Anyone have info on BMS “BJ” stamp crank

[GBGN1]

Picked up an older longblock build 153 stage 2 block and the I’m trying to identify the crank material . BMS with “BJ”
Stamp on the crank. Very little info on here. Just taken a shot at anyone having info. Thinking when I take it apart to inspect I may take the crank to get analyzed to see what the make up is . Hope for 4340.

 

[Chuck Leeper]

T

Thread 'BMS Raw Forged Cranks'

Dec 1, 2005

Several (4 left)
RAW CRANKSHAFT FORGING P/N 25500008 COST: $575 shipped - "This unmachined even-fire crank forging give Buick V6 engine builders the freedom to use non-standard stroke dimensions. It is forged from tough 4140 steel (30-34 RC Hardness), and it will accommodate strokes from 2.66" to 3.625". The extra-large counterweights will provide proper engine balance with heavy-duty piston/rod assemblies."

Forgings have surface rust. The rust will not affect the integrity as much of the material will be removed (10-15 lbs). These forgings will require machining at your expense...

• TYRFRYR
• Replies: 0
• Forum: Stage II Tech

This is what you have. You can ID it by the pt number 25500008.
Not 1 of mine. I had 4 of them that I had Kings Crankshafts finish. They would have had info on the ft of the ft counterwt.

 

[GBGN1]

T

Thread 'BMS Raw Forged Cranks'

Dec 1, 2005

Several (4 left)
RAW CRANKSHAFT FORGING P/N 25500008 COST: $575 shipped - "This unmachined even-fire crank forging give Buick V6 engine builders the freedom to use non-standard stroke dimensions. It is forged from tough 4140 steel (30-34 RC Hardness), and it will accommodate strokes from 2.66" to 3.625". The extra-large counterweights will provide proper engine balance with heavy-duty piston/rod assemblies."

Forgings have surface rust. The rust will not affect the integrity as much of the material will be removed (10-15 lbs). These forgings will require machining at your expense...

• TYRFRYR
• Replies: 0
• Forum: Stage II Tech

This is what you have. You can ID it by the pt number 25500008.
Not 1 of mine. I had 4 of them that I had Kings Crankshafts finish. They would have had info on the ft of the ft counterwt.

Thanks Chuck, I figured the part number was a generic BMS number for a forged crank. Did't know I could get a material spec with it . Obviously I wish it was 4340., lol.