454 v 502 mag cranks, differences?
02-18-2013, 05:00 AM
#1
454 v 502 mag cranks, differences?
My Yr 2000 Gen VI 454 Mag has suffered oil starvation and spun the bearings, one journal is too badly damaged to take a grind so I am looking for another crank.
It appears that 454 and 502 mags have the same one piece forged crank with a 4.00" stroke with the same 6.135" long 7/16" bolted dimple rods. However since the 454 has lighter pistons it seems that the crank counterweights are correspondingly lighter than on the 502 is this the case? certainly MerCruiser quote two different part numbers; 429-811522 for the 454 mag and 429-843083T for the 502 mag.
I would prefer a straightforward bolt-in solution rather than having to get the assembly balanced and therefore presumably having gone from external balance I would need a new flywheel and balancer as well?
So do I need to look for a 454 specific crank? and does anyone know how I tell the two types apart? Casting/forging marks numbers etc.
Anyone got a good uncut one available?
It appears that 454 and 502 mags have the same one piece forged crank with a 4.00" stroke with the same 6.135" long 7/16" bolted dimple rods. However since the 454 has lighter pistons it seems that the crank counterweights are correspondingly lighter than on the 502 is this the case? certainly MerCruiser quote two different part numbers; 429-811522 for the 454 mag and 429-843083T for the 502 mag.
I would prefer a straightforward bolt-in solution rather than having to get the assembly balanced and therefore presumably having gone from external balance I would need a new flywheel and balancer as well?
So do I need to look for a 454 specific crank? and does anyone know how I tell the two types apart? Casting/forging marks numbers etc.
Anyone got a good uncut one available?
02-19-2013, 05:45 PM
#2
Nobody know?
It seems I have answered my own question with a bit more digging, yes it appears the cranks are differently balanced, as best as I can work out: -
454 Mag Gen VI Crankshaft is Mercruiser part# 429-811522 = GM part# 14096983
This forged steel crankshaft (forging ID #14097044) is made from 1053 steel. It is a Gen. V & Gen VI 454 (7.4-liter) big-block design with the one-piece rear main seal. It is externally balanced.
502 Mag Gen VI Crankshaft is Mercruiser part# 429-843083T = GM part# 10183723
This forged steel crank shaft (forging ID #14097044) is designed for use in the 502 cid (8.2-liter) big-block V8. It is a Gen. V & Gen VI design with a one-piece rear main seal. It is externally balanced, nitrided and cross drilled.
Hope that helps others, and if you know of one please let me know.
It seems I have answered my own question with a bit more digging, yes it appears the cranks are differently balanced, as best as I can work out: -
454 Mag Gen VI Crankshaft is Mercruiser part# 429-811522 = GM part# 14096983
This forged steel crankshaft (forging ID #14097044) is made from 1053 steel. It is a Gen. V & Gen VI 454 (7.4-liter) big-block design with the one-piece rear main seal. It is externally balanced.
502 Mag Gen VI Crankshaft is Mercruiser part# 429-843083T = GM part# 10183723
This forged steel crank shaft (forging ID #14097044) is designed for use in the 502 cid (8.2-liter) big-block V8. It is a Gen. V & Gen VI design with a one-piece rear main seal. It is externally balanced, nitrided and cross drilled.
Hope that helps others, and if you know of one please let me know.
