JessZ

Well I spoke with Stephen today and his shop is running a little behind schedule. I will research the P-head more tonight and get back to you Jon; this does sound like an option I will condiser. Dan if I go with the N42, I drink Patron--and lots of it...

I bought my block and head from a guy who lives near Oakland, Ca. He has/had many turbo parts, including an exhaust manifold.

Well tomorrow I will just order up the flat tops and call it good. As for the head, I'll have the cam custom ground to the appropriate valve train. Jon I know you're all for running the full advance on the timing. I'll just add the octane booster and give the distributor a flip when I'm at the track kickin' some azz. I'm looking forward to posting some vids when the car's back together--don't hold your breath.

The LENGINE calculator seems to be crunching out reasonable numbers for what I'm thinking of doing (don't know how accurate it is taking into account the variables). This coupled with Dan Baldwin's post and my spinning head, I feel that I just need to commit. Jon's advice with the larger duration cam is going to happen, now it's the head work. ahhh I don't know. I just want fun and reliable; this is probably why I stuck with the stock L24 for so long. It seemed so easy about a year ago, now that the engines at the shop waiting I'm stumped; too many oppinions for me.

First, as Jon mentioned Norm, Stephen is not worried about replacing the seats; his problem with the head is that attaining that .035" qunch distance you mentioned will prove difficult with the flat tops. Stephen asked me why not use the dished pistons I have, as they are all in order. From what I've learned on this site, until this last post, and what I told Stephen, is that the flat tops are the way to go. Norm you also mentioned doing a .080" shave on the head and dished pistons, thanks for the advice, and thanks to all others who chimed in on the dished pistons option. Jon the web addy you gave up about the P-series heads was great, thanks again. One more thing here please. About shaving the N42 head and dished piston option, which shave is it the the head:.070", 080", or .090"? And about the head gasket: 1mm or 2mm?

This link shows a N42 head. Mine has these brass, or gold colored rings pressed into the intake port, and a silver one in the exhaust. Does this seem right?

I know it's a never ending debate, and I applogize for pressing. Stephen just made sense with his comments, and I started losing confidence with the N42. I guess we'll just see. Thanks again.

Okay Jon and others, I'm a bit confused. I took my block and head into Lesco (engine shop) and Stephen (the mechanic) said my head is not too good? I am doing the L28, N42 head, flat top piston set up, and from what I've learned here it is a great set up, proved a correct combo by Rebelo. The head is in great condition, this is not the problem, the deal is that Stephen said this head had a poor quench area and that the brass intake and exhaust valve seats may prove detrimental. When Stephen mentioned this about the valve seats I thought of the N47 head. I thought it was the N47, and not the N42 head, that had those emission valve seats. Stephen asked if I had another head, and I do, it's the early E88 head. I don't want to spend thousands on a head, in fact I prefer to just polish it up myself. As I've read the N42 is a great choice for a street perfomer and needs nothing more than a polish, if anything. I need to get back to Stephen to let him know what's up. At first I felt like I knew what I was doing, now, again, I'm not sure.

I am in a similar situation as you. I'm doing an L28 setup and the engine shop wants me to bring in the flywheel and clutch assembly so they can balance it to the internals. I thought this was the way it's done, but after reading this thread I'm not so sure now. However, the shop I'm using, Lesco, is very reputable. Jon Mortonson from Hybridz had his L series done there I think, so I guess I will just trust them. According to Lesco having the flywheel and clutch assembly balanced to internals just allows the engine to spin that much more freely, but it also seems I would not have to hard press my Lesco guy to leave that part out if I just wanted to save some money. Just go for it, I bet you'll be stoked either way. And this forum is so technical it's easy to keep second guessing youself that you'll spin out of balance ---Hope this helps.

DAW commented that one could "Take the N42 dished pistons off their rods, have the rim of the piston dish turned down until it is just in the same plane as the floor of the dish. Install milled pistons onto L24 rods (in the process, match up the weights of piston/rod assys and match rotating masses onto common crank throws)." I am curious if this is a proven technique that works. Jon has talked me into using my L24 rods for my L28 build, but if I can save $600 by using my old dished pistons rather than buying new forged flat tops that would be great.

Saweeeeeeeeet!

A few people recommended that I use L24 rods and Arizona Z flat tops (.040 overbore) with my N42/N42 setup. The Z calculator said this would yield a compression too high for daily driving: 14.06:1. If this is the case then I should just stick with the L28 rods, right?

By the way, the block is the N42, not the F54. Not sure if this makes a difference with the piston application.

Zeiss 150 brings up a good point. I have a '71 L24, those are the 8mm bolts are they not? Can I simply change the bolts, and how big of a deal is it that if I do run the L24 rods with the 8mm vs the 9mm bolts going to make? And, Jon, in terms of running the L24 rods, what kind of performance up grade is this? I know Arizona Z sells the rods too, but for the set it like $350.

I just picked up my F54 block and N42 head this weekend. They are beautiful. I am so excited to get this rolling and will take pics and keep everyone updated. My next step here is to buy some new flat tops. Does anyone know where I can get these? I want to use the L28 rods, so I think Arizona Z is out of the picture. Thanks everyone I have learned so much.

I just picked up my F54 block and N42 head this weekend. They are beautiful. I am so excited to get this rolling and will take pics and keep everyone updated. My next step here is to buy some new flat tops. Does anyone know where I can get these? I want to use the L28 rods, so I think Arizona Z is out of the picture. Thanks everyone I have learned so much.

Good enough Jon, thanks again.

I am on the verge of doing this, but I am hesitant to commit. Jon, or any others, will this cam/head work with a flat tops .020 over and worked SU's for day to day street driving on Ca. gas? I have been leaning towards turbo because of the pinging scare I have developed learing about the na motors. But I still love the idea of a lopey sounding Z. BTW the head and cam cost $500. My build is coming soon, I will supply pics as I build, if I can make a intellgente choice. Thanks again everybody...Jesse

I PM'ed you with some questions and comments.

so I learned that I can't have the N47 head ported. the N42 head seems like the best bet here?

Jon sorry for the "Jim." I value your advice, so thanks again. I guess I'll go for it then. The N47, which actually comes with the N42 block, but adding the flat tops won't be a problem, right? And Daw you mentioned, "I think I'll be better off with the .460" 270/280 cam I'm putting in." Is this combo going to yield a solid street motor?

are you getting a good enough ground to crank the motor?

Are the battery terminals clean?

I've seen Jim claim that the MN47 head yields too much compression for a California pump gas flat top L28. Is the MN47 head the same head that came on the N42 280z block? By using the Lengine caluclator the N47 flat top L28 yields a 10.08:1 ratio, which from what I've gather will make a fine daily driver motor. Is this a mistake for me to grab the flat top block and put this N47 head (that came off a N42 block) together? Should I just hold out for the N42 head? I see people disagreeing about what head is the "right" head for a 10:1 L28 daily driver, but agreeing that both heads flow very well. Am I confused that the MN47 and the N47 head are the same head? It seems that once I think I have a good combo in mind, I read more and just get more confused. Is my '71 series II E88 head a good choice for a daily driver on a L28 flat top? Thanks guys...

http://www.craigslist.org/eby/car/137775940.html oh, man if I had 12G!