Re: GMForged Rods on Turned 401 Cranks

[Guynn <amx69@xxxxxxxxxx>]

Brien, Lynn,
I must agree with everything Lynn said, but I will also add to what he 
said.[my opinion, yours may vary]

Well  you can certainly turn amc 401 cranks [any of then, 290 thru 401] 
down to different Chevy sizes and you can run cheaper aftermarket rods, 
AHEM.... To some extent. It is not always that cut and dried.

The 401 crank has 2.249 rod journals. Bigger than a BB Chevy. [in fact 
you can use BB rods on AMC] However, when you turn ANY , not just AMC, 
Steel crank much past .020, you have efectively turned off all the 
surface hardening of the crank. You are down to SOFT Forged steel, not 
Heat Treated surface.

So, if you want to run a set of Chevy rods, and have your stuff live, 
yoyou will need to spend money on Crank Prep Work. Follow along for the 
needed work. , On a normal crank turn job, the crank grinders, both 
machine & man running it, they turn down and polish an average of  .015 
off the cranks. Most less than .010, some out to .020, a few out to 
.030. But very, very seldom do they remove .149  the amount needed to 
get even the 2.1 big journal Chevy rod on. The grinder runs longer, eats 
the wheel quicker, the crank work costs more. And, after you pop off 
that .149, you need to get the journals surface treated, PROPERLY. 
Unless you got a free crank grinder and crank heat treat equipment, you 
can expect to spend about $400.00[2 years ago] around here [Texas] to 
get the work done. I know  machine shop prices are almost double that in 
some areas.

Offset grinding can be done when you turn the crank to Chevy size as 
well. Same deal, you need to re-treat the journals. Some shops charge 
about the same to Offset grind as a Straight grind on that big a cut.

Now to Cheap Forged Rods. #1, You get what you pay for EVERY TIME.

The Good Chinese rods start in price at about $349.00 These would be 
comparable to thje SCAT pieces that some thought were too high at $379, 
then $399, then $450, And now I am told $650???? Scat as example sells a 
cheaper I beam rod as well. But they get so cheap that the low ball ones 
you can get for less than $200.00 a set, while the ''grading'' of the I 
beams goes up in about  $269.00 Some other Import rods I have seen on 
Close Outs at $149.00 a set.

So, you get the cheapest junk rods and put on your just done crank, and 
one lunches out on you, WAS IT SAVING A LOAD OF MONEY ON RODS?>?????? If 
you  must spend extra money on the crank in order to run even the Better 
rods, not cheapos, is that really better than just running the same old 
Forged rods that cames in the 401 to begin with???

A ""CLAIMER'' motor is one built to win the race, with the CHEAPEST 
parts you can buy, because someone else you are racing can CLAIM your 
engine for $1500.00 if you win and they pput up the money. This is what 
the El Cheapo import rods are made for, not to use on a everyday drive 
around vehicle, much less a Hot Rod, the person is 'INTENDING I Hope''to 
build and drive And hammer on a fewYEARS.

In my Opinion, If you Want or Need to build Throw Away engines then buy 
throw away parts. If you want to build something to lastr over the long 
haul, buy the better parts..Pretty basic, Quality parts and labor costs 
more than cheap parts and labor. But in the long haul the quality way is 
much better.
CHEAP also comes into play with labor. If you are shopping machine shops 
for the lowest prices, you are just asking for engine machining 
troubles. You shop for a Machine shop by learning if the are competent. 
Once you have found a Good Shop with Good personel, PAY THE PRICE, it is 
much mi, much cheaper than re-doing what gets ruined by the Cheap shop.

If you get an AMC crank ground for Chevy rods, and the person grinding 
the crank does not watch the Journal Radius, you could very well cause a 
bearing seasure, and, if you Cheap out and don't re-treat the journals, 
you will have scrap metal in a short while.
So, Yes, you can indeed Turn AMC cranks and put on cheap Chevy rods. Do 
you save a Load of money?? Not really.

Regards, Randy Guynn