Draw through carb turbo setup

[Serban]

Greetings fellow Z enthusiasts!

I just picked up a very very rough Z (which will go to the scrap yard), but it came with a supposedly built L24 with a draw through carb turbo setup. In my internet search, I found something similar, made by Crown many years ago. What I have is very similar, but the log manifold that connects the two carb manifolds is different, and looks custom made, also, very nice piece despite all the rust.

The guy I bought the car from said the previous owner had about $9k worth of engine work done, I won't know until I pull the engine out and get it checked out. What I found interesting about this whole setup was the use of pipe fittings and valves everywhere, pretty sure this setup was done before AN fittings were available

The carb inlet pipe has two nozzles in it that spray right into the carb, not sure if that's for extra fuel? A single SU carb doesn't seem adequate for a turbo setup in my opinion. The fuel line was connected to a T that goes to the custom made balance tube, and on one end was some kind of electric sensor, or switch? It could be that someone just stuck a hose on that fitting over the years to cover it, I don't know for sure. I also have an adapter for using a Weber carb with this turbo.

I'd love to hear more from those of you who may have some info on this setup, it's pretty unique. If this is a fully built engine, and still good, I struck gold for sure! At that point I might just ditch the carb setup, and go for a more modern EFI setup. This will eventually make it's way into my 280Z which I recently converted to carbs since I was tired of all the EFI problems.

Here's some pictures of this thing:

[Patcon]

If it was purpose built for a turbo the compression may be too low for a good NA setup. That would be there first thing to check. Also I would pull the head and check the crowns of the pistons and the condition of the head. If it was under fueled and had a lot of detonation, the engine may need a total rebuild...

[Serban]

If the engine checks out and I go EFI, it will be with a more modern turbo. I still have all my 280Z parts, intake manifold, etc. I even have an L28ET manifold that I can use if I decide not to use this one, which is a stock exhaust manifold with an up pipe for the turbo.

[madkaw]

Talk about a tuning nightmare :0

[ksechler]

Do you know if it ever worked?  I don't mean to be a doubter but I am...  I wonder if that setup lead to the car being the neglected rust bucket that it is.  

Edited July 19, 2016 by ksechler

[Serban]

19 hours ago, ksechler said:

Do you know if it ever worked?  I don't mean to be a doubter but I am...  I wonder if that setup lead to the car being the neglected rust bucket that it is.  

The guy I got the car from had 3 more rust buckets in his yard, and you can tell they have all been sitting for a long time. His brother bought all these cars over the years with hopes of fixing/rebuilding, etc. He passed away, and now the city is asking he gets rid of them.

The story I got from this car was the guy who built it had to sell it due to a divorce (and I'm wondering if all the money he spent on the car is what lead to the divorce). I don't know if and how it ran, but I did take the valve cover off and the head looks very clean, also fresh oil in the engine, and crank spins freely, so far so good! I hope to get the engine pulled over the weekend and start digging into it.

[Serban]

Hey everyone, it's been a while since I posted on this thread, but I finally got around to pulling the head off. Pistons look fine. This is an E31 block, and E31 head. It's got dished pistons which I'm told is not the stock piston on the E31, and the bore is 83mm. I haven't measured the valves yet to see if they're oversized. But what is everyone's thought on this?

The head looks pretty clean. I guess next step will be to drain the oil and pull the oil pan off and investigate a little more. 

Edited June 14, 2017 by Serban

[esmit208]

Doesn't appear to have been abused but since you have it all apart why not put in some new muscle?

[Serban]

Don't really want to build up an engine, but if I did, I'd probably do the L28 that's in my car now. I'm more curious than anything to see how this runs. I'll get some new gaskets, redo the oil feed and return lines to something more modern, and have that turbo checked out. Not trying to do a big budget engine, just refresh it, drop it in, and see what it does. If anything, I'll leave that engine in there just for the unique factor  

[Patcon]

With the rust in the cylinder bores, gaskets may be a waste of money. If I were that far in I would break it all down and at least hone it out and check or replace the bearings, but I have less time than I use to when I was younger. I don't like doing jobs twice

[Montezuma]

I have that same set up on a 71 I picked up from Les at Classic Datsun Racing. The last registered owner was Willie Buchanan of the Green Bay Packers and San Diego Chargers. Mine is in the que to be restored at my friend's shop.

Sent from my SAMSUNG-SM-G870A using Classic Zcar Club mobile

[Serban]

9 hours ago, Montezuma said:

I have that same set up on a 71 I picked up from Les at Classic Datsun Racing. The last registered owner was Willie Buchanan of the Green Bay Packers and San Diego Chargers. Mine is in the que to be restored at my friend's shop.

Sent from my SAMSUNG-SM-G870A using Classic Zcar Club mobile

Have you driven with this setup? I find the lack of wastegate concerning, and plan on adding one. Is one SU carb sufficient, or will I need to rig up a hobbs switch like the previous setup had?