240ZMan

The N42 and E31 (along with E88) are all square port exhausts. My header is square as well.

texasz, you're right. When I put the L28 in my '73 240, I switched the head to the E31 from my old L24 engine (which had replaced the stock E88 if you're still with me). But even with a header, 2 1/2" exhaust, I wan't making any power at higher revs. The "new" head solved that.

Keep in mind there are two versions of the E88. The later ones from 73 have a larger combusition chamber and hence a lower CR. They're not bad, but not necessarily desirable either. So I have to ask why you want to switch your N42 head to an E88? While there's nothing wrong with an E88, the N42 has larger valves and about the same combusition chamber size as the better of the E88s. If you're planning to rebuld a head and add a cam, I'd suggest you keep your N42 and use the money you were going to spend replacing it towards that project. BTW, I just put an N42 head on my L28 dished pistons with a mild cam. Much improved high end power and almost no loss of low RPM torque. I replaced a stock E31, FWIW.

He told me he had the rockers resurfaced, but I don't know if they kept the lash pads matched. But given the new cam has a different profile, I suspect the swept area on the rocker is not centered anymore, and this is what is causing the noise. I probably have to deal with this eventually, but I'd rather do it when convenient as long as I don't cause other problems.

http://www.classiczcars.com/forums/showthread.php?t=6748&page=1&pp=15&highlight=valve+clearance I just installed an N42 head with a mild cam (.441 lift and 260 degree duration). The person I bought it from said he had a machine shop go through it, resurfaced the rocker arms, etc. He ran it for 2k miles and decided he would go with one of his other heads. He warned me the valves were noisy, and they are. They sound almost like a diesel truck idling. I've adjusted the valves hot and that's not going to resolve this. The thread above suggests that the lash pads are not the correct thickness for this new cam and the valves are not being closed properly. I will say it pulls really strong to 6k now, and overall I'm very happy with the performance. FWIW, I also noticed the exhaust sound at idle is now somewhat flat, compared to the nice deep sound with my stock cam. I really don't want to tear it apart again, and I'm not sure I have the accurate tools to measure as required to get the size of the new lash pads. So my question is if I am going to do damage driving this as it is, and just ignore the noise?

On the door switches, if I remember correctly, you can pull the switch out, open it up, and clean the contacts. A simple but not necessarily long-term fix, is to rotate the shaft so that the contacts come together in a different way. For me on my 73, that was enough on one door to make them work nearly every time. For the spark plug loom, check either MSA or VB. Can't remember which one I bought from, but it was cheaper than most of the ebay solutions. Just add it to an order of other stuff so you don't get killed on shipping.

You didn't say this, but I will assume that this has been going on for some time and that you can still start and drive your Z without the battery going dead. This would suggest that your alternator is able to supply just enough current to run things during the day, but can't keep up when any additional load, such as lights or fan, are added. Given you have already replaced the VR and battery, I'd suggest you take the alternator to a local parts store such as Autozone where they can bench test it. They will be able to tell precisely how much current it can put out. Assuming it's only a few amps, you know the problem. If it passes with 50 or more amps, I'd be looking at the wiring around the alternator and VR to see if there is a problem between the two. Another thing to check if you didn't when you changed the battery is the condition of the connections to the battery. Excessive corrosion/oxidation can cause the VR to improperly read the voltage of the battery. Look for broken, rusted, cracked wires around there as well. Good luck.

I too bought the MSA 6:1 header and premium 2 1/2" pipe system and had problems getting things to fit. Got my independant local muffler guy to do the work and add a glass pack to knock the noise down a little - my neighborhood doesn't have much of a sense of humor. You should call Sal at MSA (x201 if I remember correctly) and work something out. I would have been happiest if it had all bolted up as advertised, but in the end Sal made it right.

Just spoke to Sal at MSA. Turns out their '74 260Z bars will fit on the '73 with factory mounted brackets, but the included hardware does not work with the factory brackets. We're going to improvise with poly bushings for the stock bar which I'll enlarge, and some used plates. Now I can't wait to get them on the car!

Thanks Beandip. For the bar you found at the yard, was it the stock one, or was it bigger? I ask becasue I want to go with a 1" in front and 7/8" in back to dial some understeer out. My understanding is that the stock 260 bar was smaller than 7/8" so that option might not work for me. I may take you up on the offer of the plates - still trying to get in touch with MSA to get this worked out.:tapemouth

I'm getting ready to do the same thing, escapedan, on my '73. In talking to MSA they tell me that if I want to use the existing factory brackets for the rear bar, I need one from a 280, not a 240. Given these things are heavy and shipping is slow and not cheap, I'm trying to pin down in advance what I really need. Which year rear bar did you put in? And just to be clear, here's a picture of the brackets on my car. Do they look like yours?

Vicky, I'll guess you're being kind with taking their word at gaining 2-5 HP. I'm guessing closer to zero. Which means the $$/HP ratio is infinite. Such a deal!

Hi all, this weekend I did the swap and all went well. The level of pedal effort to stop is a bit less now, and more importantly, it's much easier to modulate the brakes when stopping hard. I also noticed that the fronts will lock up much earlier than the rears (I suspect this was the case before, but I'm noticing it more now). Actually, I haven't been able to lock up the rears at all, or at least that I noticed. I realize this is better than the reverse, but my question is now that I have more front stopping power, is there some way to add some more bias to the rears? I know I could get an adjustable bias kit, but I'm hoping there might be a simpler solution. Has anyone whose done this caliper swap found a better answer?

Of course, you did give me what I needed anyway. Thanks.!

Thanks Ed, only now I feel stupid. I meant to ask about the nut. :stupid:

What is the size of the bolt that holds the front bumper guard (not bumper itself) to the bumper on a '73 240? The bolt on mine is MIA.

FWIW, I did something kind of like what halz asked. When I swapped my L24 for my L28 I kept the E31 head and round top carbs. I also added headers. When I first fired the engine up I hadn't changed any carb settings. Actually ran pretty well. You would have thought with the bigger bottom end and addition of a header it would run lean. But the L28 has dished pistons which lowered the CR. Also, my L24 rings were shot. In the end I am about 1/2 to 3/4 turns farther out. Also switched to SM needles .o1 smaller than stock given I live at altitude. Not sure what this teaches us though :stupid:

For anyone trying to upload pictures, often the image coming straight from the digital camera is too big - either in file size, or in the size of the picture itself. Microsoft has a great little utility from its Power Tools for XP called Image Resizer. It let's you right click on an image and select how much to shrink it. Very easy and fast to use. You can get it here: http://www.microsoft.com/windowsxp/downloads/powertoys/xppowertoys.mspx It only works if you're using Windows XP though.

Can anyone who has done the vented conversion give me some input?

Ed, I took the liberty (I hope you don't mind) of posting the two pictures. They look great, and I see what you mean about bending the lines. Thanks, and good luck getting them on the car!

Thanks Ed, that would be great. Please use daniel@nospambailin.org, and drop the "nospam" from the address. BTW, did you go the vented or solid rotor route? What do you think of it?

http://www.fonebooth.com/brakes_zcar.html

Just found a website with pictures (and for good measure I just pulled a front wheel) and now realize that the way the rotor attached to the hub won't change the positiong of the front wheel on the car. So please ignore my #1 question. But I'm looking for feedback on #2 and 3. Nothing like answering your own questions!

I know there has been a flurry of discussion about front brake conversions for early Z's but I have not seen a few details discussed. For example: 1. If you go with the 300ZX vented rotors and wider Toyota calipers, I know you need spacers for the hubs (~1/2" I understand). Does this mean the front wheels are now "pushed out" 1/2" wider? If so, what does that do to the steering geometry? Also, seems this would cause the lugs to have 1/2" less threads to hold which concerns me. Or did I miss something here? 2. Can the stock brake lines still be used? I've read that the answer is yes, but they have to be bent differently. I'm looking for feedback from someone who has done it already. Do you use a special bending tool? (I know you can use braided steel lines, but I'm trying to keep the cost down.) 3. If you go the vented rotor route, besides new calipers, rotors, and spacers, is there anything else that needs to be changed? I'm trying to decide which route to go. Since my rotors are nearly worn out already, I figure it won't cost more to buy vented rotors and calipers vs. solid. The only extra cost, at least as I think I understand it, is for the spacers (~$100). Am I right?

I think you hear the tapping when warm because as the metals expand with heat, you land up with a greater clearance between the cam and follower. If you're lucky you just need to adjust your valves, preferably hot. I have a similar issue with my E31 head. In my case no amount of adjusting gets rid of the tap at idle. Near as I can tell I must have a strange wear pattern or something like that on one of my lash pads so I just live with it. It's been like that for about 5k miles now. Of course, you can't hear it at full throttle, so maybe that's the solution? :classic: