Tomzern

Sean Dezart who runs Zstory in France makes some really nice SS headers and complete exhaust systems for the Z at a reasonable price. On his facebook-page "Zstory" you can see customer photos of the headers and exhausts installed. Looks really nice! -Tomzern

OK, so today we looked further into this, and we have confirmed that all the marks are lined up perfectly at TDC. We have also more or less confirmed that the problem is with the ignition. I hooked up an ignition wire tester on a couple of plug cables and it showed sporadic and very weak sparks. Just to rule out the cables, we took the cable set from my car (which is running good) and tested them on his car with no improvement. I then hooked up the wire tester between the coil and distributor and even then the sparks were sporadic and weak. We tried changing the brand new coil with another brand new coil with no improvement. The points gap has been adjusted and controlled several times. We tried a positive wire directly from the battery to the coil, and a negative wire directly from distributor to coil, but no change. We have not yet checked for the same symptoms with the 280Z electronic distributor installed, but the points distributor installed now has new points, new rotor and new cap so I doubt the problem is there. What else can cause this?

When the problems started, the car had a 280Z distributor with a GM HEI ignition module. The first thing we did was to change the plug wires, but that did not help at all. We tried changing plugs, but that didn't help either. The problems started out with the car running OK at idle, but started spitting and misfiring alot as soon as we tried revving it a little. Then it got worse, when it wouldn't even run at idle. We tried changing out the 280Z distributor with a stock 240Z distributor with point ignition. This got the car running seemingly good. Good enough for us to believe that the problem was fixed. He left my workshop that day as a happy man, but it lasted for about 1 mile and we had to tow the car from there... Since then it has been more or less like in the video. In the video we have switched back to the 280Z electronic distributor. We will try to buy a new set of plugs and confirm that every plug fires! That is what I think as well! Is there any possibility that the chain has skipped a tooth or something like that?! Seems impossible to me, but I feel we have tried almost everything now

Hi A friend of mine has some problems with his Z, and is about to give up so I want to give him a helping hand He was out driving when suddenly the engine went sour and stopped. This was about a year ago. Since then we have tried lots of things, like new plugs, new plug cables, different distributor, new coil, ignition adjustment ++ When we changed the distributor we got it running good, but it only lasted for a short trip and then back to the same starting point. Here's a video of how it is at the moment: https://youtu.be/7Jx_rV4Z62s Can this be carb related? All the plugs are getting wet, but it sounds like it's only igniting on one or two plugs. Regards, Tomzern

Sooo, back on topic; It's now a fact that I have to make those relieves in my block to get the MN47 head to fit, BUT do I need a different headgasket with relieves as well, or can I use the normal L24 headgasket I already have? I originally thought that I had a conventional N47 head, but now that I know I have the "famous" MN47 head another question comes to mind; Should I use the MN47 head instead of an N42 head (which I also have) for my L31 stroker build? The MN47 has better "quench design", but the N42 does not have the exhaust liners which makes it possible to do some improvements to the exhaust ports as well. hmmmm Appreciate all the help -Tomzern

So it seems like I have a maximal N47 head. I brushed out the relieves. The block is stamped W24

My guess (and hope) is that I have a newer european version of the US "MN47" head (ref 84-89 build year for the Laurel L24e) I'll be back with pictures tomorrow! 2:17AM here now, so might consider calling it a day Oh, and thanks for all your help so far!

I don't doubt that, and I am no engine machinist or engineer, but the way those relieves look tells me that they are not knocked out by the valves. Especially since they are looking exactly the same on all 6 cylinders.

It's a bit more realistic that the relieves are there from factory, than that they have been nicked out by the valves over time. I will post pictures of the relieves on my L24E block tomorrow. They definitely look machined. Another thing. My L24E comes from a laurel that was produced from 1984 to 1989. The maxima L24E was used from 1981 to 1984, so there may be a few differences on those two engines as well.

I have the L24e block that the N47 head came from, and it has relieves for the valves. I don't know if my N47 and the Maxima N47 heads are the same. Will check for the sensor between plug 5&6 tomorrow. As for the exhaust manifold, I have already mounted the manifold from the L24e on my car. It was a direct replacement to the original smog manifold, except I had to cut a little in the collector pipe to make it fit the outlet flange on the L24e manifold. Post #3 here shows how I did it: http://forums.hybridz.org/topic/121668-w48-diamond-exhaust-manifold-on-240z/ So the exhaust is already in place and will not be an issue. The relieves on the L24e block are milled out about 2mm into the deck. Im thinking it would be better to use som sort of milling bit on an air die grinder to make it as close to the original relieves as possible, since I have the L24e block for reference. What do you think? I was planning to use a stock L24 head gasket. Are there headgaskets with relieves also, or is that not an issue? The noise probably comes from worn out valve seats/guides, Have tried adjusting a dozen times, even tighter than oem specs but no difference. Thanks, Tomzern

The head is actually from a Nissan Laurel C32 found here in Europe:) Ahh, those relieves are an issue:/ I am standing here looking at the L24e block just to know what you mean and I understand. How can I add those relieves to my old L24 block?

Hi! I have an L24 with the original E88 head on it now. This head makes bad noises and needs work, but I have an N47 head that I took from an L24e engine. Can I mount the N47 head on my early L24 block with SU's and stock head gasket without any issues? Will this give a CR bump? Only concern I can come to think of is that the L24E had dishtop pistons, and I am pretty sure that the E88 L24 has flattop? Just trying to find the cheapest way to get rid of the bad noises as this is just a temporary engine Regards, Tomzern

I definitely have the forward-mounted diff. The driveshafts are angled towards the front of the car when looking straight up from under the car. Not in line with the hubs. I also have the R180 diff. I tried the same movement when I pushed the propshaft all the way into the transmission. The play was almost gone, but there was still a little bit left. Starting to think that maybe my transmission is shorter than the 4-speed. The shifter also comes up closer to the engine than stock. I think I will order the bushing you mentioned Mark. I like the theory about this play being the cause of the previous shaft failing. It is the most probable cause the way I see it now. Thanks for that!☺

Thanks for helping me guys☺ I have just measured the shaft center to center between the u-joints and it is exactly 21" long. Here's a video showing how much further into the transmission the shaft can go: https://youtu.be/LzmrVwc8s6A The diff is in stock 1970 position with the straight mustache bar. Does the shaft have to be lengthened when swapping from 4-speed to 5-speed?

Wow, what a useful read this has been! Thanks guys! I have just placed the order for an ATV700 joint to replace my lower steering U-joint. I have the early clip style joint. Here's a video of it that I shot today: http://www.youtube.com/watch?v=3qMfJfhjvFw I think a new joint might be noticable