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

 

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.

 

http://www.carcraft.com/techarticle...5_high_performance_engines_bearing_clearance/engine_bearing_clearance_tips.html

Some good info there about rod bearing clearances.

 

http://popularhotrodding.automotive.com/45424/0711phr-bearing-clearance-control/index.html

More good info on bearing clearances.

Not trying to post whore, just posting this shit as I find it.

 

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

Not if you're putting together an oem engine.

 

Thats the way I USED to do it. Like you implied, its definitely a bad idea. I use a rod stretch gauge now to tell.

 

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.

 

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?

 

All you 4G63 engine builders throw up what you know. If I see this thread full of win with a lot of participation, I'll sticky it.

 

That would be greatly appreciated Steve, there's already a ton of great info here.

 

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

 

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.

 

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.

 

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

 

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.

 

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.

 

Awesome info but I do wanna reinforce that copper spray on all dry gaskets is a must. When I built my last engine I had oil leaks everywhere and it was irritating cause I put them all on dry. Such a nightmare.

A good machinist is a must. One you can trust. Not some door knob that tells you everything is fine w/o paying attention to detail.

OEM replacement parts are best for simple things such as water pumps and oil pumps. Currently I am guilty of running aftermarket of both but I also get the aftermarket pricing of next to nothing. I'll be paying for it later down the road when I gotta tear it out cause I bought junk. I'll kick myself for it then.

Build in a clean, stress free environment. No distractions. No cell phone at your side. Just you, your parts, and a guideline.

Finally. DO NOT RUSH!!! I to have been bitten by the bug of get it done now cause I wanna drive it. It'll only lead to loose bolts and sitting on the side of the road. Keep a steady pace and set a goal for every time you sit down to work on it.

 

I've run 30lbs on my built motor without ever once using copper spray in my career. It is not necessary if the procedure is done correctly.

 

Back to what I was saying after reading the links in first post, most people improperly torque bolts due to inaccurate wrenches, insuficcient lube and most importantly, relying on the "click" of the wrench when that almost NEVER is right.

I only use ARP lube to torque with my SNAPON torque wrench.

I coat EVERYTHING in the lube, surface which nut will apply pressure to, threads, all over the nut.

I torque, losen, torque, losen until i'm satisfied that the torque reading is proper.

Now this is only for torquing, if you do proper preparation and torquing you will never have a blamed HG failure which WAS NOT your own fault, when installing a dry headgasket.

**I'm not saying to forget about copper spray but i'm a professional and I don't use it since my dad never has and the manufacturer would tell you to use it especially knowing the engineering of the 4G63 people. If you do it correctly, no need for anything fancy.

 

Stuck! Keep it going guys. :tree:

 

Everthing I know about assembling the bottom ends of these motors is in my build thread. Starting around Post #150 & I think I did a good job of sharing it.


http://www.dsmtalk.com/forums/showthread.php?t=199473&page=4


.

 

Never use spray on gaskets, people that do are only fooling themselves, maybe it makes them feel like they have a second line of defense? not sure but the factory didnt use any sealer on gaskets and neither would any professional, I personally own dsms with over 300,000 on them (plural) and they have never been apart and the factory gaskets dont leak, so that goes a long way for no spray. You would want an inside micrometer for determining bore size and rod bearing to crankshaft clearances, and you dont want to buy any tools that are made in china, Mitutoyo or Starrett brand micrometers/dial gauges are what you want here and more importantly you want someone with plenty of experience to use them, I cant stress that part enough because I can use a micrometer or bore gauge five different ways and get five completely different readings, it takes much experience to learn where the right reading comes from, that may not be what some people want to hear but like it or not thats the way it is and its what seperates good machine work from failure.

The bit about prying on your crankshaft is bologney, do you think there is some Jap in the factory prying on all of the 4g63 crankshafts whilst someone beats on the bearing cap with a hammer? got to be kidding, the stuff that people come up with through urban legend/wivestales is shocking to say the least. Snap on or better torque wrench is a must! if its less than $300 you might as well not use one at all, you would be better off.

I am in a position to make these statements as I am a tech for a living and have been in four shops in my time, so plenty of experience here, I am the engine guy/and the guy that machines (bores, valve seats, guides etc) we are lucky to be able to have the equipment to machine in house and I see plenty of screw ups as you might imagine, if anyone has any specific questions I am as always here to answer where I can.

 

Factory gaskets on the return line from the turbo to the pan probably leaked.

Any OG want to verify?

 

Wow, a lot of great info here. I would still be scared doing a bottom end by myself w/o some professional supervision lol. I'd rather learn with a teacher than learn the hard way by myself and blow things up within 5 miles.

 

My return lines never leaked personally, and at least once I even reused a 10-15 year old gasket when I upgraded turbos and still no leaks.

 

Snap on or better torque wrench is a must! if its less than $300 you might as well not use one at all, you would be better off.

I did torque wrench calibration for the air force as a side task when no electonics were broken on my aircraft for 6 years, I helped to calibrate many peoples home torque wrenches, including my own torque wrench, on my lunch breaks using the multi-million dollar air force calibrating equipment in a tempature and humidity controlled testing enviroment. The $125-150 "no frills" craftsmans you can buy at sears hold there own. They are fine right out of the box and can last for years w/o being calibrated, they did just as good the snap-ons we had at work. The chinese torque wrenches where like + or - 5 ft lbs within the same day. I calibrated a 10 year old craftsman and after being calibrated it held A/F spec for years when I tested it every six months there after. If you have any question, Send me your wrench and I'll get it tested if you have a month or two you can be with out it, I'm still cool with those guys.

 

They get sent in regularly (depending on use) to Snap on to get recalibrated actually, thanks for the offer! As far as holding calibration, I've never had any luck with other brands nor have I known other techs that have, they all ended up switching over to Snap on/Matco etc after having their cheaper ones checked and they were always quite a bit out, of course as techs I'm sure we use ours more often (daily) than the average joe.

 

I have a question. If replacing the pistons, would it be best to use a standard size? Is an oversized piston going to change the compression ratio?

 

This thread is awesome! Tabboo's quoted post made me smile a bit; I'd almost forgotten about his slightly abrasive, but super-knowledgable persona. This thread, and threads like it are the reason I keep coming back to Talk, over and over again. Ben, the bits contained in your Journal were awesome, too.

 

Simply going to an oversize piston will not increase the compression, whether you bore an engine or not is based on the wear on the cylinder itself, a quarter millimeter to a full millimeter is removed to provide a new round, scuff free surface with the proper piston to cylinder clearance (around .003" to .004" (three to four thousandths of an inch) for proper operation). You may have heard hot rodders talking about having a "bored and stroked" engine, in this case they are refering to removing ALOT of material to actually increase the engine size, we're talking say 5 to 10 millimeters worth of cylinder wall material, and in a case such as that then the answer is YES it will increase compression because he is increasing the engines displacement unless the builder purchases special pistons to set the compression lower.

 

Yes, I know what it is, I just had no idea on the numbers. Thank you very much. It was very helpful