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after some advice, fitting a known good r34 motor to a gtr, is it advisable to change to arp rod bolts without changing bearings? are the factory bolts a weakness? Id rather not disturb the short motor but if it will be ok to keep the bearings and retourque without taking the caps off im happy to. Also running 264 cams , whats the thinnest head gasket I can use to bump compression up?

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I'd change to arp rod bolts with 400rwkw. (known a gtr to lose a bottom end on the dyno due standard rod bolts at that power level) But there's more than just putting the bolts in however, you need to torque them up then hone the main journal rod end for round and correct size so it's pull engine apart time. I'm not sure how you'd get the rod bolts in without disassembly though (if that's what you mean?)....That said, I have a spare set of standard rods with arp rod bolts that have been resized/honed and are ready to go, pm me if interested

post-48345-0-63929200-1394888689_thumb.jpg

Ah, what rods are in the engine?

If you have standard rods the bolts need to be press fit into the main rod body, requiring removal from engine. I'm guessing you have arp rod bolts that are for aftermarket rods that screw in from the cap side? (These won't work with stock rods- arp also do rod bolts for stock rods that are different). See attached pic- left is aftermarket and right is standard, you can see the difference in how the bolts fit.

Edited by doo doo

What do you know about the history of the block? If you don't know for sure just bite the bullet and pull it apart, measure and replace as necessary (rings and bearings or whatever is necessary for your more than 400Kw goals).

My first reply was probably a little short. There have been a few cars these days running stock rods and bolts over 400rwkw. The main reason I turned away from changing them is because as mentioned above, by the time you fit them, resize the rods, fit new bearings. You will have the pistons out and the head off, it can easily escalate to a full engine rebuild. So it's a bit of a weigh up between, do you risk running the bolts over 400rwkw or invest more money than you were planning on the engine.

At 400rwkw you have more to worry about than the rod bolts

I would be putting a Tomei oil pump and large volume baffled sump on it before i bothered with the bolts. If your that worried about it all letting go rebuild the whole thing and be done with it because you will never be happy with it until you do

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