Youngthrill
69 GT
so i have came across a few threads were people say they put a 273 crank into a 318.....but never really specified why...shorter stroke ???gain rpm or do you gain torque is my real question...:colors:
Does it not also depend on the year of the 318? The older ones are steel.
Didn't truck 318 have a steel crank as well?
Does it not also depend on the year of the 318? The older ones are steel.
Actually the 273 rod is a little bit heaver than the same bushed 340 rod...The 273 cranks are forged, but the main reason is weight. They are a good bit lighter than the 318 cranks. Much like the 273 rods.
Actually the 273 rod is a little bit heaver than the same bushed 340 rod...
I was surprised when I was balancing up Vic's 273 as to the weight of the big and small ends.
:coffee2:
Check your 318 crank and see if it's a forged one. If it is, use it. If you're not running over 400HP I wouldn't worry about a cast crank. The converter might be an issue if you need a particular high stall one for racing as it will have to be made. Having the crank drilled might be a better option so you have many more converters to choose from. If you're running a manual trans, the only issue is the pilot bearing. You would have to have a bushing made for the crank if it's the automatic version and not finished. Every one I've seen is drilled deep enough but some just didn't get the final machining for the bushing. The crank bolt pattern is the same for all V8's (except hemi) as far as I can remember.so one of the 273's i bought had a forged crank....next step im going to use that for my 318 build....is this converter thing going to be a big issue?? im useing the 904 i currently have..well im going to rebuild it..what sort of converter should i be looking for....or should i use the original 318 crank??
Just the 273 and slant 6 had a small converter hole and only up through '67.Depending on the year of your 318,
The deference could be the pilot hole in the center of the crank for the converter. I an not sure of the year but the early small blocks have a much small pilot hole, than the later ones. I think all 273's are the smaller hole. Really narrows down converter selection. But I to have been thinking about using a foraged 273 crank on my next engine. I would think any machine shop could open the pilot hole up to the later size. At least that is my hope!
Good to know!Just the 273 and slant 6 had a small converter hole and only up through '67.
What would be the p/o#'s on the forged cranks??
The '68-71 318's were mostly cast cranks too. Some truck and other industrial engines still used forged ones, even after '72, but not all. I mainly found them in manual trans applications. All the '67 and earlier small blocks had forged cranks. In swapping around small block internally balanced cranks between engine years and sizes, always check the converter hole diameter, pilot bushing hole if it's a manual trans application, and rebalance the recipricatiing assy as the bob weights are all different. Use the balancer that matches the year of your pulleys.318's had forged cranks until 72. No benefit to using one really.