Building a motor ( I am a noob for a reason)

[1G_FL_AWD]

If a block is bored for a .20 over build do I need pistons forged to match to .20 over bore or do i need rings to match the .20 over difference??

I searched every kind of pistons sold on extremepsi.com and found no pistons that say they are bigger than stock....
but they show piston rings @ 85.5 mm or 85.75 mm....

Like I said im a noob for a reason...i can keep my car running but building the motor is another subject.
someone let me kno wats up...guidance is much needed

 

[slowboy101]

yes you would but alittle advise for you, have a shop build your engine. That way if something goes wrong then you can pin it on them and if you need to know that you needed pistons to match your block then your not ready to build your own engine

 

[1G_FL_AWD]

its not that i didnt kno, its that i couldnt find any on the website no matter what brand i chose...so i second guessed myself,
i wasnt gonna do it myself anyway...

Can you point me to a website that sells .20 over pistons??

 

[donniekak]

EXTREME PSI : Your #1 Source for In Stock Performance Parts - JE Forged Pistons w/ Rings: Mitsubishi Eclipse 6-Bolt DSM Scroll down to options and select .020". Although you would want to have the pistons taken to the machine shop with the pistons to have the bore matched to the pistons.

 

[half-cocked]

You can look through the supporting vendors to find a parts house, use ebay or you can call a dealership for stock pistons. I bought mine from slowboy but that was years ago.

 

[slowboy101]

also check out modern automotives web

 

[KaLo_o]

pretty much all of the pistons on extremepsi has the .020 overbore option, you just needed to scroll down to take a look, it gives you the overbore options. depending on how much horsepower you want will depend if you want forged pistons or not... if you just want a stock rebuilt block, go with topline pistons. they are a good stock replacement and they have a ceramic coating on them. you can buy them on extremepsi

 

[FUNWHEELDRIVE]

If you buy pistons, i wouldnt recoment Slowboy. They have screwed me along with MANY other people. Lots of their parts they send out are USED aswell. Ive seen that many times and i got a used part from them aswell when i ordered new. And than they blame everybody else but themselves.

 

[asb2106]

Ive heard many bad things about slowboy racing. They burned someone around here pretty bad i guess.. in the very recent past.

 

[rx7ttlm]

Ok, it sounds like your rather new. I would suggest having someone build it for you. If you really want to build it yourself you will need to learn a bunch of things like measuring etc. Example, when I send a block to the machine shop for measuting. I dont care who it is, I send the damn thing with instructions. And when you bore and hone a block I tend to hone it to X value larger than the piston. Not just order pistons for the hole you have cause they will rarely be correct for your build when done that way.

But MAP, slow boyracing, magnus, English racing, Automotosports, and a crap load of people sell them .020 over, even summit racing.

ASK questions!!! and get a factory manual read it and love it. sleep with it, read the clearance ranges and understand them. like oil clearance is NOT the clearance on either side of the crank.. little things like that can make the difference between an engine that you blow up at 50k miles or an engine that throws a rod out of the side of the block at 5 miles.

 

[FLASH1970]

Not sure why you're having trouble finding different bore sizes on ExtremePSI. Scroll down a little and under the "OPTIONS" it asks you for bore size. Typically pistons and rings come in a set so you get the proper rings for the size pistons you have.

Take your engine to the machine shop and make sure they have a torque plate for the block. If they don't have a torque plate, then take the engine somewhere else. Once you get the block to the machinist, he'll tell you what size pistons and bearings you'll need. Buy them and drop them off at the machinist. I've had good luck buying from MAPerformance and Extremepsi. The machinist will then machine the block to the pistons. He can also put the pistons on the rods for you, gap the pistons rings, assemble the whole thing...

What are your power goals for the build? Do you want to change the compression ratio at all? What is your budget for the build?

 

[1G_FL_AWD]

its more of a build as I go...with no real budget. Ive got the money for .20 over block (from a good source) and im gonna use the topline pistons...In the next month ill get the crank and rods..just want a fresh motor not looking to make crazy power now. and i dont want to rebuild my motor because its my dd...no time for down time...Ill either rebuild my head or find one and build it.

 

[FLASH1970]

I wouldn't buy a block that's already been bored out without the pistons it was bored out for. Different pistons require different clearances so you really shouldn't just buy a block that's already been bored and just drop pistons in it.

I'm in the same boat kind of. I bought a spare 6 bolt engine to build for my DD. I took it to a machine shop, he told me what bearings and piston size I needed. So I bought some ACL tri-metal bearings, ARP rod bolts, Wossner forged pistons, stock rods, stock main bolts. I was going to go with 2g pistons on 1g rods and machine the rod's wrist pin diameter but there was a clearance on forged pistons so for another 75 bucks I just bought those. Just a basic 6 bolt build but it will handle more than I ever plan on throwing at it.

 

[rx7ttlm]

its more of a build as I go...with no real budget. Ive got the money for .20 over block (from a good source) and im gonna use the topline pistons...In the next month ill get the crank and rods..just want a fresh motor not looking to make crazy power now. and i dont want to rebuild my motor because its my dd...no time for down time...Ill either rebuild my head or find one and build it.

95% of the time you run into clearance issues like that. If your on a budget, I would suggest NOT getting topline pistons. Get 2g or better yet evo 9 pistons. they are less expensive and for the 2g they will take a hammering of about 400-450 hp, and the evo 9's will take more power than you can throw at them in the near future (500 or so hp). Get a set of stock 1g big rods, have them sized, shot peened, and machined for the larger wrist pin. and you will have a good dd engine that you can throw 20 pounds of boost at when you get an itch.