All Small Six 200 6 cylinder questions

[nxslt1]

I'm rebuilding the 200 in a 78 fairmont and I'm having trouble finding standard size main bearings. I see some but they list the years covered as up to 75, not 78. Did ford change the main bearings on this motor in 76 or are they all the same after 65 when they went to 7 mains?

 

[nxslt1]

Alrighty then. I reckon I'll just order some and see if they fit.

 

[alwill923]

go to pdf page 257, then go to section 60

 

[78_200_C4]

I'm rebuilding the 200 in a 78 fairmont and I'm having trouble finding standard size main bearings. I see some but they list the years covered as up to 75, not 78. Did ford change the main bearings on this motor in 76 or are they all the same after 65 when they went to 7 mains?

I found high quality standard main + rod bearings on eBay for my 78 Fairmont 200.
The prices were great.
I bought a set of standard Hastings piston rings on eBay for $15.00 free shipping.
The 7 main bearing set should be the same regardless of the year.
I made a cam bearing tool out of a black water pipe along with a slightly modified wheel bearing type driver.
It worked great.

 

[drag-200stang]

I found high quality standard main + rod bearings on eBay for my 78 Fairmont 200.
The prices were great.
I bought a set of standard Hastings piston rings on eBay for $15.00 free shipping.
The 7 main bearing set should be the same regardless of the year.
I made a cam bearing tool out of a black water pipe along with a slightly modified wheel bearing type driver.
It worked great.

Early 7 main bearings where fully grooved and later 7 main bearings where top groove only.

 

[78_200_C4]

The new 7 main bearing sets (being sold today) look to be the same regardless of the year.
ENGINETECH BC309J main bearing sets are sold for 65 to 78 as far as I looked.

"Fully grooved main bearings should be avoided in any engine. The lower shell needs to have a flat, uninterrupted surface for the hydrodynamic oil wedge to be properly formed between the bearing and the crankshaft journal. With the groove running through the lower shell, the oil wedge does not form at all, which results in metal-to-metal contact between the bearing shell and the crank pin.
Half groove (180 degree) upper shells work the best at getting oil into the eccentric area, adjacent to the parting line, which results in formation of the hydrodynamic oil wedge as the crankshaft rotates."

 

[drag-200stang]

The new 7 main bearing sets (being sold today) look to be the same regardless of the year.
ENGINETECH BC309J main bearing sets are sold for 65 to 78 as far as I looked.

"Fully grooved main bearings should be avoided in any engine. The lower shell needs to have a flat, uninterrupted surface for the hydrodynamic oil wedge to be properly formed between the bearing and the crankshaft journal. With the groove running through the lower shell, the oil wedge does not form at all, which results in metal-to-metal contact between the bearing shell and the crank pin.
Half groove (180 degree) upper shells work the best at getting oil into the eccentric area, adjacent to the parting line, which results in formation of the hydrodynamic oil wedge as the crankshaft rotates."

That may be true but fully grooved has been working for me. I am more concerned about oil to the rods and fully grooved helps them and have not had any rod or main bearing problems. At this point I am reluctant to change.