swinger340
Well-Known Member
I was kinda thinking the same thing when the guy told me all the work he had done. About like the 68 dart racing in Maine with a big block Chevy in it. It is fast, but id rather see Mopar running gear in it myself. JMO
Off set crank grinding
- Thread starter rumblefish360
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I was kinda thinking the same thing when the guy told me all the work he had done. About like the 68 dart racing in Maine with a big block Chevy in it. It is fast, but id rather see Mopar running gear in it myself. JMO
I would never grind through the hardening on a crank and not reharden it. Why would you think all cranks are hardened. This is the reason you grind a crank and not cut it. Define general purpose. Never running it would be the only safe way. And if you offset grind it who is to say you didn't cut throught the hardening on one side but not the other. Carbon from everyday use will eat a non hardened crank up.
Also when I stated GM rods I thought you would know I was refering to pin size. I wouldn't buy a stock GM rod or any stock rod. But I have done what you are asking about. They used Wisco pistons and eagle H beams GM sized. The deck was 890 and they couldn't get mopar pins under the rings. 14 pulls on the Dyno and the motor was junk. The crank was also egged. Just advise you could use or not.
General Purpose is just driving around with or without performance parts added on. I did not re harden my first crank. The 318 lasted 10 years before I decided on a bigger engine. No issues running or burning oil. No wear on the bearings or crank surface. Ran 14's.
Aaaaa bomber. Consider the cost of a well prep'd engine, it is amazing how some people (here) will poke fun at and ***** over what amounts to just simple lunch money. At least around these parts. Perhaps it's a week worth of groceries for some old people on a fixed budget. But the should t be building engines anyway, lol but your right. Something's are getting cheaper and possibilities arise. Me? I'm just simpley wondering..
Finally,an intelligent tech question!
Finally,an intelligent tech question!
moper
Well-Known Member
In my case - lunch money is significant. Even if that investment is $5, I want $10 back over the service life. That return is easy to get when the costs are low, but spent in the wrong way that ease of return turns into doing things twice and spending twice.
CPMotorworks
Well-Known Member
Just to clear up some things about cranks-
Only steel cranks get any kind of induction hardening/heat treat done, cast iron/nodular iron cranks are not.
Cranks are ground and not cut/turned because grinding leaves a better micro finish and makes it easier to put a corner radius in.
Only steel cranks get any kind of induction hardening/heat treat done, cast iron/nodular iron cranks are not.
Cranks are ground and not cut/turned because grinding leaves a better micro finish and makes it easier to put a corner radius in.
I've never read anything regarding cast cranks not being hardened, BUT it makes sense, because I've torn down literally thousands of engines in my lifetime. I can tell you that unless there was some kinda failure, the steel crank engines had much less crank wear, so that could certainly explain it. I must assume then that the steel crank is actually softer so that it can flex and therefore must be hardened as opposed to the cast, more brittle crank. Would that be correct?
powerwagonpaul
Well-Known Member
Ed
how are you coming up with 300ci? I was "thinking out loud" one day and posted this on .org http://slantsix.org/forum/viewtopic.php?t=42617&highlight=stroker I only came up with 255 cubes. I think it can be done but im not sure your gonna increase your displacement by 1/3
805moparkid
Slant and AFX Guy
I don't want to mud up robs post anymore than I already have with the slant references but you are not thinking outside the box... I can get almost 300ci but I have to find out something's in reference to the deck... pm me if you want more murky suggestions! LOL
No you'll have more than 300 cubes IF you can do the 305 chebbie piston and the 4.5" crank.
Bore X bore X stroke X .785 X number of cylinders (6).
3.875 X 3.875 X 4.5 X .785 X 6 = 318.25616 cubes.
Bore X bore X stroke X .785 X number of cylinders (6).
3.875 X 3.875 X 4.5 X .785 X 6 = 318.25616 cubes.
805moparkid
Slant and AFX Guy
wrong bore, its 3.736"
God! What a weasel little bore. That rounds to 296 cubes.
805moparkid
Slant and AFX Guy
better than 3.4!
Mud away! It's all good. My focus is the 360 crank and its max off set.
(Crap, was it ever answered?!?!)
Post away on the /6! Interesting stuff. Not for me. Couldn't careless.
But I can not see it not being posted!
805moparkid
Slant and AFX Guy
im not sure where your not having your question answered?
CPMotorworks
Well-Known Member
Cast iron is hard, brittle, and wear resistant by nature. Steel is softer and more elastic. The steel needs that hard surface added to increase the wear resistance.
When iron fails it begins to break down fast into grit that chews up the bearings and journals on the crank faster. Steel usually will just build heat and deform/smear.
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