I'm in the middle of a rebuild (unforged type) and i need some experienced oppinions. That's right, room for your own oppinion. I've been told 3 differant things pertaining to this dilema. I'm trying to decide if i have to, or if i should, balance my bottom end before re-useing it. My dumb ass took little notice in remembering which cylinder each piston+rod came out of. Origional assemblies are still together...ie rod caps, rods, pistons etc. They were never dissasembled. However i forgot which cylinder each one came out of. I've been told by my shop, which now includes a 2gnt member (he was my replacement) that i don't need to but should if i can. The machine shop i priced told me that as long as the origional parts were all together in the same way (ie piston with same rod and cap) then they should all weigh the same and that balancing it is unnecesary.

This seems a little obvious to me but am asking to make sure.

Most basic rule of thumb is NEVER take anyones advice when they are not sure, especially in regards to motor balence. Frankly ^^ post is completely and utterly useless.

Factory does a piss poor job of balencing motors. A machinest will try to make all 4 piston/rod combo's equal weight and balence the crank to that measurement. This way all 4 piston/rod combo's are swapable when installed.

your motor is used. If you want to do a quality rebuild and expect the motor to endure all kinds of piss poor tuning that your going to throw at it then balence it. If you want to just slap it together and pray for good luck then just ASS-U-ME it will be fine.

A proper engine rebuild involves magnafluxing the block for cracks, shot peening the rods and checking them from straightness. Measuring the piston skirts for out of round conditions is a very common practic as well. Placing the rods on the table and trying to wobble them just not check them for starightness either. Did you bother to check the trueness of the crank bore to make sure all the block journal's are perfectly straight (line boring)? Did you check the crank journals for out of round or Taper? Did you bother to disassemble the rods/pistons to make sure there wasnt any scoring in the pistons wrist pin journals? I am willing to bet you didnt do any of this so why would you actually balence it?

Before you decide to hop on the coat tails of widebody mike and tell me i am full of shit i suggest you do your homework and spend a lot of hours reading, working around a machineshop/autoshop, and more reading.

I'll summarize - Do it right or go home.

I marked everything on my last rebuild b/c I wanted the finished product to last. But could the motor function for quite some time if the rods and pistons were rearranged? Quite possibly so.

The issue described by Terry above, that a stock engine is not superbly balance to begin with, somewhat mitigates your situation. These engines last a very long time when they are not perfectly balanced to begin with. In addition, an inline four cylinder by its very nature has vibration associated with it (unlike a boxer, inline 6, or v12 design), so imbalances are going to magnify themselves and cause increased noise/harshness/wear.

So yea you can proceed with a half-ass rebuild, but do so at your own risk.

2gnt: '99 RS-T, killed by a toyota, pending rebuild...
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I do have one x factor to throw in. The engine was completely rebuilt from top to bottom, less than 3,000 miles ago (right before i bought it). I barely even used the thing. However it was my fault the engine broke. But, because of quick reaction (and fresh oil) it saved the engine. <--(theory) It was removed soon after with less than 12 mild miles on it after it broke. I'm very astute and notice things right away so i can confidently say it was right after it happened i noticed.

Once i had it apart i found the bearings on one and four to be spun. No other damage of any sort. No head damage. Not piston, main bearing, or any other damage. Because the engine was rebuilt so recantly i felt that it is probably still in spec. I have looked it over completely and it seems fine. I feel that my machine shop is a better worker than advice giver, no bad reports of poor work, i just feel they aren't gona be helpful. Which makes me kinda uneasy. I have no alternatives in machine shop.

When i say the engine was rebuilt i mean from top to bottom, possibly a $2000-3000 job. I'm thinking it was exactly $2200...what i paid for the car. lol

Thank you for your help. I already have new bearing and rings. And am just waiting to decide on this. I've read the links for the rebuild and have a excellent 2gnt member close at hand to help assist. I'm just trying to make the best descion. But like all things i can't be spending money i don't have. I'm sure you understand. Your best oppinions are all that i expect and i understand that the outcome is entirely my responsibility.

I have read the above and thought it over, and i'm looking into many of those sugestions to make sure it is in spec now, just to make sure. Thank you.

Not to deminish in any way your advice, but i do understand the nature of vibration in a 4cyl. Thats why they make most of them with balance shafts, however these diminish power, while they do increase durabilty and driveability (sp). Other engines have enough cyls to cancel the vibrations internally. I don't need and uber strong engine, I'd like to make it last as long as possible, but i am on a budget...kinda. We're lucky...we don't have to play with the whole balance shaft issue.

Also, if you could please, provide any info on what type of exhaust port jobs work good on a mostly n/a nitrous (50-75shot) setut with normal bolt ons. Mild, streetable, but anything better than stock. Doesn't need to be really specific. Pictures are best. Thanks.

I love my car...
I love Horsepower...
I love reliability...
So why do i own a DSM again?

Ever hear the saying, you can have it cheap, reliable, and fast. You can only choose 2. If you want the motor to last a long time, do not spray it.

Exhaust port jobs.....there is only 1 that works well and that is porting with the use of a flow bench. Since your on a budget, you can count that out.

Just because 3000.00 was spent on a rebuild does not mean anything was done correctly. You dont seem to understand very many aspects of the automotive world!

No, i can count that it was done right. He gave me a list of the things that were done. The engined failed because of me...

Yes, i do recognize it. The quote is from someone i detroit i think. It was either an owner of GM or Henry Ford...although i think it was the GM guy. Idk off the top of my head.

I just wondered if because they already balanced it properly that they all do weigh the same. I guess i'm just gona have to check and find out. Anyway.

On to my other question. So you can't provide any pics or info? Its a fully stock head running at 10-1comp. We're just cleaning the exhaust side up. I have an experienced tuner, i was just hoping to give him some idea to work toward or along. But i guess i can try and source a bench. Damn. All this for a decent stock engine. lol that's the price we pay to play i guess.

I love my car...
I love Horsepower...
I love reliability...
So why do i own a DSM again?

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99 Eclipse GS turbo: MSpowered, everything custom built, 223.8 HP-199.8 TQ @8psi through auto-tranny. The first time around...

I'm not for cutting corners, just against spending money on unnecesary work. Thats all. I guess i'm balancing it. I believe the money is in the budget. So, thanks for the help.

I love my car...
I love Horsepower...
I love reliability...
So why do i own a DSM again?

In regards to your head, a picture of mine wont help you at all. You cant tell where to remove material based on a picture. If you really want to do it cheap without a flow bench, i would say to just smooth the casting, do not remove or reshape anything. At the same time you cannot go around claiming to have a ported head. So if its bragging rights you want, you will need to have it ported on a flow bench.

Speed braggs all by itself. I'll talk about my parts but i'm extremely honest about my car. I;m no a pretend street racer. I'm just a guy with a car, trying to make my toy go faster. I've also considered using a b20 honda motor as a comparison, considering i'm assembling an intake manifold with a B series manifold. I know its a Riceroni...but if it works i'm gona have a talk with Skunk 2...:o

How much would you charge to flow bench...or how much would you pay to use a flow bench. Can you tell me some things avout them. Questions or ideas i need to have ready if i do go use one.

I love my car...
I love Horsepower...
I love reliability...
So why do i own a DSM again?

a port job on a flow bench will usually run 800-1200.00

I'm just stopping in to pass the torch.

If you want great port work at a reasonable price, see AMM on this board. One of the best.

Captain Caveman

96 RS Turbo 11.414 @ 119.62 MSNS, Crower 2 NA cams, BW366, 10.5 comp, UDP, 60mm TB, W/A intercooler, 3.55 tranny 567.9whp 430tq
97 RS NA 13.188 @ 103.87 MSnS powered 12.5 comp, Crower 3's and 219.4whp with 175tq
98 RS DD 12.5 comp on stock ECU, LTH, Crower 2's, Koni, GC, Hypercoil, DG hats
99 OZ 5sp Stocker 15.856 @ 85.97
99 GS stocker auto 17.7@77mph!

wiki home page:http://www.2gnt.com/index.php?d=bullettdsm

AMM, that the username? I'll check into it. See what i can get.

Ya, the only flowbench in my area cost $900 an hour. Uh...that's almost half the worth of my UNPAID for car. lol

Also, more importantly. I am sourcing a tig welder. (sp?) To help me put my riceroni intake manifold together. I'm sure i could source one localy for a decent price, but if i could get a good deal here it would help maybe price wise...and because of what i'm tryin to do. I figure a 2gnt person would be able to understand better the clearance issues i'm workin with.

I love my car...
I love Horsepower...
I love reliability...
So why do i own a DSM again?

Jesse, your probably not going to find a tig welder that is in the price range you are wanting to spend. Best bet is to send your OEM intake manifold off to AMM if you where wanting a ported intake manifold. The work I have seen on here and on neons.org is amazing. I'm not sure how much he charges, thats something you need to pm him about but he does great work.

Yeah to start with a decent TIG is going to cost over 2000.00, mine cost 4000.00 and its still an average model. Your manifold is Aluminum and unless you have been through welding school, you do not have the skill to weld alum. The fact the the intake is cast alum is even more difficult. For that you need to find someone well experienced in welding cast aluminum.

Oops, let me reword. I ment i'm tryin to ind someone who can do it for me. I have no intention of tryin. lol
I love my car...
I love Horsepower...
I love reliability...
So why do i own a DSM again?