1974 Datsun - Engine Options / Decisions

[moorethomas1026]

 Hey Guys!

 

I have been following post on ratsun for a long time, but this is officially my first post. Once some one teaches me how to upload photos I will add them to the thread... 

 

I have been raised on Datsuns, and I decided to build a truck around the last seat my dad ever upholstered... by pops did upholstery for 30+ years and when he got to the retirement stage I picked up the closest 620 I could find had him do one last seat for me! This truck is really special to me, and I've had it for about 3 years.

 

The last 2 years of that it has been sitting at a mechanic's getting the "engine rebuilt".

 

I overpaid some mechanic to make my engine look brand new... instead of working on my truck he lost my engine to some other mechanic in a shady sort of deal (probably involving drugs) needless to say I'm eager to find another engine and get this beast moving again!

 

I had an L20B in the truck, which I know is not stock in the 74' 620s so the guy before me must have put it in. I have been looking for a while now and need help deciding on which engine I should track down...

 

Here are the options, in helping me decide please spare no details on why this would or would not be your choice...

 

L20B Options:

 

1. An L20B that I would have to drive 16 hrs (round trip) to get. The engine has everything there and was running when he took it out, because he's doing an sr20 swap. It has a weber carb and the guy is only asking $100 because he feels crappy about my situation... with gas the total cost would be $200... and a 16 hr drive.

 

2. An L20B that is just a little closer about 15 Hr drive. The engine has almost everything on it as well, but now weber carb. This engine supposedly has a CAM and has been ported as well. The guy is asking $150, and with gas it would be $250 altogether... but then I would have to buy a weber carb and a few other things. Also pretty long drive as well.

 

Other Size Options:

 

3. Next I have an L16 that is about 12 hrs round trip to pick up. The guy is a friend of mine and says I can just have the engine... it is missing quite a few things though (flywheel,starter,alt, manifolds all that stuff). All together I would spend about 70$ to pick this one up.

 

4. Last, is full pickup that I can pickup for $200 it is the first year of 720 so it's the "datsun by nissan model". This comes with the z22 engine and would need a little work to go in my 620. My brother is the previous owner of this pickup and he got it running like a top with a weber carb, and he deleted all the emissions crap for the most part. This pickup hasn't been in the family for a while now but went and looked at it today and it still seems really clean. This one is close to home so the total cost would only be $200 and I could part out the rest of the pickup...

 

All these options seem good to me, I really just need to know if swapping out the z22 is going to be a pain in my ass? 

 

Do any of these options scream red flag?

 

What would you all do if you were in my shoes?

 

Thanks in advance for any and all assistance!

[datzenmike]

6 minutes ago, moorethomas1026 said:

 

 

Do any of these options scream red flag?

 

 

 

Any engine you can't drive around is a totally unknown quantity. You have a history of making poor choices with your original engine so I see no reason why these other sellers would be any different. If they can't be run they are just $300 a ton for scrap metal. That works out to $42.75. $100 or $150 is ok for a rebuildable block but the chances that  they are runners that you can pop in and drive away with are pretty remote.

 

Can you drive your brother's 720? Then do so and see how well it runs. If it starts and runs, will restart when hot, is quiet, doesn't have a blue cloud following it around it's worth twice that amount. This is you only option.

 

The first year 720 was 1980 and it had an L20B so if a Z22 it's an '81-'82 or the Z22 and transmission was swapped into it. If it's a Z22 you will need to swap the engine AND transmission. 

 

 

[moorethomas1026]

1 hour ago, datzenmike said:

Can you drive your brother's 720?

 

 

 

 

Hey Mike! funny seeing you here 😉

 

I see your comments on every thread but didn't figure it was that easy to get a response out of you. The links above are some images of my 620 I definitely have put some time into this little truck and prefer it a hell of alot more than the 720.

 

I think you make a fair point though, I can get the 720, and get it running then once I get to that point swap it into my 620. I know a good mechanic that put an engine in my 79' KC so I know he can do this for me really quick, and affordable. I know that all those options sounded cheap but I'm also a fairly decent hagler! 

 

Here are some pictures of the engines I was talking about. The red one is the L20 that I could pick up "option 1" and the z22 is obviously the z22. 

 

https://imgur.com/gallery/DaH84G2

 

Interior Video - 

 

https://imgur.com/gallery/2XmSbhh

 

 

Would the z22 engine and tranny swap require a lot of modifications? I just want to get it running then sometime next year do the LZ20 style head swap haha. I love hearing your thoughts Mike, it's even cooler that it's on my little datto! 🙂

 

[datzenmike]

 

 

Definitely a Z22.

 

The L and Z series sit at different angles to each other so if you just try to swap the Z22 onto the L series transmission they won't line up. There's ways around this but as you have a transmission on the Z22 anyway just keep them together.

 

The 720 rad won't fit the 620 so just cut the Z22 hose and extend it over to the left side so it reaches the 620 top rad inlet.

 

I put a Z24 and speed in my 620. Use the Z22 engine brackets and rubber isolators. 

 

 You will have to use the 620 alternator because it uses an external regulator that won't work with the 720 alternator. Plus the 720 alternator is much larger and a tight fit.

[moorethomas1026]

3 minutes ago, datzenmike said:

Definitely a Z22.

 

You're the man Mike, thanks for the advise I am going to get the 720 up and running as quick as I can. 

 

As the build gets better I'm sure I will get better at this whole forum thing, and my post will look a lot cleaner. 

 

As I'm working on the z22 and the swap should I plan to keep this thread going, or start a new one altogether?

 

I guess I'm not sure what common courtesy is on ratsun?

 

I'll keep you all posted on when I go pick up the 720 as well! 😁

[datzenmike]

Get it running satisfactorily in the 720 first then swap.

 

It should start every time within a couple of turns.

It should restart when hot

It should idle strongly and smoothly

It should not over heat when idling or driving

It should pull smoothly when driving.

It should be quiet

It should not burn oil or loose coolant

It shouldn't leak oil or coolant.

[moorethomas1026]

17 minutes ago, datzenmike said:

Get it running satisfactorily in the 720 first then swap.

 

It should start every time within a couple of turns.

It should restart when hot

It should idle strongly and smoothly

It should not over heat when idling or driving

It should pull smoothly when driving.

It should be quiet

It should not burn oil or loose coolant

It shouldn't leak oil or coolant.

 

 

Thanks Again Mike for the information!

 

I will be trying to pick up the little 720 tonight, and I will have pictures up as soon as I can...

 

The 8 commandments above (it should…) will be my new life motto until I get the 720 running exactly how it should again. I will also track down some before and afters of the little 620 so you all can see exactly what I have done on it so far!

[DanielC]

It should have good compression.

It should have good oil pressure.

[moorethomas1026]

9 minutes ago, DanielC said:

It should have good compression.

It should have good oil pressure.

 

Oh shit Dan!

 

We officially have the 10 commandments...

 

So gentlemen, I am having a problem finding what was needed to get rid of the emissions shit for the z22...

 

My bro thinks he did it right back in the day, but I would like to see if we missed anything when putting the webber in!

 

Can someone help me find the forum where it's been talked about?

[datzenmike]

720 forum? The emissions equipment don't do much and removing them can add problems that weren't there before. I can think of one that increases mileage and another that increases engine life by about double. Stock carburetors almost never have vacuum leaks but what? 30% of people installing Webers have one or more times where they have to take it off then or later and reseal and tighten the bolts. If careful and done properly there's no change in performance and certainly no increase. Sometimes it does run better but because a cracked hose was removed which would have been a lot easier to simply replace.

[moorethomas1026]

5 minutes ago, datzenmike said:

 Sometimes it does run better but because a cracked hose was removed which would have been a lot easier to simply replace.

 

That's really good to know now, and I wish that I could have known this sooner... Hindsight is at least 20/40 in this case 😉

 

To me it seems like my family has always been preaching that the only way to go on the z22 and z24 was to get rid of all the emissions junk and put a Weber carb on it.

 

Are you saying that the z22 is actually a good engine, and if I were to just revert back to stock I would have less of a headache?

 

I will dive through the 720 rabbit holes, and see if I can't find what I am looking for!

[datzenmike]

Too late now. Once it's off there's less to go wrong later. If you had a working system it's easier to keep it working. It's common to fear what you don't understand. If you knew what the emissions did and how they worked it would be easier to keep and keep it running. Anything that is complex is both easier to go wrong and harder to keep going. The Z series is much more complex than the L series engines. Don't worry about it.

 

The Z22 is a great engine. Lots of torque for pulling a truck but not a high revving barn burner. But this is how it was designed. The Z24 has even more power but has a habit of blowing the head gaskets.

[SONOFK-E]

I have a 620 kingcab  I will be doing a 95 s14 240 sx with a 5 speed swap soon