OH NO! Not another L28ET swap question! (I swear I've searched beforehand)

[Guest Z Draci]

I've been searching and reading previous posts on this forum for the past 3 hours to make 100% sure I didn't miss anything. If I did, it must have been in the dozens of broken links encountered along the way. Please bare with me! I'm an amature!

 

I am planning on doing an L28ET swap into my 240Z. I would like to get it running in fully stock specs before I go for my target of 250hp. I already have a 280ZX NA transmission and its corresponding 3.9 differential. I've already located a donor car that's supplied by a friend of mine.

 

Apart from the parts I can get off a 280ZX Turbo, what else is needed or recommended for the swap? I've heard people saying that a BOV is necessary. I know I personally would like a boost guage to replace my broken clock in my dash and also a turbo timer for summer weather. What is the general consensus here? What else would I have to buy?

 

Can the fuel vapor tank in the rear be removed and replaced with a surge tank? Can I just plug up all the holes on the fuel tank that is connected to the vapor tank? Is it recommended that the vapor tank be retained? What are the consequences of my choices?

 

I also need to get opinions on this one. Since I have a 3.9 differential in my car right now, would it be wise to switch to the 280ZX Turbo's 3.54? I remember reading that the 280ZXT's differential has a different number of bolts on the flange so there would be a fitment issue. I'd prefer to go with the 3.54 until I can find a good deal on a 3.7 LSD.

 

While I'm back there with the differential, I want to swap out the U-joints for the CV's from the 280ZXT. I will just have to buy the adapter from Ross!

 

I appreciate any of your help. If you have spare parts laying around that may help me out, please let me know! I'd prefer to buy parts from the Z community than elsewhere.

[z-ya]

Like YOU said, just get it running good in its stock configuration first, then worry about BOVs and boost gauges. Once it is running good then you can do upgrades knowing that you are starting with a fundamentally sound engine swap.

 

Yes, you can use the vapor tank as a surge tank (I think I'm the first to do that), but again, it is not needed just to get your stock turbo motor running good. Think of it this way, the more stuff you take appart, the more you have to put back together. It is much easier to take stuff appart than put it together. If it ain't broken, don't screw with it at this point. You can do all the bling stuff later. Just get the motor in there and running good.

 

Concern yourself with getting the motor and transmission in there first, you can deal with the rear end later. The R180 and stock half shafts you have in there will handle a stock turbo motor easily. What transmission is in the 240Z now? If it is a 5-speed, use that, otherwise put the Borg-Warner T5 from the ZXT in there. Unless you have access to a 280Z or 280ZX NA tranny. These will fit more easily into the 240Z than the T5.

 

I'd focus on getting the motor installed, wired, and running good. If you keep thinking "while I'm in there I might as well ....." then you could be at this for a long time. I think you would like to be driving it, and with a turbo motor in there, you definitely will!!

[SleeperZ]

For only 250hp, your running gear (n/a tranny and 3.90 rear) will do nicely. You don't need CV shafts either, even for 250 hp. I dyno 313 rwhp and still run stock half shafts with no breakage, even with drag radials and 1.8x 60 foot times.

 

Good advice here: Stick with installing the stock engine and getting it running. Then focus on building more power -- a "BOV" comes later with higher boost and an intercooler.

[Guest Z Draci]

Thanks for screwing my head back on! I was thinking so far ahead that I lost sight of the most important thing of making the car un first!

 

I think that's good advice for everybody doing the swap.

 

Once I get it running well, I'll start worrying about what I don't like or what I want to improve on.

This means I'll have to repost again in a few weeks!

[Guest bastaad525]

I agree about not 'building up' until you get it running smooth just stock, but I sorta disagree with the BOV thing... I installed a BOV on my stock J-pipe at the same time as I was doing the swap. I wanted the added safety for my turbo. Anyways a BOV is just that... more of a safety device than a real performance mod.

[Guest Z Draci]

I actually acquired the donor car today--250+k miles w/ 60k miles on rebuilt turbo. As I was driving home in the car (it started and ran around the block perfectly), the engine temp needle began to crawl higher and higher. When I was only 10 minutes away from my house on the freeway, I saw steam from the right front corner of the car and noticed that the engine temp needle was all the way to the right now.

 

Turns out that all the coolant had magically disappeared and the steam popped open the resevoir tank lid. As there were no turnout shoulders for what seemed like an eternity, I kept my eyes on the oil temp meter as I crawled to a stop. There were no prior symptoms that would have caused this to happen. The car ran fine after I filled it up with some water (temporarily until I finished the last 10 minutes of the trip).

 

I'm going to make the engine run well in the donor car before doing this swap. It has difficulty with cold starts and an unstable idle when "cold." The head makes a knocking noise when idling too. I need to address these problems as well as the disappearing coolant problem. My guess is that the headgasket may be leaking and that a valve adjustment is in order. I haven't really looked at the car after that trip so who knows. I'll take a good look at the car this wekk and read what's in the archives and learn from there.

 

The boost engages smoothly and there is no hesitation when accelerating at WOT. The color of the exhaust is clear except for a white puff at startup. I can't really see anything wrong that can be of major concern.

 

Does this sound like a good engine candidate for a swap?

It also had a gearbox that shifted as smooth as silk. I was surprised especially for a 250k mile car! The rest of the car is in fair condition, but 100% original.