Rebuilding a 78 280Z - need advice

[Casper0878]

So I recently purchased a 1978 280Z from the original owner.  The car ran but the water pump was bad and the owner broke 2 of the bolts when trying to replace it.  The car started up perfectly every time and shifted fine so I took it as is.  The paint was in great condition and I found very little rust.  A couple of weeks ago I pulled the motor and last night took the head off.  Haven't taken apart the head or block but everything seems to be in really good shape.  Besides the broken bolts plus the one I broke taking off the thermostat housing since it was so corroded.

 

I have been doing a ton of reading trying to learn as much as possible regarding these cars and the motors so I can decide on a good build that will suit my driving.  I am not a speed freak by any means.  My current daily car is an RSX-S and my last car was a GSR, so you can see I don't go very fast lol.  They're nice peppy little cars but not FAST by any means.  Even so, I hardly find myself going over 70 when cruising back and forth places.  

 

My original plan was to get a 350Z and do an LSx swap.  When doing a CL search for a 350Z, I came across a post someone had tagged selling their 280Z.  I had totally forgotten about these cars.  I started to read more about them and saw plenty of people doing the same swap to these cars.  This caught my attention.  Being that I am an automotive student I thought having a project car to work on while I go to school would be a lot of fun and a great learning experience.  And also being able to restore a car from the same year I was born, yes I am 36 not some young dumb kid, made this project more personal.

 

Right now an LSx swap is just not in my budget (I have the money but would like to save it for a house).  Not sure if I will still want to do it later down the road but for now I am shooting for just a rebuild.  I would like to get some more "pick up and go" out of the L28 motor without swapping to the L28ET or changing to this head or that block.  After reading around for quite a while, I am still not sure exactly what the best route would be for me.  I live in California so I am limited by 91 octane as well.  This is what I have planned so far:

 

Transmission:

280ZX 5speed

280ZX R200 3.9 differential

Lighter flywheel

New clutch and pressure plate

 

Block:

Hone or slight bore

Dished pistons (was going to do flat top but having to get a bigger gasket and retarding timing doesn't seem worth it)

 

Head:

Very little machine work as I heard the N47 exhaust port should not be messed with.  Maybe just some slight work on the intake port for better flow.  A little unshrouding

Maybe bigger valves (have not looked into this yet)

Maybe bigger throttle body (have not looked into this yet)

I was thinking bigger cam (then I read that I would need to upgrade the EFI which I know nothing about, Megasquirt??)

 

Header

2.5" exhaust

Intake 

 

What do you guys think?  Any advice would be greatly appreciated.  This will be for weekend driving and cruising.  I just want a fun car to drive.  

 

I do have How to Modify Your Nissan/Datsun OHC as well as How to Rebuild your Nissan/Datsun OHC Engine

[NewZed]

Read BRAAP's EFI tips here, along with the other threads - http://forums.hybridz.org/forum/90-l-series/

 

You won't get much bang for the buck with what you're planning for the engine.  The ZX transmission with the 3.9 will have a better gear spread than what the 78 has.

 

If ti started and ran fine, it probably was fine.  Might be best to just get a new HG and put it back together.  The stock Datsun parts are of high quality, even used, compared to much of the "rebuild" parts you'll find.  A bore means all new pistons and rings, for no real benefit.  A hone means new rings, for what, if it ran fine?

 

The first three things, and the exhaust system will add some pep, the rest, not much.  You can do those with the stock EFI system.  Many would say that getting a modern EFI system, like Megasquirt, and keeping the the stock engine, would be more worthwhile than the engine mods you describe.

[Phantom]

I'll second NewZed.

I would add to get a 5-spd out of an 82/83 280ZX as it has the best set of gear ratios in it to go with the 3.90:1 R200.  The others will work but won't be as optimal.  The other thing you might consider is the head and cam out of an 82/83ZX since you already have yours off.  They had a broader torque range than what you have in your 280Z. Not sure about the exhaust ports matching though.  Been a very long time since I last looked at that.

[Casper0878]

I read through the thread by BRAAAP, and since the price of Megasquirt is so low I am considering buying one for better gas mileage if nothing else.  With MS installed, what other mods can I benefit from?  I read the stock cam is actually really good for delivering low end torque and high end HP.  Upgrading to a bigger cam would come at the cost of low end torque.  I wanted to also swap to the ZX distributor and a better ignition system.  

 

Doing some research I found out some people do not like the polyurethane bushings due to squeaking and too much stiffness.  Some actually breaking suspension parts due to not having any give.  Not gonna track my car, just drive around town maybe smashing on the gas every once in a while so I won't be cornering hard or anything like that.  

[Casper0878]

Are there any parts I should be focusing on replacing?  I know the half shafts are the weak point in the back, so I was going to upgrade to the 300zx.  Brakes are on my list, not sure if I want to convert the rear to disks though but definitely upgrading the front.  Suspension wise, not sure I like the idea of my lowering springs not seating properly.  I heard some people use zip ties.  Doesn't sound very safe.  The BC Racing coilovers look nice, $1,500 with swift springs

Edited May 1, 2015 by Casper0878

[NewZed]

You might be reading too much, and picking out the odd little bad things that have happened to people in the past.  Planning for 400 ft-lbs of torque and wide tires, before you've even chosen an engine.  The lowering springs thing is only an issue if you're unseating a spring during racing, or blasting over speed bumps.  The breaking suspension parts is just the T/C rods, and there's a simple way to avoid it.  The half-shafts are fine for most people, unless they're drag-racing.

 

More good reading - http://forums.hybridz.org/forum/83-drivetrain/

 

http://forums.hybridz.org/forum/80-brakes-wheels-suspension-and-chassis/

 

Note though, that Hybridz is race-oriented so much of the advice is more than you really need if you're " Not gonna track my car, just drive around town maybe smashing on the gas every once in a while so I won't be cornering hard or anything like that. "   You'd have much fun with just a well-tuned stock engine and chassis.  

 

And don't forget emissions testing.  78 is in the test-zone, I think.

[Casper0878]

Just picked up an L28ET out of an 82ZX.  Going to drop this into my 78Z instead of the original motor.  

 

I know the preferred turbo when upgrading these motors is a hybrid t3-t4, is there a brand that has better reputation over others?

 

I heard Spearco makes a really nice intercooler, but what is the best setup for the piping?  I have seen some run it under their oil pan.

 

I read that the 3.59 differential is good for a turbo motor.  Was planning on getting the close ratio 5 speed and the 3.90 differential (when I was going NA) but not sure if that is still the way to go.  I know if I get the T5 transmission I will have to modify the driveshaft to fit.

 

Any advice on what to look out for from people who have done this swap already??

Reading the following:

http://forums.hybridz.org/topic/38461-240z-260z-280z-turbo-swap-guide/

http://forums.hybridz.org/index.php/topic/34469-a-quick-fi-and-ignition-280zxt-to-s30-turbo-swap-guide/