20 over machine shop

[but]

I want to get my block bored .20 over what do i tell the machine shop guy?

 

[jrohner]

You'll need to bring him the pistons. You can't just say a number, have it bored and honed, and then find some pistons and throw em in.

I think you mean .020 over.

 

[LiquidX]

You have to give him the pistons and rings. If you are using new bolts for the rods and mains, you'll have to take the whole assembly for sure. If you don't know what to do, call the machine shop and they will tell you exactly what they need.

 

[spoonman]

We need more information. What parts you will be using? (pistons) What is your horsepower goal and what type or fuel will you be using?

 

[but]

Thanks guys i dont know what i would do without you

I got .020 ross pistons 8.3.1 should i tell him what clearance to set them at or should he know?

 

[LiquidX]

If he is a reputable machinast, he'll know what clearances to run with the HP/goals you are going to run. Did the pistons come with any paperwork about clearances? My Mahles did so that's why I'm asking.

 

[but]

yes they came with paper work that says they require more clearance? i dont know why. I just have a really hard time understanding what clearances are and mean. i read about them but i cant picture them in my head for some reason. It is gong to be my daily driver and i eventually want to get it to 400 whp.

 

[mitsubishi_gsx]

Clearance, as in space between.

IE:The distance between the piston and block. Some pistons expand more than others.

 

[BogusSVO]

what are your goals? how much HP? boost level?

the clearances we are speaking of are the piston skirt to cylinder wall clearace.

.20 is a HUGE over bore... .125 is one eighth of an einch and .250 is a quarter of an inch....

you mean .020 over bore which is twenty thousandths of one inch

 

[but]

My goal is close to 400whp daily driven. i want to run atleast 22psi on a 16g and supporting mods. Ok so the rings have nothing to do with clearance? sorry guys i just dont know these things. Oh and when I go to assemble everything do i need to measure clearnce then also?

 

[Benshooter]

My goal is close to 400whp daily driven. i want to run atleast 22psi on a 16g and supporting mods. Ok so the rings have nothing to do with clearance? sorry guys i just dont know these things. Oh and when I go to assemble everything do i need to measure clearnce then also?

The only thing that will need to be measured on the rings is the gap between each end.

As long as the machinist does his job properly you shouldn't need to re-measure anything when you do the assembly.

If you have the extra money, I would suggest you have the motor balanced as a rotating assembly.

 

[Jankenshank]

it sounds to me like you in over your head,
building a engine to be reliable requires lots of mathematics and measuring, some of which were covered in this thread (piston to wall clearance) over that you have ring gap depending on your compression and PSI rating, bearings....ect

lots of measuring required with a feeler gauge and micrometer.


(but if the machinist is reputable in 4g63's id recommend you have him/her assemble the block at least.)

 

[but]

Ok thanks because i got standard size main and rod bearings i will bring along to the machine shop with me.

it sounds to me like you in over your head,
building a engine to be reliable requires lots of mathematics and measuring, some of which were covered in this thread (piston to wall clearance) over that you have ring gap depending on your compression and PSI rating, bearings....ect

lots of measuring required with a feeler gauge and micrometer.


(but if the machinist is reputable in 4g63's id recommend you have him/her assemble the block at least.)

I want learn on my own i have to start somehwere why are you trying to put me down?

 

[mitsubishi_gsx]

He's not putting you down, he is trying to save your engine.

 

[LiquidX]

He's not putting you down, he is trying to save your engine.

+1

I understand you want to learn how to do this and the best way is to have someone else walk you through while building it. That way, you are doing the work while they are supervising you so you don't forget something or jack up a measurement. One mistake can cost you a new motor.

You already ordered main and rod bearings, did you get measurements on the crank already and have it micropolished if it's not brand spanking new? Are you going to be using aftermarket bolts/studs internally? If you do, you need to get the parts machined to ensure 100% roundness and that will affect the bearing as well. You shouldn't buy anything until the machinist say's what is able to be used. Just FYI

 

[Benshooter]

I completely support a DIY attitude, but this isn't something where you can just "wing it"

People who know engines (even ones as basic as essentially basic as a 4g63) admire how much stress, precision, and organized chaos is going on in there and you need to respect that or you'll end up on the side of the road waiting for a tow.

IF you buy the right tools, do enough reading and research, you MIGHT be able to pull it off. If you've never overhauled an engine before, I wouldn't suggest doing it yourself. If you don't have a spare engine or car, I wouldn't suggest doing it yourself.

I've built more flat-4 VW engines and V8's/V6's than I care to admit but you can get away with a lot more on those. I'm still nervous about rebuilding a 4g63 and when I do I'll still have the machine shop down the street double check all my work and numbers for me.

+1

I understand you want to learn how to do this and the best way is to have someone else walk you through while building it. That way, you are doing the work while they are supervising you so you don't forget something or jack up a measurement. One mistake can cost you a new motor.

You already ordered main and rod bearings, did you get measurements on the crank already and have it micropolished if it's not brand spanking new? Are you going to be using aftermarket bolts/studs internally? If you do, you need to get the parts machined to ensure 100% roundness and that will affect the bearing as well. You shouldn't buy anything until the machinist say's what is able to be used. Just FYI

Aaaaand you beat me to it.

 

[but]

+1

I understand you want to learn how to do this and the best way is to have someone else walk you through while building it. That way, you are doing the work while they are supervising you so you don't forget something or jack up a measurement. One mistake can cost you a new motor.

You already ordered main and rod bearings, did you get measurements on the crank already and have it micropolished if it's not brand spanking new? Are you going to be using aftermarket bolts/studs internally? If you do, you need to get the parts machined to ensure 100% roundness and that will affect the bearing as well. You shouldn't buy anything until the machinist say's what is able to be used. Just FYI

oh ok i didnt know. i already ordered main and rod bearings. the engine ran fine before it just had 130 thousand miles on it. i am reusing my oem crank with eagle rods. I wish i had someone to walk me through it but i dont.

 

[LiquidX]

oh ok i didnt know. i already ordered main and rod bearings. the engine ran fine before it just had 130 thousand miles on it. i am reusing my oem crank with eagle rods. I wish i had someone to walk me through it but i dont.

In that case, you'll need to take the crank with you to get gauged and micropolished. There is a slight chance that it'll be needing oversized bearings, but prob. not. If you use the ARP2000 bolts that come with the rods, you'll be fine without having to check roundness on them as they are pre machined.

Just call the shop and see what they tell you about what you'll need. MAYBE they can show you how to rebuild the motor and for a fee supervise and/or show you how it's done.

Good luck with it but just remember, it's better to research for 2 weeks than to buy 2 weeks in advance.

 

[but]

Hey thanks man i really appreciate your patience and knowledge sharing it with me it means alot to me.

 

[LiquidX]

Not a problem, that's why we are here. Grantid this has been discussed before about rebuilding a motor and a lot of people will say use the search button. I'll help out when I can.

 

[but]

I just didnt know that i would have to measure my rod and main bearings after the block has been machined. I use a micrometer and T gauges for that i read. You have helped me alot if i could send you some money i would,but obviously you cant send money in the mail haha

 

[LiquidX]

Well your welcome, just make sure you really talk with your machinist and discuss what you are planning to do and he will also tell you exactly what he will need from you. Mention any internal parts you are going to be using. Remember, the motor isn't just some pieces of metal, it's a precision machine and every single part needs to be in harmony with the whole to function properly.

 

[but]

thanks again!!! I will end this thread now so it doesnt become a huge long thread.