Replacing rod bolts from the bottom

[skyline_steve]

Is it possible to replace the rod bolts on a RB26 from the bottom by removing the oil pan? Has anyone done this?

[mcfly]

yes it's doable

[skyline_steve]

Doable, is it worth doing since the motor is out? i know the Rod bolts are a big weakness.
If you have any other information please indulge me.
thanks

[4jo3]

the rod that u are replacing the bolts on should be a bottom dead center... it is the only way i could see doing it. so you will have to crank the motor by hand. i think it is a 30mm socket but cant remember. shouldn't be a big deal... just make sure your torque spec is right... which should come with the new bolts. good luck.

[rb-racer]

the engine is going to be out of the car correct?

[skyline_steve]

Yes the engine is out of the car as we speak.

[GT-R Glenn]

I would be very reluctant to do them like that.
You need to be 100% sure the head is seated exactly right on the rod or you run a huge possiblity of braking the head off them.

[4jo3]

how else would you do it? i just took apart a motor... i didnt break any bolts and everything came out easy. mind you, i dont think i'm using the crank, rods and pistons, which shouldn't make a difference but i'm sure someone can use it. So just take your time and everything will be fine. i find i break most bolts when im rushing but i have never broken a rod bolt. Also use a 6pt socket instead of a 12pt... it helps.

[brett]

When you build the motor from ground up that's where you end up anyway. If you want to upgrade the rod bolts, now is the time to do it.

[Crazy 88]

Doable? Yes. Should you if the motor is already out? Not a freaking chance. Don't take a chance of the bolt head not settling right on the rod, if it doesn't it will shift, relax and say bye bye to your rod cap. It's like having sex with some pig you met at the bar at 2am when you were drunk and desperate and not wearing a JimmyHat, you dick might be OK, or it might just fall right off.

I've done it, but on a motor I didn't really care about and it was still in the car. If your motor is out, do it right, pull the pistons.



Jon.

[mcfly]

you had sex with some pig from a bar at 2 am?

Jon, you have surprised me.

[Rapier46]

replacing rod bolts from the bottom...isnt that the ONLY way to do it?

[brett]

replacing rod bolts from the bottom...isnt that the ONLY way to do it?

That's kinda what I just said. You drop the pistons in and then.....??

You can't put the rods and pistons on the crank and THEN drop the crank in, well you may be able to, but that would be insanely tedious and require 6 close friends!

[GT-R Glenn]

replacing rod bolts from the bottom...isnt that the ONLY way to do it?

No, thats the stupid way to do it...
You take the rod out of the block...
Change the bolts make sure they are 100% seated correctly, refit them to the cylinder, etc:
That is the ONLY way to do it.
Its really important to get a rod that uses a headed bolt & a nut, rather than a stud or single bolt to secure the cap, seated correctly.

[brett]

Hey Glenn... what's being said is that you can't put the rod bolts in "from the top". You are just saying to pull the head to remove the pistons to do it out of the block, but I think skyline_steve is talking about a stock block, with stock pistons and just wants to upgrade the rod bolts without tearing down the motor. I know several people that have done this without failure. I agree it's not "ideal" conditions, but not something I would completely avoid in Steve's situation.

[GT-R Glenn]

Yes, I think some of the people who have replied dont realise the question is "replace rod bolts"
And saying putting them in from the bottom is the only way is not correct.
Obviously you can swap a bolt like that, but then you run a huge problem of not seating the head right.
Just look how many failures from rod bolts snapping the heads off are documanted on gtroc and au...
its quite an important part.

[Crazy 88]

Drunk at 2am picking up some hog was a buddy....*cough*, *cough*.



Really though, the motor is out, don't be cheap, if you have to replace the head gasket so be it. If you just put it together don't sweat it, you should be able to re-use the HG with no issues, I've done it many times. If you use spray-copper on a new HG you can re-use it multiple times, my last engine was re-freshed twice with the same HG's, if they still look good no reason not to reuse.



Jon.

[Rapier46]

how the fuck are you supposed to take the rod/piston out from the top when it is bolted to the crank at the bottom? you have to remove and replace from the bottom.

[mcfly]

how the fuck are you supposed to take the rod/piston out from the top when it is bolted to the crank at the bottom? you have to remove and replace from the bottom.

you have the engine out
you removed the oil pan
remove the head
remove the crank girdle
unbolt the rod caps
separate the rods
remove piston out of the top of engine.
:p

[Rapier46]

That is EXACTLY where I ended up with my engine, remember?

[mcfly]

you had issues splitting the caps right?

[brett]

You split the caps on install?

[Rapier46]

A little, I didn't wanna hit too hard, but they were fine after I figured it out.