then i read about this 'rotator option by the keeper...if i were to add that to all my valve assays perhaps that would provide the proper pre-inserted tension? for now i am experimenting with the longer 59ab springs.
so basically can i ...should i try ordering those rotators and installing them?
Click to expand...
the tappets have 2 small holes 90 deg apart. one horseshoe retainer fell out by itself when i had the short block upside down on the engine stand. this is the engine they installed the rear main seal clocked so an oil pan would not fit. there were no bolts in the water pump water outlet. perhaps this was a just for practice engine in shop class??
 
AI search:

"Ford flathead valve rotators were introduced by Ford in 1951 for the 239 cubic inch V8 engine (part numbers like 1BA-6505 for valves and 1BA-6513 for springs) to compensate for the removal of hardened valve inserts in the engine block. These rotators were used until approximately 1953 to help clean valve seats and prevent sticking, utilizing a two-piece retainer design that allowed the valve to rotate slightly with each cycle, aided by the rotational torque of the compressed spring.

Key details include:

Mechanism: The design uses a cone-shaped insert between the valve stem and the upper retainer, allowing the valve to spin independently of the spring retainer, which remains static.
Identification: Rotator-type assemblies are distinguished by shorter valve springs (2.20" vs 2.48") and specific two-piece retainers, whereas pre-1951 engines used longer springs and single-piece retainers.
Modern Context: Many original rotator assemblies are missing or have been replaced with earlier non-rotator styles during rebuilds; however, they remain hard to source. Modern enthusiasts often debate their necessity, with some removing them to prevent excessive seat wear, while others retain them for historical accuracy and seat cleaning benefits.
 
Ok thanks for the reply...here is the question i should have asked:
After i assemble an 8ba flathead v8 valve assembly (valve,guide, spring, and keepers), i assume the spring should be compressed even before installing into block...using 2.2" long springs, i have loose springs on the bebch and only slightly compressed in the block. Using 2.45" long springs solves that proble but that longer spring is supposedly fo use with earlier mushroom valnes?
 
Most important this is the spring tension measured at installed height. Stock cam 40-50lb. Seat pressure. The length of spring is not too critical. Many different manufacturers of flathead valve springs over the years and the free height can vary.
 
glennpm said:
https://thirdgenauto.com/product/ford-flathead-stainless-intake-exhaust-valve-set-see-notes-in-ad/
Click to expand...
s-l500.jpg
 
Near all the blocks set up for rotators were the 1BA block identified by the 1BA casting indicator in the valve chamber. This also indicated that the crankshaft was changed to allow use of the automatic transmissions. The two different valve types are interchangeable in sets but I wouldn't mix any components between the two types. Either run all non rotator or no rotator so that stuff doen't get mixed up. A person might consider adjustable cam followers if it doesn't have them.

Valve springs have a free height dimension. A person should make sure the springs meet the free or unloaded height requirements. Ford made them different colors but aftermarket didn't. Make sure you have springs that work with the type of valves being used. Also, stainless valves need hard chrome on the stems or the valve guides really should be lined with the thin bronze/brass sleeves. Bare stem stainless valve stems like to gall on the cast iron guides. I experienced a lot of problems with that in aviation engines. They use hard chrome guides now but that's not available for the old flatheads.

I wouldn't be too surprised about anything that was built up by school students. The instructor may not have known much more than they did about the older engine types.
 
KiWinUS said:
Most important this is the spring tension measured at installed height. Stock cam 40-50lb. Seat pressure. The length of spring is not too critical. Many different manufacturers of flathead valve springs over the years and the free height can vary.
Click to expand...

8BA's came with either Rotator (late) or non-Rotator (early) valve assemblies that used different springs. Surely, you're not saying "The length of spring is not too critical" between the two different type, are you?
 
tubman said:
8BA's came with either Rotator (late) or non-Rotator (early) valve assemblies that used different springs. Surely, you're not saying "The length of spring is not too critical" between the two different type, are you?
Click to expand...

Probably dismantled well over 100 8BA engines and rebuilt dozens so I’m well aware of the differences.
Rotator or no rotator you need 40-50lb seat pressure and of course the springs will be different with rotators to without rotators to achieve this. Very basic.
 
KiWinUS said:
Probably dismantled well over 100 8BA engines and rebuilt dozens so I’m well aware of the differences.
Rotator or no rotator you need 40-50lb seat pressure and of course the springs will be different with rotators to without rotators to achieve this. Very basic.
Click to expand...

I know that; given your experience, I was just wondering why you would make such a generalized statement. Is there something going on that we aren't aware of?
 
tubman said:
I know that; given your experience, I was just wondering why you would make such a generalized statement. Is there something going on that we aren't aware of?
Click to expand...

This is engine building 101. Very simple and factual I have stated twice what the most important part of setting up flathead valve springs for a stock cam to help the OP. I do not know what you are asking or don’t understand.
 
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