Built engine- 3sgte

[Redlyne_mr2]

To many track days, to much boost, to many awesome times = time for a new bottom end.

Engine is a gen 3 3sgte 2.0l

Precise has my shortblock right now, I'm having new forged pistons installed and I wanted to list off everything that's being done to make sure I'm not missing anything.

Polish and balance crank
Install new pistons (overbore)
Install new race bearings (rod and main)
Shot peen and resize the rods
Deck the head and the block
Install new frost plugs
Clean everything

Am I missing everything?

thanks

[stevo 27]

ryan are you gonna get them to put in arp rod bolt's before they resize the rods?

while it's there might as well do a line bore/hone to make everything nice and straight

a inline 4cyl is a neutral balance so all your rods and pistons have to weigh the same just balancing the crank wont do anything

ive seen pistons out of the box with a 6-8 gram variance

[Redlyne_mr2]

Originally posted by stevo 27
ryan are you gonna get them to put in arp rod bolt's after they resize the rods?

while it's there myswell done a line bore/hone to make everything nice and straight

Yah Steve,
What do you think of rod bolts? Necessary?

I'm assuming they do the bore when they install overbore pistons. What happens when they line/hone?

[stevo 27]

rods bolts yea why not you have to resize the rods after you put in new bolts ( thats the most expensive part) the bolts themselves are cheap so since your resizing the rods anyway why not put some in.

yes they will bore/hone the cylinder walls to match the new larger pistons what are you going .030 or .040 over?

a line bore/hone is when the bore/hone the crankshaft mains

so everything is perfect round , straight and true

[tomt64]

Make sure you ask them how much they decked the block and head, too much will affect compression ratio. Use this to help determine head gasket thickness you want to run.

What power are the stock rods good up to?
How much did you tell them to bore out the cylinders?
What piston size did you give them? Just looked up stock bore and stroke is 86mm each.

If you gave them crank/rods/pistons they will balance rotating assembly if they are assembling your bottom end regardless.

[Redlyne_mr2]

Yah I'll just have it lightly decked, I'm using a new stock headgasket (metal from the factory). You're right stock is 86mm, going to 86.5mm. Do I want to buy stock rod and main bearing? I see that large ones are available but I'm not sure why you would want to up the size of your bearings.

Stock rods are good to 700hp or something like that. So yah the rotating assembly will be completely balanced.

[texasnick]

Bore and Hone the cylinders....they'll have to do this for O/S pistons anyways

.....and definitely use new rod bolts. For the amount of money they cost, and how much of a PITA it would be to tear the motor down again if they give you might as well.

I would get some forged H beam rods just to have the added security, but from what I've read the stock rods don't seem to fail much.

Don't bother with O/S bearings, just use Toyota ones and make sure that you size them right when you're building it.

Only other thing I can think of is a metal headgasket (gen 3 HG should be good to go) and new headstuds.

Also might be worth considering a new timing belt, tensioner, water pump, seals, gaskets, all those kind of things. Might as well get them out of the way while the engine is out.

Also, weighing and matching each piston/rod assembly is really good advice. They are usually a few grams off from eachother if they are off the shelf parts.

If you don't mind me asking, what let go in your motor and what boost were you running at?

[Redlyne_mr2]

Why is it a waste to go with race bearings? Rod and main bearing are around $200, can't see Toyota being much cheaper but I'll check it out. In terms of sizing how do I know if they're sized right. Since I'm only changing the size of the pistons and the rods I'm assuming I can use std size rod and main bearing correct?

All other gaskets, seals, t belt, waterpump, oil pump, etc etc are brand new.

thanks for all the help thus far everyone.

[Ymerej472008]

From what I understand ACL Bearings come in 3 sizes? (correct me if I'm wrong) Maybe just with Honda's?

"Standard" is the most common size, Ive also *heard* guys that measure them with a Vernier and they are out by a couple thousandths.

Don't quote me on that though, its just something out there that you could research upon. Call some high end shops and ask for their opinion?

[texasnick]

I can only really speak on behalf of the Honda engines I've dicked around with, but there are typically like 6 different OEM bearing sizes for each engine. In the Honda world they are referred to as "colors". On the block and on the crank there are letter codes like KJG or something like that which corresponds in the FSM of the car with a specific bearing "color". There will also be a standard clearance range which is considered by the manufacturer to be acceptable.

OEM bearings will likely be more expensive than a set from ACL or similar. Aftermarket race bearings claim this and that about reduced friction coatings and materials and what-not, but I don't think that they amount to any sort of increased reliability as long as you size and install them correctly.

I would personally just go for OEM for simplicity's sake, but by all means I see no reason (reliability or performance wise) to not get aftermarket bearings if the price point is good. Again, just make sure you have proper clearance.

Best way to figure out the size you need is to find out what the clearance is supposed to be (FSM) and use plastigauge on the assembly sans bearing (torqued to spec) to determine how thick of a bearing you need. Keep in mind that you need clearance above and below the bearing so don't forget taking that into account in your calculations.

If you're getting the crank polished, you're going to end up with slightly different clearance sizes. Best and 100% sure-fire way to know you did it right is to plastigauge all of them. It takes time, but it's worth it to know you did it correctly.

Also, there are people out there that like to be closer to one end or the other on clearance values when they build a motor. I've found that some people like their clearances tighter than others for specific builds or motors that will see a lot of abuse via racing. Some people will use all one "color" in a motor that calls for 2 different sizes. The engines typically do okay. Not exactly my cup-o-tea, but as long as the clearance lies within the factory specified limits, it should work just fine. Keep in mind though it's likely that your clearances will be uneven even though they're still considered kosher.

IMO pick a value right in the middle (or close to it) of the acceptable clearance range, get the closest sized bearing to that, and make sure all main clearances are the same, and all rod clearances are the same (or as close as possible).

[texasnick]

I just realized I didn't ask, are you going to assemble the rotating assembly yourself, or are you getting a builder to do it? Reason I ask is because if your situation is the latter, I would just go with whatever bearings the engine builder wants to use.

[Redlyne_mr2]

Oh yah having the builder do everything so I'll let them handle it.

As for the engine, cracked ring in cylinder number 3. Common on the 3rd gen 3sgte. I tracked the car like 7 times last year and ran 17 psi on a stock block with a gt3071.

[texasnick]

I thought it might have been. Seems VERY common on these motors. I've even heard of people with outstanding compression finding out the ringlands had been busted for quite a while only after they took the thing apart for a rebuild.

Good luck with your build man. One of these days I'm sure I'll be in the same boat as you....rebuild wise....not likely turbo wise haha:(