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Discussion Starter #1
I used to half ass building motors. I didnt realize the error of my ways until I started messing with 4g63 engines. I have been own by the 4g63 a couple times for not paying attention to details.

That being said,


http://www.rosspistons.thinkhost.com/resources/RINGINSTALLATIONINSTRUCTIONS.pdf

There is some good info in there. What I didnt understand is how do you check piston ring "end gap"?

Then I found this:

http://www.muller.net/sonny/crx/rings/index.html

Makes it pretty simple. So far, now we know how to calculate what end gap we need and how to achieve that.

There seems like there is more as far as adjusting the end gap(like if you are boosting ALOT it seems like it would be best to run a larger gap) than listed. Hopefully, Kmanstsi or someone else that knows alot will chime in.

I used to also just torque my rod bolts to a certain torque with no attention to rod bolt stretch. That is bad. Here is why:

http://www.chevyhiperformance.com/tech/engines_drivetrain/shortblock/49258_rod_bolt_torquing_stretch_info/index.html

What I'm not sure aboout is how to check main and rod bearing clearances. Its just the diferance between the size of the journal on the crank and the rod bearing surfaces right?


http://www.circletrack.com/tipstricks/4636_crankshaft_rod_bearing_installation_tips/photo_06.html

Hopefully this will help some people and I will get some info!
 

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Im not really sure about gap when under slot of boost, but as far as rod bolt stretch, I have always made sure the the rod bolt and nut are both clean and DRY, no oil or lube then just tighten the bolt down in fractions( If final torque is 80 ft/lbs- do 30 then 60 then 80). To check you rod and main clearance you will need plastigauge. Install the bearing and do not apply any lube, lay a section of plastigauge across the journal and torque your caps to final torque. No take the caps back off and see how much the plastigauge was stretched, there will be a chart on the plastigauge. That is your bearing clearance. Hopefully this will help
 

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To check you rod and main clearance you will need plastigauge. Install the bearing and do not apply any lube, lay a section of plastigauge across the journal and torque your caps to final torque. No take the caps back off and see how much the plastigauge was stretched, there will be a chart on the plastigauge. That is your bearing clearance. Hopefully this will help
Yep, that's how I did mine, and it turned out well. I actually did this for every 120 degrees of crank rotation, just to check for possible differences around the surface. I figured it was good enough, since all my findings where nearly identical to mfg. specs.

Lacking all the measuring tools a proper machine shop has, I found plasti-guage to work suitably well. This was a fairly basic rebuild, reusing the stock crank and installing new, OEM bearings (leaving less of a chance for varying tolerances).

...Good thread, keep it going.
 

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Discussion Starter #8
Plasti gauge isnt as accurate as a gauge. But everyone already new that probably.

If your building a motor with really tight or really loose bearing clearances, then there is enough give in the plastigauge to make it too loose or tight, respectively.
 

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but as far as rod bolt stretch, I have always made sure the the rod bolt and nut are both clean and DRY, no oil or lube then just tighten the bolt down in fractions( If final torque is 80 ft/lbs- do 30 then 60 then 80)
I ALWAYS use a lubricant on the threads, never oil, but something to relieve friction. If you read one of the articles above it explains how torqueing (sp?) is only an estimated measurement of bolt stretch as calculated by the manufacturer. Torque alone is not enough to determine is the fastener is held on properly and preloaded to the correct specifications.

Again, torque is only an estimate of pre-determined mating conditions. Always torque and then check for stretch, and then retorque until proper strech is reached.
 

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Clevite assembly lube on all bearing surfaces.
Measure all gaps to factory specs.
Feeler gauge for rings - measure at top and bottom, square in bore
plastigauge for bearings - 2 on top, 2 on bottom, then rotate crank 90 degrees
Copper spray + dry gaskets = win
chase threads with taps and dies
Loctite on fasteners that may rattle loose or are vitally important - blue or red depending on how often you'll be servicing
ARP lube for torquing fasteners like rod bolts, main bolts, and head studs
Measure bore diameter with dial calipers if you can't get bore-dial-gauge

That's all I've got for now. I'm sure there are more details, but those are some basics
 

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Dont use STD size rings on an engine with 50k or more miles the bore will have increased and your end gaps will be huge and eng. vacuume low.
And ensure clean clean clean.
 

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Discussion Starter #15
taboo said:
Don't worry, assembling the bottom end is much easier than it sounds. First you need to prep the block - reverse the front balance shaft bearings (if eliminating the balance shafts = highly recommended), lightly break the edges of the cylinders and mains (if the block was align-honed and decked), deburr and retap (using preferably bottoming taps) every single hole, use bottle brushes to clean the oil gallery and all oil passages in the block. Clean the entire block with soupy water (high-pressure washer works best) over and over - 'til it's squeeky clean. Dry it with towels and compressed air and spray the entire block with WD40 since the cylinder walls and any machined surfaces start to rust almost immediately.

The difference between turning and polishing the crank is in the amount of removed material. If the crank is turned, oversized bearings need to be used. Preferably, one shouldn't have to turn the crank if its journals aren't deeply scored. Have the crank, flywheel, crank sprocket and harmonic balancer perfectly balanced (same with the pistons and rods). You can polish the main and rod journals of the crank yourself, using a strip of 600 grid sandpaper and a long rawhide thong (the sandpaper strip needs to be as wide as the journal, then just wrap the sandpaper around, wrap the rawhide around the sandpaper - two full turn and pull on the ends of the rawhide back and forth to make the sandpaper spin around the journal. Be carfull not to remove any material, just polish the surface of the journal). Once done, clean the oil feeds and the entire crank and spray it with some WD40 to prevent rust.

The rest is just a standard procedure - install the main bearings dry, drop the crank carefully in and use Plastigauge to check the clearances with the mains torqued to specs. If you don't use the ARP studs (unless you're building 500+HP monster), use just the OEM bolts (without the CRCO kit). Once the clearances are checked, take the crank out, lube the mains with assembly lube, drop the crank back in, torque the mains to 10ft.lbs., push the crank toward the front of the block by gently tapping a big screwdriver between the counterweight and the block, tap the cap of the thrust bearing toward the rear of the block, torque all the mains down and remove the screwdriver. Check if the crank spins freely and check the crank endplay. If everything's within specs, assemble the pistons, rings and rods + bearings and insert pieces of rubber tubing on the rod bolts to protect the crank from getting scratched. Oil the entire pistons and carefully install the piston/rod assemblies using a suitable ring compressor while making sure you don't nick or scratch the cylinder walls and/or the crank journals. Check the clearances of the rod bearings with Plastigauge (dry) while torqued to specs, then take them apart again and lube them (just like the mains). Torque the rod bolts to specs, rotate the entire assembly and check the clearances beween the rods and the crank.

That's roughly all there's to it..
What a fucking epic post.

Thats the procedure to align the gurdle to set thrust play correctly!

I didnt do this on my last build and I had a destroyed crank and thrustbearing in less than 1500 miles on my 95 seven bolt.
 

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First off, sorry for the noob questions but I searched and found dead end threads. I am about to purchase ACL race rod and main bearings for my build but I am confused as to what size bearings I need.

Do I need to disassemble my engine and check the clearances on both main and rod bearings and then figure out if I need oversize bearings?

I read that if you are going to cut the crank you will need oversize bearings but if you polish it standard bearings are fine, is that true?

I am going to follow this guide to disassemble my engine, is there anything else I should check before, during or after disassembling?

http://www.dsmtuners.com/forums/articles-engine-fuel/305034-4g63-engine-disassembly.html
 

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First off, sorry for the noob questions but I searched and found dead end threads. I am about to purchase ACL race rod and main bearings for my build but I am confused as to what size bearings I need.

Do I need to disassemble my engine and check the clearances on both main and rod bearings and then figure out if I need oversize bearings?

I read that if you are going to cut the crank you will need oversize bearings but if you polish it standard bearings are fine, is that true?
If your crank is uncut, then you want standard bearings for rods and mains. Standard bearings are fine for a micro-polish job too, but you really should have a machinist measure the journals to verify they are in spec.
 

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This is an excellent thread
Keep it going.

I had a question about Piston Ring Filers & Rod Bolt Stretch Gauges in THIS THREAD where others spoke up about what ones worked for them and it helped me decide which ones were right for my build.

I'm still in the process of following all the links in this thread, but are you builders using a bore dial gauge like this one, or are you having no issue with using dial calipers in their place?
 

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Discussion Starter #19
Keep it going.

I had a question about Piston Ring Filers & Rod Bolt Stretch Gauges in THIS THREAD where others spoke up about what ones worked for them and it helped me decide which ones were right for my build.

I'm still in the process of following all the links in this thread, but are you builders using a bore dial gauge like this one, or are you having no issue with using dial calipers in their place?
I watched my machinist measure it(he is also a DSM guy) so I was pretty confident. I am going to buy that tool now though.
 

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This is an epic win! This thread needs to be stickied red.

That being said, I'd like to add one thing. Make sure whatever your going to reuse,(Block, crank, etc) gets magged. You want to make sure you are using parts that are good.
 
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