LEXCROB rb20 build

[lexcrob]

Time for me to show the rb forum some love back.

I didn't plan on following through with this, but SR powered buddy called me out so i've got some new motivation.

95 240sx (rb20det/mickinley kit/eibach sportlines) picked it up for cheap /rod knocking around 3k all the time / did an oil change not too much tinker bell sparkles

compression test was 140/140/140/105/140/140 wet brought #4 ->105 to 125?






So first thing is first RIP IT OUT



and """"""""THREW IT ON THE GROUND!"""""""
http://www.youtube.com/watch?v=gAYL5H46QnQ
^WATCH THIS TO GET THE MOOD HERE

[lexcrob]

Ok so before I tear the one above down I was given ANOTHER RB20DET a few months back that ran good for 2yrs.

compression was 140/120/120/140/140/0 pulled clyinder head found burnt exhaust valve from broken studs on that cylinder #6....

CARLH came though for me and sent me a whole set of exhuast valves for a steal!
DOUBLE THUMBS UP

So tonight I decided to start tearing it down!

[lexcrob]

Hit one friken speed bump............



Guess im gonna have to drill it and get a power steering puller huff......

Pulled out the pistons and what the heck happened to these guys!!!!!. I havent pulled to many pistons but ive never seen all of em munched up like that on the sides.




Anyways shutting down for the night -----pistons are FUBARD.
Every engine bearing looks in great condition so that is a plus.
Crankshaft and rods look nice wrist pins free no binding.

Too bad the pistons are poop at least everything else seems to be going ok. Ill update with cylinder wall measurements soon as i get that DEMON crank sprocket off.... hopefully my other motors pistons are in better shape.

[Yellow4g63]

Dang I'm surprised it didn't crack the rings.

[Carl H]

proly a lean mix which lead to detonation, the burnt exh valves would point to that...the lean mix that is.

[breadbox]

Whoo a fresh RB20 Build.

This should be interesting.

[lexcrob]

proly a lean mix which lead to detonation, the burnt exh valves would point to that...the lean mix that is.

Carl I believe your spot on! I asked few other techs I work with for opinions and seems lean and or HOT so the side of pistons were MELTED!!!!!!
This is the engine that had the PROM chip and serial cable wired in that I asked about a while back. REPS tuned by SFIT?


None of the piston rings were cracked all actually look GREAT hence the compression still 120 lowest. I even considered just thowing a valve in the thing and running it that would have SUCKED.



Just picked up the steering wheel puller so I guess drill two holes and away she comes hopefully.

[Yellow4g63]

Dang RB20's are tough .

[lexcrob]

I got the sprocket off the other night. WHAT A PITA!

Ill have time this weekend to get some more stuff done and pictures up.

ive been trying to figure out my plan for the body work. Really just trying to find a place to paint it. Convinced a buddies uncle to let me use his garage. I even get one of the painters I work with on board. Trying to make this thing right! I honestly just hate the current paint and have always wanted to do a dark metallic green 240. I have a complete supermade kit that got banged up in an accident that im going to try to salvage.

FINGERSCROSSED FOR GOOD WEATHER TOMARROW!

[lexcrob]

I decided I didnt have the time to paint a car so I got with a local painter. Randy from PAINT IT BLACK came out to my house and looked over the car. Ive seen his work and its about as good as it gets. He quoted me 1800$ which is way out of my budget. This will be the first car ive had painted and want it done right. Im having him paint it the same color he did his ac cobra and it will be gorgeous!

He took a look at the kit and the only thing that made it is the supermade side skirts. I think it will look pretty good as is so im dropping it off in 3wks too get her hooked up.

[lexcrob]

So back on the rb20's
Got my other motor on the stand so hopefully pistons are in good shape!

Looks unreal clean like its been hot tanked previously!


No visible signs of damage to number 4 from the top!

Got the crank out # 3 rod bearing is toasted. Thats what was knocking!


Heres the low compression number 4 melted pistons again this was the worst one!

Heres some of rod bearing number 3.

Shot of preping to pull that crank gear off AGAIN!!! what a pita....

So another one ripped apart and not a single piston made it. All MELTED now paper weights....
(not a single one was broken and all the rings were still visibly in good shape..... WOT RB's are tanks.




long story short im gonna need pistons.......
Looks like my only option is supertech 4032 alloy? is that good for street motor. Maybe ill call wiseco...



----thinking out loud here:

Im reusing head bolts and going with a stock headgasket. Im going to reuse bearings from first motor I tore down as everything looked great. Just bore and fit new pistons and rings.

Im going to run stock turbo and everything for break in that way I dont fubar 1st start up and all that. Shooting for reliable power set up id say 250-300 eventually should be easy to get.


Decided to focus my attention/money too traction this time around. Maybe an aftermarket lsd?

I only run the 1/8 mile so maybe an aftermarket tighter gear set? Im running 18 x 10 xxr's so im aware that will make my gear longer...... Might have to part with them and get some smaller wheels.

[Carl H]

had cp pistons in my car, worked well...pretty quiet for forged pistons.
get arp studs, cheap insurance as well as arp rod bolts...reused stockers tend to lead to self ventilation of the block.

DO NOT REUSE BEARINGS!
ESPECIALLY IF THEY ARE NOT FROM THE SAME MOTOR, each motor has different bearing shells based on clearances marked on the crank and block.
ACL race bearings are cheap and work well...if you're gonna put pistons in the motor then why cheap out on bearings.

break it in on a dead stock ecu and turbo and you'll be fine.

[lexcrob]

Im using everything from the 1st engine I tore down minus the pistons.

The bearings dont even have hairline scratches or scuff marks. They look brand spanking new! Ill plastiguage rods and mains for assurance but shouldnt be any problems.

As far as the head bolts they will be fine Ive reused them on engines too many times to count. Specifically subaru cause I work at a dealership.....all will be fine!

Ive never heard of an issue reusing rod bolts if torque to factory spec and didnt suffer damage.

I use arp's newest fastener lubricant for all internal engine stuff if that helps!
Yes I will be running stock ecu and turbo for break in!
Also going to run dual stocker s14 fuel pumps for now as I have a spare.
(probly what killed both engines just oe pumps in both cars DAMM KIDS)

CP pistons are like 850$ which is UNREAL....but if they the best bet ill go for them.

I really just need a set of oversized OEM rb20det pistons and rings! Obviously the stockers can take a friken beating!

[lexcrob]

Just got off the phone with wiseco since they dont list rb20 pistons in their catalogue.

800$ for any bore or compression ratio

900$ with their coating

A little better on the price and have always heard good things from all forged piston manufactures. (mostly ends up machine shop error or poor communication) My thought was bore it out a bit maybe 80-82mm and drop compression a hair 8.0:1. I see people running thicker headgaskets on turbo motors to drop compression a bit more. Makes higher hp attainable on pump gas right......


Im up for what ever CP pistons if you guys think those would be better.

[Yellow4g63]

Carl has a lot of experience with the rb20 take his word about the rod bolts.

[lexcrob]

Im most def. not an experienced engine builder but I read all the time. Ive built 3 motors now and the first one has 20k on it. I just did a compression test the other day. PERFECT all the way across. Didnt plastiguage or do ring end gap! That was 4 years ago threw the thing together and that was an ebay rebuild kit......

Last motor I did just a few months ago. I measured every thing you could possibly imagine wrote down all specs. Technically I "blueprinted" it to factory specs although that term is used loosely.

Ill take your guys word if I need arp rod bolts and head bolts Ill get em.

At that point I might as well address the oil pump issue Id imagine.
(i can see that tiny little nub coming of the crank that is supposed to turn the pump what a FAIL.....)

Point me to build threads to support your set ups work. Or shoot out a list of all the stuff you would recommend for me too get. Im up for what ever I want this thing right! I guess I may be a little on my own since rb build documantation is either spread across 6 forums or never finished threads......

[Yellow4g63]

I have a crank collar kit that I bought a while back that I never got around to using since I won't be rebuilding my RB or any RB lol.




$65 and it's yours.

[lexcrob]

I just pooped in my pants.......
Note the *BORE 84mm****and 2mm headgasket
Although, I dont know where you would get 84mm stock rb20 pistons.


http://www.240sxforums.com/forums/rb-te ... gines.html

facts about RB20 engines

--------------------------------------------------------------------------------

Just like to put down some of my experience about the overlooked potential of an RB20

I'm curently in the middle of knowing how far can I push an RB20 internals, these being stock con rods, stock pistons/rings and stock cams.

The setup car is a 1991 240sx (w/stock canadian VLSD), pretty much gutted out, weighing @ 2520lbs (2700 w/me in it)

performance parts list

-RB20DET swap (stock con rods, pistons/rings, cams)
-SDS stand alone engine management
-Turbosmart manual boost controller
-Custom intake manifold (Greddy type)
-Innovate Motorsport LM-1 wideband kit
-Garrett GTPR turbo, Hybrid by Tial, T04E Compressor:3'' inlet, 2'' outlet, A/R .60; Turbine: T3 inlet, 2.5'' outlet, A/R .63, T4 bearing journal core w/big T4 shaft
-OEM cast iron exhaust manifold, wastegaste bong added
-Tial 38mm wastegate
-Tial BOV
-Nismo low temp thermostat (165 degrees)
-custom copper 3 core rad
-2MM multi-layer metal head gasket, 84MM bore
-ARP main cap bolts
-ARP con rod bolts
-ARP head bolts
-N1 oil pump
-HKS fine tune timing belt
-444cc injectors (oem GTR)
-Walbro 255L/hr fuel pump (with 3/8 line from back to front)
-Custom FMIC
-Q45 80mm throttle body
-B&M short shifter
-ACT HD street clutch 512 ft/lbs capacity
-Custom one piece drive shaft
-Nismo transmission mount
-Custom 3inch exhaust from front to back (no cat)
-Vibrant 3inch sleeper muffler
-VLSD (oem '91)
-Adjustable rear toe control arms
-Adjustable rear camber kit
-Adjustable rear traction rods
-Faze gauges, oil pressure and engine temp
-Mickey Thompson E/T Drag 26 X 8.5 X 15
-TIC brake line lock

1.521 60', 11.07 @ 128mph is my best 1/4 mile ET so far with plenty room for improvements

[lexcrob]

Just went out in garage and took a look at both oil pumps and "drives" and they both look like crap. Looks like the thing is about to shear off on both of them. I read the collar thread
oil-pump-and-crank-collar-gurus-t185427.html

took a look at the pictures of these magic collars

http://proengines.com.au/collar.html

NO BRAINER never knew you could run the same pump. I thought you have to get the N1 or whatever SHOVELTOFACE......

I just got figure out if my local machine shop can put the thing on. Im assuming its a simple procedure? Just bring the crank alone or maybe the block, pump, and everything.

PM sent yellow!

[Carl H]

ah proengines...i did a collar group buy years ago (6-7 now?) for them.
had one on my rb20.

[lexcrob]

Did some searching around on the rod bolts thing. Seems some people never reuse them and swear they will fail no matter the engine. Some people have no problems running them for "street" mild engines. I've build 3 motors reused rod bolts every time all still run like champs. (but they are OE rebuilds and street driven) Its not like rod bolts arent allowed to be taken on and off. If torque correctly and not damaged from outside influence (look at their bearings) I dont see why you wouldnt reuse them.

---------That being said since I now have the crank collar on the way my plan for "mild street" is turning into "wild" ....probly a good idea to go ahead ARP it up for assurance.

Ill give the machine shops a call and see how much they charge for the works.

[Carl H]

you'll have to trust experience here...i've seen enough 'properly assembled' blocks self ventilate due to reused stock rod bolts.
spinning a motor hard and making double rated crank hp at the wheels you dont want anything to let go.

[lexcrob]

So crank collar ARP rod bolts are both getting a visit to the machine shop.
Whats your take on main studs?
Headstuds and OE headgasket?

Will the collar alone resolve all the oil control issues? drain? orfice?
Maybe deburring the crank case would help a bit.

Ill have a bit of time for busy work waiting on body to get painted up.

[lexcrob]

Update:
YELLOW- I GOT THE CRANK COLLAR IN LIKE LAST WED.... WHAT A BOSS!
I've been trying to get garage cleaned up and sell some parts.

Courtesy Nissan never got back to me hit them twice last week nothing back. Seems they're gonna run roughly 75$ a pop from other forums so thats not really a good option anyways.

Supertechs fit the budget better but i've been reading here and there all over the place. Wiseco for 800$ sounds like the win but what bore and compression ratio?

[lexcrob]

Update:

Just got off phone with my favorite machine shop.
Charlies Machine Shop in Smyrna, TN.
--- they built my last ka ---
--- I tore it back down measured everything ---
--- PERFECT exactly what I asked for* ---

~175 $- install ARP mains and line bore
~175 $- install ARP rod bolts and line bore
~145 $ - Bore/Hone/Hot Tank
~150 $ - install crank collar

So ball park (650 $) is what ARP installation machine work is gonna cost. Im gonna put it together myself this time to save a little doe.

He said I can install ARP stuff myself not big deal. Which is a relief because I thought I had to measure rod bolt stretch with that special tool seems its over kill. I got the "torque plate" "temperature controlled" hone feeling! Reserved for poop your pants powa 24 hour lemans stuff.





So ARP headstuds are now on the build list.

Which headgasket and pistons still up in the air......



ON THAT NOTE:
Just ordered a greddy gracer front lip last night to complete the "aero" before paint. Hopefully it will flow with the supermade side skirts.

[Yellow4g63]

It's nice to have a good machine shop to help you do your builds right the 1st time.

[Carl H]

no need for arp main studs...plenty of high power motors on stock mains.
rob at RIPS uses stock main studs.

rod resizing seems a little steep, i paid 12$/rod when i had my arp rods fitted...crank collar was like 80$.

[lexcrob]

I read some stuff on line boring the mains. I see what you mean Carl about changing the bearings and not line boring mains. As the bearings are all standard but size but the backs change to compensate for machine tolerance. A machine shop can also file the caps flat and peen the sides for more "surface area". Also read a note that plastiguage does not "read" if journals are egg shaped or *out of alignment*(hence the diff oem bearings) . At least thats how I understood it all.

I keep pricing stuff and the Spool Imports kit is looking better and better at this point.
Just get cylinders bored/block align bored/ crank collar installed.

http://www.spoolimports.com/spool-engin ... ebuild-kit

[BigBoss]

man this is awesome, i started an rb20 build thread a while back and i havent updated it yet because ive been acquiring parts but your pretty much doing all of the same things im doing lol were like build buddies! lol jk but i am happy that i have someone to compare too now!

[lexcrob]

I saw your build thread"BOSS" the other day were def. in the same boat!

Did some prepping on the body today pulled dash wiring harness and all that good stuff.
This little guy was a fighter just about got the baseballbat out.

My moment of GLORY shot!!!


Ripped this hacked rat nest junk out of there too I cant even believe it ran. Butt connectors scotch locks straight garbage wiring job. Looks like its been gone though be multiple people maybe it was nice on inital install.

Putting in that work on a sunday!


Its a work in progress........