Xnke

Zrevival, I'd say go for it. I'd love to see something other than the L28 modified, but around here, you just won't find that information. I've been trying off and on for a while. Maybe someone will realize that not everyone is going to go for an L28, but i think you will be a pioneer in this field. Don't let it discourage you, it hasn't me!

NOTE: this event happened before I became a Z lover. After this experience, I couldn't wait to get my own! Why would you even need to remove the pistons? I've dropped the crank out of several similarly built cars without pulling the motor...transmission was already gone, so you just gotta pull the oil pan and front cover, and be very careful not to tear anything up. That front crossmember will get in your way, though, on second thought. Best to just pull it, and be careful how you pull the crank. By the way, when that crank falls out and hits you in the face, it WILL break a cheekbone...even if it's only in a little four banger... After I did this in a few transversely mounted I-4's, I grew to love the large, roomy engine bay in the Z.

Z or bust, i am seriously considering rebuilding the L24 that i have, as it's not my first, just my first L series. Built lots of little Honda I4's for the local rice crowd, they bring me the parts and I put them together. Attention to detail is something many would-be engine builders lack, and I've got more than enough to go round, some would say. I have, on two occasions, chromed the interior of the oil pan for some folks, just because the rest of the engine was all chromed-out. Even if no one else ever opens that engine, I know the bling is in there. No worries about the chrome coming loose and killing the bearings, because expected life for one of these bored-out, turbo-eating screamers is only 10-12 months, the way the local kids drive them. But, when you bore the thing out so thin that the cylinder walls crack and pop the head bolts neatly after you fill the cylinders with water at 80MPH, what do you expect? I'm asking because I've been presented with two options: Get a strong running L28e from Tony C. and convert to carbs, (LOVE the classic look and sound) Or rebuild the L24 I've got. Right now, it'd be cheaper to get the L28, but as I've got a generally just tired matching numbers L24 for my car, I am hesitant to swap engines. those numbers mean a lot to my insurance company, I get a big boost in coverage for having the original engine.

As some may remember out of the thread "Mild Mods for the L24", I have a weakly running L24 out of my '72 that I am going to rebuild. The PO ran it with no air filter for god knows how long, and compression is down to 80-81-78-82-80-80. Since it will probably need to be bored, and when you start cutting cylinders it doesn't matter how much you cut, it all costs the same round here, I might as well up the displacement a bit. Assuming, of course, that I can obtain suitable pistons and rings to fit. This is where I hit my snag. I'd like to use L18 pistons, due to the 85mm diameter, and ~4CC dish. With the E88 head, that means a CR of 8.5:1, (83/87 octane, save that dime a gallon!) and displacement of 2.5L. This puts the bore/stroke ratio at 0.867, and rod/stroke ratio at 1.805. Are these values better or worse than other options, or does it even matter? Stroke it out with L20A rods, and the LD28 crank and you can get close to a 1.00 bore/stroke ratio. Reading through "How to Rebuild Your Datsun OHC Engine", I read that a 2mm overbore is the max for the L series. Does anyone have a maximum overbore size for the L24 engine, or is it the same block as the L28, just with a smaller bore? Again, before the "get an L28 and be done with it" crowd shows up, keep in mind that for the one local L28 that I have been able to source, the guy wants $800 for the engine sans water pump and distributor, and even then it'll have to be rebuilt to run again. Any Kentucky/Tennessee area Z nuts got an L28 engine they'd like to swap for?

I'm interested. PM is on the way.

After reading a LOT on the elimination of the exhaust fumes from the Z, I'm going to try something else. I want to move the exhaust, as well as seal up all the holes. Instead of running the exhaust straight out the back, has anyone here run the exhaust out the side, just behind the drivers rear wheel? I'm looking for a "hidden" type system, but at the same time I don't want a hot exhaust pipe ruining my paint. Does anyone here have any pictures of their side-exit exhaust systems?

Ok, so i've thought up something that i can do now to improve performance, and that can transfer to the L28 block later: Triple SUs. I've already got three SUs, the two on the car already, and an extra rear carb. Time to put those welding skills to good use! Seriously, I've seen many of these cars with triple carburetors. Mikunis, Webers, Dellortos, Solex, but only two with triple SUs. I hear that they don't work so well due to the L-XX series firing order, but I think that got debunked somewhere on the boards here. Any Thoughts on this? I know it can possibly improve flow, but there are many other things to do before it makes much of a difference.

well, this all makes sense. Time to look for a L28...thanks guys!

Very good points, all around. I see the homebrew-L27 vs L28 money argument, and understand that. Even if I am doing the machinework myself, it's still gonna cost money to get the pistons and pins, so I agree on this point. The only reason I considered it is that this block probably will need boring anyway, as the PO ran with no air filter for some amount of time, and when I got it the dry compression test ran 82-85-85-75-90-92. Ick. (For those who wonder how I came up with the numbers: the CA18XXX engines use a 84.5mm piston, and from all references I can find, it's got a 38mm pin height, making it essentially a drop-in replacement for the L24. The L-26 crank came from all the folks who'll be dropping the LD28 crank in, leaving lots of stock out there. See, I was kinda thinking. The fact that the L24 made more horsepower than the L26 or L28 also had me a little swayed.) EFI is out of the question, I already will be reworking the wiring harness in this car, and don't need anymore complications. Besides, I think the dual SUs are pretty sweet myself. And like you said, they are capable of good mileage too. Exhaust work is in. I'm a good welder, according to my instructor at school, and welding coke cans with a torch is my specialty. (Not at the rims, mind you, but actually slashing the can up and welding it back together.) Having access to a good pipe bender, and a CNC plasma cutter machine up at the school makes a custom header simple, as long as I'm buying the material. So, what are we left with? lesse.... Find a solid L28, -400$ (5-7 paychecks) sell off the uneeded head and EFI intake, +200$ or so sell the extra L28 electronic distributor, I've already got one. +30$ sell the worn L24 block, ???$ So, that's about 200$ to buy the new block, pistons, ect. (playing fast and loose with the numbers here.) Considering that the headwork cost should be minimal, (as if that even applies here, minimal is still costly) what kinds of things should I search for here as far as E-88 modifications? Thanks for the warning guys, had I not found this forum, I could have wasted a lot of money. Guess i better start looking for that L28...

Before you all go on about how I should drop the L24 and spend money on getting an L28 and a turbo, (which is not what I'm after) please read the following goals. 1. I want to work with the L24 block, E88 head, and E88 intake manifold, dual SUs. 2. I want to be able to run 87 or 89 octane gas. (87 is cheaper on the college wallet, and leaves more money to buy parts. 89 is the "good stuff", while 93 octane around here is just too expensive for me.) 3. I am not going to be living on the track. This will be a fully street-ready, comfortable car. There WILL be A/C on this car, I'm not a total masochist, it gets hot in the summer. 4. There is no minimum horsepower. However, I'd like to shoot for 180, as bone stock it pushes 150hp. ANND..... 5. Shitty fuel economy will not be tolerated. 20Mpg minimum! Now, given that I've searched all over and found very little on this, I think I've got a decent post. I'm still restoring the body, and so I'm not going to be ready for engine work for some time. That gives me time to plan and save. Here are some of my ideas so far: 1. a reasonable bore, maybe 1-1.5mm over stock. 2. L26 or L28 crank. lotsa people don't need them when they build a stroker, and I'm sure i can get a good one for not a lot of money. 3. Electronic ignition. I've got a Holley unit that came with it, but it's got some bugs, and needs to be cleaned and set up. Other than that, it's in good shape. 4 Head work. I'm handy with a rotary handpiece, and have access to a flow bench. I'm a competent machinist (I've patterned, cast, machined, and assembled a complete model inline-6 gas engine, and it does run pretty good.) 5. possibly a different cam. I don't know much about this. As you can see, I'm new to working with auto engines. I'm also a college student, so progress is slow, but steady. Money is hard to find, but I understand that you don't want the best you can afford, you want the best you can get. Does anyone have any ideas or suggestions on what they would do, given that what I'm trying to do is rather unknown territory?