[CAP632]

Hi there has anyone on here ran a stroke biger than 4.750 in abb 10.2 deck block via a ofset on rod journal thanks

 

[ordinary builder]

explain what you mean by ..."offset"...

a 4.750 crank stroke is larger than common,...allthough some are as long as 5 inches.

or are you confusing this with the smaller diameter ROD journal....???

 

[Bolt]

I think he means an offset ground journal crank, that wound up with a 4.750 storke?

 

[ordinary builder]

then,...without welding,

what stroke is it all starting from...???

you aint going to gain much stroke from a 2.200 journal that is reduced down to say a 1.888" journal diameter...
a legit level of power making engine is going to have strength issues...make it a forging or a billett....



I do not think that by the mannor if his question,

that he understands what he is asking...



PLEASE EXPLAIN...

and then we will do our best to explain.

 

[ordinary builder]

??????

every added stroke crank is "offset"

by what means is different.



a "stock stroke" can be started from a 3.76" stroke...
or
even a 4.000" stroke...

both were "stock" from chebby factory.in a car

 

[LilJohn]

I think he is asking if anyone has started with a 4.75 stroke crank and then offset ground it to get 4.8, 4.85, or 4.91 depending which rod journal diameter you use 2.1,2.0, or 1.88

 

[CAP632]

Your rite liljohn how far can we ofset a 4.750 crankif we use say a 2.0 or 1.880 thank you

 

[LilJohn]

There's yer answers. Glad I could help.

 

[scott foxwell]

Your rite liljohn how far can we ofset a 4.750 crankif we use say a 2.0 or 1.880 thank you

If you offset grind the 2.200 journal to 2.00 (theoretically) you move the center of the journal .100", which increases the stroke by .200" to 4.95 with a 2.00 journal.

 

[LilJohn]

Ok so I forgot to double it. Doh.

 

[ordinary builder]

post reply #9 is correct..
only issue is that most 2.200 journal cranks will not be the correct width between the shoulders to fit a PAIR of 1.880" journal rods.
some cranks, depending on maker and how the oil holes were located and drilled will not accept the smaller 1.88" journal..
...the oil hole passsageway will be thin or break thru...


other issue is the reality that you will have to buy an ODD length connecting rod or piston to get it all to fit.

just buy the correct CRANK with the stroke that you want

proper balancing is allways an issue with the cranks that are over 4.75 stroke...!!!!!!!