BlueStag

Finally mounted a micro switch. Long lever with a roller end. It is mounted on the balance tube and closes when the screw holding the throttle arm to the shaft turns to WOT. Had it set up to act at about half throttle and went out on the 5 with it. Wow, did it honk along! I'm trying to set it to kick in at more than 3/4 throttle, but before full open. I am very much happier, it does keep the trans in lower gear as I am accelerating and drops it when I want. I think I am going to be enjoying this much, much more. This ease the pain for a turbo engine.

Thanks, I'll look into those suggestions.

Guys, My SU's are acting up. The choke tubes tend to stick down in the enriched position after the cable is released. I have two new throttle bodies from Z Therapy, and boy, not sucking air past one of the shafts makes a world of difference in performance. The pistons rise and fall cleanly, with a satisfactory thud or even a click. So I think that means I don't want to re-center the nozzle. I think the pull-down levers exert a sideway force against the nozzles that causes them to bind against the throttle bodies, causing them to not let go when the choke knob is released. I struggled with them as I put the carbs back together. I certainly am not in a hurry to pull them off the car. Any easy fix?

No, the current engine is an L26 with a pair of SU's. It is all very nice and all, but I am seeing no more than 125hp at the flexplate. Which is comparable to what the 3.0 V8 of the Stag produced. Possibly a bit less torque. The OD trans is out of a Maxima, yes. Obviously, wherever you can mount a L26, you can pretty much mount an L28ET. That package can be easily juiced to give 200hp and similar torque. Hardly even trying. Which will certainly get my Stag moving down the road. So I'm inclined to use the tougher 4sp attached to many of the V6's, including the 300ZX. Oh, I did need to reshape my trans tunnel to get the trans in there. I'm not eager to go thru that again, so the E4N71B might be the final choice. They certainly are available.

I was going to post this over on the "drivetrain" forum, but for some reason I am not being allowed to post there. Which is OK, as my questions are specifically for the L6. Two automatics were paired to L6's, to my knowledge: L3N71B was the three sp offered with Zs, and L4N71B was the same transmission but with an overdrive hung on it for 4sp offered on the Maxima. These are Jatco transmissions and thus are made by Nissan, and so you should not be surprised to find many Nissan products using these and other Jatco transmissions. Both of these transmissions are pretty old school hydraulic units. The E4N71B was similar to the Maxima unit mentioned above, but heavier duty. It was run behind 300ZX's, and lots of V6 trucks. I want to believe that the bell housing off the Maxima unit could be used on the heavier trans and still mounted to an L6. Nisan also build a series of more modern 4sp autos that were much more electronic, using an ECU, etc. I'm looking to chat with someone who can guide me to more information. I want to find something that will shift a little smarter and more aggressively, withstand the torque of a 28ET, and keep the fuel consumption under control. Hell. Jatco even makes 5sp automatics...... In other words, how far up the food chain can I go while keeping the L6?

I'm picturing it now. Just next to the throttle cable cam that you asked me about.

Madness.

I don't think I would alter this transmission, not until I had a back-up. There is a slightly more modern one that is electronic in its shifting and has an ECU. Yes, I have installed a switch, which the throttle peddle should activate. But the carpet is in the way. I need to engineer something mounted on the balance tube and have the switch there. Some sort of cam that comes up as the throttle rotates. And make it adjustable such that I don't need to go to WOT to get the downshift. And I have a switch to drop the OD (this box came out of a Maxima with OD), but it is a bit of a reach. The ergonomics of the Stag are a problem for me. Tony, you should have taken me up on the offer to drive it. But I respect a policy of not driving other people's cars. So much grief avoided..... I find if I set my seat such that I can reach the console controls, that my right leg is bent back and my ankle fatigues quickly. (The steering wheel is adjustable for rake and reach) I set my seat all the way back, despite the fact that I am not at all tall (5' 7") Re-engineering the switch. Not too daunting nor expensive. A thing to do when next business slows down. Probably next week.

No doubt I am. Autoboxes are inefficient in a number of ways, not least that there is more friction in one than in a manual box. But the thing most aggravating about an autobox is its hesitancy to let you spin the motor very fast. Horsepower is dependent on spinning the motor quicker (broadly speaking) and my slushbox rarely permits the L26 to spin much faster than 3500, which is just where the hp and torque are beginning to happen. I could get a 5sp for next to nothing, if I ask around nice. And I don't need a competion clutch. I could enjoy the car a little more if I was rowing thru the gears. But this is LA and I do like the auto box out on the freeway. I am wondering what sort of low-end torque brute could be built with an L28 and SUs? Seems to me the first item to consider would be the cam..... Or just find a turbo.

Seriously. What would be the maximum likely HP and torque on a 2.8 fitted with SUs? 1:10 compression ratio and 91 octane. Tractable cam (needs to idle at nearly 1000 rpm smoothly. Go ahead and specify the best head and a good header. I especially want it to produce torque at lower RPM, as this is to be mated to an automatic trans. Somehow, I cannot imagine more than 175 hp. Which I'd never see, as the engine would need to spin faster than the trans would let it get to.

Now there, there is a project that I need to respect: machining your own flat crankshaft for a V-8. Just yesterday a Ferrari V-8 ran past my daughter and me with that wonderful "ripping of sails" braaaap. The kid fancies herself a budding engineer, I've forwarded her this thread. I've owned a small hobby lathe for quite a while, made many bits and bobs. Nothing like an engine component. I'd like to see an engine crack carved out of a solid billet of steel. That has to be cool. Even if it took six weeks to get it done.

OK, and while we are talking L26's, how much performance improvement can be expected by swapping on a P79 head? Which supposedly breathes better than an E88?

I've checked it a dozen times.

The clutch is not locked, the fan spins easily by hand.

Finally. I hope. But I have mastered getting the intake off without breaking it down......

OK, I MAY have defeated the exhaust leak: cast iron exhaust manifold to down pipe. Finally figured out that the cast iron manifold surface was way not flat. I had to saw off the last original stud and helicoil for it. Got it all back together today and my word,. it is much quieter. Now, I am bothered (well, have long been bothered) by the whirring of the fan hanging on the water pump. It has a centrifugal clutch. It should resist spinning at low rpm. But the whole rig whirs painfully. Question: is the fact that I have no shroud around the fan makes it more noisy? If I was to construct a proper shroud around it, would it be a lot quieter? Remember: this is not a z that this is in, but rather a Triumph Stag.

My 8" Makita belt sander is doing wonders. The whole surface is shiny. And it is much flatter than it was. As I wrote earlier, the web between the two pipes was distinctly proud of the two outer points. I'm getting there. What I am not going to do is load up some crazy coarse paper on the sander and wade in. I prefer the control of 80 grit, even if it means that I will end up burning thru ten belts. The belts are cheap compared to the manifold. I might take it back tomorrow to Morse and see if they will give it a spin against their machine, now that I have got it much closer. As for the ZX Turbo, I'll save my pennies and get back to you. If you see a silly good deal, just go get it. If I can't afford it, someone in the community will take it off you, yes? Or you will just build another motor for fun. Yes, the oil pump has the virtue of being replaceable without tearing the whole engine out of the car.....

Oh, if anyone wants to complain about us chatting on a thread, I say they should get a life. I don't know when I'll have the scratch for a turbo swap, lord knows there are about 200 other ways that I could spend $1000, and have my wife not kill me. Be sure to come around when you are back. The local Triumph guys meet at the Bob's Big Boy in Toluca Lake 1st and 3rd Sats of the month. Come eat breakfast with us.

And how the hell do you have a photo of Morse's sign? (Blue used to live near me. I'm counting on his return before I work the turbo swap. Blue is about 30 years younger than I am and I don't have a son, it sure helps to have help that is agile.)

Now I just need the $1000. I find it hard to imagine putting a FI engine into a car without rebuilt or new injectors.....just like you would replace the plugs and wires. And you'd probably want to replace the water and oil pumps, or at least look them over. Which is a strong argument for buying a whole car that one can test drive. Still, I just don't see my luck running to $1000. Back to this pile of poo. Just how flat does the manifold surface need to be to get a valid seal with a felpro gasket?

What benefit do you see in this process? As mentioned, you will be removing mass from the very center of the crank, so that should have no effect on how rapidly it spins up. And you surely are not doing this to lighten the car. You are proposing to remove metal from what is the very heart of the engine?

So, nothing is for nothing. When the muffler shop owner handed it to his guy, the guy took it to a huge spinning sanding disk and buffed it a little, then declared it so distorted that it was going to take at least one disc to flatten it and that he'd need to charge me $60 to do it. Back to my garage and out with the large belt sander. I used some relatively (considering how hard the cast iron is) fine paper (80 grit) in order that I not remove too much material too rapidly. Also I used a large magic marker to blacken the surface as I got closer to being even and flat. It was radically out of flat, with the web between the two exhaust ports being very much higher than the outer edges. I am on my fourth belt and have just about got the two circumferences close to flat all across, although the outer edge of the two outer ears are still back a bit from the ideal line. At some point I need to call it good and put it all back together. If you ever need to get a cast manifold off a SU equipped L6 in an hour, I'm your man. I dread putting it together yet again and having it leak, but I also do not intend it to sit in the garage unused for days on end.

I'm talking about a few thousands of an inch. The flange is less than three inches across. The drop pipe is about two feet long. Six thousandths translates to .050th at the rear tip or there abouts. Which can help. A slight difference like that will be OK at the studs, which will flex over a thou or two at the end of the torquing, and all will be flat.

Moris on Burbank by the Five Points. I'll direct you there when next you are in town. As for a header: that is over $200 for a single component. Swapping to a solid un-rebuilt stock zx turbo, assuming that I could get lucky enough to get a little help from my friends, will cost me what? $1000 to $1500? I'll save my pennies.