Is it possible to replace rod bolts without droppin the engine out of the car?? only reason i ask is because i want to put arp rod bolts in my LS block .. soon ill be putting brain crower stage 2 cams.. spring and retainers in my LS and i want to rev higher but i've been told that ls stock rod bolts cant go pass redline

 

short answer: no

you have to have the old bolts pressed out, new ones pressed in, and the big end's resized.

 

??? i thought you just unscrew the old ones and then screw the new ones in...... by pressing out did you mean the wrist pin? that connects the rod to the pistons?..im not changing the whole rod.. just the bolts at the bottom that hold the rods to the crankshaft..that are attatched to the caps that have the rod bearings

 

yes you can been done before

 

Stock piston rods have rod STUDS, not bolts. The cap is installed, and then nuts installed to hold it on. I believe ARP makes rod bolts, but stock uses studs.

So no, you cannot replace them with the engine still in the car.

 

Ook ... i did not kno they had studs..i bought eagle rods and they came with arp rod bolts..i thought stock rods would be the same setup.. but thanks.. i rather just finishin buildin my block out of the car lol

 

yea stock engine uses head bolt and rod studs, while ARP changes them to head studs and rod bolts LOL.

I read a really good explanation on the head studs - that being that stock head bolts pull up on the block, while ARP studs/nuts pulls down on the head, thus making for a better seal. I suppose there is some similar benefit from changing the stock rod studs to ARP rod bolts.

 

You just made things 100% clearer for me ..thanx.... it makes sence so you wont blow your engine revin at 9grand

 

Well I don't really know how much ARP rod bolts would help an engine be able to withstand 9000 RPM. The big issue there is things like valve float, which is what upgraded valvetrain components are for.

 

Are you sure? And in what sense would they be "studs"?

Because they come out, and go in just the same as the ARP rod bolts.

The stock LS rod bolts aren't threaded into the rods, just pressed easy,
with a nut on the bottom to lock everything down.

Not trying to argue, just do not think they can be considered studs.

 

i have changed the rod bolt/stud on a ls from factory to arp and did not take the motor out of the car

 

Can someone clear this up, I'm hearing 2 difference thing. I'm in the process of replacing my b20V with Arp rod bolt. I really don't want to take my motor out again can you just take off the oil pan and replace the stock one with Arp?

 

Yes with the motor still in, but the crank and block must be removed.

 

cant you leave the crank in and just remove the oil pan and head. pull the piston and rod out from the top??

 

my bad, I was looking in my Helms manual and it didn't show them as bolts, it just showed the threaded portion of the bolt sticking out of the rod, so I thought they were studs.



That shows them, but since the bolt head is on top, the piston would have to come out of the block.

But take it from me, if you're going to go to the trouble of dropping the oil pan, pulling the engine head, removing the crankshaft, probably replacing bearing and doing all the plastiguage stuff - just pull out the whole engine! It will be 1000x easier doing all that with the engine on a stand than while it's in the car.

 

Yeah, that is actually the only way since the rods can't be removed from the bottom of the block.

 

you dont need to pull the head just the pan

 

If you don't remove the head, how will you remove the rods to resize the rods after the arp rod bolts have been pressed in?

 

why would u need to resize the rods if your just changing the rod bolt

 

My machine shop guy said after pressing in arp bolts there is a possibility of the big end warping or changing shape/size when torqued down. Might even have to due with the arp bolts being of stonger material. Either way he said I would need them resized after the new bolts were in.

 

See I'm still hearing all kind of difference thing.

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01-08-2009 09:25 PM
iwanttokillgod Re: Replacing rod bolts

i have changed the rod bolt/stud on a ls from factory to arp and did not take the motor out of the car
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Quote:
Originally Posted by iwanttokillgod
yes you can been done before

Yes with the motor still in, but the crank and block must be removed.
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Quote:
Originally Posted by iwanttokillgod
you dont need to pull the head just the pan
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If you don't remove the head, how will you remove the rods to resize the rods after the arp rod bolts have been pressed in?
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why would u press them in if you just have to screw the bolts in and torque them properly????

 

what is number 3 called in that diagram

 

that what i thought too screw the off and torque them back to spec.

 

has anyone ever done it before?