L20b Crank Specs -> Custom Rods

[That4doorKiD]

Hello, I'm looking for the specs to get some custom H beam rods done.

It will be for my L20b, I do want long rods made so...

They are asking for these specs Please help me out guys, I couldn't find some of the answers. Nor do I have an accurate caliper

 

Center to center : 152.5 (long rods)

Small end diameter : 22mm (readily available sizes for an 86mm)

Big end diameter : ?

Big end width : ?

Small End Width : ?

Edited October 14, 2019 by That4doorKiD

[datzenmike]

Why not Z20 rods? they are 152.5mm or 6" and the pistons are flattop. Put on an L20B crank and an open chamber W58 head you get 9.945 compression.

 

Why not get rid of PB. I can't see your 510 at all.

[G-Duax]

Well, the L20B rods take a 21mm wrist pin, same as all the other L4 rods.

The FJ turbo used 22mm pins.

 

Why are you trying to build a custom engine, without a good set of calipers ?

[Bastard_510]

7 hours ago, That4doorKiD said:

 

Big end diameter : ?

Big end width : ?

Small End Width : ?

big ed diameter: 2.0869

width: 1.054

small end width: .827

 

if you call carrillo they already have the specs just tell them its for a l20b.

[That4doorKiD]

22 hours ago, Bastard_510 said:

big ed diameter: 2.0869

width: 1.054

small end width: .827

 

if you call carrillo they already have the specs just tell them its for a l20b.

awesome, thank you for the info

[That4doorKiD]

On 10/14/2019 at 4:19 PM, datzenmike said:

Why not Z20 rods? they are 152.5mm or 6" and the pistons are flattop. Put on an L20B crank and an open chamber W58 head you get 9.945 compression.

 

Why not get rid of PB. I can't see your 510 at all.

 

On 10/14/2019 at 9:08 PM, G-Duax said:

Well, the L20B rods take a 21mm wrist pin, same as all the other L4 rods.

The FJ turbo used 22mm pins.

 

Why are you trying to build a custom engine, without a good set of calipers ?

I am aiming for pretty high horsepower. My experienced head porter told me the rods are good til 400hp even being cyro treated and polished

My motor will be an L20b 450+ hp

I am looking to use components that will be readily available off the shelf that will fit my compression. With the closed penut head I have and a set of evo 8 pistons, the compression will be in my likeable range.

[That4doorKiD]

If anyone in the future runs in to my question... I just found this spec sheet with the valued info.

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

[john510]

450 HP L-20B ??? good luck.

[datzenmike]

That's exceedingly ambitious. I fear you will end up with a scaled down dragster engine that is useless for anything but a dragster.

[scooter]

300 is doable. im trying for 400whp next spring ( two nitrous kits) basically running two 125hp fogger kits on a 2.3. head is hella ported. 

i got through a season with the single 125 kit on it.

 

you wont get there without race gas and a little luck, and creeping up little by little. expect to kill a couple head gaskets and melt a few ground straps off plugs getting there. 

the head has to be able to flow 450hp through the exaust valves. thats gonna be a tall order with the bore constraint of an L20b. 

 

im fully expecting to lift a head with the second kit. starting at a 50 shot on the second stage and working up on a pass by pass basis. 450whp wont be doable for highway pulls or standing mile, it will melt shit. above 300hp you will melt shit in 1/8th mile passes if you fuck up anything

 

Edited October 18, 2019 by scooter

[G-Duax]

On ‎10‎/‎16‎/‎2019 at 12:19 AM, That4doorKiD said:

With the closed penut head I have and a set of evo 8 pistons, the compression will be in my likeable range.

 

You will be hard pressed to do that power level with a peanut head, as they shroud the valves too much.

Every high power L-series I have seen has a peanut head that has the shit ground out of the chambers, then get the compression back with custom domed pistons.

I picked this head up in Japan:

 

By the way, bottle fed engines are ranked right up there with turbo, and supercharged engines.

Not considered a NA in any class of racing.

And for the dangers inherent with NOX, I would prefer a turbo, or blower over bottle fed any day. 

 

To me, a high power NA means ALL MOTOR.

Edited October 18, 2019 by G-Duax
To add some personal opinion....

[scooter]

i love spray motors. I think overall more power can be made turbo though. 

 

baack to the post, go for it. even if you dont make your goal, if you get close your car will go like stink anyway. 

 

that japanese head has massive room for improvement.

 

think this way a 450 hp L20b is equivilant to a 600hp L30. people have come close to that or are making that in all out drag form. it aint easy.

 

The OP didnt say how this is gonna make the claimed power. 100hp/liter is capable out of an L series NA but thats about it. that is also a good place to put one on the sauce or a massive turbskie.

 

id love to see an l20b-24 build with a gtx3071R or  3076R on it and try to go for it. or a GTX35 and try to go for 600+ on methanol. if you can keep it from detonating and keep the head on it, and not have the exhaust valve melt off, it may be possible.

 

BTW ive had those pauter rods in my lz23 for the season now (the l20b length ones) in this 92mm stroke motor with no problems. its seen lots of 8000rpm nitrous fuelled passes.

if you dont end up with long rods these hold up to the task.

 

[banzai510(hainz)]

450HP ???????

This will be in "Ripleys Believe it or NOT"  They need to hire you at Rebello Racing. Or Troy Ermish needs to hire you.

 

the think the rod bolts will break even if ARP, maybe 1 or 2 runs then it DETONATES!

 

 

You must be Rich

 

Time to move to the 510realm

 

 

Let us know

 

https://video.search.yahoo.com/search/video?fr=yfp-t&p=blondie+dreaming#id=1&vid=acd3f881d418fb1f82caf25ca30bfd38&action=click

Edited October 18, 2019 by banzai510(hainz)

[datzenmike]

This is not feasible and will be undriveable unless to win a bet. The NA LZ20 made 220 HP but had dry sump oiling, used a gear cam drive, 4 valves per cylinder and dual cams.  The later ones with turbo made over 500 HP, more than the current F1 engines of the time. You can buy a 'kit' for over $2,000,000 but at least it will stay together. 

[Stoffregen Motorsports]

A good street driven 2300 can make 250hp. 450 is not going to happen unless you have power adders, like Nitrous and a turbo. You will probably need a custom billet crank to handle anything over 300, or at least a knife edged, nitrided and cryo treated OEM crank.

 

But why that much? I know guys with tons of HP in 510s and they just aren't fun to drive. There is a guy I met at a track day at Thunderhill who had a 450hp (to the wheels) SR20 turbo, and he said anything over half throttle, in any gear, it would just smoke the tires. To get all that power to the ground, you will need fender flares and 10' wide tires, minimum. Then the car starts to become as wide as it is long.

 

Be realistic and stick with a 240hp range motor. You won't have to rebuild the head every year and you won't have to worry about breaking every part of the drivetrain when you hit the track.

[scooter]

On 10/15/2019 at 10:19 PM, That4doorKiD said:

 

I am aiming for pretty high horsepower. My experienced head porter told me the rods are good til 400hp even being cyro treated and polished

My motor will be an L20b 450+ hp

I am looking to use components that will be readily available off the shelf that will fit my compression. With the closed penut head I have and a set of evo 8 pistons, the compression will be in my likeable range.

cylinder pressure wise the stock rods will hold as they are effing strong. the problem is l20b rods are like 730-750 grams each. if you try and turn it more rpm youll lose the rod bolts and window your motor. they will take somewhat more than stock with bolts but to make 450+ your gonna have to be above 8000 under high boost and this isnt stock rod territory. gonna need the pauters or a set from carrillo. and some good pistons. i personally think the crank should take it, probably a good idea to have it nitrided and get a bhj or ati balancer on it and a light flywheel. 

 

on the note of rod WEIGHT my engine runs ALOT smoother with lighter rods. approx 200 grams lighter per rod...

 

in another thread a guy tried to use RB30 rods, which are close but are too narrow. if you use these then you need to get pistons built to run them piston guided. the jury is still out on using piston guided rods in datsuns.

Edited October 19, 2019 by scooter

[datzenmike]

The rule of thumb for red line for stock internals is 4,000 fee per minute piston speed.  Take the stroke in inches (in this case 86mm or 3.3884") X RPM /6 = not over 4,000.

 

3.3884 X 7,000 = 23,718.8/6 = 3,953 ft per min.

 

Four thousand feet per minute (in this case 7,000 RPM) is the safe continuous operating RPM that stock parts, rod bolts and caps, will sustain without stretching or breaking. Imagine if you will an L20B crankshaft rolling along the pavement beside you as you drive at 45 MPH!!! The crank turns at a steady amount but the rods and pistons have to accelerate and decelerate to a full stop at TDC and BDC and it's maximum speed is not half way up the cylinder but where the crank shaft throw and rod make a 90⁰ bend, about 10 o'clock. To be at half way up the cylinder the rod would have to be infinitely long. So from about 10 oclock till 12 the rod and piston are decelerating and from 12 till about 2 it is accelerating. I calculated from 9 till 12 and got 530g deceleration but it's a shorter time than this and most of the deceleration is well before TDC. So 530 is very conservative. Rods are 730g and pistons are 530r or around 1,100 g or roughly 2.5 pounds X 530g = 1,282 pounds stretching the rods followed by 1,282 pounds pounding on it to accelerate it... and all this at 7,000 times a minute or 116.66 times a second. his also does not include rings and bearings.

 

I'm no math wizz so if anyone want to dispute this I won't argue. The point is that there is massive g acceleration/deceleration involved.

[banzai510(hainz)]

450hp on a dyno is a one time run if it’s even possible. Plus a Ford 9in axle !mike I can’t believe you even respond with a long detail awnser.this is not happening

[datzenmike]

I'm just having fun.

 

 

[scooter]

1 hour ago, banzai510(hainz) said:

450hp on a dyno is a one time run if it’s even possible. Plus a Ford 9in axle !mike I can’t believe you even respond with a long detail awnser.this is not happening

maybe not. the fun part though is to try. if it has an expert ported head with good rotating assembly bits and ALOT of boost if the stars align this will happen. you can fairly easily order rotating bits to make an L survive at that power level. ITS THE HEAD. the intake flow isnt even that bad. its trying to pack 500hp around that exhaust port bend.

 

you guys are dead on about one of these NA. but you take that 220hp L and put a big ass wonton war whistle on it with some good fuel this will happen.

[banzai510(hainz)]

headgasket issues?

if he makes 100k a year I will maybe believe this is possible.

better yet take the money wait for a market crash and put it there will be better.

[distributorguy]

Cometic will make head gaskets if you send them a sample to work with.  

With boost, this is possible but as has already been said, it won't hold up long.  I can attest the oil pump drive gear won't last long, so plan on dry sump.  The cam towers , well, you're going to want a few spares.  Ceramic coat everything internal to prevent meltdown.  Buy better rods than Pauter, or get them resized before install.  Don't stick with stock rod journals if you;re ordering everything else custom.  Pick a common journal size that allows you to get 2 or 3 sizes of quality race bearings - like ACL in a +1, +10, +20 or you'll need a new crank on each rebuild because cheap rod bearings will last minutes not days.  180-200 hp NA is "easy" and can be built to be streetable, then add 40 lbs of boost...  This could be a really fun, drivable street engine.  Mike should drive my race truck so he can see how streetable it could be.  The only thing temperamental about the whole truck is the driver with the limited visibility from the race seat and cage.  

[G-Duax]

Hm, I called Cometic a few years ago, thinking they could easily make L4 head gaskets, seeing they already made an L6 gasket, and they flat said NO !

[scooter]

Kameari already makes a 90mm  mls L4 gasket and i can tell you its good for at least a 125 shot of nitrous. 

 

I havint seen oil pump drive gear problems yet but if anyone is gonna kill one its going to be distributorguy with the long sustained land speed runs for sure. 

 

I disagree about the rod bearings, other engines have been making more power on larger and smaller bearings than the datsun size. 

 

Im going to try for these power levels with spray, i think it will be easier with a turbo though.

 

theres alot of capable individuals here, id really like to see how far we can really push an L4. There is 700-800hp L6’s in existance so the potentials gotta be there.

 

[datzenmike]

On 10/15/2019 at 10:24 PM, That4doorKiD said:

If anyone in the future runs in to my question... I just found this spec sheet with the valued info.

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

 

Oct 15 wasn't just his last post, it was also the last time the 'KiD' was here so.....