L20b optimum performance

[Braden]

ok so i am getting close to start my engine build and ive searched and searched and with no results i wanna ask this, what have you done and what can you do to you L20 to get more out of it, ok so heres what i know, i have 44phh carbs, gonna run a peanut head, hotter cam, etc, what im curious about is swapping the z22 crank and what is all involved with that, also what about bigger valves? have any of you run big valves? if so what size and where did you get them? how about block boring? 10 20 30 40 50 over???????? please post what you have done to your engine, what you know you can do to your engine etc. i dont wanna go throwing different cranks and heads and shit on and the clearance not be right, that would be one expensive firework, and may be an unnecessary cost, i have a mcahine shop that can do anything i want, thanks guys

[Braden]

oh come on 31 views and not one of you has a response???? seriously???

[DanielC]

Your question is kind of vague on what you want to do with it. All we really know is that you have a L-20, and I am guessing it is going in a 620 truck. We do not even know what transmission you are using.

It is going to be a daily driver, a show truck, or are you building something for a drag strip?

Are you going to build some lowered streamlined truck, and run it at Bonneville?

Give us a little more to go on.

[Braden]

Your question is kind of vague on what you want to do with it. All we really know is that you have a L-20, and I am guessing it is going in a 620 truck. We do not even know what transmission you are using.

It is going to be a daily driver, a show truck, or are you building something for a drag strip?

Are you going to build some lowered streamlined truck, and run it at Bonneville?

Give us a little more to go on.

well yes it is going in a 620, not that that matters, its gonna be a whenever the weather is nice driver, i dont mind buying premium, thus the peanut head, i guess you could classify it as a show truck (not that looks has anything to do with performance factor) but i will drive it not baby it, as far as bonneville i was thinking something more along the lines of sealing off the cab, adding o2 tanks in the bed, and orbiting the earth a few times, maybe with the occasional trip to the moon, come on man its an l20!!!! i guess what i am asking is about the z22 crank conversion and a good source for some nice valves and rods

[Braden]

oh yeah i forgot to add i have a fresh 5 speed tranny, once again like that matters, my question was about the engine, i can do trannys and differentials (lsd)

[datzenmike]

gonna run a peanut head, hotter cam, etc, what im curious about is swapping the z22 crank and what is all involved with that, also what about bigger valves? have any of you run big valves? if so what size and where did you get them? how about block boring? 10 20 30 40 50 over????????

 

Using only an L20B and a Z22 crank? Bore the L20B block by making a 2mm cut or just shy of 0.080". (this is scary thin on an L20B block but do-able, a Z22 block would only need a 1mm cut) Install the Z22 crank and L20B rods with Z24 pistons (if you are sure that you will be using a peanut head) If using an open head use KA24E pistons. This will keep the compression reasonable and give you a 2.3 liter motor. This is all well documented by Jason Gray.

 

The L20B is valve shrouded by the cylinder wall as it is, so larger valves will just be worse, plus they will be slightly heavier than stock. Lighter is always better for moving valve train parts. If you use larger diameter valves you should also enlarge the cylinder walls near the valves and port the head. After all there's no sense improving flow past the valves if you don't improve flow in front and behind it too.

[Braden]

Using only an L20B and a Z22 crank? Bore the L20B block by making a 2mm cut or just shy of 0.080". (this is scary thin on an L20B block but do-able, a Z22 block would only need a 1mm cut) Install the Z22 crank and L20B rods with Z24 pistons (if you are sure that you will be using a peanut head) If using an open head use KA24E pistons. This will keep the compression reasonable and give you a 2.3 liter motor. This is all well documented by Jason Gray.

 

The L20B is valve shrouded by the cylinder wall as it is, so larger valves will just be worse, plus they will be slightly heavier than stock. Lighter is always better for moving valve train parts. If you use larger diameter valves you should also enlarge the cylinder walls near the valves and port the head. After all there's no sense improving flow past the valves if you don't improve flow in front and behind it too.

 

thanks, i will look into jason gray, i guess it would be better to run a z22 block, then you have timing chain, and water pump issues dont you? i know rubberman is running an lz22 but he has to run an electric fan and had some other problems

[datzenmike]

The Z22 and the L20B are the same block height so everything forward of the L20B block: timing cover, chain, tensioner, oil pump, dizzy, pulley, sprocket water pump.. everything can be mounted on the front of the Z22 block. Just swap the oil pan and pickup and an L head on and you have a 2.2 liter L20B basically.

 

If you bore the Z22 block and use the KA pistons on L20B rods you would have a 'big bore' 2.3

[bonvo]

The Z22 and the L20B are the same block height so everything forward of the L20B block: timing cover, chain, tensioner, oil pump, dizzy, pulley, sprocket water pump.. everything can be mounted on the front of the Z22 block. Just swap the oil pan and pickup and an L head on and you have a 2.2 liter L20B basically.

 

If you bore the Z22 block and use the KA pistons on L20B rods you would have a 'big bore' 2.3

 

so about $1000 in parts and machine work for an extra .1 liter seems like a lot of work for 6.1 cu more displacement then a lz22 hybrid

[DISLEXICDIME]

so about $1000 in parts and machine work for an extra .1 liter seems like a lot of work for 6.1 cu more displacement then a lz22 hybrid

 

 

that's why horse power is measured in cubic dollars !!!! :lol:

[datzenmike]

so about $1000 in parts and machine work for an extra .1 liter seems like a lot of work for 6.1 cu more displacement then a lz22 hybrid

 

It does if you go out and start buying parts. I have everything but the Z22 block which I donated to a friend. :blush: Just parts that collect around me when I'm not looking. :D If the Z22 block is worn you would have to bore it over anyway.. might as well go to 89mm. The rest is just used parts.

 

An LZ22 should be capable of 120 hp with an L head. Byron got just over 130 RWHP on the dyno. That .1 liter displacement represents 6 hp. Built in, never goes out of tune.

 

But yeah, if you have a good Z22 and just swap L head on it. That's the cheapest way to go. If you are looking at re building it first, all you need is KA pistons.... I mean everyone has a set of L20B rods right?

[Braden]

the l20b that is in my truck now i can use for parts, and actually it sounds better to me to swap a motor than rebuild mine, i really love the nostalgia but damn i cant get power out of these motors, so with the big bore 2.3 and a ported head, fat cam and mikunis im good to 150hp max!! that blows ass, i could sell my mikunis, and my 4 speed and my l20b and buy a damn sr20det, the only thing that sacres me about the sr20det is the computer tuning and trying to get all of my speedo temp, oil pressure, and all of that shit woring correctly, i want to keep my stock gauges and tach, i dont mind fabbing up engine mounts but damn i really dont wanna cut up my trans tunnel

[DISLEXICDIME]

It does if you go out and start buying parts. I have everything but the Z22 block which I donated to a friend. :blush: Just parts that collect around me when I'm not looking. :D If the Z22 block is worn you would have to bore it over anyway.. might as well go to 89mm. The rest is just used parts.

 

 

i know what you mean i had so much l series crap last summer i filled a hl with block's and transmissions just so i could have room to work in my garage !

 

dont over look a z20 slap a l head on a z20 ( the one that has flat tops) and get the head ported and put in some 44mm z valves with a cam and you got a screamer. But don't forget to really take advantage of upping compression or larger valves or a cam. You are going to need a good set of side draft carb's or fuel injection !

[datsunfish]

Z22s rods will also work with a 2.3. Whats wrong with 150hp? Thats pretty bad ass for a datsun. Youll be roasting tires with ease and flying past many modern cars. Hell thats better than the common KA24 swap folks do. You could also go the fineline route and turbo it for 200 hp.

[Braden]

Z22s rods will also work with a 2.3. Whats wrong with 150hp? Thats pretty bad ass for a datsun. Youll be roasting tires with ease and flying past many modern cars. Hell thats better than the common KA24 swap folks do. You could also go the fineline route and turbo it for 200 hp.

that sounds really good, but dollar for dollar i could almost buy a sr20det, 220 hp off the crate, a few simple mods push it to 250, only thing is then i will need mods to just about every single chassis part to be able to handle the power, i am a welder by trade so thats no problem, but the time factor sucks

[Patch]

2.3 sounds pretty sick imo

[DISLEXICDIME]

that sounds really good, but dollar for dollar i could almost buy a sr20det, 220 hp off the crate, a few simple mods push it to 250, only thing is then i will need mods to just about every single chassis part to be able to handle the power, i am a welder by trade so thats no problem, but the time factor sucks

 

My cousin putt a dual cam KA in his 78 620 and it was almost a bolt in a fair. as far as engine mounting if i remember right he took a body hammer and dolly and put a divot in the pan to clear the steering arm then he just bent then he persuaded the pick up a way from the divot. Then he slotted his stock trans cross member. and shortened his drive line .

then he used a $60.00 ebay header and a $80.00 summit fuel pump and some relays. man that truck is fun to drive! it only took him a month to do it and half the time was waiting on his parts from e bay. his screen name on here is slinginabullet

its cheaper then a sr

[fastdadd]

if anyone wants to donate to the cause i would build one and run it

[datsunfish]

I have a z22s block rods crank etc,some z24 pistons,L20b gear,twin mikunis,peanut head etc that I will be building soon. I just like the L motor for vintage power sake and simplicity so thats what im gonna do rather than a ka or sr. I would prefer to see any L series under the hood of an old 620 510 521 than a modern motor. 50% increase in power NA sounds good enough to me but its all opinion. 200 or 250 would be great but yeah you gotta build the car to handle it.

[Braden]

well because its fairly cheap to build an l20b i think i will do just his, i have in my posession a brand new l20b ready to drop in, i will get a peanut head, get it rebuilt, throw a fat cam in it, throw on my mikunis and call it good, all the while i will save dough back just incase i want more power, if i like the l20 i will keep it, if not i will get an sr20

[bonvo]

there is also this to consider

 

an stock sr powered 620 and built l series powered 620 break down at the same time next to eachother

 

which one is gonna drive away after about 20 minutes some ducktape and bailing wire

 

and which one is going home on a tow truck

[banzai510(hainz)]

this is me here.

I say run the stock L20 block and put a cammed head on with the sidedrafts set cam timming to 2 or 3 and see how it runs. Done. truck down time minimum.

 

I been in Lz motors and sometimes cant tell the difference.

 

http://www.guba.com/general/search?query=hainz&set=5&x=0&y=0

[TrevDaddy]

Alright I'm gearing up for a 2.3L of my own as well. I understand that L20 parts will swap over to the z22 block and that with a peanut head, I should run ka24e pistons with a .01" bore. Then I will source L20 timing parts and Mikuni setup with my L16 exhaust mani.

 

Should I run L20 rods and crank or Z22 rods an crank? Which one is more durable? Lighter? Also, will KA24DE pistons work?

[datzenmike]

Should I run L20 rods and crank or Z22 rods an crank? Which one is more durable? Lighter? Also, will KA24DE pistons work?

 

Already answered for you...

 

Using only an L20B and a Z22 crank? Bore the L20B block by making a 2mm cut or just shy of 0.080". (this is scary thin on an L20B block but do-able, a Z22 block would only need a 1mm cut) Install the Z22 crank and L20B rods with Z24 pistons (if you are sure that you will be using a peanut head) If using an open head use KA24E pistons. This will keep the compression reasonable and give you a 2.3 liter motor. This is all well documented by Jason Gray.

[Farmer]

ok so i am getting close to start my engine build and ive searched and searched and with no results i wanna ask this, what have you done and what can you do to you L20 to get more out of it, ok so heres what i know, i have 44phh carbs, gonna run a peanut head, hotter cam, etc, what im curious about is swapping the z22 crank and what is all involved with that, also what about bigger valves? have any of you run big valves? if so what size and where did you get them? how about block boring? 10 20 30 40 50 over???????? please post what you have done to your engine, what you know you can do to your engine etc. i dont wanna go throwing different cranks and heads and shit on and the clearance not be right, that would be one expensive firework, and may be an unnecessary cost, i have a mcahine shop that can do anything i want, thanks guys

I guess I'll be the first to show pics of an L20b. There old pics, but havnt really changed since then

 

 

Just your typical rebuilt.'

 

L20b block

bored +1 with l18 pistons

mid cam, 3 angle valve job,new valves

Closed chamber head ported to 1.5

crank balance and polished

cam sprocket on #2 timing

Su's with 1.5 inch ports

L16 exhaust mani

Stage two clutch setup

 

Thinking about going FI.

 

The guy who built my engine is working on a LZ2.3 for his 620. But may sell it. Doesnt have time.

 

Larry