GM Forged Rods on Turned 401 Cranks

["Nick P Alfano" <nick.alfano@xxxxxxxxxx>]

Brien,

Yes it is true you can turn down a 401 crank to fit a GM rod but saving 
money by buying Chevy rods you won't.  By the time you pay the cost to 
turn down the crank (about $300), buy the rods (another $300-500 depending 
on rod and similar rods to the H-beam 360 rod will cost as much or more), 
custom pistons to run with floating pins and the Chevy rod length and then 
the extra fitment and assembly time, you will spend far more money than 
just taking the same crank and turning it down to use the H-beam rods and 
then buy the floating 360 we already have available.  390/401s already 
have forged rods so if you were sticking with that combination, there is 
no need for a different set of rods unless you are either going with 
extreme horse power and RPM or yours are damaged and you can't find 
another set.  This is why the 290-360 rods were built and the 390/401 rods 
are being built to be stock replacements and not some off the wall 
combination like someone on the list thought they should be made.  Make 
them so that they will fit the majority of what is out there and let the 
few who want something more specialized to either alter them or buy 
something custom.  Also, when fitting parts not originally made to fit our 
engines, the assembly costs go up.  Don't let people kid you into thinking 
you can save money by buying Chevy parts.  When it comes to custom parts, 
they are all relatively the same.  For off the shelf parts, a stock 
replacement Chevy part itself might be a few dollars less, but all the 
other associated cost, with fitting them to an AMC engine is going to be 
much higher.  The H-beam rods and Ross pistons are the same or less money 
than the same Chevy part (notice the notation to same as in quality and 
style).  I hated it that we had to go buy these other make parts for our 
engines just because parts designed for AMC weren't available in the past. 
 Yes, you can get creative and make different length rods, different pin 
diameters and so on but that will not fit the majority.  Since pistons and 
pins are readily available to fit all your stock parts, there was no need 
to make the rods fit a Chevy pin and the slight difference in size would 
be negligible in regards to weight..  If Scat would have made them they 
way they were told, you could have put them right in with your stock 
pressed pin cast pistons if you so choose to.  There was no communication 
problem with them like some would like you to believe.  They were told on 
many occasions Don and myself, were sent stock rods to go off of along 
with the spec sheets they had on them and the contract from Don that 
stated what was suppose to be made.  They just screwed up, plain and 
simple.  They even told us once that they had a rough finished rod in 
their hands and how they were done in an I-beam pressed pin which was 
totally false.  I said, Kirk, you physically have it in your hands right 
now and he said yes, they should be done in a week.  That was 3 months 
before they were really done.  In reality, they didn't even have the cores 
from over seas at that time and were just trying to string us along.  Then 
it was, oh did I say I-beam, the foundry sent us H-beam cores.  Again, oh, 
you wanted pressed pin with only 10 sets bushed, well my guy in the 
finishing area doesn't understand English very well and he machined all of 
them for bushing.  In fact, they were told at the end before they started 
the finishing work to not bush any of them because it was going to take 
longer.  The only reason we asked for 10 sets to be bushed was we had a 
few guys who wanted floaters and having Scat do the from the start would 
save the buyer at least $175 verses buying a pressed set and having their 
machine shop bush them.  That is what this is all about, getting the right 
part, designed for an AMC engine at a big three part price.

Now for a 360 stroker combo, you can take a 401 crank, turn the connecting 
rod journals down to 2.09, put it in a .030 overbore 360 with 360 rods and 
have approximately a 391.  You might have to notch the block slightly but 
that is par for the course.  This should be a stump pulling, high 
torque/good horsepower engine combination that should out perform a 
regular 390 for most purposes and it won't break the bank.  Offset grind 
the crank and you can play with cubic inch numbers up and down around that 
and get a real nice rod/stroke ratio.  Rod/stroke ratio is something you 
need to think about when stroking or de-stroking and engine.  It will 
determine how much RPM you can spin as well as how fast and how 
efficiently it will turn those RPMs.  It really depends on if you want an 
engine with a ton of torque and middle range RPM (5500 - 6000 redline) or 
do you want a high horse power, high RPM spinning engine.

Nick Alfano



Isn't it true that you can have the 401 crank turned to a GM
dimension - thus saving a pile of cash on Forged Rods ?


             Brien.
         NEW YORK
   eagle registry #501
eagle kammback registry