Chevy86 IROC-Z

iTrader: (17)

I just rebuilt my engine last year and I threw another rod. Fed up with this junk. So Im going to just get a NEW roller long block. So does anyone know what the original casting number to a 87 IROC-Z engine is? Currently in the IROC i have this one 14093638 1987-1995 350 1 peice rear seal 4 bolt main roller.

But then theres another one for the 1987 too 14101148 1987-1990 350 4 bolt main 1 piece rear seal. I dont know if this one is a roller.

So which should I shoot for? My budget is under $2000

Listen to the knock here... http://www.youtube.com/watch?v=_fjiWr5zHf4

Sonix

iTrader: (1)

Wait, you threw a rod, or you have a rod knock? That's a pretty different situation eh?

Why do you want a new block altogether? Is the block damaged, or do you just need to turn your crank, and put new bearings in, and replace a rod?

Sorry, I can't view youtube at work, so I have no idea how severe this is. Any idea the cause? improperly torqued rod caps? poor crank machining? etc?

Chevy86 IROC-Z

iTrader: (17)

I did this burn out here..http://www.youtube.com/watch?v=x7CxKA5CSxg before the noise.

WAIT A MINUTE!!. You should be working. . Just playing with you. I did the burn out and as I was going back home, I noticed the loud ticking sound and I thought that I had a arching spark plug. So when I got home, I really heard the sound. So I told my wife to record the sound with here Iphone. Its a loud ticking sound and I cant really tell where its coming from. Sound kind of louder when under the car though. Well the crank was polished prior to installation. Everything is new (rebuilt). The connecting rods are the originals. I want to get a new short block because I just dont want to put up with the worry of something breaking , as it is common with used and rebuilt blocks.

Chevy86 IROC-Z

iTrader: (17)

Here is another clip of the loud ticking/knocking from 3 different spots (driver, passenger side and underside) http://www.youtube.com/watch?v=GTvfvybmQvA

BlueWrath92

iTrader: (1)

I have like this tiny ticking noise, I can sometimes hear it in my wheel well when I listen really close, sometimes I haer it and it sounds like it might be commin from throttle body or under the passanger side valve cover, not loud at all and dont seem to be hurting anything.... i dunno

Chevy86 IROC-Z

iTrader: (17)

You may have a valve that is out of adjustment (incorrect valve lash) if the sound is coming from the valve cover.
But that is nothing compared to the sound coming from my engine bay.

dimented24x7

iTrader: (2)

Doesnt sound like a rod to me...

Pull the valve covers and have a look at the valvetrain.

dimented24x7

iTrader: (2)

FWIW, if you threw a rod, you would probably know immediately when it happened. At high RPMs, a lot of the time the end of the rod will come out thru the side of the block. At the very least, it will make a hell of a racket. Not a simple little tick tick tick.

Chevy86 IROC-Z

iTrader: (17)

Well it's making a similar sound like in my 2003 thrown rod incident (never went through the block either). Im stumped. Im gonna pull the covers tomorrow and check the lash with my fingers (twisting the push rods). Thanks for the reply bro. Ill let you know my results tomorrow. Do you know of a way to redirect the oil from splashing everywhere? I dont have a valve cover with the cut slot or the clips.

tkcaraudio

This may sound stupid but I have found it works

Take a wooden broom stick(by its self no broom lol) Put one end up to Valve Cover put ear on other end while motor is running listen to it see how loud it is

Then take it and put on block by spark plugs and listen

If its louder on top its in valve train if its louder on botttom its in rod/crank area

If its in the middle its ris pin or something in that area

Did you polish your rods too?

Take that motor out since its original years
Bore 30 over
Grab a scat crank for 300
put some good bearings in it (CHECK CLEARENCES WITH PLASTI GAUGE ITS LIKE $2 TO SAVE A $1500 MOTOR)
Put some good pistons in it you can get reasonably cheap


Check out
Speedway Motors( www.speedwaymotors.com ) for cheap scat cranks
Power House Performance ( www.enginekits.com )

Hope this helps

My dads a machinest and tought me all his old tricks to know

Just build ya a lil 355 or 383 and run it you will be more happy on the spending limit you have

tkcaraudio

Go to autozone or napa and get a set of cheapy oil reflectors or go to pick in pull near you and pull a stock cover(dont have to be perimiter bolt cut top off and use it

ASE doc

Hey Bro, You should know that every good race motor starts with a used block. The difference between a motor that takes the abuse and keeps on screaming and the motor that breaks is all in the choice of parts and machine work. BTW, dont waste time with plastigage. Have your machinist clearance your motor. We used to call it blueprinting. He'll precisely measure all the parts and verify roundness and clearance. My motor was clearanced within .0001 Its not that much extra. Also have your rotating assembly balanced at 6,000rpm and use a good balancer. I run a fluidamper. That way when youre winding on it, its in perfect balance and less likely to fling parts.

Chevy86 IROC-Z

iTrader: (17)

I use a clear tube to search for hiddin noises. But thanks, thats the first that Ive heard about a broom stick. Its a rebuild by me and my uncle. Everything is new except the connecting rods, crank (polished of course). The machinist that hot cleaned my block did all the necessary measurements. Cylinders where standard (4 inch), honed, crank had slight wear so I was recommended a high vol. oil pump. Never heard of polishing the rods before. Ill check to see if I have to pull out the engine. If so, building a 383 sounds very tempting now that you mention it. Ill keep my options open. I was reading up on the ZZ383 block. Makes me have a nicotine withdraw., and I just quit!!!!

Chevy86 IROC-Z

iTrader: (17)

So if the block is still good, I should invest my money strictly on that block? I like the advice of the other member (383 build). So to have a blue print, I should take everything to the machinist and have him put it together? Or just have him check all the important stuff (clearances).

ASE doc

Have your machinist prep the block. Dont tie his hands by refusing things like line honing or decking. Be sure to have him bore with deckplates for greater accuracy. Have him balance and clearance the rotating assembly. My race motors, including the one in my IROC are all built using ARP studs throughout. Get these before you go to the machinist so he has them when he does the clearancing.

If youre confortable doing it and you have a good torque wrench, do the assembly yourself. It has to be done in a clean, dust free environment. Use lots of moly assembly lube.

383s are cool for the street. They dont like high rpms very much. They like to break cranks and throw rods when wound on alot. If youre going to do a 383, be sure to use moly rods and a steel crank.

Chevy86 IROC-Z

iTrader: (17)

Good advise flowing from left to right. Thanks fellow members. So what would I need to make a plain old 350 block a 383? Another steel crank and a .30 over bore?

dimented24x7

iTrader: (2)

Have you even determined whats making the noise yet???

FWIW, this is what my engine sounded like when I had a lifter come apart internally. Not exactly a catastrophic failure. The problem could even be as simple as a stud thats backing out. Determine whats bad first before you go and buy a whole new motor. Thats a rather draconian approach to fixing the problem.

Chevy86 IROC-Z

iTrader: (17)

Havent had a chnce yet. Cookin for my children right now. Once done, Ill make like a baby and head out,,,, to do some troubleshooting.

ASE doc

Hey Buddy, Just listened to your vid. I agree with dimented. Do your best to diag the noise before you jump at the ultimate solution. Its hard to tell from the vid, but it sounds a little high pitched for bottom end. Cracked flexplate comes to mind.

Chevy86 IROC-Z

iTrader: (17)

Well after a few pieces of advice, I tried the spark plug removal method. Let me tell you. That was the first time I have around 40,000-45,000 volts jump from my finger tips and all the way down to my stomach. HOLY CRAP!!!!! That hurt. So I tried to move on and ZZZAAPPPPP!!!!!! I gave up on the 4th plug. So today a board member (good friend of mine) asked me if I found the source. I said no and he pretty much told me to suck it up and complete the test. Made me feel less than a man because of his comment. Anyway, tomorrow Im gonna try the rest of the plugs to see if its spark knock, spun bearing, bad rod, or cracked flex plate. Ill keep you guys posted on my progress. Thanks guys.

Chevy86 IROC-Z

iTrader: (17)

Curious about my 2002 thrown rod incident? Of course you are..

http://www.youtube.com/watch?v=nHja0312gSo

InfernalVortex

iTrader: (4)

How is polishing the rods going to help anything? There's a bearing between the rod and the crankshaft... all polishing will do is make it a little easier for that bearing to rotate, but even then it's already pretty smooth to begin with, that's what the little tang grooves are for.

I've heard of shot-peening rods, though. Grinding off casting lines, sharp edges etc, to remove stress points.

Chevy86 IROC-Z

iTrader: (17)

I thought the little tangs on the bearings/rod where to keep the bearing from spinning around the inside of the rod at the crank.

Chevy86 IROC-Z

iTrader: (17)

To check the flex plate, I would have to drop the tranny right ASE doc. Im gonna visualy check when I can without dropping the tranny. But fisrt Im gonna pull the plugs to rule out piston knock, rod knock,and bad valve adjustment.

88IROC350TPI

Sounds like it could very well be an exhaust leak to me.... Not uncommon for gaskets to blow out at higher RPM's.

From that video it looks like your front tires are scary bald, too...

92RS_Ttop

iTrader: (3)

Sounds just like my leaky header. Mine is leaking at the gasket between the block and the header on #7. Easy way to test is to CAREFULLY feel for the exhaust gasses blowing past the gasket. I can feel the air puffing out pretty easily on my leak when I slip my hand down between the header and firewall.

Auggie

Well, I had a simler problem but it may not be your problem. I ran the engine up to 5700 in 1st and 2nd gears, backed off and I hear this loud rapping like noise coming from under the hood and I go oh no I blew a rod bearing. I limp it home and raise the hood and it is really a loud noise. i use a long 3/8" drive extension and when i get to # seven cyl I go what the hell??
Well it turns out to be a cracked air tube going into the #7 cyl header. I have to tell you it sounded just like a rod knock. I cut the air tubes off of the header and welded up the holes. PHEW!!!

Auggie

tom3

Take a piece of hose, one end at your ear, other use as a microphone, to check around headers and spark plugs. Take off inspection plate for the flex plate, right behind oil pan. Have to look close to see cracks but also check the tranny to engine bolts, if loose will sure crack the flexplate. I use an ice pick to short out plugs to check for rod/piston noises, sharp end to penetrate the plug boot while laying the metal rod against the header or manifold. HEI doesn't like unhooked spark plug wires.

Chevy86 IROC-Z

iTrader: (17)

All good info. Thanks guys. yeah I learned the hard way about the HEI and disconnected spark plugs wires. My buddy called me what someone would call a cat (example from Shrek "PUSS" in boots). So now I gotta man up and start pulling plug wires. I wish I had a ice pick.

Chevy86 IROC-Z

iTrader: (17)

I will try the other methods too. Thanks agian guys.

Chevy86 IROC-Z

iTrader: (17)

The tires are used tires. I needed them bad. I figured a pair of $25 each would get me through the following income tax season.

InfernalVortex

iTrader: (4)

That's exactly what they're for. That's what I meant when I said that.

Again.. that surface never sees any friction or oil, so why polish it?

Chevy86 IROC-Z

iTrader: (17)

tkcaraudio asked me if I polished the rods. Not sure what he meant. But anyway. Earlier I pulled all eight plugs, one at a time and ZZAPPPPPPP. Damb, I think I got use to that because after the 2nd time of 40,000-45,000 volts running through my arms, I kind of expected it to happen and I just went for it. So after the 8 plugs got pulled, each and everytime, the click/knock was still there. There was no difference. So I guess that rules out a spun bearing, rod knock, piston knock. So can it be a bent rod,broken flex plate, blown exaust gasket? Not sure yet but Im gonna try the tube to ear test to see whether or not I got an exaust leak. How would the Camaro respond if the harmonic balancer was bad? I always had a rhythemic vibration that went RRRRRRR RRRRRRRR RRRRRRRR RRRRRRRRR when I would floor the IROC. It's vibration would increase in speed when the IROC increased in speed. Might it have something to do with the issue which lead to this knocking sound?

dimented24x7

iTrader: (2)

From the video, it sounds like the sound can also be heard thru the oil pan. Check and see if the sound is coming from the pan area. If it can be heard loudest thru the bottom of the pan, but not around the trans or other areas, then that points to a possible valvetrain or lifter issue.

Auggie

Yah, I had that RRRRRRRRRRRRRRRR sound and I fought it on and off for a couple of years and finley figured it out. It was the lock-up torque converter. I replaced the lock-up converter with a non-lock-up converter and installed an Art Carr kit to rerout the ATF in the trans. Man, does the car ever run smooth now and no lock unlock lock unlock BS any more. Oh you might want to remove the dip stick just to make sure.

Auggie

ASE doc

After 35 years in the industry, I dont remove spark plug wires from HEI motors with the engine running. Not with my bare hands. I use a special pair of spark plug wire pliers that I made with a ground lead attached. I attach the ground lead to a good engine ground with the aligator clip I installed on its end and then I can remove and install wires without getting shocked. Another method is to use a test light attached to ground and pierce each wire at the dist cap boot. Sorry I didnt specify how to remove the wires for this test.

Chevy86 IROC-Z

iTrader: (17)

Yup. I know about the plug wire plier pullers. It was a good experience though having that much volts surging my arm .
I was planning to do some trouble shooting today but I just got out of work and my wife wants to go to Mexicali Mexico to eat some carne asada tacos. So tomorrow will be the day that I so some testing.

Chevy86 IROC-Z

iTrader: (17)

Torque converter, thanks for the heads up Auggie. When I drop my tranny to rebuild it (lost reverse), Ill look into the torque converter.

Chevy86 IROC-Z

iTrader: (17)

It does sound louder through the bottom. This is driving me crazy.

Chevy86 IROC-Z

iTrader: (17)

Ohh. Another clue perhaps. There is no clicking/knock during the cranking. I had to give it push the pedal to activate anti flood mode because the IROC wouldn't turn on. So it cranked for about 6 seconds and I noticed that the noise wasnt present. So obviously the noise has to do with centrifical force or pressure?

ASE doc

Sounds again like a possible cracked flexplate.

slowmaro87

youde be amazed at how much a f'd up flexplate can sound like a rod knock i was lol

Chevy86 IROC-Z

iTrader: (17)

I just talked to my neighbor and he told me that he had a 3rd gen Pontiac way back in the day. He told me that my turbina (spanish for flexplate) is probably broken. I cant jack up the dang IROC though because of the asphalt (not very strong when subjected to concentrated weight). Danb apartments. They are so strict to mechanic work. Check this, if manager sees an oil leak, we get hit with a fix it notice with a 1 week grace period, or we'll face eviction. Horse crap if you ask me. Still im gonna raise up and inspect. Should I inspect the flexplate with the engine on?

Chevy86 IROC-Z

iTrader: (17)

have you experienced a jacked up flexplate?

ASE doc

I have run into it three times that I remember off hand. One vehicle, the owner was prepared to replace the motor. A dealership tech had pinpointed the noise to be a rod knock. It took me ten minutes to peel the cover off to reveal the cracked flex plate. Replaced it and saved the customer 1000s. Too bad Im so d**med honest. I could be alot richer.

Unfortunately, the flex plate on the 3rd gen is harder to get to. You can try unbolting the TC and pushing it back as far as you can to get a better view. Then with a good light and a mirror you may be able to get a good look at the bolt circle. Thats where the crack will be. Starting at the crank bolt circle and running out from there. I have had to unbolt the trans before and push it back to see the crack.

Chevy86 IROC-Z

iTrader: (17)

So then I'm gonna do the obvious tests first such as locate the source of noise. Then if the noise is coming from the tranny engine area, then Ima tow to my uncles shop. Hopefully tomorrow is a good day.

Doom86

I agree.

Having spun bearings and cracked the flex plate on the same car I can tell you that's very true.

Doom86

No need to have it running if it's anything like mine was. You could move it with your hands and tell it was busted. Mine was barely holding together though, it cracked around the bolts.

I'm almost certain mine was from not having the bell-housing bolts tight enough after a motor swap.

If the dust cover is off it shouldn't take long to check it out. Just need a tire tool or something to rotate the flex plate to inspect it.

Chevy86 IROC-Z

iTrader: (17)

Ok. Ill do just that. I think I might drive over to my dads to use his ramps. I only have a small $20 hydaulic jack from Big Lots.

slowmaro87

ya we just bought an 84 fired it up and we were very bummed out thinking that the 350 that was in the car had major problems ...it sounded to be knocking like crazy ...we were just scrapping the car anyway and pulled the engine for future projects if it where savable well come to find out the "knocking" was the flexplate cracked between every bolt hole the flex plate was literally in two pieces lol