HomemadeTurbo - DIY Turbo Forum - LS Rod Swap.... How To

LS Rod Swap.....

things you need:

calipers or micrometers
4 ls rods, preferibly w/ same journal #s
1 of your old rods
1 d series wrist pin
12" of silicon bronze (avail @ Crower for $60. shipped)

a lathe
a surface grinder
a drill press
a verticle press

now for my motor i chose to use new Wiseco pistons w/ spiral lock pins.

***YOU CANNOT USE/REUSE PISTONS THAT HAVE PINS THAT HAVE TO BE PRESSED IN***

i reccomend that you get them shotpeened before you machine them, *remember to put the old bearings in them before shot*.

step 1:
measure your stock (old) rod on both ends where it looks machined, twice. (i say twice just so you're sure of what the measurement is)
http://img.villagephotos.com/p/2004-...Picture187.jpg
http://img.villagephotos.com/p/2004-...Picture188.jpg

step 2:
measure the ls rods in the same locations, twice ;)

step 3:
math time!!! subtract the ls rod # from the si rod # and divide by 2.
these are not actual #'s but....
(ls).936" - (si).896 = .040" / 2 = .020" that you have to grind off of each side of the rod. now you should do this for both ends of the rod, but i only did it for the crank journal end and left the other end normal so that the pistons didnt have a chance to wander under high rpm.

step 3:
it's time to goto the surface grinder. (DICSLAIMER) now if you have never used a surface grinder or lathe before, find a place that has a skilled hand to do this. because there's a 95% chance that you will scrap a rod and you will scrap all of the bushings you're about to make.

grind the equeal ammount off of each side of the rod in light passes. approx -.005 Z travel at first, and .001 for finish. now they don't have to be *deadly* but make them as close as possible! Grindhand should take his time grinding. you do not want these heating up.

double check measurements and compare ls to si rods.... happy? ok... to the lathe

step 4:
*same disclaimer as above*.
take your round of silicone bronze and chuck it up in the lathe. 900rpm @ 1.5 IMP. measure the inside of the ls wrist pin journal (should be .827") and measure the si pin (.748)

start turning...... only do one bushing at a time. length is about 1 inch to allow for cutoff bit.
http://img.villagephotos.com/p/2004-...Picture039.jpg

now you're gonna have to oversize the "OD" of the bushing so that it won't spin in the rod, .8285 is perfect (use a good set of micrometers on this!!!)

take the OD to .8285", now it's time to do the ID. get your .625 drill and sink it about 1." into the end of the rod. next comes the carbide boring bar. take small passes when your close to your #. take the si wrist pin and make sure it "glides" in and out real nice, NO SLOP!!! dont forget the chamfer. grab the cut off bit and cut that baby off.

repeat for the next 3 rods

step5: sand the edges and debur the bushings... be carefull tho, there is only .030" wall. these will bend easier than you think.

step 6:

press the bushings in using a verticle press. make sure it's straight, guys. you don't want to have to make any more of these than you have to.
http://img.villagephotos.com/p/2004-...Picture043.jpg

step 7:
Ream. get on the drill press and run it at about 100rpm, travel down slowly, and use alot of thread cutting oil.

now it all depends upon what pistons you are going with. like i said i went w/ Wiseco that have spiral locking pins. so i decided to make the pistons free-floating. if that is the case, use a .749" reamer.

if you are going to press the pins in (FOR FEAR OF WEAR ISSUES) you have to go w/ a .7475" (or pressfit 19mm). this will not put alot of strain on the bushings, it is just to ensure that the pins won't wear the bushings after time
http://img.villagephotos.com/p/2004-...Picture047.jpg
http://img.villagephotos.com/p/2004-...Picture046.jpg

chamfer the other side on the drill press, that you wern't able to do in the lathe.
http://img.villagephotos.com/p/2004-...Picture041.jpg

well i think that's about it...
good luck!
and if you're unsure that you can do it... find someone that can
http://img.villagephotos.com/p/2004-...Picture047.jpg

lates..
mike

just to clear some things up:

now, when i ordered my acl bearings the LS and A6 were the same part #'s

no, there is not any machining needed to be done to the A6 block!

for really good (i mean SUPER CHEAP) prices on ACL bearings($19.65 for the set of rod bearings and $29.68 for the set of main bearings) and rebuilding parts go here... www.autohausaz.com !!!