1983.5 4x4 - retirement truck

[bottomwatcher]

Nice job on the injection. So many on here want to do a KAe swap but want to carberate  it because they are scared of the injection. Others say that there Weber runs just as good as fuel injection. I was of the same mindset until I did my KAe swap with the factory fuel injection and there is good reason the carbs have been relegated to history. That took some fortitude to get where you are. Enjoy the instant reliable starts at whatever temperature, better mileage and cleaner oil of fuel injection.

[Madkaw]

18 hours ago, bottomwatcher said:

Nice job on the injection. So many on here want to do a KAe swap but want to carberate  it because they are scared of the injection. Others say that there Weber runs just as good as fuel injection. I was of the same mindset until I did my KAe swap with the factory fuel injection and there is good reason the carbs have been relegated to history. That took some fortitude to get where you are. Enjoy the instant reliable starts at whatever temperature, better mileage and cleaner oil of fuel injection.

Thanks . It’s a lot of work , but in the end it’s pretty cool to tune with a key board . Honestly the carb started up better than my EFI - because it takes some dialing in to get it just right . The Weber just dumps fuel during start ( verified with wide band ) and it kills your mpg during cold starts . My starts get better as I go . You only get 1 try per day . 
The engine has handled a lot of timing too, but I only run 4 plugs . 
 

[Madkaw]

Well I might have a problem . Truck has been hard starting lately - but I have been playing with the tuning and thought that was the issue. Running pretty good besides that .

I checked my coolant level and it was low by more than a 1/2 gallon . My oil doesn’t look right or feel right . 

I did a pressure test and the coolant pressure is stable with no leaks - odd .

Maybe HG is breeched between oil and coolant passage ? 
 

[Madkaw]

Had some guys in FB chime in and said to look for a crack in the head around #4 . Oddly enough I have had an issue with oil seeping from #4 plug . Also have a tick towards the back of the engine when it gets hot . I assumed it was a bad guide . The head was rebuilt the same time as the engine .

Are cracks as typical as blown HG’ s with these motors ? 

[datzenmike]

Virtually impossible for the oil passage to breech into the coolant. And I say oil into the coolant not coolant into the oil. Oil is at 50 psi, coolant at most 13 PSI.

 

More likely the head gasket is simply blown into the coolant jacket. Water gets sucked in little by little and turns to steam and most will go out the tail pipe. Given time a small amount will push past the rings and condense in the engine crank case and mix with the oil.

 

Don't run it with water in the oil. Fix the cause and then replace the oil and filter.

 

 

Head has to come off to replace the head gasket. Set engine to TDC. Be sure to secure the timing chain tensioner to prevent it falling out and save yourself 4 hours of extra work to fix this. Mark chain and cam sprocket so it goes back together in the same position. The rest is just wrench turning. The exhaust is easy to get at to unbolt from the head and just shove over out of the way. You might consider leaving the intake on and lifting it out together. Don't set the head face down and risk bending a valve. Plug wires have to be pulled off anyway so remove the distributor cap so it doesn't get bumped and broken.

[Stoffregen Motorsports]

Bummer. Yeah, drain it soon and spray the cylinder walls down with WD40. Just in case there's coolant in the bores. Otherwise, the rings could rust to the cylinder walls creating a low spot in the bore.

[frankendat]

On 1/13/2022 at 12:48 PM, Lockleaf said:

You could also consider (if useful and enough space) adding to the brake booster spacer, making a little more space behind it?  just a thought. I'm not there looking at the problem, so there is too much I am not considering.  either way, big fan of your build.  I have long wanted to FI a Z24 with the Z22E manifold.  Just never pulled the trigger.

I realize this makes me a necro poster, but what do you see is the advantage of a Z22E manifold over an injector notched Z24 manifold?

 

[Madkaw]

I have a rebuilt head sitting on a shelf that just needs to be assembled - on stand by.

 

 NOT thrilled that this blew so quickly on a rebuilt motor .  I guess this is 720 life 

[frankendat]

I really enjoy your thread. (1)Do you (or did you and I missed it) post part numbers? I am interested in information on your fuel injectors. Are they the stock Hitachi? Also, (2) have you been able to determine mpg? Hopefully, you find imitation flattery, because I watch and attempt to copy, most of what you do. My truck is the same year and same (before your repaint) color. I pulled a Prius column years ago for a different project, and had not considered it in a 720 and have considered electric fans. All that I find supports mechanical fans as superior, but the focus was on cooling and not drag dropping mpg. There are flexible solar panels that can slapped on the hood and the roof to keep you charged. There are even car batteries composed of lithium ion cells, that withstand the charge cycle better, last longer, are lighter, but are costly. With dual lithium ion, some have their alternators on a clutched wheel that disengages when batteries are at a set charge point, but it is doubtful these power misers run stereos or ac.

Question on the (3)distributor removal, aside from the cool factor, what benefit is the flywheel sensor over a Z24i distributor? Not entirely sure of the terminology, but I believe the Z24i either can be or has a CAS, that operates similar to what is installed on your flywheel. I am neither looking to debate nor have any documentation that assess one superior to the other. I only ask for your thought process and experience.

Thank you

[frankendat]

1 hour ago, Madkaw said:

I have a rebuilt head sitting on a shelf that just needs to be assembled - on stand by.

 

 NOT thrilled that this blew so quickly on a rebuilt motor .  I guess this is 720 life 

This is random and the questions in my previous port are the priority, but what parts do you replace when rebuilding a head?

[datzenmike]

The Z24i only used a CAS distributor.

 

 

SR20 transmission from an S13/14 has a CAS that reads the flywheel teeth? We didn't get this engine only the KA on the right.

[Lockleaf]

On 6/18/2022 at 12:43 PM, frankendat said:

I realize this makes me a necro poster, but what do you see is the advantage of a Z22E manifold over an injector notched Z24 manifold?

 

 

Hey Frankendat,

 

The reason I want the z22e manifold is that it's fully multi point fuel injection designed.  Ports, plenum, throttle body, etc.

 

Usually a notched z24 would refer to a head not a manifold.

[Madkaw]

Notching tool!

[Madkaw]

Head is ready and disassembly has started on motor . Looks like my exhaust collector gasket is gone ! It was a new Nissan gasket. What is it with these trucks eating parts ! 
Coolant looked like shit , but not very oily . Seems this block bleeds rust constantly . 
Haven’t drained oil yet . 

[Madkaw]

The disassembly starts . At least all the bolts break loose easy . The Nissan collector (steel) gasket was there hidden under the rust - intact ! 
oil was watery . Can’t wait to see under the head . 

 

[Madkaw]

3&4 I guess 

[Madkaw]

How often do I need to be retorquing this head ?  I just rebuilt this motor not too long ago and already checked the bolts once .

head studs do any better ?

[datzenmike]

Once a year is plenty.

[datzenmike]

3 hours ago, Madkaw said:

3&4 I guess 

 

Looking at the head I would have said 1 & 2 but the clean pistons it's 3 & 4.

 

Borrow a straight edge and check the head for warp. Max allowable warp is a 0.004" feeler gauge under the straight edge.

[Madkaw]

10 hours ago, datzenmike said:

 

Looking at the head I would have said 1 & 2 but the clean pistons it's 3 & 4.

 

Borrow a straight edge and check the head for warp. Max allowable warp is a 0.004" feeler gauge under the straight edge.

I’ll check it - though I have another head rebuilt ready to install . 

[NC85ST]

There seems to be a lot of rust?, in the water jackets on 3&4 exhaust side or am I seeing it wrong?

[powderfinger]

6 hours ago, NC85ST said:

There seems to be a lot of rust?, in the water jackets on 3&4 exhaust side or am I seeing it wrong?

 

I was thinking the same thing. They look clogged, hopefully it's just the angle the picture was taken at.

[Thomas Perkins]

 I would take it to a machine shop and have them check it out.You might need a new head.When my 2.4 blew a head gasket.I had jack do the work,he always had the head sent to a machine shop and they checked and adjusted the valves and pressure tested it.I think it was a few hundred bucks.With that look something major is wrong.Just cleaning is not going to work.Could be bad piston rings.My original engine piston rings went bad,so I got another engine.With my bad piston rings,my spark plugs were oily.I have 380,000 on my tac and I have seen a bunch of things go wrong,28 years of stuff.Certain things I can do,and this is not one of them.But I have a pro Nissan mechanic that knows our 720's better than anyone.I now have a Jasper engine that he installed back in 2009,have 96,000 miles on it.My head gasket was blown from a clogged up cat,believe it or not.That was 5 years ago.It caused  the head gasket between cylinder 3 and 4 to blow and cooked 3 and 4 spark plugs and was making a noise from their.If a cat clogged up like mine was,the flow backed up into the engine.It didn't have anywhere to go.That cat didn't have 9 lives,but it has been removed.He also replace the exhaust pipe leaving the exhaust manifold and the exhaust manifold was recently replace,my whole exhaust is fairly new.This is the original head on my 720...Where my valve cover and gasket sit on top,it is very important to torq to specs to keep from leaking and put gasket adhesive in screw holes and 2 half moon gaskets on ends.I got rid of the screws that hold the valve covers down many years ago,they were the phillip screws,hard to torq,now I have hex heads. That blue wire you see goes to my new a.c. compressor,Jack rewired the heating and Air when he installed the new custom made system.How many people do you know that can do that...All the Nssan heating and air is gone.See the new hose going into the compressor.

 

Edited June 23, 2022 by Thomas Perkins

[Madkaw]

20 hours ago, NC85ST said:

There seems to be a lot of rust?, in the water jackets on 3&4 exhaust side or am I seeing it wrong?

There has been a lot of rust in this engine . I flushed it once already . It seems to be never ending . 

[datzenmike]

 

Needs proper antifreeze in it at all times. Use only distilled water in the mix. There is a brass drain plug on lower rear driver's side for draining the block and over the counter flush kits. 

 

I've used CLR in the radiator, probably would loosen/dissolve rust in the block also.