l20b performance on a 720

[ZackTheImpaler]

Ok so after lots of talking to you guys and other datsun owners, and after now being an official datsun owner for one year, or 35,000 miles, whichever you prefer, I'm starting to have a pretty solid vision of my 720.

 

I contacted Redline weber last week and tried to buy a 32/36. All that ended up happening is being convinced of what I wanted to do in the first place, which is get a 38. I haven't yet, because I wanted to talk to you ratsuners first. You know, consult the A-team.

 

 

I've always been a huge fan of ratrods, which is why I got an old pickup truck in the first place. I thought it would be awesome to make a ratrod out of a different era than what typically seen. Low and behold there happens to be ratsun. Because I'm not a mechanic I figured I would have an easier time rodding this out as opposed to some sort of 59' Apache. Which has been true.

 

So I see alot of guys doing alot of different things to an l20b. You wouldn't believe how much time I spend reading all of the forums.

 

My questions are what in the long run are things that I could do myself without machining to get loud, obnoxious, get up and go power out of my l20b?

 

I figured that going with the Weber 38 would be a good start, and immediately after switching out to a header. Which kind of headers should I look at? From what I know going with a ceramic header is a good idea as opposed to steal, but you guys know more datsun specific info than some of the people I talk to.

 

I've also been reading alot about swapping to a different head, and my manager owns a nice 510 with an l18, and he was talking to me about me switching out my pistons to some from an l18. Is that a possibility and would it give me better compression? Are there other pistons I could swap to?

 

And does anyone have rim measurements that I should be looking for to get a wheel flushish with my body? I like the kinda stubby look.

 

 

 

I'm not scared to sacrifice fuel economy, after all I don't think I know a good ratrod that is economical. That was the decision I came to more than anything. I just want a sexy ugly loud truck, and I fucking love my Datsun so I better do it with her.

[Hoosier77]

get up and go power doesnt come from l20b's it is my experience that you can spend alot of money on them and they make alot of noise but there just isnt any larger hp numbers to come from an l series engine. They are durable, easy to work on, and awesome engines but if you want power then you need something thats dual cam and has a corssflow head and or some type of forced induction.

[DAT510]

i know tuning it, is one inexpensive way, also Rebello himself told me about advancing the cam or something of the sort. im not entirely sure what he meant, but he told me that the cam sprocket has 3 holes, the L20 is put on the 2nd because of smog, he told me just to put it on the first, or something along those lines. if Hainz can chime in, he'll tell you everything you need to know

[Skib]

get up and go power doesnt come from l20b's it is my experience that you can spend alot of money on them and they make alot of noise but there just isnt any larger hp numbers to come from an l series engine.

 

 

 

[ZackTheImpaler]

Yeah skib, I was hoping you or mike or someone was going to reply haha.

 

 

I'm definetly aware that an l20b has a versatile engine. That's why i held off to buy a 720 built in 79.

[Skib]

it just depends what sort of power your looking for, you can get good street power from an L motor no problem.

 

 

the L series motor isnt the most advanced being single cam and non cross flow but its way over built and very versatile

[budsaipan]

It just really depends on what fast is to you. I'm actually amazed of how fast this little motors can be for what they are. Try what you can and if you're not happy, then swap out engine.Or try an lz22.

[ZackTheImpaler]

I'm not necessarily looking for more top end speed, atleast not now. A bit more torque atleast would make me happy.

 

They are fast little motors. I've got quite a few new parts, and I have a few new ones to go, and each thing has added a bit more. I've got it pretty close to running atleast to how it most likely did new.

 

I'm not looking to win a drag race, but I don't mind putting that sort of money into it. I don't need a NOS system or something, I'd just like a mean little engine.

This is my only vehicle, and I'm not a broke ass. I just want it to be alot of fun.

 

 

But no objections to going with a weber 38 to start? Should I make any changes to my engine immediately to get the most out of that swap?

 

 

I'm going to keep the original engine. It's not that I'm not happy with it. I'm very happy with the L20b, and I love the nostalgia behind it. I'm aware that I won't be pushing 200hp, I'm not a Jr. Bacon. I'd be happy with 140hp and no gas economy, as long as I can smoke my co-workers Ford Tauras station wagon.

[ZackTheImpaler]

And does anyone have a recommendation on headers that I should look at?

[Skib]

And does anyone have a recommendation on headers that I should look at?

 

 

just get an L16 non smog mani.

 

header really just add noise on a street car in the case of an L4

[budsaipan]

See thats what I mean. Doesnt have to be the fastest in the world as long as it's fast enough for you.

 

Check if you have round port or square port before you decide on the header. If your l20b is the stock motor, then it should be round port. Check the code on the head. W58 is round port. There isn't much choice out there on headers besides shorty headers or nismo headers (I dont think nismo will fit the trucks without modification). Stay away from bills datsun headers. They are POS.

 

Anyway, I sent you a pm. I have a weber 38 and round port shorty headers if you're interested in saving money for something else. Can use the left over money for some cams.

[datzenmike]

L16 exhaust....

 

L18 may have EGR tube...

 

4 into one header (top) and L16 4 into 2 into one exhaust system. See the one at the top? They co$$t to buy. The bottom one is cheap and can be got for $20-$30 (or free) Top one lasts longer if you spend an additional $100 to ceramic coat it otherwise it will be rusty in a few months. Bottom one NEVER wears out for the life of the vehicle. Top ones often don't fit well but the bottom one always fits and doesn't leak. Top one is noisy so your $2,300 stereo sounds like $350 one, bottom one is quiet. If you get the top one save your old manifold for when you want to switch back. Good luck trying to find those extra horse power the maker claims.

 

 

 

 

You have the W58 head with round exhaust ports but it will still work with the square manifolds..

[budsaipan]

 

Well you can get them cheap if you find one used. I personally like those shorty headers (black one). Alot lighter than stock manifold.

[ZackTheImpaler]

I got your message, you are missing the choke? Are those fairly easy to replace? How many miles on it?

 

I'm kinda leaning towards getting a new one, just because everything I've gotten so far has been new except for aesthetic parts. Might as well keep at it!

 

I'm curious on that l16 exhaust too. I've been looking around craigslist for the past hour and ebay and I'm not having much luck. Do you guys have any horded down in oregon?

 

I am definitely looking for durability as well. I'd like to be able to put it on and not having to worry about changing or fixing it every roadtrip.

 

Mike you are awesome. That's the kind of answer I'm looking for. I don't believe what I read when it comes to the person who is selling it, and I'm smart enough to know what I'm not going to get from spending a buttload on a new shiny piece. If I can find something used that would work I would just have that spruced up if I want it to be pretty. Those headers look jankity anyway.

[budsaipan]

It came out of a running 720 before my friend sold his truck. You can find a choke for 20 bucks on ebay, Id get the electric one or manual choke. But you know, it's really up to you. I can understand getting it new too. You can also rebuild a used one just to make sure and still save much more than buying new. Then again, your car and your choice. :)

 

Heres stock manifold on classified right now: 60 + shipping. 80-100 shipped?

 

http://community.ratsun.net/topic/31599-exhaust-manifolds-a26-4-2-1-refurbished-other-items/

 

Edit** those are square port exhaust manifold. I heard it's fine to use on round port head. Mine's a round port shorty headers that is actually made for that head plus it's kind of rare to find round port header.

[banzai510(hainz)]

I dont even use the choke. I pump the gas a few times before starting itEzet for you is bolt the 38/38 on there and call it good.

 

I hate the later L motors as full of emission shit and the manifold bolts are a pain to get at so just bolt the 38 to make it simple. Thats my opinion.

 

if your truck is running good dont worry about it. To get real power out of these you got to spend 4 times to get quarter amount of HP

 

build a clean emission free L20 on the side and take your time. when parts come along cheap. never rush

[bikenut4life]

The new header in the above pic looks like a Racetep 510 shorty header. True? Are you saying it will fit the '80 720 truck and not interfere with the torsion bar? I'm doing a motor swap now and am looking for alternatives to the stock manifold.

THX

[banzai510(hainz)]

Later L20s have a round port exhaust manifold. Whats does your head say? W 58?

 

datzenmike says it will fit

[bikenut4life]

Welp...I ordered a 510 shorty from Top End Performance. I'll let you guys know if it fits on my 80 720(fingers crossed).

A