Jump to content

Hot LZ23


Bastard_510

Recommended Posts

6 minutes ago, Bastard_510 said:

2.3500 one is 2.3494. The crank probably went through some shit before i got it. It’s not hard to bend them .0005” which this one was. 

 

The bearing numbers match mahle’s catalog for a z20. The rods are thinner and the tang is deeper. I sent them a email so we will see. 

 

I run aluminum in everything. My l had 0 oil pressure at idle for months and when i went in to fix it the bearings were hardly touched. 

 

 

 

I need to re read this? I thought u had 6 inch l series rods? Do u have 4 rb30 rods?

 

ive seen alot of smushed and turned aluminum bearings vs tri metal but they do alot less damage when they turn vs a tri metal. Good to hear your positive experiences

Edited by scooter
Link to comment
  • Replies 265
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

37 minutes ago, scooter said:

 

 

 

UNADJUSTEDNONRAW-thumb-1e40.jpg

here what im talking about thats a bearing out of a z20 i have i know its a z20.

 

 

UNADJUSTEDNONRAW-thumb-1e41.jpg

heres the box

 

 

 

UNADJUSTEDNONRAW-thumb-1e2c.jpg

our serdi went out of alignment and sunk my valves 20 thou across the head so i did end up putting diesel seats

 

 

UNADJUSTEDNONRAW-thumb-1e30.jpg

 

hot tank stain

 

UNADJUSTEDNONRAW-thumb-1e4b.jpg

 

 

 

G6u-Isuz6-Rc-OM92r-Gp-Tv-WOg-thumb-1e50.

 

 

i just had to have a little fun. i stuck the new bearing between the rod and crank to see if the pistons were good.

UNADJUSTEDNONRAW-thumb-1e55.jpg

Edited by Bastard_510
  • Like 1
Link to comment
2 hours ago, Bastard_510 said:

 

 

UNADJUSTEDNONRAW-thumb-1e40.jpg

here what im talking about thats a bearing out of a z20 i have i know its a z20.

 

 

UNADJUSTEDNONRAW-thumb-1e41.jpg

heres the box

 

 

 

UNADJUSTEDNONRAW-thumb-1e2c.jpg

our serdi went out of alignment and sunk my valves 20 thou across the head so i did end up putting diesel seats

 

 

UNADJUSTEDNONRAW-thumb-1e30.jpg

 

hot tank stain

 

UNADJUSTEDNONRAW-thumb-1e4b.jpg

 

 

 

G6u-Isuz6-Rc-OM92r-Gp-Tv-WOg-thumb-1e50.

 

 

i just had to have a little fun. i stuck the new bearing between the rod and crank to see if the pistons were good.

UNADJUSTEDNONRAW-thumb-1e55.jpg

Call scat by the looks of that maybe ka24 bearings. Piston height looks minty. What did it measure?

Link to comment

Those are L series bearings. Mine have the same tang all the way out to the side, 3 different manufactures, Perfect Circle, Vandervell & Clevite. I'd measure the big end thickness to see if that is the same width as the crank pin. Just looking at the bearing to big end thickness I would say the rod is to narrow to be a Z20 rod, maybe KA? Thought it kinda weird that you could find aftermarket Z-20 rods.

Link to comment

well fuck. im done with scat. my buddy had a problem with his ford rods now me. its the right legnth and the right bushing for the piston. its even the right size on the big end but the width is smaller....about 1/8". well too late to stop now. if scat doesnt have/will make  them ill have to have customs made. stupid mistake

45 minutes ago, datzenmike said:

If 152.5mm long they aren't KA. KAs are also roughly 0.2" narrower than L and Z20s

 

They do look a little narrow for the bearings. Ask where you got them, what they recommend.

 they are that long i confirmed with the pistons.

 

UNADJUSTEDNONRAW-thumb-1e58.jpg

Edited by Bastard_510
Link to comment

Again, this is why you mock up an engine. You never know what you're going to find.

 

As per the crank, it took years of a working relationship with one machine shop to get them to understand what we wanted and how they should do it. Every machinist on the planet claims that his mics are correct, and you can't tell them how to do anything. I would go around to the machine shops we used with my mics to compare against their mics. I then wrote on my mic cases, the differences for each shop. That way, when I gave a shop a measurement, I knew ahead of time what to expect.

 

Nissan cranks are very stout, but they do bend. A very good shop will straighten a crank before they grind it. Using v-blocks, the straightening involved a brass bar and a big hammer. A good machinist will know just where to hit the crank to get the desired results.  I would never have the thrust clearance ground into the crank, I would always sand it out of the bearing. Best to have the crank at stock specs.

 

Measuring crank thrust is best done with the crank in the block and using a dial indicator. When assembling the bottom end, before the center main cap is tight, tap on the back of the crank with a hammer to set the thrust bearing halves flush with one another, then torque the cap.

 

 

Edited by Stoffregen Motorsports
Link to comment
29 minutes ago, Stoffregen Motorsports said:

Again, this is why you mock up an engine. You never know what you're going to find.

 

As per the crank, it took years of a working relationship with one machine shop to get them to understand what we wanted and how they should do it. Every machinist on the planet claims that his mics are correct, and you can't tell them how to do anything. I would go around to the machine shops we used with my mics to compare against their mics. I then wrote on my mic cases, the differences for each shop. That way, when I gave a shop a measurement, I knew ahead of time what to expect.

 

Nissan cranks are very stout, but they do bend. A very good shop will straighten a crank before they grind it. Using v-blocks, the straightening involved a brass bar and a big hammer. A good machinist will know just where to hit the crank to get the desired results.  I would never have the thrust clearance ground into the crank, I would always sand it out of the bearing. Best to have the crank at stock specs.

 

Measuring crank thrust is best done with the crank in the block and using a dial indicator. When assembling the bottom end, before the center main cap is tight, tap on the back of the crank with a hammer to set the thrust bearing halves flush with one another, then torque the cap.

 

 

yes stroffregen i know i am mad at myself but then again im not. about a week ago the block was still being cleaned, valve seats being ground, blended, guides were being installed (not in that order), guides were still being honed, i was still blasting glypthal out, decking, and cleaning the head. so this was really the first time i had to mock the whole thing up. also ive ordered many rods.i have yet to get this fuck up till now so i wasnt on the hunt for it.

 

i said this above but i sent it out straightened. when i took it pout of the block the first time it was bent a thou. i took it to the shop and i got it back bent 1.5 thou. yes i know to have the bend down and to lean a rounded flat chisel in the fillets with it leaned all the way over. heres how i know it was someone. if you had a bend in a crank and ground it it would read straight after. but it was 1.5 thou bent. also it was bent with the center-counterweights  facing up 

Edited by Bastard_510
Link to comment

Is KA crank pin dia the as same L?  If so, options are to weld crank pin journal sides to decrease side clearance then regrind crank again or machine your pistons and add spacers/bushings whatever you want to call them to use piston guided rods.

Link to comment
33 minutes ago, docbainey said:

Is KA crank pin dia the as same L?  If so, options are to weld crank pin journal sides to decrease side clearance then regrind crank again or machine your pistons and add spacers/bushings whatever you want to call them to use piston guided rods.

ive made up my mind. i will talk to scat and inform them of the mistake. i have a feeling someone in 2002 wanted 6" rods for a different engine and scat has them listed as z20. its a big problem for them because thats a shit ton of rods that are useless. im going to call carillo on monday and order a set of customs...no secrets anyone want a set?

Link to comment

Carrillo made our U-20 rods back in the late 70s. Sent them a rod and basic dwg to show what dimensions we wanted. If I remember, about $150 a pop back then. Bitches would hold to together @ 9K +, over a 100gms lighter then stock. I'd still look at the piston guided rod option if you can find bearings. Just need a good Bridgeport & lathe and somebody who knows what they're doing. A place in Georgia, I believe, can do it for you. Sht Wiseco should be able to do the machine work on the pistons. Just a matter of making precision pin spacers. I don't think you use spirolox to hold the pin in but use Teflon bushings.

  • Like 1
Link to comment
7 minutes ago, docbainey said:

Carrillo made our U-20 rods back in the late 70s. Sent them a rod and basic dwg to show what dimensions we wanted. If I remember, about $150 a pop back then. Bitches would hold to together @ 9K +, over a 100gms lighter then stock. I'd still look at the piston guided rod option if you can find bearings. Just need a good Bridgeport & lathe and somebody who knows what they're doing. A place in Georgia, I believe, can do it for you. Sht Wiseco should be able to do the machine work on the pistons. Just a matter of making precision pin spacers. I don't think you use spirolox to hold the pin in but use Teflon bushings.

ive never had to deal with bushings. the bushing i was talking about was for the pin but i see what you are talking about. this thing will go on road trips and i would rather just have rods that fit. ill use the scat small end dimensions and stock big end. shouldnt be a big issue. 

Link to comment
38 minutes ago, Bastard_510 said:

ive never had to deal with bushings. the bushing i was talking about was for the pin but i see what you are talking about. this thing will go on road trips and i would rather just have rods that fit. ill use the scat small end dimensions and stock big end. shouldnt be a big issue. 

We used to spin a lot of bearings with stock rods, they didn't have a small enough dia on the big end, even though they where at factory dimensions. Had our Carrillo rods made a touch small on the big end, then blued the bearings to look for to much crush. Adjusted accordingly, also don't overlook side clearance to your crank. Can always take material off, its a bitch to try and put it back!

 

The piston guided rod thing is used in all CRASHCAR motors & I believe Mercedes road cars. Severely cuts down on frictional loses. Instead of having 360deg frictional losses on the crank pin, you only have minor angular losses on the piston pin dia.

Link to comment

Spirolocks vs pin bushings - Spirolocks are more common these days. The only application that I ever assembled that could not use a spirolock was a 948cc BMC A series in a Lotus. This pistons had to go in through the top, but the rod big ends were so large that they couldn't fit down the bore. I had to push the pistons down the bore to expose the pin bores, then attach the rods inside the crank case.

 

 

Link to comment

Those rods are for either a RB30 - 6.0010" long with a big end width of 0.8580" or a VG30 - 6.0630" long with BE width of 0.8170". Both have the same big end dia as L series, VG does have a 22mm pin though Vs 21.02mm for the RB which is the same as L series.

http://pauter.com/parts/rods/infiniti-nissan/

  • Like 3
Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.