DAW

I'd be interested if, and only if, the headlight covers and trim rings were available also. DAW

Tensioner and slack side chain guide are two different things. If .080" head shave correlates with one link of L6 timing chain, then why not take a link out and use a Mercedes Benz connecting link to put it back together? DAW

Check to see if the cam timing is off (if you don't know how, look it up in a service manual). If it's off and set to #1 hole then your chain is stretched. You could set it to #2 or #3, whichever puts it on (or closest to) the proper timing ("line" in the "V"). If it was out of cam time the performance will improve, but I wouldn't leave it at that. Replace the chain if you're on hole #3 and the cam timing isn't advanced some. If, on hole #3 the timing is OK, make a note that you need a chain but might make it until you tear into the front of the engine for some other reason (such as not wedging a block into the lower chain when you adjust the cam sprocket position), or until summer comes around, etc. DAW

You'll need a rear-sump oil pan because the Maxima is front-sump. I'd recommend getting an oil pan from an L28ET because the turbo oil drain tube is already on the pan and can be used in place of the drain tube that's on the LD28, on same side of the engine, for the drain oil from the LD28 vacuum pump driven off the back of the alternator. The LD28 starter is a hefty gear-reduction unit. The a/t uses a lower stall speed torque convertor than the na L6s and a different pitch on the gear teeth of the flexplate and starter drive. I don't know if there were LD28 m/t cars, there may well be, I just haven't noticed any. If there aren't any, then I'd recommend using the LD28 a/t. It's better than the 240-280Z a/t's because it has a lock-up convertor that the Z cars don't. There is an LD28 280Z in a magazine I've seen before, I think it was a history of 240-280Z's type magazine from over 10 years ago. I think what would make your project even more interesting would be to add an intercooled turbo setup to your LD28. The L28ET exhaust manifold and turbo appears to be a bolt-on and you could use an intercooler from a Saab, Volvo or Starion to keep costs down. You will need stronger front springs if you install the diesel engine as it is a lot heavier than a na L6 due to the cast iron cyl. head and injection pump. Good luck! DAW

8.3:1 just like an N42 engine. DAW

Searched: no results. I'm not asking about the virtues of the engine vs other engines. I'd like to know if anyone has fitted this 2.6 liter turbo engine, using a PU truck rear sump oil pan. Thanks. DAW

Back to the original question by the 16yr old '74 260Z owner, I think the budget and experience level are key here. The bang-for-the-buck quotia is the most important thing here. I see two options as the most practical here: swap the L26 E88 head for an E31 or early E88 (E31 type chambers) and transfer the L26 exhaust valves (larger) into the earlier heads (L26 83mm bore has factory-cut reliefs at the top of the bore for the larger exhaust valves that the L24s don't have, although L24Es do). Non-leaded seats should be installed too, which adds expense and the early heads can't easily accommodate f.i. Next option is to go to the JY and get a Maxima L24E head, which already has hardened valve seats and provision for f.i., and the larger (L28 sized) exhaust valves. For performance, it needs the cam and intake valve springs replaced and this can be accomplished at the same time that a mild cam & spring kit is installed (use late L28E spec cam so it has lobe oiling not spray bar for use on N47 style head). Larger L28 intake valves & seats could be installed but on a 2.6 liter na street engine the money could be better spent. I would recommend the second option, plus buying the head with the f.i. intake and exhaust manifold on it as a unit and getting all of the matching f.i. components (harness, AFM, fuel pump & relay, etc) to set aside for a later stage. It might be more economical to buy a smashed Maxima with a five-speed and scavenge all useful parts. Use the twin SUs (get some early round tops) initially to simplify (tune needles for c.r. & cam); or just go ahead with f.i. using 280Z fuel supply lines, etc. and tune it for the higher compression, cam, etc. One thing to keep in perspective is the displacement re head choices. We're talking about only 2600cc here (with no practical way to increase it); not 2800-3100cc. The combustion chamber size choice is limited so P79 & P90 stock or cut 0.080" isn't useful, nor is the L28E N42/N47 uncut useful to increase c.r. As an aside, and off the topic, is that one overlooked performance option for an F54 L28E is to retain a P79/P90 head and instead of cutting it 0.080" & shimming, etc., substitute euro-spec raised-top pistons for the flat-tops to increase compression. DAW

Justin, the L24 rods are a direct bolt-in but use only late '72-on rods (after engine serial # L24-096180) as they have large bolts (9mm vs 8mm) and are stronger. The Maxima L24E rods can't be used, they have smaller journals. Late L16 rods (after serial # L16-369553) from pick-up trucks will work too. I would discourage any further shaving of your N47 head if you go to flat top pistons (for a street driven engine) because ping/fuel octane problems become a headache once you get above c.r. 10:1. You'd also be bringing the valves closer to the piston tops if you cut the head, better to overbore the block to increase both displacement and c.r. Your cam and increased c.r. go together and the sum is greater than the parts. Good luck. DAW

Tony D., you're right about the LD runner size and it seems that the runner length would help low-end off-boost power as well. Hood clearance issue aside, has anyone out there tried this manifold (with injector bungs added)? DAW

The cam timing may be off but that is not the big problem here. If you have a stock 280Z bottom end and head (N47) then you have only 8.3:1 c.r. and that's not going to make any significant power with that cam (or any other cam for that matter). At this point, IMO, the fastest easiest path to a significant gain in power would be to either get an F54 L28E short block (or whole engine and sell the head) and swap it for the short block in you 280Z. This will give you a bolt-in c.r. increase from 8.3 to about 10:1. Or you could remove the pistons from your short block (short block still bolted into car), have the tops machined down just until the edge of the dish is gone, swap the L28 rods (130.4mm) for a set of late L24 rods (133mm). This will give the same 10:1 c.r. and the added benefit of improved rod/stroke ratio. An alternative on this approach is to buy a set of new pistons made by Sterling which have 86mm (L28) dia. but the correct pin ht. to use with the L24 rod length. If you decide to do any of these approaches don't make extra work for yourself. You can remove the head and intake assembly (once the headers are unbolted) as a single piece and it doesn't take much time to open up a lot of space to get to the shortblock. Personally, I would bolt-in an N54 short block and have fun with it while building or shopping for a separate turbo engine. DAW

Your lower shaft/gear is probably off on the crank gear setting but don't drop the oil pump to set it right, just move your plug wires around one cylinder distance and that may be what you need to put you in the proper timing adjustment range. If you're running points, make sure the dwell is set properly before setting the timing. When you set your valve lash, be sure to check the camshaft timing (advanced, retarded, etc.) as this can have a large effect on performance. DAW

Oops, make that 186.5mm. (140mm + 46.5mm) DAW

I looked at those pistons but I think there was a conflict re the valve pockets. They are set up for evenly staggered intake-exhaust valve orientation, The L6 is not set up evenly, some cylinders are intake-exhaust reversed compared to the Toyota. There's no way to orient them so that the appropriate valve pocket lines up with its corresponding sized valve. How about using a Z22E rod (148.6mm) and a L28ET piston? That's a 0.060" overbore. If you're buying pistons new, then you can get 87mm L28ET pistons, a 0.100" overbore. This would be for a turbo engine. If you're building a na engine, then you could use late model (F54 flat-top) L28E pistons. If you want higher compression with a na setup then consider flat-tops with an N42/47 head. BTW, VG30 rods look good on paper due to their length, pin dia. and correct journal size but they won't work because the big ends are too narrow. Just saving you some headaches if you're crunching numbers. Use 184.5mm as your rod length + compression ht working number which should give zero deck ht. Good luck, DAW

Good rapor; tough choice..so let's let the deciding factor be e.t., or 0-60, correlated to the c.i. of the engine in question. Does a 265 c.i. sbc (larger in size than an L28) actually outperform the L28 in a first generation Z-car? What about the turbocharged version of the 265 c.i. sbc vs the L28ET? Bang for the buck, L28ET gets my vote, hands down. DAW

I think it would be worth it only as a budget build up and that means no overbore or replacement pistons, just a L28 block and pistons with L24 crank and rods. The small displacement is the main issue. Look at the specs for the current generation 350Z engine. It is large bore and short stroke, but it has the displacement to make significant power. The L28 stroke (79mm) is certainly not excessive and the F54 block can be overbored to 88 or 89mm which still gives you an oversquare engine with a substantially increased displacement. The issue is the rod/stroke ratio which goes away when you increase the stroke in the L24/26/28 block. You could run LD28 or FJ20 rods (140mm) and have custom pistons made (I think the c.ht. needs to be about 28-29mm). The LD28 crank is not an excessive stroke at 83mm but it is not best-suited to high rpm use when combined with an abismal rod/stroke ratio. I think the answer is in a taller block ht, just as Nissan did when they evolved the L16/L18 block (=L24/26/28 ht) into the L20B block as they increased the stroke from 78mm to 86mm, in order to restore a favorable rod/stroke (130.4/78 vs 145.9/86). Nissan did the same thing when they increased the stroke in the L6 from 79mm to 83mm, i.e., they improved the rod/stroke (130.4 vs 140/83). So what's the point? Use the LD28 block when using the LD28 crank, that's why Nissan paired them up. Lots of documentation of fast 3.1 strokers using the L28 block...how much faster would they be with longer rods? Lots of rationalization re short rods. "When the only tool you have is a hammer, you tend to treat everything as if it were a nail". DAW

Glenn, those small-block (LA) engines have block mounting pads/mounts far forward on the block, vs sbc that are more mid-block located. Do the Mopar mounts line up with the Z crossmember, and is there a firewall clearance problem? Thanksin advance. DAW

Petrol, with all due respect, you should be posting this thread in the Fuel Delivery forum. Also, go to Barnes & Noble and pick up a book on SU carbs. "How to Build & Power Tune SU Carbs" by Des Hammill is excellent. DAW

Wrong site. DAW

Once again, you might try running the engine then promptly remove the float bowl covers and compare the actual fuel level between the bowls. As pointed out in a post above, you are not going to be able to sort out problems or set the carbs up properly without using a Uni-syn. DAW

When referring to turning the idle mixture knurled ring (or notched ring) in then out 2.5 turns, this means clockwise in until it stops (as you would be doing if you were lying on the ground under the car and looking up at the bottom of the carbs), then back out 2.5 turns counterclockwise. Since you won't be under the car doing this, from above the turning action of your hand on the idle adjustment rings will be to turn the ring to your left to run the jet all the way in then to your right the 2.5 turns. Make sure the choke is not on at all and ensure that the jet is not hung up in its travel. Remember that when you do this idle mixture adjustment on an SU is actually raising or lowering the main jet and this will affect the mixture across the entire rpm range. Reach into the carb inlet with your finger, raise the piston, and let it drop. You want it to drop smoothly and easily. If it's sticking it will really screw up the way the engine runs. RE the fuel supply, run the engine, shut it off and remove the carb tops to see if the fuel level is the same. You could have a plugged supply line and even though the float level is right and the needle/seat are clear to flow, they may not be seeing adequate fuel flow or pressure. If the car has been sitting, put some fuel system cleaner in a fresh tank of gas before you tear into things. The engine will barely run with contaminated fuel. DAW

The R200 rear-axle set-up for the 280zxt uses CV jointed axles, while the non-turbo R200 had u-joint half-shafts. If you need a lower gear in the diff, get your R200 out of a turbo 200SX, as late a model as possible; or V6 200SX. Came as 3.90 and 4.11 from the factory. DAW

Thanks TM, I hope you pursue this and keep us appraised of what's being found out. DAW

This is a great thread. Z-rific, do you have an idea of how much the 4.1 weighs? Are they iron or aluminum head engines? I've seen a lot of these in junkyards, as in they are abundant, not that they were the reason they're there. (their squared). Thanks. DAW

Congrats David, I think the most enticing feature of this item was the statement in the eBay ad that it was removed from a 240Z, and it is shown with stock exhaust manifolds. If it came out of a Z, how tough could it be to put back in one? The bore/stroke relationship is not unlike a 302 Z28 sbc. Good luck. DAW

Welcome Jim! Does the oil pan sump on the BMW clear the Z crossmember OK? Do you know how the weight of the BMW I6 compares to the L6? DAW