BlueStag

DUDE! DO YOU HAVE A PROPER GROUND BETWEEN THE BLOCK AND THE CHASSIS? If you have no real ground between the block and the chassis (remember, you have rubber engine mounts that do not transmit electricity, right?) then you do not have a valid path for all the current demanded by a starter. You were asked this several responses higher up. Do you have a proper ground between the block and the chassis? This would be a honking big piece of wire, or a woven strap, capable of carrying 200 amps for two minutes without damage. It must be well connected to the chassis, and to the block. On my Triumph Stag with an L6 Z engine, it all is handled at the LH engine mount. I drilled the chassis for a sizable bolt and bolted down a cable (the diameter of my thumb) and bolted the other end to the block where the engine mount attaches. The juice has no difficulty flowing thru the block to the starter. There is a lot to be said about a cable directly to the battery, but if you do not have a proper grounding cable to the block, that is the place to start. The lack of it would explain all your symptoms.

But I gotta ask: if you have a 280zx turbo donor, why keep the smaller engine at all? The 2.8 will drop right in.

Hey Blue. How are you? You really think a good set of SU's can be had for that? If you say so. I personally would not trouble with anything not rebuilt by ZTherapy, and that is going to set you back a fair bit more than that. But I would be the last to say that you are wrong. My front carb is CERTAINLY sucking past the throttle shaft. I am scratching together $325 to get a set of bushed carb bodies from ZThrerapy. (The carbs are essentially sound, I just need the proper bushing). I still would like to stumble across a full turbo motor........

Not only can it be done, but it can be done to very great effect. Go spend many a happy hour reading http://datsunzgarage.com/ Don't expect to just buy a pair of SU's and slap them on the car. A fully prepared set with manifold and balance tube is going to cost you serious coin. If you are spending less than $1000 then you are either really lucky or you do not have a set of carbs that will work well. You need to study SUs. They are excellent devices if you understand their limits and foibles. They wear disastrously where the throttle shaft passes thru the body. This creates a vacuum leak that makes them utterly untuneable. This is commonly repaired. It is tricky and a hobbyist needs to be quite talented to get it right. There are many competent businesses that will do the fix. I think I am correct to say that ZTherapy has the best solution and the best price. For a bit more than $600 they will take a set of rebuildable carbs and polish them to a fair-thee-well, and install in the place where others install bushing, needle bearings that are sealed against air leaks. This solution is essentially forever. Do a web search. They know their business absolutely. What you need to be VERY careful of is to not buy rubbish SUs to start with. If they cannot be rebuilt, they will be useless to you. And it is not as if there are simply millions of Hitachi made SU's sitting around just looking for a good home. The Fuel injection might cost a bit more to get back together, but I bet every part that you would need to replace is available from half a dozen reliable suppliers. A point to think about.

Does anyone KNOW the diameter of a healthy SU throttle shaft, the proper round top carbs, of course.

Found it. A web article posted on several MG sites: http://www.chicagolandmgclub.com/driveline00/1001/jasw.html Bushings: http://www.mcmaster.com/#catalog/117/1115/=f42bpg Reamers: http://www.use-enco.com/CGI/INSRIT?PMAKA=329-1124 Now: what is the actual dimension of a Hitachi carb shaft? I'll need to find my micrometer and give that a read. I don't know if it is metric, now do I? I find the idea a bit daunting, especially as if I botch it I will be without a functioning carb. In my considerable experience of the world, I find that a straight six running on three cylinders is prone to disappoint....... I admit that sealed ball bearings are attractive. I wonder where Z Therapy gets theirs?

Holy hat. I'll be happy enough with about 200 hp.

Tim, Excuse me if I am a bit dense here, but: Why was all this necessary? Have you transplanted a ZX turbo into an early Z, meaning that the gas tank is just not designed to provide a rapid enough delivery of fuel to the injectors? I ask because my long-term ambition for my Triumph Stag which currently runs a carburated Z engine with a 2.8 Turbo. I'll need to look into the question of how the fuel system will need to be adapted. It might be the largest issue to tackle when I get there.

Guys, So I'm running a pair of SU's that were rebuilt twelve years ago by Z Therapy, before they changed management. The process back then was different, Z used conventional bushings rather than sealed ball bearings, which must be VERY nice. The car sat for a decade (don't ever buy a house!) and it turns out that it is sucking air past one of the inner bushings. Being cheap and competent and wishing for a turbo eventually, I'd like to just get a bushing and a reamer, and replace the bushing. Search as I may, I cannot find a source of conventional bushings for my SU. Thoughts? Please resist the urge to tell me to swap out for a pair from Z therapy. Yeah. I have considered that.

Yes, the carbs being correctly adjusted being rather the nub. I think my front carb sucks air past the shaft, and refuses to run properly at anything but full open needle/seat. I had the damned things rebuilt well long ago, but apparently not well enough.

Sorry, I'm getting about 15mpg. But I am running an automatic. And I am not getting much by way of acceleration. I am going to swap in an L28 turbo with 300zx electronics as soon as I can scratch together the scratch.

round

Hey guys, I have had my Triumph Stag with a Datsun L6 down for a month or so, after 9 years on stands (don't ever buy a house) and I am glad! But I wonder if my fuel economy is poor? I've got a 2.6 with a pair of reasonably sound SUs, with a Maxima automatic and (I think) a 3.7:1 The Stag weighs about what a 280 does and has 14" wheels, all much like a 70's Z. Does anyone think I am wasting gas? The exhaust does smell rather gassy.

Where are the TurboChargers?

In AUSTRALIA???? Are you daft, lad? Isn't the island just lousy with Brit cars? I am next to sure that some old codger of a Brit has retired to your suburb, and is aching to tune your SUs. Just to keep his hand in.

Thanks, blu. How you doing? Find a weekend afternoon to come glare at the Stag, and I'll serve you a beer.

Thanks, blu. How you doing? Find a weekend afternoon to come glare at the Stag, and I'll serve you a beer.

I was into Brit cars long before I owned a Z engine, which is in my Brit car expressly because the Z engine has SUs on it. Kind of stupid, when you think of it.......... A pair of 2" SUs can be matched without any issue to a 3.1L straight six. Now, the trick will be getting the right needles into them. You need to have the SUs evaluated by someone who really knows their ear from their elbow on SUs. For that I would call Z Therapy and ask them for a price to just evaluate the carbs. Hopefully you know that the throttle shaft has almost certainly worn the carb body, and that sleeves or some such will be required to make the blessed things breathe without sucking air in at the throttle shafts. Next you need to find a Brit car carb tuning dude. Likely he is about 110 years old. A dyno and about a dozen needles. Or two dozen. And possibly more than a few pairs of springs to push the piston down. If you can find a list of approved needles for various Brit cars, you might get lucky. Here's the trick: An Austin Healy 3.0 may have about the same size straight six, but that engine will have nothing like the potential of a properly built 3.1. Possibly only 2/3rds. Jag built some smaller straight sixes that you may not even be aware of, but they might have about the potential of your stroker. Those engines would likely have about the needle that you need. Fuel injecting the SU's? News to me. Gotta go look that up. This one is mine:

You drove from LA to San Fran over night, alone, in an old Z, just for grins? I used to be young, too.

A few photos of my 1973 Triumph Stag, currently running a 2.6 with SUs and a ZX distro. Behind that a Maxima 4sp auto, down from that a 3.7:1 180 diffy, and Z half shafts, finally into Triumph hubs. Should have ditched the hubs for Datsun hardware. Currently lusting for a 280 Turbo..... Teenaged girls featured, no, you may not date them. And me getting it down off stands for the first time in nine years. The kid helped.

I'll go make a thread about my over all project in due time, but here are some photos of the project:

I am pretty sure it is not crud flaking off the fuel tank, as I had it boiled and sealed some time ago. I could see replacing the fuel filter and lines in the trunk. Those in the engine bay are fresh.

That's a point. Still not crazy about the idea of a plastic tube not rated to fuel or pressure with an endless supply of fuel in the engine bay. But I see how it could reveal the level long enough to understand if my floats are set correctly. I'm lusting for a L28 turbo.....

Oh, I am aware of it. It certainly is not of much use when the air cleaner is on. But I take your point, get two fittings and two Ts, and see what there is to see. I certainly am not going to go buzzing around town with clear plastic tubing with pressurized fuel in it.....I'd be real interested in some good rugged glass in that role. Actually, I just installed a glass fuel filter that could serve, just do without the filter. But it is a bit large in diameter, I am not sure there is space. Much as I'd like to put it on a dyno, I don't think my budget is open to that just now. How much do you think that time costs?

Long term, this is a great thread for me, as I hope to swap away from my 2.6 with SUs to a 2.8 Turbo. Trick is? I am running it all in a '73 Triumph Stag, which never say fuel injection. I assume that I will at some point need to pull the fuel tank out (again, it has been boiled and sealed in the past) to have one or two fittings brazed in. AFTER being boiled out again, of course..... Is stainless steel tubing REALLY necessary? It must be pricey. Aluminum is not available for much less, yet impervious to rust? Aluminum cannot take the pressure, which really is not that high? Honestly, when I set my Stag up for the Z engine, I just used brake line. Not that it sees much pressure at all.