8 bolt crankshaft stroked to 3.900

[BIGWILLIE]

I have a 8 bolt std main std rod stroked to 3.900 for my 426 hemi engine.
What is the best engine to use this crankshaft ?
I bought it from Mile High Crankshaft as a new shaft.
We are changing the plan build to a 8 bolt 4.150 stroke shaft for the 426 engine any help will be appreciated.

Will sell this crank and buy a new 4.150 shaft.

Thanks Willie

 

[Fran Blacker]

Need to put it in a for sale ad. Ad should have main and rod journal size.

 

[Budnicks]

If it had the B-engine 2.625" main journals ground already
(RB is 2.75" mains)
it'd be the best bang for the buck, get std bore. 4.25" 383/442cid
(is + 59cid)
to around 455cid cid 0.060 over 4.31" out of a 383cid
or a 400 B, 4.35 std bore = 463cid (is + 63cid), 4.40 bore max = 474cid
again expensive pistons
when you can get them with a 4.15" stroke combo
easily & find pistons off the shelf (or a 4.25" or 4.5"strokes even)
not many people running that 3.90" stroke combo anymore

used to be an 0.200" offset ground deal,
somewhat affordable combo
when people weren't forging all kinds of crankshafts
in something other than stock strokes
& they were usually running BBC 2.20" rod journals, smaller rod journals
in that offset ground crank too

I had one in a 426 MW with a blower, in my altered way back in the early 80s
with a std bore 426cid 4.25" bore x 3.90" stroke = 442cid
vs std 3.75" 426cid
3.90" stroke, it only gains 16 cids...
(Joe Pisano's) Venolia pistons/flattops with valve reliefs
& Childs & Alberts, rings, rods & bearings

formula;
bore x bore, in inches x stroke, in inches x #of cylinders x 0.7854 = cid

In an RB block 0.150" more stroke, doesn't add a bunch over a 3.75" stroke
when the 4.15", 4.25" & 4.5" are all relatively readily available
pistons 3.90" crank/stroke combos will be harder to find,
probably not off the shelf anymore
&/or custom rod lengths etc.
not a big bang for the buck/$$$

sorry not trying to burst your bubble, may be a great crank

good luck

 

[BIGWILLIE]

If it had the B-engine 2.625" main journals ground already
(RB is 2.75" mains)
it'd be the best bang for the buck, get std bore. 4.25" 383/442cid
(is + 59cid)
to around 455cid cid 0.060 over 4.31" out of a 383cid
or a 400 B, 4.35 std bore = 463cid (is + 63cid), 4.40 bore max = 474cid
again expensive pistons
when you can get them with a 4.15" stroke combo
easily & find pistons off the shelf (or a 4.25" or 4.5"strokes even)
not many people running that 3.90" stroke combo anymore

used to be an 0.200" offset ground deal,
somewhat affordable combo
when people weren't forging all kinds of crankshafts
in something other than stock strokes
& they were usually running BBC 2.20" rod journals, smaller rod journals
in that offset ground crank too

I had one in a 426 MW with a blower, in my altered way back in the early 80s
with a std bore 426cid 4.25" bore x 3.90" stroke = 442cid
vs std 3.75" 426cid
3.90" stroke, it only gains 16 cids...
(Joe Pisano's) Venolia pistons/flattops with valve reliefs
& Childs & Alberts, rings, rods & bearings

formula;
bore x bore, in inches x stroke, in inches x #of cylinders x 0.7854 = cid

In an RB block 0.150" more stroke, doesn't add a bunch over a 3.75" stroke
when the 4.15", 4.25" & 4.5" are all relatively readily available
pistons 3.90" crank/stroke combos will be harder to find,
probably not off the shelf anymore
&/or custom rod lengths etc.
not a big bang for the buck/$$$

sorry not trying to burst your bubble, may be a great crank

good luck

Thank you very much I had a hint it was not going to be a good crank for my 426 just wanted to be sure, Do you have any experience with the eagle cranks they seem a bit cheaper than others. I hate to match price with quality but without asking how would I really know cant believe the salesmen.

Thanks again for your help on the project.

 

[Fran Blacker]

Domestic Crank Shafts – Molnar Technologies

 

[Budnicks]

If I was building an all-out racing 10,000 rpm & boosted
these 3 below is who I'd source one from 1st
or high compression like 15:1 NA 10,000 rpm combos
#1 Callies
#2 Molnar
#3 Ohio Crankshaft

I've had good luck with all of them 3 above
type of material used in the crankshaft & style or diameter of the counterweights
or rod journal sizing too, can vary vastly & any of the harder & or lighter
more exotic materials cost more, and billets are way more
Malory heavy alloys, used to balance them, aren't cheap either/rare earth materials

if you're building a street strip car up to like 550 10:1 comp.
to outside ranges of a *11:1 - 12:1 comp. 750-800hp-ish
9-10-11 second car combo
or a milder (like upto 7,500rpm NA or even mildly boosted) 'race combo'
maybe something from these 4 established suppliers below

*need good cylinder heads to flow just as well

Eagle
(is a reputable product, for the cheaper performance lines)
I've had a couple wedges with Eagle Cranks & Rods,
no failures
even running 8.58 @ 156 on N2O

Scat
(has 8 bolt cranks too, other cheaper performance lines)

440source
(has a couple 8 bolt cranks/strokers, but IIRC they have 2.20" BBC rod journals,
{hemi rod journal, std in 2.375"} lots of rods to choose from going that route,
all depends on exactly what you're building
& how it's going to be used, with the std. sized Hemi/RB 2.750" main journals)
they have a lot of in-house or "Made in USA" parts
they have come a long way in the past 10 year
affordable too

Mancini Racing
(has a decent selection, most are Eagle 4340 Crankshafts IIRC)
4.15" stroker kit, rods pistons rings bearings crank is like $2,800

that'll give you a few to research

-------------------------------------------------------------

Ray Barton

or

Arrington Hemis are good sources too

or

Keith Black

you do get what you pay for, go big buck for big power