Go Back   Club Lexus Forums > Lexus Model Forums > SC Models > SC 400/300 > Performance & Maintenance
Sign in using an external account
Register Forgot Password?

1j crank walk

Reply
 
 
 
 
Thread Tools Search this Thread Display Modes
Old 05-31-12, 08:13 AM   #1
baconbomb
Driver School Candidate
Trader Score: (0)
 
Join Date: Jul 2011
Location: Wa
Posts: 12
Default 1j crank walk

recently finished my 1j swap and went to drive it and noticed that when the clutch is pushed in the engine bogs down and eventually dies depending on how far the clutch gets pushed in. I was reading up on stuff and sounds like it could be crank walk.

I went out and looked at the harmonic balancer when someone stepped on the clutch and the harmonic blanacer had noticeable movement. Am I correct about whats going on. Is it crank walk?

If so what is the best way to go about fixing it. I was thinking about doing a 1.5j using me GE block. But what extra parts are needed for that. Ive read you have to get GTE pistons? Anyone know anything about this?
This ad is not displayed to registered members.
Register your free account today and become a member on Club Lexus!
baconbomb is offline   Reply With Quote
Old 05-31-12, 08:21 AM   #2
stockhatch
Lexus Champion
Trader Score: (12)
 
stockhatch's Avatar
 
Join Date: May 2009
Location: Southport NC
Posts: 2,536
Default

Yep. Sounds like crankwalk. I think the 1.5JZ is a good idea. You may not have to get GTE pistons. Do some research, as I am not sure what the CR will be on GE pistons. I know Biggu is running GE pistons, but he also is running E85, so CR is not a big deal like it will be if you run 91/93 pump.
__________________

87 GZ20//1jz//BW83-75//TR8//r154
stockhatch is offline   Reply With Quote
Old 05-31-12, 08:58 AM   #3
Biggu
Lexus Champion
Trader Score: (12)
 
Join Date: Aug 2007
Location: ohio
Posts: 1,783
Send a message via AIM to Biggu
Default

Quote:
Originally Posted by stockhatch View Post
Yep. Sounds like crankwalk. I think the 1.5JZ is a good idea. You may not have to get GTE pistons. Do some research, as I am not sure what the CR will be on GE pistons. I know Biggu is running GE pistons, but he also is running E85, so CR is not a big deal like it will be if you run 91/93 pump.
Correct but I also have a 2.5mm headgasket which lowers the compression quite a bit as well. most people that do a ge bottom end with 1jz head do a TT gasket which is 1.1 MM iirc and that puts it at 9:0:1 IIRC. Mine should be lower.
__________________
1.5jz,e85, 35r, Vertex Ridge, Weds and a few more gooddies, 600hp/654 TQ at 29psi before 3700 rpm
Biggu is offline   Reply With Quote
Old 05-31-12, 10:29 AM   #4
blk&blu*j
Lexus Test Driver
Trader Score: (1)
 
blk&blu*j's Avatar
 
Join Date: Dec 2008
Location: fl
Posts: 1,534
Default

Quote:
Originally Posted by baconbomb View Post
recently finished my 1j swap and went to drive it and noticed that when the clutch is pushed in the engine bogs down and eventually dies depending on how far the clutch gets pushed in. I was reading up on stuff and sounds like it could be crank walk.

I went out and looked at the harmonic balancer when someone stepped on the clutch and the harmonic blanacer had noticeable movement. Am I correct about whats going on. Is it crank walk?

If so what is the best way to go about fixing it. I was thinking about doing a 1.5j using me GE block. But what extra parts are needed for that. Ive read you have to get GTE pistons? Anyone know anything about this?
You are correct the thrust bearings on the crank are probably in the oil pan and you have most likely scared the crank.

What clutch are you running and have you done the clutch start delete if not, would highly recommend.
the 1.5 J is a definite option and most just use a GTE HG ARP studs and pending on the bottom used 2J or 2J GTE will be the determination as to CR if your running E than don't worry about CR if not you may want to consider as stated above a GTE piston as they are 8.5CR.
GL.
__________________
95 RHD SUPRA fully built bottom end Ferrea head 1mm over fully ported 74mm Bullseye,Tilton Quad,TRD lsd,Getrag 1319 hp at 45 psi on E-85 Megasquirt MS3Pro BUILT at Big Daddy Performance Tuned by Jordan T Turbo Jew
blk&blu*j is offline   Reply With Quote
Old 05-31-12, 12:22 PM   #5
xspsi6
Lexus Champion
Trader Score: (31)
 
xspsi6's Avatar
 
Join Date: Jul 2007
Location: Leesburg FL
Posts: 2,706
Default

What clutch are you running? If you have a heavy pressure plate then this is most likely the cause also bypass the clutch start switch as there is no oil pressure when you have the clutch pushed in without the car running then add in a heave aftermarket clutch and that my friend is a recipe for crankwalk!
__________________
1994 supra 6spd 612whp pump gas
1997 RSP/black sc400 (1jzgte,BWS366& supporting mods on aristo trans and wire harness, built auto all under way)
xspsi6 is offline   Reply With Quote
Old 06-01-12, 10:47 AM   #6
Ali SC3
Na-T Guru
Trader Score: (10)
 
Ali SC3's Avatar
 
Join Date: Oct 2007
Location: CO
Posts: 6,982
Default

You do not have to change the pistons and you don't really want to. Its just alot of cost to reduce your power alot. I am not sure why I keep hearing this all the time but the best thing to do is just change the headgasket.
get a fresh ge block and keep it that way, dont start ripping into it.. lol.
The only reason would be to lower the compression ratio all the way down to a regular gte, which most people agree is too low for the fuel these days.
The GE pistons are just as reliable as the TT, and with a TT headgasket you will be around a 9.1:1 which is still very boost friendly (what most na-t run on pump gas including myself).
If you are running e85, you could just use a stock ge headgasket and enjoy closer to 10:1 compression and have a torque monster all day with no problems at all (except finding a e85 station before you run out of fuel).
Either way I would have to agree with blk&blu and you should install arp headstuds while you are in there.
__________________

1995 Lexus SC300 5spd Na-T ( TT Ecu Mod + a few others)
Ali SC3 is offline   Reply With Quote
Old 06-02-12, 05:08 AM   #7
baconbomb
Driver School Candidate
Trader Score: (0)
 
Join Date: Jul 2011
Location: Wa
Posts: 12
Default

Thanks guys. Im not sure what clutch im using id have to look up the receipt. But Ive personally only started the car 5 or 6 times so i feel like it was a preexisting condition. I have a few more questions.

1. How do you route the oil and coolant for the turbos? The same as you would on an NA-T setup is what im assuming.

2. The 1j I have has ARP headstuds and a new head gasket. I dont think i can but can i reuse the headgasket since its literally been running for only 30 mins tops? Or is it crushed and I need a new one. Im fairly certain I can resuse the ARP headstuds. Am I correct?

Thanks for all youre help. Cant wait to get this thing running
baconbomb is offline   Reply With Quote
Old 06-02-12, 11:55 AM   #8
spoolxexo
Lexus Test Driver
Trader Score: (4)
 
spoolxexo's Avatar
 
Join Date: Dec 2010
Location: ME
Posts: 1,014
Default

Wait, wait.

Where did this 1jz of yours come from? A Supra? A Soarer? A Chaser/MKII?
spoolxexo is offline   Reply With Quote
Old 06-02-12, 04:03 PM   #9
baconbomb
Driver School Candidate
Trader Score: (0)
 
Join Date: Jul 2011
Location: Wa
Posts: 12
Default

Its from a soarer. Why does that matter though?
baconbomb is offline   Reply With Quote
Old 06-03-12, 07:40 AM   #10
spoolxexo
Lexus Test Driver
Trader Score: (4)
 
spoolxexo's Avatar
 
Join Date: Dec 2010
Location: ME
Posts: 1,014
Default

Because 1jzs don't just crankwalk for no reason.

IT seems the earliest Supra and Soarer have this issue. I'd like to know why it happens. This happened a lot on the 4g63's back in the day.
spoolxexo is offline   Reply With Quote
Old 06-03-12, 09:33 AM   #11
xspsi6
Lexus Champion
Trader Score: (31)
 
xspsi6's Avatar
 
Join Date: Jul 2007
Location: Leesburg FL
Posts: 2,706
Default

Quote:
Originally Posted by spoolxexo View Post
Because 1jzs don't just crankwalk for no reason.

IT seems the earliest Supra and Soarer have this issue. I'd like to know why it happens. This happened a lot on the 4g63's back in the day.

Yes correct and the main culprit was aftermarket clutch sets and the fact that you need to push the clutch in before you start the car so as long as you disable that feature they would last, This alone could most likely be the cause of your crank walk.
__________________
1994 supra 6spd 612whp pump gas
1997 RSP/black sc400 (1jzgte,BWS366& supporting mods on aristo trans and wire harness, built auto all under way)
xspsi6 is offline   Reply With Quote
Old 06-03-12, 09:40 AM   #12
INTIMAZY
Lexus Test Driver
Trader Score: (3)
 
INTIMAZY's Avatar
 
Join Date: Jan 2011
Location: NY
Posts: 953
tomhasfastcars
Default

Any particular reason why pushing in a clutch at startup causes so much stress? Just curious. I don't understand why clutch disengagement at startup would cause more strain than pushing in the clutch when just shifting gears.
__________________
Daytona Blue 350Z (VQ-35DERevup)
Imperial Blue Trailblazer SS (LS2)
Royal Jade Pearl SC300 (2JZ-GE+W58 --> 1JZ-GTE+R154)

CT12A twin turbo @23psi (gone)
TO4S 60-1 P-trim T4 .70A/R @ 21psi (gone)
BorgWarner S366 T4 .91A/R @26psi

AEMv2/BC272/SP-QSV/Kaaz SQ-LSD/LQ9coils/water-meth/4"single/S366/T51R compressor cover--- build in progress
INTIMAZY is offline   Reply With Quote
Old 06-03-12, 12:18 PM   #13
scoobySC3
Driver
Trader Score: (1)
 
scoobySC3's Avatar
 
Join Date: Feb 2012
Location: Utah
Posts: 178
Default

Quote:
Originally Posted by INTIMAZY View Post
Any particular reason why pushing in a clutch at startup causes so much stress? Just curious. I don't understand why clutch disengagement at startup would cause more strain than pushing in the clutch when just shifting gears.
The way my feeble brain understand it is that when the engine is running you have oil pressure, which the main and rod bearings "float" on, but with the engine off, you have no oil pressure, so the bearings are in direct contact with the crank as they do not have the oil as a buffer. So when you push in the clutch with the engine off you are moving the crank, and putting more stress on the bearings, then you turn the key/start the engine with the clutch depressed and you get a moment of no oil pressure and the engine internals rotating with all of that stress from the crank not being in good alignment, so it would put extra wear on all of the bearings. Now with the car running and the clutch depressed, you have that oil pressure/buffer so it should not put as much stress on the bearings, but probably still not ideal to have the crank move forward/aft at all.

Does that sounds right lol?
Thanks,
Rick
scoobySC3 is offline   Reply With Quote
Old 06-03-12, 12:30 PM   #14
ArmyofOne
U.S. Army-Retired.
Trader Score: (0)
 
ArmyofOne's Avatar
 
Join Date: Sep 2004
Location: Van Alstyne, TX
Posts: 6,204
Send a message via AIM to ArmyofOne Send a message via MSN to ArmyofOne Send a message via Yahoo to ArmyofOne
Default

Quote:
Originally Posted by scoobySC3 View Post
The way my feeble brain understand it is that when the engine is running you have oil pressure, which the main and rod bearings "float" on, but with the engine off, you have no oil pressure, so the bearings are in direct contact with the crank as they do not have the oil as a buffer. So when you push in the clutch with the engine off you are moving the crank, and putting more stress on the bearings, then you turn the key/start the engine with the clutch depressed and you get a moment of no oil pressure and the engine internals rotating with all of that stress from the crank not being in good alignment, so it would put extra wear on all of the bearings. Now with the car running and the clutch depressed, you have that oil pressure/buffer so it should not put as much stress on the bearings, but probably still not ideal to have the crank move forward/aft at all.

Does that sounds right lol?
Thanks,
Rick
Pretty much nailed it!
__________________
Diesel Technician-Peterbilt/Kenworth
Cummins, PACCAR, CAT, International, Detroit, ASE Certified.
-2014 Mazda CX-5 Touring in Sky Blue Mica-2.5L of SkyActiv Awesomeness-20% tint all around, 5000k HID's w/ projector's--
1994 Ford F-150 Super Cab-5.8L V8...passes everything but a gas station.
2002 Ford Focus ZTW Limited Wagon-loaded, slammed, 17x7 Drag DR-19's 6k HID's, LED DRL's, Projectors, CCFL Halo's, tinted, tunes and commuting. 173k miles and counting.
ArmyofOne is offline   Reply With Quote
Old 06-03-12, 12:40 PM   #15
SEXC
Pole Position
Trader Score: (2)
 
Join Date: Jan 2005
Location: California
Posts: 316
Default

I have never heard of this happening to any other motor besides the 2jzgte. Like stated before the supra community lowered the chances of this happening by doing the clutch bypass mod. Hope you get your problem sorted out and come back stronger. Good luck
SEXC is offline   Reply With Quote
Old 06-03-12, 12:40 PM
 
 
 
 
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
The timing belt saga continues hoosier58 Performance & Maintenance 5 11-10-13 06:33 PM
Suprus's 1JZ swap thread suprus SC 400/300 91 12-03-12 06:30 PM
Weird issue, harmonic balancer related. Kzoosho GS - Second Generation 2 04-09-12 12:57 PM
Removing your crank pulley bolt for the TOTALLY BROKE Dedik8d1 SC 400/300 10 09-02-11 10:12 PM
Long story but car wont start, any help appreciated. Biggu Performance & Maintenance 9 08-30-08 08:57 AM


Tags
15j, 1jz, 1jzgte, bearing, bottom, clutch, crank, crankwalk, ge, interest, possible, powered, stock, vbulletin, walk

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Forum Jump

All times are GMT -7. The time now is 07:19 AM.

Join ClubLexus
Advertising


Copyright © 2000-2008 Internet Brands, Inc. All Rights Reserved
Privacy Policy | Disclaimer | Terms of Use | JOBS


Get all contact info