4.75" stroke RB?

I see Ohio Crankshaft has an overstock sale on 4.75" stroke RB cranks with BBC rod journals...

Anyone build such a beast? Lots of block grinding required, I'd imagine? What would be a good bottom end combination to use it an old style megablock?

Does'nt the 4.750" stroke require the raised cam block? , would think it would be pretty tight otherwise , depending on rods should'nt be too bad clearancing the cylinder walls , i changed from eagle rods & had to clearance the walls another .050" to clear the rod bolts , this was a 4.625 stroke (605" megablock).

The raised cam requirement really depends on the cam being used and the rod type, but assuming this is a race motor running a high lift solid roller, then yes a raised cam block is in order. I built a HEMI with this stroke for a high torque street engine running a hydraulic roller and H-beam rods and it cleared the cam.

On another motor with only a 4.5" stroke and aluminum rods I had to switch to a raised cam block.

Thanks for the replies, the block I have has the std cam location and was looking for crank deals for it.

For a high torque street/strip motor with something like a <.650 lift solid roller (maybe flat tappet, probably not), and steel rods, is it a workable combo?

What would be a good combination of rod length and piston compression height for something like that? It's not too bad to figure out what is theoretically possible but I have no idea what would fit/have the best clearance to other pieces and work the best.

How about a small base circle cam? I think that's how the SBC guys go when they start trying to pack a bunch of arm into a mouse block.

-Bill

I have the OHIO crank-4.75 (8 Bolt ONLY)and have a reg cam location Indy Maxx block..First of all the Crank was spot on..everything checked out fine..i also had them cut .180 off the OD of the counter weights when i purchased it.. it is a chevy rod journel..(2.20) there was a small amount to be clearanced off the rod shoulder,mainly the rod bolt.. i have about .100 of clearance between the rod shoulder and the cam..what i did to help with clearance was to stay smaller on the cam profile and stepped up on the rocker ratio..but donr get me wrong..i do have room to grow and if needed later i will clearance again since i really didnt take that much off of them..i will post pics of what i did..my cam profile with the 1.5 was .700/.715 roller now with the 1.6 rockers i am .747/.765 and that is plenty to make my heads flow and i still have .100 clearance...my block was clearanced for a 5" stroke but dont hink i will ever need it...

here are the pics of the rods and the clearancing done before they were reworked at the machine shop..

2nd pics of rods

3rd view of rods

Yea , had to clearance more for the K1s as opposed the Eagles.

Is 7.100 the workable rod length to go with, then?
Works out to about 1 and 1/4" compression height, give or take?

On paper it looks like 7.000 would leave alot more more room for a street type ring package, but not sure if anyone makes that length for bbc.

Very helpful to see the pics, thanks

i am using the 7.0 (K-1 tech.)long chevy rod and my block is 10.720 deck height and my piston is .008 out of the hole..but my pistons were from my 543ci set up first with a reg rod length ,then i found the 4.75 crank and sold my other crank and rods and using the new crank(4.75) and existing pistons...i needed the 7.0 rod instead of buying a assembly together like you will do..so yes, the 7.10 will be the rod you are looking for... http://www.k1technologies.com/Rods/tabid/57/Default.aspx http://www.flatlanderracing.com/K1-rods.html

Thanks again.

I'm liking the idea of the 1.35 CH the 7.00 rod would theoretically allow at std deck height, no need for oil ring spacers and it could use a standard ring pack...but no guarantee my block will be straight at standard deck either so it's just food for thought. Good to see the rods are a shelf item somewhere, did not know that. 7.100 seems much more common.

Lots of things to consider and think about, appreciate the responses.

Good luck..if you need anything else let me know..

for a street type package you should consider using a 6.800 length rod,leaving approximately a 1.55 C.H.
the crankshaft should already have cam cut counterweights (not round) to allow the shorter rod. that will give you longer service life and a very stable piston and ring pack for long term street use.

Thanks Dan, appreciate the input there.

If the crank doesn't have that feature, I wouldn't be opposed to modifying it.