is there an rb25 FSM / guide with info for piston replacement

[ANVIL]

for some reason i always thought this info was in the fsm i have but just tried to look for it and its not. i want to prep myself with what exactly needs to be done when i reassembly my block. no i am not doing it alone but i just want to be prepared and have all the specs/tolerances ect available as well.

wanting pretty much all the info for the crank/rods/pistons to be replaced. thanks

[ANVIL]

Does anyone know if the rb26dett procedures and specs would be the same for rb25det?

[ANVIL]

Bump... anyone who has a built rb any help pls?

[ANVIL]

Bump! Still looking for rb25 specific or if someone can confirm rb26 is the same for assembly

[hanzbrady]

Okay so this isn't RB specific, but engine building is all generally the same. There's not specific values for every engine like many people believe. Your torque settings are basically the values that you hardware can handle while supporting the clearances needed. That's why torque specs change with hardware but not machining. Anyways enough back story, to figure out what tolerances you need you have to specify what your use for the motor will be. For example an all out race built motor will be much "looser" built than an OEM street machine.

[ANVIL]

Well its going to be a summer DD ~6months a yr and weekend warrior for races. Putting in forged internals in the block and new bearings. Will probably be around 400whp when tuned with meth which will be part of DD

[hanzbrady]

Then you're looking at a middle of the road to looser build. You'll be looking for .0015" and .002" for you mains and rods. Don't run any looser than .002" though as that's going to only go bad. Make sure you run an oil that will accommodate what ever clearances you decide to run as well. Something else to consider is your ring gap which should also be wider on a car that's run hard.

On my personal car my clearances are (approximate, I have my blueprint sheet at home to give accurate numbers)

Mains- closer to .002"
Rods- in the .0015"+ zone

And then my rings are gapped as follows

Top- .0022"
Bottom- .0024"

This is a loose set-up built for high boost on my SR20det and will be running Valvoline VR1 10w-30.

This is by no means a "universal" set-up but shows how much builds vary by use.