Need help identifying crank and rods...

[J Banning]

I need some identification help here. I've got two cranks, and two complete sets of rods. I'm pretty sure that one set is from a 86-87 motor, the other set I'm not so sure about. Here goes...

Crank #1
- Pretty sure this is factory 86-87. Jives with info on gnttype.org
- Casting number - 877.
- Rolled fillets on rod & main journals.
- Number near 2nd main journal: GM9.
- 10/10, but needs to be cut again.

Crank #2
- Casting number - 877.
- Rolled fillets on main journals ONLY.
- Number near 2nd main journal: GM7.
- Numbers near crank snout: 2, E25.
- 10/10

Rod set #1
- Pretty sure this is factory 86-87. Jives with info on gnttype.org
- 2 dots on beam
- The numbers on the other side of beam: 3, 763
- Letters near rear main: D, N

Rod set #2
- I can't find any info on these rods other than 3 dot is not what came with 86-87 VIN 7 motor.
- 3 dots on beam
- The numbers on the other side of beam: 8, 873


How fast/how much HP can you make with the 877 cranks that only have the fillets on the mains? I've heard of people running 11's with some N/A cranks (I'm one of them). How about this one in particluar? ANyone gone faster? Anyone have one fail?

How about the 3 dot rods? Aside from the end caps being larger on the 2 dot rods, I don't see any differences. Anyone have personal experience running these rods?

It sure would be nice if there was some more info online on these parts.

Thanks,
-Banning.

 

[Kip]

Either rod will work fine. I would use the crank that is rolled on the rods and mains if it were me.
See ya, Kip

 

[FJM568]

crank #1 is a turbo crank...

crank #2 is a NA crank...(ALL NA cranks have rolled fillet mains)

As for the rods, pretty much the info you gave on them is correct...I really don't know too much about the second set of rods you listed...

The turbo cranks can have several different casting #s on them...229 and 877 are the ones that I have seen, but am not sure if there are more...Other than the different casting #s, there shouldn't be any difference in strength between the 229 and 877 turbo cranks...They just used a different casting form to cast them(therefore, different casting #)...

The key to making a NA crank live at high HP/torque limits, is to keep detonation NON-EXISTANT!!! But if you have a choice between a turbo crank(ground at std/std, 010/010, 020/020, etc., as long as rolled fillets are intact) or a std/std NA crank, the turbo crank will be stronger and would be my choice...

 

[J Banning]

Thanks for the replies guys.

Obviously I'd use the turbo crank and rods over the other ones. If I want to go faster than I am now, I'm going to use the right parts. I'm just trying to figure out what the other pieces are that I've got, and what I could use them for, how far I could push them, etc.

...crank #2 is a NA crank...(ALL NA cranks have rolled fillet mains)

I did not know that. Thanks.

...The turbo cranks can have several different casting #s on them...229 and 877 are the ones that I have seen...

Yes, I seem to remember hearing the same. From what I've got, not all 877's have the rolled fillet though.

Thanks again. More comments welcome.
-Banning.

 

[REDS HOT AIR]

if the rods are 86-87 turbo motor rods they will have sps on the end of the rod bolts...they are good bolts dont know why other guys change them.

 

[FJM568]

My 86 NA motor that I bought to build into a turbo motor had SPS rod bolts on it already...

 

[REDS HOT AIR]

you got a good one !!

i pulled down an 87 n/a 109 block that has never been apart and it didnt have then and my 85 turbo motor dont have them either?

lots of diesel motors are sps bolted

so we have diesel pistons and rod bolts..

 

[FJM568]

hmmm...I've heard that it was sporadic...I'm guessing that they had different parts suppliers and they used whatever was available when they came down the line...Some got em, some didn't...

But I have heard that the SPS bolts are every bit as good as ARP bolts...