6-bolt crankwalk?

[game-hunter]

Hopefully somebody can tell me my 90GSX 6-bolt is not getting crankwalk. The car itself has over 200K miles on it but I just had the engine rebuilt less than 1000 miles ago. I had the shop assemble the rods, crank and head. I put the rest together but didn't double check the clearances on the crank. I also think it was making the knocking noise before the engine was rebuilt. I could be wrong though. The car is setup as follows.

1mm Oversized SS valves. 3-angle valve job.
8.5:1, .020 Ross Pistons
Eagle Rods.
ARP Main Studs
ARP Head Studs
Clevite Main Bearings
Clevite Rod Bearings
Cometic Head Gasket
Balance Shafts removed.
New style Lifters
Crower Springs and Titanium Retainers
New Timing belt/Tensioner/Pullys
New Water Pump
Fidanza Lightweight Flywheel
ACT 2600 Clutch with street disc.
OEM Throw out bearing
Prothane Motor Mounts
2G Ported Exhaust Manifold.

Just tested my compression last week, 160 across the board(~5600ft elevation). I just measured my crank movement using the following method. http://www.angelfire.com/pa4/awdcrankwalk/
I measured .26mm of play.

Here's a video of my car while I push the clutch in twice. The rpm's drop 100 whenever I push the clutch in. The engine was still a little cold when I took this video so rpm were approx. 1200.
http://www.kenjim.com/~james/clutchin.wmv
I currently have my warm Idle set to approx 880. If I set it to 750 my car likes to stall when I come to a stop.

Here's a video where you can hear the knocking sound. Almost sounds like the crankwalk.wav floating around. Sorry about the audio quality the vid was taken with my digi cam.
http://www.kenjim.com/~james/knock.wmv

I'm not really sure what to do besides drop my oil pan and inspect my crank and bearings.

 

[98TsiAWD]

Originally posted by game-hunter
Hopefully somebody can tell me my 90GSX 6-bolt is not getting crankwalk. The car itself has over 200K miles on it but I just had the engine rebuilt less than 1000 miles ago. I had the shop assemble the rods, crank and head. I put the rest together but didn't double check the clearances on the crank. I also think it was making the knocking noise before the engine was rebuilt. I could be wrong though. The car is setup as follows.

1mm Oversized SS valves. 3-angle valve job.
8.5:1, .020 Ross Pistons
Eagle Rods.
ARP Main Studs
ARP Head Studs
Clevite Main Bearings
Clevite Rod Bearings
Cometic Head Gasket
Balance Shafts removed.
New style Lifters
Crower Springs and Titanium Retainers
New Timing belt/Tensioner/Pullys
New Water Pump
Fidanza Lightweight Flywheel
ACT 2600 Clutch with street disc.
OEM Throw out bearing
Prothane Motor Mounts
2G Ported Exhaust Manifold.

Just tested my compression last week, 160 across the board(~5600ft elevation). I just measured my crank movement using the following method. http://www.angelfire.com/pa4/awdcrankwalk/
I measured .26mm of play.

Here's a video of my car while I push the clutch in twice. The rpm's drop 100 whenever I push the clutch in. The engine was still a little cold when I took this video so rpm were approx. 1200.
http://www.kenjim.com/~james/clutchin.wmv
I currently have my warm Idle set to approx 880. If I set it to 750 my car likes to stall when I come to a stop.

Here's a video where you can hear the knocking sound. Almost sounds like the crankwalk.wav floating around. Sorry about the audio quality the vid was taken with my digi cam.
http://www.kenjim.com/~james/knock.wmv

I'm not really sure what to do besides drop my oil pan and inspect my crank and bearings.

What is .26mm in inches? I believe endplay spec is .003 to .008" correct?
so convert your metric measurement and see if its good. My crank is at .004" that I just put together.

 

[game-hunter]

.26mm = .01in

 

[UndergroundR32]

.01 with 1000 miles on it you can pretty much call it walked and replace your block. I have a 6 bolt that was just rebuilt. forged bottom end and a knife edged crank with an OEM flywheel that was resurfaced by someone who has done race rebuilds on a number of 4g63's. I dropped my trans because of a grinding problem and out of curiosity I pushed and pulled on the clutch/flywheel/crankshaft and I heard a click when I did it back and forth with as much force as I could.. I got nervous and checked it by using a dial indicator and putting the magnet of the indicator on the oil pan and the actualy indicator shaft against the pulley. I pushed all the way to one side and marked the number, then pulled all the way to the other. To my surprise it measured only .005 but I'm still nervous. To be extra sure that it's crankwalk you may want to drop the oil pan and measure the gap at the thrust bearing. That's the sure fire way to check. Also, I would be a lot more confident using a dial indicator instead of those calipers. Just my 2 cents.

 

[thejeebus]

Did you set the thrust bearing on that rebuild before you tightened everything up and installed that ACT 2600? If not, I'll bet you that you've destroyed your crank. However, all is not lost. This happened on my friend's GVR4 and all he had to replace was the crank and bearings. Bugger of a job but better than a new block.

You have to set that thrust bearing if you are doing a fresh rebuild with a heavy duty clutch. If you don't this is what happens.

Scott

 

[game-hunter]

I had my engine builder put the short block together since I'm a noob at building engines and didn't want to mess things up.

I've spent the day tearing the car down and trying to figure out what I want to do. I was only able to remove the bottom part of the thurst bearing. Does anyone know of an easy way to remove to block side without removing the crank?

Here are some pics of the lower thrust bearing. I'm really not sure if these are good or bad. I thought that there's not supposed to be any wear but I don't know.
Pulley side
http://www.kenjim.com/~james/pulleyside.jpg
Clutch side
http://www.kenjim.com/~james/clutchside.jpg

I'm thinking of just replacing the thrust bearing and removing my arp studs on my thrust main. Is this a bad idea? Should I replace all my main studs with the oem bolts or is it ok to mix and match with 2 different torque specs?

Also how do I "set" the thrust bearing?

Thanks.

 

[thejeebus]

The way I set mine (done it twice now on two different engines) is to put th crank in the block just put the thrust bearing and cap on then wack it 2-3x on each side with the last hit being from the clutch side. When you put the bearing cap on (before you start hitting it) torque it to like 20 ft lbs. I used a small sledge hammer.

I know this sounds gorilla like but it works fine.

Scott

 

[game-hunter]

Update.

I was only able to replace the lower thrust bearing since I couldn't get the upper part out from behind the crank. I did replace the ARP studs for OEM bolts on the thrust bearing cap only. I set the thrust bearing by hammering on the crank pulley bolt and pushing the clutch (since it's still in my car). I finished with pushing my clutch. I put it back together and started the car up. My knocking sound is still there and my rpms still drop with the clutch, although not quite as much only around 50rpm vs. 100rpm. I really think the knocking sound is coming from the head. I measured my rod endplay and they were all fine.

I think I'm just going to drive the car around for the next couple of weeks and see if it gets any worse or better.

Any feedback you can give would be great.
Thanks

Edit:
Here are some close up pics of my crank where the thrust bearing sits.
Clutch side
http://www.kenjim.com/~james/crank_clutchside.jpg
Pulley side
http://www.kenjim.com/~james/crank_pulleyside.jpg

 

[talon1979]

6 bolts can suffer from crankwalk, but it is very rare.

 

[crankbender]

Seriously dude if you have that much play it is going out. do you get those measurements from inside the oilpan as well?

 

[game-hunter]

Actually I did not get the .26mm measurement from using feeler gauges on the thrust bearing. It was around .17mm or .006in I think. Although I was getting mixed results with the feeler gauges depending on where I tried to stick them.

I was reading around the site that had the how to measure endplay and he also noticed worse numbers when using the external method. Could this be because of a groove in the crank or is the whole engine moving a little inside the engine bay