Thread: ARP rodbolt torque specs

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hello!
can anyone tell me what torque I should use for the arp rodbolts for a FE engine?

the instructions go as far as telling to prestretch the bolts with 50 lbs/ft (doing that 3 times in order to get the desired stretch)

but what I don't see, is the final torque-level...is this 50 lbs/ft also?
I know it isn't as much as the level, used in the books with the standard fomoco bolts...but 50 seems a little on the low side?!

ow...using the arplube and the 190.000 PSI type bolts....

arp molly cut the torque need to stretch them so do it the way it saids. it sounds rigth.i have use a lot of the arp rod bolts torque them the way they tell you if you used oil the torque need would be much higher.

My spec's.. say stock at -40 to 45 & arp at- 53 to 58 which I used 2 years ago on my 428...18,000 miles 475 HP and still buying tires...

Originally posted by hot428ford
My spec's.. say stock at -40 to 45 & arp at- 53 to 58 which I used 2 years ago on my 428...18,000 miles 475 HP and still buying tires...

hmmm...hope to accomplish something like that... but have trouble rotating the cranck right now, so I figure I have it a bit too tight right now! (only two rods mounted at the moment!)

btw, had the bearings checked for size, came out ok...anything else I'm not seeing here?

thanx for the specs!

Did the crank turn before installing rods ? Use any plasti gauge when putting in crank & was it line bored ? Putting mine together with a little lube the crank turned like a window crank before installing pistons then I turned it over with two bolts in the back of the crank and a long screw driver. good luck..

yep! it turned before installing rods...

besides the initial torque I need to get it turning (the moly-compound seems to stick a little?!) it turns relatively easy...

but right now...nope, not one tiny bit of movement

it wasn't linebored, but checked for straightness though (came out ok, not great, but within acceptable limits, at least according to the machine shop...it's not a racer, but a streetblock)

I think I'm going to check if switching the rods will help any...
(maybe I have to go with a designated couple each time?!?!?)

Originally posted by Tommie
yep! it turned before installing rods...

besides the initial torque I need to get it turning (the moly-compound seems to stick a little?!) it turns relatively easy...

but right now...nope, not one tiny bit of movement

it wasn't linebored, but checked for straightness though (came out ok, not great, but within acceptable limits, at least according to the machine shop...it's not a racer, but a streetblock)

I think I'm going to check if switching the rods will help any...
(maybe I have to go with a designated couple each time?!?!?)

molly compound should not be used on any bearing surfaces oil or oil base assm lube make sure you rods housing bores are to size they may be to small when recond con

Originally posted by DennyW
You did mark your rods ??

that's the problem! the rods have been back and forth to the machineshop so many times, I don't know anymore what's what...
ok, so they are matched to a particular piston, numbered 1 thru 8, polished and machined down at the top-end to fit the custom pistons...clearance at wristpintowers is half a mm now...

can't make out the matching pair anymore, have to find out by trial and error, with the available clearance as my guidance...

damn! I should've had them engraved!

finally...
all 8 are in, everything turns and is torqued to spec...pfew!

Originally posted by DennyW
Make sure that piston notch faces forward also in the bore. Glad you got it. Yes, always mark them babies.

well, everything needs to be learned at some time
maybe after I'm done, I might sell and start over!!

got flattops with only one pair of eyebrows, so there's only one possible way to place them (the wrong way, ofcourse!!)

If you look in the rod big end bore, you will see that one side has a wider chamfer than the other. That side faces away from the other rod on the crank pin. It is there to make room for the radius between the crankshaft web and crank pin. If you install the rod facing the wrong direction, it will lock up your enigne. A hard to turn engine is normal. I had to ues a big screwdriver or prybar in my flexplate to roll my engine over during assembly. 7,000 miles later it is still tight but sure runs great.

Originally posted by pat mccarthy
molly compound should not be used on any bearing surfaces oil or oil base assm lube make sure you rods housing bores are to size they may be to small when recond con

The lube ARP ships with their rod bolts has moly in it. It is basically the standard engine assembly lube you buy in the tube at your parts store but with a little extra graphite in it.

oh yes i know what it is . but it hang on for ever and it has no place on the bearing. you can use it if you want . it has grit to it not good for bearings. but i works on new flat type cams and arp bolts or studs push rod ends shoe rocker balls you laces all that crap in the rod and mains and if it throws it on the pistons walls the rings my not seal up oil base or lithium is all i use on the bearings all .that molly in the oil is not good for the rings.on the brake in that why i said oil base assem lube on the bearings

In your fingers that moly graphite lube may feel kind of gritty, but under pressure in a bearing it becomes very slick. So what if it stays on the bearing for a while. That is what it is supposed to do. It stays on the bearing and protects it until there is sufficient oil flow to wash it out. The moly also helps to fill in microsopic imperfections in the surface to make the bearing even slicker. I generously used moly graphite based assembly lubes in my bottom end and in the heads. I just used a little 10w30 for the cylinders.

Originally posted by 76GMC1500
So what if it stays on the bearing for a while. That is what it is supposed to do. It stays on the bearing and protects it until there is sufficient oil flow to wash it out. The moly also helps to fill in microsopic imperfections in the surface to make the bearing even slicker.

that's excactly why I used it in the first place...

I thought it was wise to have some tough lubrication for the first "dry" start, when the engine is finally finished (still have a long way to go though!)
it says it's safe for use on bearingsurfaces and it mixes very well with engine-oil, so it doesn't clog up the oilfilter or any galleries