scooter Posted July 7, 2019 Report Share Posted July 7, 2019 (edited) 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 July 7, 2019 by scooter Quote Link to comment
Bastard_510 Posted July 7, 2019 Author Report Share Posted July 7, 2019 1 minute ago, scooter said: I need to re read this? I thought u had 6 inch l series rods? Do u have 4 rb30 rods? Hold on I’ll get some pictures 1 Quote Link to comment
Bastard_510 Posted July 7, 2019 Author Report Share Posted July 7, 2019 (edited) 37 minutes ago, scooter said: here what im talking about thats a bearing out of a z20 i have i know its a z20. heres the box our serdi went out of alignment and sunk my valves 20 thou across the head so i did end up putting diesel seats hot tank stain 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. Edited July 7, 2019 by Bastard_510 1 Quote Link to comment
datzenmike Posted July 7, 2019 Report Share Posted July 7, 2019 Z20 and L20B. Both use the same rod bearings in fact both engines use the same U60 crankshaft. You can see that the bearing notch is over at the extreme edge of the rod. Quote Link to comment
Bastard_510 Posted July 7, 2019 Author Report Share Posted July 7, 2019 15 minutes ago, datzenmike said: Z20 and L20B. Both use the same rod bearings in fact both engines use the same U60 crankshaft. You can see that the bearing notch is over at the extreme edge of the rod. ya and the rods are https://www.cnc-motorsports.com/scat-rods-2-6002-2086-857-826-h-beam-connecting-rods.html Quote Link to comment
datzenmike Posted July 7, 2019 Report Share Posted July 7, 2019 Ask them what bearings fit their rods. Quote Link to comment
scooter Posted July 7, 2019 Report Share Posted July 7, 2019 2 hours ago, Bastard_510 said: here what im talking about thats a bearing out of a z20 i have i know its a z20. heres the box our serdi went out of alignment and sunk my valves 20 thou across the head so i did end up putting diesel seats hot tank stain 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. Call scat by the looks of that maybe ka24 bearings. Piston height looks minty. What did it measure? Quote Link to comment
datzenmike Posted July 7, 2019 Report Share Posted July 7, 2019 Those sharp edges are more noticeable now. Lots of quench area to help with cooling them. Quote Link to comment
docbainey Posted July 7, 2019 Report Share Posted July 7, 2019 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. Quote Link to comment
datzenmike Posted July 7, 2019 Report Share Posted July 7, 2019 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. Quote Link to comment
Bastard_510 Posted July 7, 2019 Author Report Share Posted July 7, 2019 (edited) 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. Edited July 7, 2019 by Bastard_510 Quote Link to comment
Bastard_510 Posted July 7, 2019 Author Report Share Posted July 7, 2019 22 minutes ago, scooter said: shitty dude yup...but an excuse for a completely custom, no off the shelf parts, engine lol Quote Link to comment
Stoffregen Motorsports Posted July 7, 2019 Report Share Posted July 7, 2019 (edited) 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 July 7, 2019 by Stoffregen Motorsports Quote Link to comment
Bastard_510 Posted July 7, 2019 Author Report Share Posted July 7, 2019 (edited) 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 July 7, 2019 by Bastard_510 Quote Link to comment
docbainey Posted July 7, 2019 Report Share Posted July 7, 2019 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. Quote Link to comment
datzenmike Posted July 7, 2019 Report Share Posted July 7, 2019 KA and L 20B, Z20,22,24 main journals are the same diameter but narrower. L20B U60 crank in an è89 KA24E crank girdle. L20B and KA main bearings. Not rod. Quote Link to comment
docbainey Posted July 7, 2019 Report Share Posted July 7, 2019 What about the con rod journals? Quote Link to comment
Bastard_510 Posted July 7, 2019 Author Report Share Posted July 7, 2019 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? Quote Link to comment
docbainey Posted July 7, 2019 Report Share Posted July 7, 2019 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. 1 Quote Link to comment
Bastard_510 Posted July 7, 2019 Author Report Share Posted July 7, 2019 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. Quote Link to comment
docbainey Posted July 7, 2019 Report Share Posted July 7, 2019 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. Quote Link to comment
Stoffregen Motorsports Posted July 7, 2019 Report Share Posted July 7, 2019 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. Quote Link to comment
docbainey Posted July 8, 2019 Report Share Posted July 8, 2019 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/ 3 Quote Link to comment
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