quick question on engine building:

i'm fully aware of checking PTW, bearing, ring gap, etc clearances, i'm only asking a "what if" question.

if you have a straight OEM 4g63 block and you are putting a non-cut (but micro-polished) OEM crank, pistons, rods with standard bearings, (new) thrust washer and (fresh) rings back in.. what is there to measure, really?

does the 4g63 vary from engine to engine so much that they may not fit?
has anyone ever had to machine a crank to fit oversize bearings in order to get proper clearances? has anyone ever seen them too loose?

THEORETICALLY, it seems you should just be able to toss it all back in and be done.

just wondering. i'd really like to put my engine together myself, as i have bad luck letting other people touch my car. but, if i let a shop put the OEM parts back in, the labor will kill me and the car will have to wait a year or two (focused on school right now).

i really like working on my own car and would prefer to say i did it. that's the most fun. but! i'm not going to ruin another engine because i insisted one DIY LOL.

i guess plastigauge is cheap.

 

You should always measure clearances. Including: piston to cylinder, rod and main bearing, rod side clearance, and ring end gaps.

 

While you should measure clearances if you are using all oem parts you shouldn't have a problem.

Oem cranks and blocks are marked with size codes that you can use to determine the right size oem crank and rod bearings.

I would suggest you take the measurements anyway. It will be a good learning experience.

 

cool that helps.

i once built a Honda engine. it was also clearly marked for bearing sizes. i ordered and installed them as needed and still ended up eating bearings. i was ... "less than happy".

not looking to go through that again. for the third time (i didn't build my last motor).

did a quick google search and can't find OEM bearings in different sizes. maybe i should contact the dealership.

 

Okay, so Mitsu does color code their bearings, I just have to find and decipher the crank, rod, and block markings then buy the right sizes.
$160+ for rod bearings, $250+ for mains. Ouch.
No wonder people use King/ACL/etc.

 

So, you could save $300 just by using aftermarket bearings. That pays for a competent machine shop to assemble the bottom end for you, FYI...

 

true. i'm not TOO trusting of local shops for short block builds, unfortunately. if i used one, i'm sure i'd have to supply the specs, which i can do, assuming they are all in the service manual.

i guess if i give them the specs, it's kinda hard for them to screw it up LOL. like i said: i just have really bad luck letting other people work on my car haha.

at least if i have someone else do it, i have a spec sheet to refer to and someone to go to if it all goes wrong again.


***EDIT: i found OEM rod bearings for $140 and main bearings for $150 + shipping and tax. better.