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Old 05-17-2010, 04:47 PM   #1
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Default Some engine assembly tips

I thought I'd write down some of the stuff I did.

RING LUBE BEFORE INSERTION INTO CYLINDERS

Don't dunk the whole piston assembly in oil just before putting em into the cylinders - use a clean finger and put a thin coat on the skirts, and work a few drops into the ring grooves. Dunking the stuff in oil will get you a lot of oil burning on first start.

PRIMING THE OIL

Or you can use "Quik Seat" product. It's a powder lube for the cylinders, and a special oil for the skirts. Supposedly all the rage among NASCAR builders. I used it.

You can pre fill the oil galleys with oil by spinning the crank by hand - if you "primed" the oil pump with a coat of assembly lube. The other way to prime the oil pump is to take the allen plug out, pour some thick (e.g. 20w50) oil in and fill er up. If you turn the crank before you put the timing belt in, it will be easy to spin.

If you have a VVT head and non stock pistons or non stock cams, be sure none of the valves are at full lift when you do this. Spin until the oil coming up in the head stops bubbling. This way when you start er up you get oil pressure right away.

LINT FREE WIPES

Use "Kimwipes" as your lint-free tissue.

TORQUING ROD AND CAP BOLTS

Torque em to spec, turn back a tiny bit, repeat 3x. This "burnishes" the threads to get a proper torque spec. Follow the oil recommended by the manuf. For stockers, use engine oil, for ARP use their special lube.


More as I remember them...
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Old 05-17-2010, 05:54 PM   #2
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Cool, i'm replacing the crank and bearings in my new GTX bottom end today. Just got done plastigauging, about to torque everything down for good. My tips:

-Roll in the new bearings, dont just push them in.
-Change gloves OFTEN! I've gone through probably 10-12 pairs of gloves so far and will probably go through a few more by the time everything is all done.
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Old 05-17-2010, 06:01 PM   #3
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My tips:
Buy a rod bolt stretch gauge. Torque is just a measurement of resistance, bolt stretch is equally important and in many ways more accurate.

After honing, a little ATF on a lint free rag does wonders cleaning out the bores.

Be sure to store your torque wrench at 0. Storing it pre-loaded will cause the spring to fatigue and become inaccurate. If you aren't sure, buy a new one.

Assemble your block in a temperature controlled environment, or at the very least avoid temperature extremes, pick a nice 65-75* day to assemble it in the garage (if your wife wont let you do it on the table ). Assembly in the dead of winter in your uninsulated garage can lead to premature bearing failure due to improper clearances.
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Old 05-17-2010, 07:00 PM   #4
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Quote:
Originally Posted by Jeff_Ciesielski View Post
Be sure to store your torque wrench at 0. Storing it pre-loaded will cause the spring to fatigue and become inaccurate. If you aren't sure, buy a new one.
Or take it to a local machine shop and have them check it if unsure. I did that with mine before I started reassembling, nice peace of mind.
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Old 05-17-2010, 07:47 PM   #5
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Yes cleaning the bore after honing is very important.
Lots and lots of rolls of shop tissue moistened with ATF of WD40 followed up by Kimwipes.
You have to wipe till you no longer pick up gray.

I heard that without a PLATEAU HONE it never stops picking up gray. Plateau honing is supposedly de rigeur these days but not all machine shops can do it.

When starting up and it catches, don't let it idle for long periods, you have to blip the throttle every few seconds so there is some load on the rings. Else you'll glaze em then they'll take a long time to seat. Check for leaks and drive it around the block, following FM's procedure, then Motoman's procedure.

Stock bolts spec torque, not stretch.
The ARP2000 bolts that come with the MTuned rods spec both. MTuned actually recommend the torque method over stretch. The stretch spec they give actually makes it one-use only.
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Old 05-17-2010, 08:00 PM   #6
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Quote:
Originally Posted by JasonC SBB View Post
Stock bolts spec torque, not stretch.
The ARP2000 bolts that come with the MTuned rods spec both. MTuned actually recommend the torque method over stretch. The stretch spec they give actually makes it one-use only.
Actually, if you use a stretch gauge to ARPs recommended limit, you are stretching the bolt to just under its elastic limit and they can be re-used multiple times according to the manufacturer. I'm not saying you shouldn't also ensure proper torque, but by no means should you chose torque _over_ stretch.

Edit: This may not be the case with ARP2000 bolts, I use ARPs standard bolts because I don't plan on making 11ty billion ft lbs of torque. I've never used any of their other rod bolts.
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Old 05-17-2010, 09:29 PM   #7
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dont use plastic gauge, invest in a dial bore guage or go to your local shop and have your block clearenced.

as said a rod stretch gauge is key, as well as using proper lube, lube under the bolt heads too. make sure to clean the big end before installing bearing and clean the bearings with brake clean before you install.

use a good assembly lube, something thick but NO grease types. permatex,lucas,ect make good ones.

hand spin the crank after you tighen each cap to check for binding.

oh and get a stone, stone your caps on the rods and block, stone the sides of the rods. burrs will give you inaccurate readings.

if using arp studs, only go hand tight into the block, with LIGHT oil. you can crack the block using to much oil, it acts like a hyraulic piston.

like said, atf and lint free towels, never use rags. paper towels work good. clean the bores good, and a light coat of motor oil before installing the piston.

just use good common sence. i have worked for a engine shop part time for the past 5 years. a little common sence goes along way
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Old 05-17-2010, 10:23 PM   #8
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Quote:
Originally Posted by Jeff_Ciesielski View Post
Actually, if you use a stretch gauge to ARPs recommended limit, you are stretching the bolt to just under its elastic limit and they can be re-used multiple times according to the manufacturer. I'm not saying you shouldn't also ensure proper torque, but by no means should you chose torque _over_ stretch.
I had this exact conversation with MTuned and they said that as you repeatedly torque it to spec then loosen back to half, repeat about 5-6x, the stretch starts to grow, and you quit when you can reach the stretch at the recommended torque. Then, you throw away the bolts if you ever take em out again.

I remember the stretch spec at 5.5 thou, and I only got 3.0-3.5 thou after only looosening a bit and re-torquing 3x. I tried overtorquing on bolt by 15%, and I only got to 4 thou. So I left it the one bolt there and called MTuned. The rest I torqued to spec (with a few slightly loosening cycles).
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Old 05-17-2010, 11:20 PM   #9
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Well since we are getting technical. The bolts that come from ARP actually comes not only with both a tq to stretch, and stretch measurements, but tq angle measurements as well. To top it off they even give you a sheet to write down pre (new) length measurements as well as uninstall measurements. Along with the sheet they give you further, a spec of what the limit of elongation is. When the bolt stretches permanently to that limit is is not suitable for reuse.

The moral of the story is that it doesn't matter what method you use. Measure the bolt before and after, and once its beyond its limit get new bolts.

EL FIN
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Old 05-17-2010, 11:37 PM   #10
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We tighten to a specific stretch at work, and Jeff is correct in that the bolts are reusable multiple times. We have a worksheet where we write down the before and after measurements of each rod bolt and when the engine is disassembled afterward for any reason we can check to see what the original bolt length was.

This is also useful if you've overrevved the engine, you can remove the rod bolts and see if they returned to their original length (they should within .001), if they don't then you got lucky and only have to replace the bolts.

I won't say M-tuned is wrong, but they're being more conservative than they probably need to be. We build engines that run 10k rpm+ (some of which cost $60-100K) and reuse rod bolts torqued to the proper stretch with no issues.
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Old 05-21-2010, 07:33 PM   #11
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This might seem like a noob question, but when getting quotes the engine builders asked:

Do miata engines need torque plates for an overbore?

I know the theory behind them but im not sure if it is needed and im sure it would add a ton to the work.
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