A community of enthusiasts dedicated to Nissan's SR20DE/SR20VE/SR20DET engines.
Start here: forum search. Be sure to search on what you're looking for before posting a new thread.
You are currently browsing the forum as a guest. In order to access special features, the image gallery, and post you will need to be a registered member. Registration is fast, simple and absolutely free so please, join our community today!
If you have any problems with the registration process or your account login, please contact the administrator.
all the motors ive assembled were easy to turn via hand even witht he spark plugs in there, i never had any problems with resistance only on the compression stroke, but u can feel that it is compression, ive never used arp rod bolts so i wouldn't know what to tell you, i just go by the specs in the fsm, and then i add 5lbs to each
since your unsure what i suggest you do is get a plastigauge, the green one i believe, and torque them till your within nissan specs, start low and work your way up, they arent the most accurate, but they work, set the motor towards the tighter end of of the spectrum to account for any inaccuracies, it should be still free spinning exp with the spark plugs out use tons of lube when ur ready for the real assembly and wd40 on the sleeves
edit also, turbo motors can be a lil looser than NA motors, but thats more for ring gaps ect, since they usually experience more heat the metals expand more,
__________________ Project Shift_Rebirth
Change is Inevitable I create my own path, i dont follow others
Last edited by Nyc Sr20PowerD : 05-12-2008 at 02:50 PM.
i will take this into consideration!
funny though, i heard to go a little tighter as opposed to looser on a turbo application.
p.s. i did use plastiguage when pre-assembling...the green. it was all within spec. im thinking maybe the arp studs are effin things up. im just going to go loose on the fsm standards. at 73 right now, it is real tight but able to be spun by hand. im going to go at 70 and see how that feels.
With the cams and sparkplugs out, you should not have a hard time rotating the crank. Based on what you have stated so far, the crank is too tight and you should retorque or redo the bearings.
If you're using arp bolts, then you should follow their recommendations on torqueing. If you're using oem, then follow FSM specs, btw factory bolts are torque to yield so you should use an angle wrench.
Tight and loose feeling is ambiguous and subjective, you should use a cheap bar type torque wrench with a needle indicator to know for sure. Spin the crank with the bar torque wrench, it should turn with 10-18 ft/lb. You are looking for the "break away torque" when the crank is 90 degrees from TDC and BDC. When the crank is at TDC or BDC, it's easy to rotate so it will skew your reading. Ideally, you should see 10-12 ft/lb. Good luck.
I did the bearings one at a time because the machine line-bored the beejezus out of the block...so bearing numbers were useless I found out later...luckily not too much later.
I realized I had installed the bearings in the reverse order. When I discovered this, I realized I had a 5 where a 4 was supposed to go but the block still rotated fine...meaning they were too loose. At that point, I was leary about everyone so I replaced them one at a time, going up a size, torquing, test rotation, if it turns, repeat with larger bearing, test rotation, if it doesn't turn go back to the previous bearing size.
Time consuming but I know they're correct now! It's one of those things you want to take the extra time on because you definately dont want to get that part wrong. It's very disheartening when you do....to hear the CLAK CLAK CLAK CLAK on your new motor.
time consuming....yes!
i talked to a buddy tonight for 1.5 hrs about things. he would like to see me strip it down and start over. im not trying to do that!!!
so, torqued at 73 ftlbs, i removed the zip-tie from the chain and started rotating. i will try more things tomorrow as i am very tired at the moment.
seems to spin freely as it is.
through the rotation though, it gets just a little snug at one point, like a compression stroke. although there are no plugs in yet....?
i am also going to call ARP tomorrow and see what they suggest about a 73ft lb torque opposed to 80.
i will get to the bottom of this!
i'll be dammed to pop my motor cause of some stupid bearings, torque, and impatience. i've got 2years, alot of time and $$$ in this to risk it all! definately dont wanna be replaceing bearings and figuring this all out from underneath the car!!!
you kinda had to snap the wrench when it was a short block, but then it spun freely.
It may just be dry. I remember mine did this and you could slightly hear a scraping sound. You might wanna try a little WD-40...or oil if you prefer, wd40 is fine though.
Definately try that before starting over however don't cut corners on a motor build or you'll regret it later.
If you can get it to turn where you can just use one hand and every thing is torqued, it's probably good. When I was testing the bearings one at a time, when I got to that next size up that was too tight, I couldn't turn the motor at all or it just required excessive force to move it....like both hands and leverage.
^^^it was directed towards you and anyone else, but not how you interperated it.
what i meant was.....further advice from anyone who has experience building a motor is more than welcomed.
as i rotate the crank as it sits at 73lbs, it spins freely. i can use one hand without force. there "is" a sorta scraping sound as you describe. i was thinking dry as well.
my only concern at the moment is that "compression stroke" feeling i spoke of in my previous post. it happens twice a rotation, when the pistons reach the top of the cylinders like a compression stroke, but there arent any plugs in yet......normal?
k, just got off the phone with ARP.
with the studs torque spec of 80ft lbs, and the crank not turning at that setting, he said i may need a line bore adjustment. i dont want to hear that.
he said there is a footnote on the instructions that suggests that with a higher than factory yeild of torque, line bore adj. may be required.
i asked him in his personal opinion if he thinks that 73 ft lbs would be ok. he seemed to lean in the direction that it would be, but would not confirm that in words so as to go against what his company reccommends. one would think: whats 7lbs difference really going to make? well i know its the difference between my motor turning and not turning.
*sigh* what to do what to do!
time consuming....yes!
i talked to a buddy tonight for 1.5 hrs about things. he would like to see me strip it down and start over. im not trying to do that!!!
Unfortunately, you know what to do...it just sucks that you need to.
It could be worse...I spent over $400 on machine work on a block that I purchased for the buildup, and after I had everything in and had done all this work, when torquing the head per FSM the threads came out of the block...sounded and felt like I broke a headbolt. Took everything out in a very ticked-off mood and went back to the machine shop. They offered to install the head for me (I'm sure they thought I just did something wrong) and so I let them - not free of course. When he was torquing the head the same thing happened to him on a different hole. Turns out the block had been overheated and it changed the properties of the aluminum, making it brittle. Recommendation: scrap the block....not what I wanted to hear either.
I lost another six months searching for another block and gathering more funds...then I got to spend more money at the machine shop to prep that block!
just lubed up some, no wd40 (PBlaster), i believe the "scraping sound to be the rings against the cylinder. that fine.
im about to head out and down to the machine shop to talk to them in terms of $$$ and bolting in the damn crank so all is well.
i shoulda just used new stock bolts instead of the ARP studs!
i used the stock grade bearings, so if anything this motor should be loose, not tight!!! i just dont want to spend more money!!!
My dad used to say, "It only costs 100% more to go first class."
I feel you on the not spending money thing! It's becoming more and more difficult to do the one thing I really enjoy...and the lack of time doesn't help at all...I just got moved to 2nd shift (not by choice) and only see my 3yr old son a couple of hours a day. And I can't quit b/c nobody else can afford me
oh, time is a whoooole nother issue!!! LOL
between waking up at 4am for work, working 4x aweek 45+hrs.
going to the gym, sleep, family, and i go to school at nights....time sux!
i hear ya on the time thing. i like your dad's saying though, actually chuckled a little outloud
just got out the shower, headed to the shop. i will update when i figure something out.
thank you very much for your help and telling me what i didnt want to hear... exactly what i needed to hear
woo, wish i worked that!!!
i got a call this morning for OT as i have thursdays off, but i didnt get the wake up call since i have no service "sometimes" at my house!!! wft. oh well!
just got home from the machine shop with plenty of ideas, even an offer for him to swing by and scope the situation out for me. he wasnt set on taking my money without me doing a little more work before hand to come to a final conclusion.
with that, i decided just for sh*ts and giggles to torque it to 80 just to see before i started taking everything apart.
to my total and complete bafflement it spins just about the same as before when at 73 ft lbs. i am so confused now!!!!!
now what comes to mind is when assembling before months ago, i was torquing with my buddys dads wrench. the thing is mad old school and just possibly a tad bit out of calibration....?
i am using a brand new torque wrench i bought to finish this build.
From what you have said.
Re torqueing the bearings is a waste of time.
Is the crank straight ?
Its common for cranks to have a bend which you effectively pull straight by doing up the mains caps.
It must be checked between centres using a dti.
Even plasigauge will lie to you if the crank is bent any amount.
If it has any bend at all regind it.
Line honing the crank journels in the block isnt a bad idea , but I think its more likely in the crank.
You should be able to fit bearings to block, drop in crank and torque up mains caps./ use lots of assembly oil.
The crank should still be very easy to turn.
It should easily rotake using the main pulley as a lever.
no amount of undoing and retorquing will put it right if it isnt straight.
make sure when you fit the rings they are gapped right and champer the outside edge of the gap.(with a stone)
Fit the pistons & oil generously and fit in bore.
Lube and fit big ends torque up rod bolts.
It should still be easy to rotate but you will find the drag from the rings is making it feel tight.
But it should still rotate easy using the crank pulley as a handle/lever
If you have to put any kind of bar on the crank pulley to turn it , its too tight.
Put the head on and time the cams
It should be starting to get hard to turn as you are now trying to open valves etc: but should still turn with no plugs in it reasonably easily.
i concluded that the torque wrench i was using was old and out of calibration. i bought a new one and at 80ft lb as a last horaah before i started taking everything apart, it spun freely as i think it should.
cams/gears went in last night, chain on. still spins nicely!
im psyched!!!!
thank you all for your help on this.
more questions to come im sure.
