BMS Crank.

[Chuck Leeper]

I still have 2 raw forgings and was planning on selling 1 to raise some roller money. I would hand deliver it to King's Crankshaft here in Denver, NC. to turn it to whatever stroke anyone wanted, it was going to be around 1600. Funny thing is the last 2 that were sold were turned down to sizes below 3.40.

"Back in the day", I had 5 BMS forgings, that I had King do. Every once in a while, I see a pic of 1 w/ Cody Mspt/ dimensions elec penciled on it....
They do nice work...At least they did on these.

 

[750H.P.V6]

We just had some cranks made by Kings for one of our R&D engines at my company. I got to measure them up and I think they are some of the nicest cranks I've seen.

Neal

 

[NY Twin Turbo]

I have a list of the crank forging ID and material used from a BMS engineer.

You wouldn't happen to want to share that list with the group, would you?

 

[750H.P.V6]

You wouldn't happen to want to share that list with the group, would you?

I agree. This would be good info that could benefit the whole Turbo Buick community.

Neal

 

[rag231]

When I get home, I will check the markings on my forgings.

 

[turbo nasty]

@David Husek I have a BMS crank as well and would like to know what is the preferred forging. Thanks

 

[tsm3089]

Dave can you id this crank

 

[tsm3089]

Other side

 

[turbo nasty]

I browsed through all my old Buick power source parts books (both sales brochures as well as the vtwo build guides) and did notice they advertised the cranks as 4140 with RH 28-34 IIRC. The Ruggles Stage 2 book he refers to the cranks being 4340. Curious as to when they changed and if the stamping #'s mentioned would dictate one or the other.

 

[NY Twin Turbo]

I browsed through all my old Buick power source parts books (both sales brochures as well as the vtwo build guides) and did notice they advertised the cranks as 4140 with RH 28-34 IIRC. The Ruggles Stage 2 book he refers to the cranks being 4340. Curious as to when they changed and if the stamping #'s mentioned would dictate one or the other.

Still waiting on Dave's input on this matter.

Dave? You out there?

Inquiring minds want to know.

 

[David Husek]

Dave can you id this crank

I cleaned up and my list of crank codes is not where it has been for years. May have been put in a file or shredded.... I remember them though

Cranks codes start with an R, T, N or W. There were 8 codes given to me. There may be others, but doubt it.

From the picture, It looks to have an N. If this is so, the only N crank was N78 and the reason I remember this is it was the only 5140 crank they made. As a reference, the early power source books referenced 5140 material. The later books reference 4140.

The best and last design was the W15, the T92 is the next best, then T70 and all three are 4340. R57 is 4140, R75 is 4340. N78 is 5140. T65 is 4340 and T66 is 4140. These are from memory and I would say they are correct.

 

[chasmat2316]

I have one here stamped BJ can anyone give me any info?

 

[NY Twin Turbo]

I cleaned up and my list of crank codes is not where it has been for years. May have been put in a file or shredded.... I remember them though

Cranks codes start with an R, T, N or W. There were 8 codes given to me. There may be others, but doubt it.

From the picture, It looks to have an N. If this is so, the only N crank was N78 and the reason I remember this is it was the only 5140 crank they made. As a reference, the early power source books referenced 5140 material. The later books reference 4140.

The best and last design was the W15, the T92 is the next best, then T70 and all three are 4340. R57 is 4140, R75 is 4340. N78 is 5140. T65 is 4340 and T66 is 4140. These are from memory and I would say they are correct.

Wow! Nice.

I thought we lost you!

This is great Information and highly appreciated. I checked mine recently and found that, although it's not the latest forging, it's still an R75. Now I feel better and I am absolutely positive I have a 4340 crank.

 

[rag231]

Both of my raw forgings have the "DU" on one side and one has "BA and 93" and the other has "BN", the one with the "BN" has an 89 stamped at the DU.

 

[rag231]

 

[750H.P.V6]

I have one here stamped BJ can anyone give me any info?

The only forged crank I have is stamped BJ also.

Neal

 

[NY Twin Turbo]

View attachment 302461 View attachment 302462 View attachment 302463 Both of my raw forgings have the "DU" on one side and one has "BA and 93" and the other has "BN", the one with the "BN" has an 89 stamped at the DU.

I'm wondering why your stampings look so raggedy.

My crank has a nicely stamped and identifiable R75 on it exactly the way Dave's picture shows his T96.

Did the stamp guy go to work hungover that day?

 

[rag231]

One crank also has the raised GM part # and the other has it stamped. Who knows what was going on that day.

 

[750H.P.V6]

I'm pretty sure it wasn't a science project back in the day. I'm just glad Dave could help shed light on the whole forging code mystery.

Thanks for the info Dave!

Neal

 

[Turbo38V6]

Curious if anyone can shed light on this code? 'BN'