[Jays76bird]

Been having a tough time finding a 4 inch stroke,3 inch main BBC 2.200 journal crank. Butler can only get the forged scat and they are at least 5 weeks out, ( and expensive !)no one carries the cast cranks anymore. There is one SGI cast crank on ebay in this size and price is reasonable, but I have never heard of this outfit. I'm not oblivious to the fact all these cranks are China made. However I notice with most Chinese products there are different levels of quality. Anyone familiar with the SGI brand ?

[Mike Davis]

I have an SGI 4" 3.25 forged that has been run hard for about 10 years. I have not seen one of their newer cranks, but they used to be good. Butler and KRE both sold them.
However, I would not trust ANY Chinese cast crank. My advice would be to save a little more and go forged.

[steve25]

Saving up for the steel crank and waiting out the month and a half could save you the cost of a whole new top to bottom motor down the road!

Only if was building a under 400 hp pure street motor that never tops 5200 rpm would I chance running a overseas made cast crank!

[mgarblik]

To answer the OP. SGI, is "Star Galaxy Inc." Yes, they are a Chinese manufacturer of aftermarket engine parts and they private label parts to various vendors. The cast iron crankshafts they produce have had some failures in the field. This startles me as in typical use, a big heavy crankshaft like a Pontiac shouldn't be under that much stress with decent support in the block and moderate RPM and HP. But yet there are plenty of pics of 2 piece cast aftermarket Pontiac crankshafts. This means the Chinese have succeeded in producing a crankshaft inferior to a junkyard core stock Pontiac crankshaft! Impressive. You make no mention of target RPM or target HP so hard to make a recommendation. I will make 2 to cover the spectrum. If your building a stock or near stock HP engine say 400 HP@ 5500 RPM and budget is a major concern, I would consider using a stock Pontiac crankshaft of your choice and sell the BBC rods you must already have. If more HP/rpm is in the build plans, the Scat forged crankshaft would be a good choice IMO. Molnar forged would be even a little better. They have excellent machining, finish and journal accuracy. In summary, aftermarket cast crankshafts from China would be my last choice for any Pontiac build. Good luck with it.

[J.C.you]

Offset grind a 400 crank and get some more cubes if that will work for you

[hurryinhoosier62]

Originally Posted by J.C.you

Offset grind a 400 crank and get some more cubes if that will work for you

Unless you know your crank is a standard journal and “on” stroke I wouldn’t recommend offset grinding one. The absolute highest amount of stroke increase you are going to get from a 2.249-2.250(nominal size for a standard Pontiac rod journal) is .040 when cut down to a BBC standard rod journal(2.219-2.220). That will leave you .010 to make sure you have completely cleaned up the entire journal and it isn’t egg shaped. A .040 offset ground crank with a .030 overbore gives you 410 ci
verses a 406 ci with a .030 overbore only.

[J.C.you]

Originally Posted by hurryinhoosier62

Unless you know your crank is a standard journal and “on” stroke I wouldn’t recommend offset grinding one. The absolute highest amount of stroke increase you are going to get from a 2.249-2.250(nominal size for a standard Pontiac rod journal) is .040 when cut down to a BBC standard rod journal(2.219-2.220). That will leave you .010 to make sure you have completely cleaned up the entire journal and it isn’t egg shaped. A .040 offset ground crank with a .030 overbore gives you 410 ci
verses a 406 ci with a .030 overbore only.

Just giving him alternative rather than doing the cheap China crank.
Sounds like he's doing a budget build?

[lust4speed]

My experience with Star Galaxy was always very good. The owner was "Chance" and he had relatives in China and imported the crank and rod castings by the container. I'd just drive down to his business and buy direct from him. What seemed to be a pretty quiet business arrangement was he would sell unmarked cranks to several of the big crank companies and they would stamp their names on them. Haven't talked to him for several years now. At the time his stuff was measuring out better than Eagle and a lot better than RPM's. Guess I should add that what he was importing years ago might or might not be the same quality as what is being imported today.

[hurryinhoosier62]

Originally Posted by J.C.you

Just giving him alternative rather than doing the cheap China crank.
Sounds like he's doing a budget build?

JC, by the time you figure in the cost of offset grinding the crank( around $400-500 by my crank grinder), purchasing pistons( more than likely custom due to the 3.790 stroke) and other associated costs it’s going to be a wash to put a 4.00 stroke forged crank on back order and wait. After seeing more than my share of the Chinese cast “garbage” cranks( .040 out of stroke) I would be hesitant to purchase one. I have heard good things about SGI forgings; not their cast cranks.

[hurryinhoosier62]

Originally Posted by mgarblik

To answer the OP. SGI, is "Star Galaxy Inc." Yes, they are a Chinese manufacturer of aftermarket engine parts and they private label parts to various vendors. The cast iron crankshafts they produce have had some failures in the field. This startles me as in typical use, a big heavy crankshaft like a Pontiac shouldn't be under that much stress with decent support in the block and moderate RPM and HP. But yet there are plenty of pics of 2 piece cast aftermarket Pontiac crankshafts. This means the Chinese have succeeded in producing a crankshaft inferior to a junkyard core stock Pontiac crankshaft! Impressive. You make no mention of target RPM or target HP so hard to make a recommendation. I will make 2 to cover the spectrum. If your building a stock or near stock HP engine say 400 HP@ 5500 RPM and budget is a major concern, I would consider using a stock Pontiac crankshaft of your choice and sell the BBC rods you must already have. If more HP/rpm is in the build plans, the Scat forged crankshaft would be a good choice IMO. Molnar forged would be even a little better. They have excellent machining, finish and journal accuracy. In summary, aftermarket cast crankshafts from China would be my last choice for any Pontiac build. Good luck with it.

X 2, Mike. I have ground one too many 454 BBC cast cranks purchased from Competition Products. They are absolute JUNK! I don’t care if it’s Eagle, SGI or RPM....Chinese cast cranks ARE trouble going somewhere to happen. When you are having to grind brand new cast cranks .030 under to correct out of stroke, taper and out of round you know something isn’t right.

[Jays76bird]

It sounds like that I should shell out the extra greenbacks and go with the Scat forged 4 inch. I am trying to build a 383. I already have the Probe pistons that Ace Brewer sold for his kit.

[J.C.you]

Budget 6.635" BBC rod takes up the slack. Just saying if one can get a oem crank done reasonable

[J.C.you]

Originally Posted by J.C.you

Budget 6.635" BBC rod takes up the slack. Just saying if one can get a oem crank done reasonable

Sorry didn't see you had pistons

[Schurkey]

Originally Posted by lust4speed

My experience with Star Galaxy was always very good. The owner was "Chance"

I see what you did.

You're saying you got some good ones, by Chance.

Originally Posted by Jays76bird

It sounds like that I should shell out the extra greenbacks and go with the Scat forged 4 inch. I am trying to build a 383. I already have the Probe pistons that Ace Brewer sold for his kit.

Why would you spend that much money to only get 383 cubes, when you could do an OEM 400 for less?

[hurryinhoosier62]

Originally Posted by Schurkey

I see what you did.

You're saying you got some good ones, by Chance.


Why would you spend that much money to only get 383 cubes, when you could do an OEM 400 for less?

Because 400s are not a common or inexpensive as they used to be. On the other hand, 350Ps are more easily found and are less expensive. I found a 350P block and crank locally for $100. The .030 over 350P bore is a common oversize for LS engines.

[Will]

Originally Posted by mgarblik

... I would consider using a stock Pontiac crankshaft of your choice and sell the BBC rods you must already have. ....

Why not just cut the rod journals to 2.2" and use the BBC rods?

[Jays76bird]

Actually I just bought a RPM forged crank for $720, 4 inch stroke, BBC rod journal 3 inch main. I read the comments about the offset grind, however I have the .030 probe pistons Ace Brewer used in his P.P.R. 383 kit. They are designed to work with the 6.800 rod and 4 inch stroke. (1.415 pin height) I haven't bought the rods yet. I know I can do the 400 for cheaper if I can find the block, but I want to stick with the 350 Pontiac.

[hurryinhoosier62]

Originally Posted by Jays76bird

Actually I just bought a RPM forged crank for $720, 4 inch stroke, BBC rod journal 3 inch main. I read the comments about the offset grind, however I have the .030 probe pistons Ace Brewer used in his P.P.R. 383 kit. They are designed to work with the 6.800 rod and 4 inch stroke. (1.415 pin height) I haven't bought the rods yet. I know I can do the 400 for cheaper if I can find the block, but I want to stick with the 350 Pontiac.

Just make sure you have your local crank grinder check the stroke and all of the journals for taper and out of round. The taper shouldn’t exceed .0002 and out of round shouldn’t exceed .0005. The stroke should be +/- .003-.005. It would be a good idea to have the RA checked as well. An RA of 15 or less is desirable. There is nothing wrong with the 350P. Ace got 485hp out of his 350P based 383. 485hp in a street engine is nothing to be ashamed of.