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Motor Pull Down And Put Back Together,need A Mechanics Point Of View Please

Gtir-keiron

By Gtir-keiron,
in Engines & Forced Induction

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Gtir-keiron Community Regular

Gtir-keiron

Posted
Posted (edited)

Say i have a forged motor for argument sake a rb26.The motor has a full forged bottom end crank rods pistons and so on.

The kit is pulled out of the block and not marked,

So piston/gudgeon pin/rod are not marked where they came from.Even the rings are in a pile....

Any one offer some insight if this can go back together saftly

Is that a massive head #$%^ and if they don t go back together the correct way is it catasrophic failure time?

Any one shed some light on this as im not a mechanic.

As much detail as possible please.

Edited by Gtir-keiron
Gtir-keiron Community Regular

Gtir-keiron

Posted
  • Author
Posted

Its been running,Pulled apart

My mechanic told me that the gudeion pins have to go back where they come in the same way they came out. from also the pistons have to go back on the rods they came from and so on and so on.

I was planning on doing new rings and bearings but i wanted to know about the other stuff.

My mechanic is anal......Things have to be perfect.. in his world of putting motors together.

just wanted a performance opinon.

Supa Steve Enthusiast

Supa Steve

Posted
Posted (edited)
Its been running,Pulled apart

My mechanic told me that the gudeion pins have to go back where they come in the same way they came out. from also the pistons have to go back on the rods they came from and so on and so on.

I was planning on doing new rings and bearings but i wanted to know about the other stuff.

My mechanic is anal......Things have to be perfect.. in his world of putting motors together.

just wanted a performance opinon.

Your mechanic is a guy who is trying to pose as someone who knows what he is doing.

Linish pins, resize and balance conrods as well as balance pistons and it doesnt matter what is what. As when they are balanced the piston and pin are matched to avoid taking too much off the piston. If you had a light piston and pin matched together you would have to grind excessive material off all the other pistons to get them to match up.

Someone who suggests putting an engine together without doing this clearly has no idea. Id say you grab your gear and go elsewhere mate.

A quick look at the early failure poll thread will show that there are a lot of guys who take on RB's without the experience with the poor customer footing the bill. Ive screwed together quite a few engines in my time but when i opted for a big dollar bill i went to the experts so the job was done right.

Edited by Supa Steve
Gtir-keiron Community Regular

Gtir-keiron

Posted
  • Author
Posted

Oh thats not what im saying.

Im saying he wants to know what gudeon pin came out of what piston and what rods it was connected to and what order the pistons were in.

Like i said hes anal about things when it comes to building motors.Hes a very good mechanic with alot of exp with RB Sr and nissan engines but sometimes i feel hes over the top and i don t want to spend money where i don t need too.

he already said i would have to replace the rings and bearing and i new that from the start.

Thats why im asking what my options are.

If i can get it all balanced and set up to as new or better then it should not be a problem yes?

thats why i wanted detailed infomation so i had options rather then him telling me i need to replace pistons and pins and things like that.

Supa Steve Enthusiast

Supa Steve

Posted
Posted
Oh thats not what im saying.

Im saying he wants to know what gudeon pin came out of what piston and what rods it was connected to and what order the pistons were in.

Like i said hes anal about things when it comes to building motors.Hes a very good mechanic with alot of exp with RB Sr and nissan engines but sometimes i feel hes over the top and i don t want to spend money where i don t need too.

he already said i would have to replace the rings and bearing and i new that from the start.

Thats why im asking what my options are.

If i can get it all balanced and set up to as new or better then it should not be a problem yes?

thats why i wanted detailed infomation so i had options rather then him telling me i need to replace pistons and pins and things like that.

i think you may have missed it so i will put it a bit more direct.

it means 3/5th's of f*ck all where what came from except for the rod caps which are generally numbered and anyone who tries to tell you otherwise is giving you incorrect information. Clean everything up and weight-match to ensure best clearance and minimum grinding of pistons. Rods NEED to be resized and balanced to ensure they are exact. If he is as pedantic as you state then this should be a given for him to understand. Pistons and pins will only need replacing if the pin has flogged out the bore of the pistons and/or bent the pins.

properly prepped and assembled serviceable parts will have your engine as good as new.

best of luck

Adriano Grand Master

Adriano

Posted
Posted

As steve said, everything can be measured to confirm where it goes, however if there is no discernable difference when measuring, then it doesnt matter where they go. Then check balance and assemble.

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