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Old 03-15-2011, 02:18 AM   #1
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Default Deciding which parts to buy for my rebuild

I've got a cylinder with a very minor scratch in it, so I've decided to freshen the motor and do a modest build. I've looked at multiple build threads, different threads in this section, and a little light googling, but haven't really found how anyone came to the decision of why they purchased X over Y brand for pistons, rods, etc. Is there a reason one brand over the other? I.E. I read (somewhere) the M-Tuned rods are good option for a low-medium budget rebuild. What about the supertech pistons? JE? etc. I'm not looking for someone to say "buy this brand" but more advice on how to wade through all of the options.

2004 MSM
Probably going .020" over.
For this discussion I'm mainly trying to decide on the piston/rod combo.
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Old 03-15-2011, 07:49 AM   #2
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Most of us on here:
Find a list of compatible widgets, sort them by price, then, starting with the cheapest widget, work your way down the list until you get to the first widget that will support your goal. Transfer that widget's information to your build spreadsheet and then move on to gizmos.

The 2 REAL questions, soon become "how risk averse are you?", and "at which point do you stop valuing the marginal gain in performance more than the marginal cost of a part or service?"

"How risk averse are you?"
ATI Super Damper / Stock Pulley
Built Oil Pump / Billet Oil Pump Gears / Stock Oil Pump Gears
ARP Hardware / Reuse stock hardware
Race Bearings vs. OEM Bearings

"at which point do you stop valuing the marginal gain in performance more than the marginal cost of a part or service?"
rods: belfab/m-tuned vs. carillo
pistons: supertech vs. wiseco
camshaft: reuse stock vs. aftermarket
valves: stock vs. oversize
valves: multi-angle port
valves: port/polish
unchanged 7" rear end vs. buy and source installation for 3.636 gears?

Last edited by fooger03; 03-15-2011 at 08:08 AM.
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Old 03-15-2011, 07:09 PM   #3
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Minimum if you are planning F/I: machine work and stronger rods.

Beyond that, whatever your pocketbook can handle to meet (and/or exceed) your power goals.
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Old 03-15-2011, 07:12 PM   #4
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the two above posts pretty much cover it completely.
Rods are a given. The cheaper ones will get the job done, the more expensive ones will get it done and weigh less. Either way you need em.
Everything else is proportional to your wallet.
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Old 03-16-2011, 01:41 AM   #5
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thanks for the advice. Fooger your comparisions were helpful.I take the block/head in thursday evening for his appraisal and then go from there. I'll come back to this thread when I get a little closer to buying.
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Old 04-17-2011, 12:00 AM   #6
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Right now I'm at ~200hp. Stock turbo maxes out at apx. 250-275 from what I understand. I'm looking to build a quick rev'ing autox/track day car.

FM WiseCo Pistons
http://www.flyinmiata.com/index.php?...0%20%201990-93
Piston selection has been difficult. Trying to find a balance of light weight, strong, and price. Somehow I lost sight of the price part and have ended up with these. Are the coatings worth the price increase? Anyone know what stock weight is 1.8L pistons?


Carillo A Rods
http://www.flyinmiata.com/index.php?...umber=04-66005
Came recommended by some of the local racers. Seem like the way to go lightweight and strong.
417g listed. Anyone know what stock weight is? Opinions on choice?

I've got the 949 race clutch to put in, and with the combo of the 2 above, can anyone comment on the how quickly it will rev up. My biggest problem is the car can't seem to get out of it's own way in the low RPMs. I just don't want to unnecessarily be buying parts for the sake of buying parts. I can buy a couple of sets of Hoosier's for the price of these internals. I'm aware of the class changes from modifying the internals.
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Old 04-17-2011, 03:17 PM   #7
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I'm running the same pistons/rods in my car, but w/o the coating.

The engine revs quick quickly, but I also have a metric **** ton of machine work done to the head and the crank/flywheel/pressure-plate combo.

As to low RPM issues, between the cam profiles and runner lengths on the Miata, you see decent life at mid-range and all the goodness at the top end.

Corky is working on a solution for F/I cars. As soon as the foundary sends enough quality parts to finish assembly, we'll test and post the results... (w/ pre- and post-install dyno runs to show percentage gain.)

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Old 04-21-2011, 01:14 AM   #8
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Well I bit the bullet and order both the rods and the pistons. Hopefully, I'm on my way to getting this to rev like a motorcycle!
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Old 04-25-2011, 11:35 PM   #9
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how do I know which bearing size to order? does the machine shop determine what size bearings to buy based on the surface finish of the crank? Bearing surfaces on the crank look great.
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Old 04-26-2011, 01:09 PM   #10
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If the machine shop is going to assemble the short block, let them order the bearings. Just let them know if you have a preferred brand/model.
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Old 04-26-2011, 02:23 PM   #11
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Quote:
Originally Posted by l_bader View Post
If the machine shop is going to assemble the short block, let them order the bearings. Just let them know if you have a preferred brand/model.
^^this
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Old 04-26-2011, 09:31 PM   #12
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IMO to have a reliable higher hp car you should be getting some good bearings (I went with ACL race's because the people tracking their high hp cars are using them) and ARP fasteners. The billet pump gears and ATI damper are more of insurance...I would get them once you got everything else and want to spend more money

If there are no gouges in the crank journals then the shop will only polish the journals. If there are gouges they would have to machine...but if you would like to be positive then get a micrometer and measure each journal and compare with the manual (it gives the tolerances in the rebuild section that tell what size bearing to get).

When you get it balanced MAKE SURE you give them the: crank pulley, bolts that go into the crank pulley, pulley for the timing belt, crank, flywheel, clutch, flywheel bolts, clutch bolts, rods, pistons, wrist pins, circlips, and rings. If the place doing the balancing says they don't need all that I would find some other place to do the work. Also make sure you do a full inventory when you get it all back, I didn't and found myself buying many things a second time :(
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Old 04-26-2011, 11:04 PM   #13
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Thanks for the advice. This is my first time rebuilding an engine (obvious). From what I've read, a lot of people use ACL race bearings so I think I'll do the same. I haven't found a good place to order or suggest where to order them for the machine shop. I'm glad you mention all of the details for balancing. I would have forgotten about the timing hardware. From what I've measured with a bathroom scale, I've lost about 16-18 pounds in reciprocating mass. Will probably need a good balance.

The pistons and rods came in the mail today, and that was like opening the N64 on Christmas day again!
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