Went to the track.....now pulling motor

[nelson8708]

I went to the track today. I got there about 6pm and did runs all the way till 10pm. I got 16 runs in ...I probably did three runs back to back then took a half hour break or so. I was on 5psi, bald street tires, welded diff. For the first 6 runs or so i couldn't get a decent launch. Were talking 2.4 to 2.6 60's. I was launching around 3K since that is what i launch at on the street but i would spin like crazy on the street and i was bogging on the track. I kept upping my laucnch rpms and when i got around 4K it didnt bog as much any more. Towards the end of the night i was launching at 4,200rpm and was cutting 2.2 60's. I think i can get it a little lower if i were to lauch around 4,500. My best time of the night was a 14.6@97 with the 2.2 60'.

Now here is were it gets bad. It was probably 9:30 or so when i decided to do two more runs then call it a night. The first run i did was an ok 14.7. I decided since i was doing my last run i would do a burnout in the box since i had not done one all night. So i did my burnout and that is when i pulled my best time. So i pull the car around to park it and watch others run for the rest of the night. When i pulled into a spot next to a car i hear this metal on metal contact.... ....i was hoping it was my exhaust since i sounded like it was coming from under the car. So i get under it and shake a few things but nothing makes the sound. I pop the hood and give it a little rev and it follows the rpms. I shut it down and go watch other cars run for 20-30 minutes. So i get back and check all my fluids and they are ok. So i start her up and here the horrible sound that is a rod knock on #4. Then i start to limp my way home. I guess on a good note i did make it home (45min drive). On the way home it didnt make any noises or act weird at all. It only seems to do it at idle. I was boosted for 2 years with no major problems until now.

Thank god its not my daily any more.

So i am going to rip her apart and see whats up. I plan on keeping the same crank and rod if they are not damaged. I have a quick question though. What would cause it to spin a rod bearing? Streched rod bolt? I was shifting at 6K. If a rod bolt is the cause of it i am going to get arp rod bolts if you can for the stock rods and throw some new rings and ACL bearings in it while i'm in there. I rebuilt this motor 15K ago (stock rebuild) so i guess i got some use out of it. I used a ebay rebuild kit at the time too ....how ever i later learned that it was the same rebuild kit TopHat sold. ......Ebay bearings (ITM)....FTL

Modified by nelson8708 at 6:44 AM 7/19/2008
Modified by nelson8708 at 8:23 AM 7/19/2008

[Florida240sx]

Sure it's a bearing not timing chain? Wishful thinking

[nelson8708]

All my buddies said it was my exhaust hitting my dump tube or some thing. It sounds like that until you open the hood. Since its at the back of the motor i kind of ruled the timing chain out. .....Its one of those sounds that when you hear it coming from your car you get that feeling in your gut. Ya never know...maybe next weekend when i get a chance to look into to it might be some thing else but, i'm not holding my breath.

I'm pretty much going to throw it up on jack stands and if everything looks ok under it then i am going to go ahead and start unbolting the transmission and what not.

[eazye2000]

What kind of clutch do you have? Stock, or aftermarket?I'm just asking because my stocker took a crap, and sounded like a 'knock'. It was either the pilot, or throwout bearing.

Sure it's a bearing not timing chain? Wishful thinking

My S14 does that. You can heat that bish' doing it's thing at idle, but if you bump up the rpm's, it goes away. I guess the oil pressure tightens it up. Or that's a sign of a bad oil pump.. who knows'. lol

But yeah, hope it's nothing bad. And the fact that you drove it home without a hitch, is a good thing.

Now that you're going to tear it down, put some fortified guts in that puppy!

[DevilMB3017]

Could be a clutch thing like has been said.

If it happens only at idle, maybe it's a valve thing? You sure it's not coming from the top of the motor? Just throwing it out there.

[480sx]

If its an RPM based ticking type sound, its almost def a rod bearing. Really surprised that you were able to drive it home though, when i had rod knock it went from being barely audible to horrible sounding within 10 min.

Time for a rebuild!

[WDRacing]

When you get rod knock it's almost always a lube problem, unless you stretched the hardware. But shifting at 6k isn't going to do that, and 5 psi isn't creating so much torque you were bending things.

I had that issue...I had knock...then I had a hole in the block. In fact 3 years later that same engine with the hole is still under the hood...lol.

[nelson8708]

As for clutch i have a WBS. Its not a valve thing. Its sounds like it coming from the bottom end. I have bad cell phone vid of it i will post that i took that night. I need to turn the car around in the garage to get ready to pull the motor in the next few weeks so i will get another vid then too. If if was the clutch shouldn't the noise change when i engage / disengauge the clutch? When i bought the car it had a bad throw out bearing that made some weird noises but it wasnt the same as this.

My buddie (also sohc) thought he had a lifter seize on him but coutinued to drive the car for about a week or two. It was a rod knock and the motor ended up seizing in his drive way after a drive home from work. So he drove it for about 1.5-2 weeks after hearing the initial rod knock.

http://tinypic.com/player.php?v=285b7o&s=4

I have a high volume 280zx oil pump so i dont think it was a pressure or volume problem. The only thing i can think of being a lube problem is that it was a 95 degree day. During my last run when it happend it had cooled down to probably 86 degrees. I was running 10w30 (only had 800 miles on the oil that was in the engine though).

[480sx]

Woulda been helpful if you reved the motor when you took that vid but... Doesnt sound good hah. Id say rod knock for sure if the noise follows through the RPMs.

You got an oil pressure gage? Hows the OP?

[nelson8708]

I have a oil pressure gauge, just not installed.lol....I got another sohc last night though. I am kinda debating on what i want to do. Me and a buddie have to go pick it up. He gets the cylinder head and i get the short block. Depending on how my bottom end looks when i pull it i will either fix the motor in the car or just swap my head onto the short block i am getting. The only thing is i dont know what kinda shape the block i am getting is in. Might be fine or it may have a spun bearing and bad compression. I will probably fix the motor that is in the car. New bearing and possibly a new crank. As long as the rod is ok i'm not even going to take the head off.

[neverlift]

that is what my bud's cobra sounded like , till it put a chunk of al. block in my driveway never got to race the ****er

damn nelson at least you got it home man

so what was your best time?

[nelson8708]

I went to the track today. I got there about 6pm and did runs all the way till 10pm. I got 16 runs in ...I probably did three runs back to back then took a half hour break or so. I was on 5psi, bald street tires, welded diff. For the first 6 runs or so i couldn't get a decent launch. Were talking 2.4 to 2.6 60's. I was launching around 3K since that is what i launch at on the street but i would spin like crazy on the street and i was bogging on the track. I kept upping my laucnch rpms and when i got around 4K it didnt bog as much any more. Towards the end of the night i was launching at 4,200rpm and was cutting 2.2 60's. I think i can get it a little lower if i were to lauch around 4,500. My best time of the night was a 14.6@97 with the 2.2 60'.

Yeah i was happy that i atleast made it home.

[nissanfanatic]

I had an issue that sounded like bad knock on the dyno after putting down 532whp. It turned out to be my flywheel bolts shearing off/backing out. I would check oil pressure, as if you have enough clearance to be knocking, oil pressure should be pretty low.

You don't run the car hard when it is cold do you?

[Hooked on 240]

guy near me has a junkyard turbo setup KA SOHC on his 90. his best was 14.4 @ 95. im very glad to see people arent throwing these motors out. nothing wrong with sohc.

[nelson8708]

I had an issue that sounded like bad knock on the dyno after putting down 532whp. It turned out to be my flywheel bolts shearing off/backing out. I would check oil pressure, as if you have enough clearance to be knocking, oil pressure should be pretty low.

You don't run the car hard when it is cold do you?

No i never beat on the car when its cold. I wait for it to atleast get up to 160-170 degrees. I believe i read on moto tune usa that beating on a motor that is not fully warmed up is one of the main causes of engine failure. When i pull it i will find out whether or not its the flywheel bolts backing out or not. I did use red lock tite when i installed them but, that doesnt mean they didnt back out. When i pull it i plan on spot welding what i can in the engine bay as well as maybe cleaning up a few wires.

Do you think it could of been the fact that i was running too light of engine oil (10w30 on a 92 degree day)? I am thinking 10w-40 or maybe 20w50 depending on my clearences if it turns out that i have to replace my bearings.

guy near me has a junkyard turbo setup KA SOHC on his 90. his best was 14.4 @ 95. im very glad to see people arent throwing these motors out. nothing wrong with sohc.

Yeah...I ran a 15.2@92 on my t25/smic setup. My clutch was already going so i didnt launch it and ran a 2.7 60' when i was at the track with that setup.

I think i could of ran a 14.5 or 14.4 (new setup) if i had launched a little higher. I was getting nervous when i was having to launch around 4K even though i was still bogging. I think the sweet spot would be 4.5K and then i would be able to cut a sub 2.0 60'. Plus i had pulled to much timing on that tune. I pulled enough timing for 8psi since i though i would be running that but, i was only on 5psi because the mafs maxed out. So with a little timing put back in and a higher launch rpm i think i could of gotten a little better time.

[nelson8708]

Update:

I am starting to think it might be the clutch like nissan fanatic said. I had to start the car today to turn it around in the garage to get it ready to pull the motor next weekend and when i stated it...it was fine and didnt make any noises. Once it warmed up a little the noise came back but it wasnt loud. I have noticed that it only does it on the down rev and because that i think it might be a wrist pin / piston issue. It does have ebay pistons in it after all. My tig teacher gave me the hint that it might be wrist pin related. He does a lot of welding for a sprint car team and he and his son use to race go karts so he knows a bad sound when he hears it, But he said that only wrist pins make the noise on the down rev and if i had spun a bearing it should do it all the time. I am still going to pull the transmission this weekend to check the clutch and if it turns out everything is ok then i will pull the motor but, probably not the same weekend. Since i still have to pull the bottom end a part to get the pistons / wrist pins out for inspection i am going to go a head and put some ACL bearing in there. If it turn out the pistons have some issues then the stockers will be going back in.

P.S.

Does any one know where i can go look at some diamond star racing wheels?

EDIT: New videos

http://tinypic.com/usermedia.p...3D%3D

http://tinypic.com/usermedia.p...3D%3D
Modified by nelson8708 at 6:03 AM 8/4/2008

[480sx]

Thats good news, means your crank is most likely OK. Still a tear down which sucks but you had a great run out of that motor.

BTW, OEM used pistons > ebay pistons any day of the week. Not trying to be an ***, i just cant believe you used ebay pistons over OEM.

Really curious now to see if its a wrist pin thats failed/failing. Good info from your shop teacher about knock on the down rev knock. Hes right about the rod knock noise, if it was that, you would hear it all the time.

[nelson8708]

At the time new pistons sounded good and they had a ceramic coating. Once i boosted it i had wished i used stock ones since i know what they can take. I plan on putting the stockers back in if i have to pull the motor apart. What is your opinion on engine bearings?

King bearings

of

ACL bearings

[480sx]

Either one is most likely going to be fine. I havnt done much research on king bearings either so i cant say one way or the other as far as they are concerned. If you want to go all out, go with either a calico coated bearing or a WPC treatment. All depends on how much you want to spend. WPC = the ish.

I would just go with tried, true, and damn cheap. ACL, 45 shipped for rods/mains, done.

[neverlift]

glad it isnt as bad as thought

I run ebay pistons bro, @75 bux shipped I will eat them if I have to, honestly the quality was as good or better than a local parts shop rings were not the best...

clevite main and rod bearing for 3x$ been reused once now....

[nelson8708]

Well i'm not going to pull the crank if i can help it. I am going to pull the head and just take the #4 piston rod out first to see if thats it. If i can figure out what went wrong then i will do bearings. The ones that are in here only have 15K on them. The only thing i plan on buying now if it turns out to be the pistons is a new head gasket.

[neverlift]

yeah I was thinking today I should have bought a copper gasket, I think I'll get one next time I open her up....

I'd pull the transmission, I experienced a strange noise I knew was my motor being pwnt, it turned ou to be 2 flywheel bolts backing out, and another time 2 pressure plate bolts..... thread lock ftl hell speaking of two's I believe my overheating is solved but now my slave cyl is dead and leaking fvckin nissan

well tyten up and let us know

[nelson8708]

You guys are really temping me to just pull the transmission now but, i already have half the stuff done i need to in order to pull the motor. I think i am just going to go ahead and pull it and if it turns out to be a clutch / flywheel related issue i will be happy to put it back in.

If i cant get ahold of a cherry picker then i will pull the transmission though.

[neverlift]

just pull the transmission with the motor and check out eveything goes back in much easier that way imho.

[nissanfanatic]

I wouldn't say your crank is necessarily "alright"...

It could come out looking like this:

You'll have to extract six of these little bishez if your flywheel shears off.

If it is a clutch issue, you should be able to feel/hear a change when you depress the clutch. Or you can just wait until your car is immobile and the car sounds like a sport bike when the throttle is depressed.

[WDRacing]

I wouldn't say your crank is necessarily "alright"...

It could come out looking like this:

You'll have to extract six of these little bishez if your flywheel shears off.

If it is a clutch issue, you should be able to feel/hear a change when you depress the clutch. Or you can just wait until your car is immobile and the car sounds like a sport bike when the throttle is depressed.

FAIL

[nissanfanatic]

FAIL

Yea, I had a naughty word in the url. Censorship reflects a society's lack of confidence in itself.

[WDRacing]

Agreed

[neverlift]

[nelson8708]

I dont think i have the power to sheer off bolts but maybe because of having ot launch so high, one may have come loose. I dont know yet but, will find out tomorrow since i got a cherry picker today but, forgot to get a chain while i was there ....

P.S.

I also found out that one of my couplers had a decent size hole in it so i might have ran faster if it wasnt for that. I will have some pics of it and the motor being pulled tomorrow night.