Leon

Nope. That number is likely over 30,000 as the E31 stayed atop L24s until mid-71. You have an L24-swapped 260Z, life goes on. One of my 260Zs came with an L24 as well, my guess of why it happens is because it's a cheap swap and people usually don't care about what kind of modifications they do when it comes to the 260Z...

FWIW, SIX of the 12 rockers I sent to Delta were not ground parallel. The rockers were done within the last 2 months.

Thanks Takashi! I'm looking forward to seeing your Z on the road!

Well, Monday turned into a throw-away day as far as car work goes. Just had too much stuff going on. As for today, I suppose I've underestimated what it takes to put a car together! We're close but no fire yet. It's gotta happen Wednesday or Thursday, because otherwise it's not happening until mid-September when we get back from the honeymoon. The guys came by again today and were a huge help. Things definitely get done quicker when there are 3 people working on the car at once, instead of just me. Here's where we're at, it's just a bunch of little things that are slowing me down right now, but I have a list and will try to get through it all tomorrow.

Great job Takashi, good to see the update!

Oh sh*t.

The scene on Saturday morning, lone head and block... Mockup from Sunday morning: The crew getting ready for some perilous maneuvering: And... it's in! Big thanks to all the awesome people who helped out, especially Yoshi and Leo. We had some hairy moments but it was a fantastic conclusion to a long, sleep-deprived weekend. My goal is to have the engine running by the end of Monday, but I have a lot of stuff going on starting at 2pm so we'll see if that happens. Tuesday should be the latest for first crank. Fingers crossed...

This is about as far as I got today, and yes it's 3am here... I did way more gasket and fastener hunting than I would like, but it is what it is as far as getting an engine in pieces and trying to rebuild it. I've got a few things on my checklist for tomorrow morning, or rather later in the morning. Gotta grab some fasteners, a gasket, and plugs/wires/coil when the stores open. Goal is to have this in the car by the end of Sunday. Time to get a little sleep...

I'm finally doing final assembly, typing this during dinner/dessert break. The head is on but I screwed up indicator reading during head install so I couldn't get a good gasket crush number, unfortunately. I'm using a Nissan gasket on a block decked by .004"/0.1mm so I'm not super worried about clearance there. When I did the P/V clearance check, I remeasured piston-to-head clearance and it was about .027" as given by the not superbly accurate silly putty. I am using cast pistons as well so expansion should be same as stock. I can't count how many rockers I've removed today and how many valves I adjusted, over and over and over... You're telling me! I'd still be searching or waiting for lash pads right now if it weren't for them, not to mention that those poorly done rockers would've probably made very bad noises at the very least.

Way too small for a stroker, IMO. Hope you have access to high-octane fuel...

Looking forward to seeing a video of the new-and-improved Z in action!

Just did the clearance check, tore it back down, and then installed the Isky springs and cam for final assembly. I used the Silly Putty again for my valve-to-piston clearance and came up with approximately .080" for exhaust and (with .012" lash at valve) .100" for the intake (.010" lash at valve). Works for me.

Well I had a crazy last few days... Yesterday consisted of 3-4 hours of driving around various motorcycle, fabrication, and engine shops, and even the Nissan dealer trying to figure out my correct lash pad thickness. I had no luck and instead came home, removed a spring and retainer, and used a combination of a stock lash pad and feeler gauges to try and replicate a thicker lash pad. This was more trouble than it was worth and the results were inconclusive at best. I came out of it estimating the correct size to be .180". Today was a change of pace. I decided to give Rebello a call and explained my situation. Dave was nice to talk to and said they could help out, so I packed the head and various bits into the S2000 and set off to Rebello Racing. Luckily it's just over an hour away from my place. I bold the word "luckily" because I'm very lucky that these guys came through for me, in a big way. I came in, quickly ogled the L28 with triple Mikunis and Kameari header, and then proceeded to explain my situation to one of the engine guys, who already had an N42 on his workbench at the time. Soon, we had my P90 head on the workbench with a very well-versed L-series expert looking over it. Long story short, I needed .200" pads on the intake and .240" on the exhaust. However, there was another revelation and it involved the rocker arms. Delta did a great job, over 50% of them were good! All kidding aside, 5 of the 12 rocker arms were ground poorly, i.e. the cam surface was not parallel to the valve surface. Others have noticed this recently as well, in various threads. Had I known of this earlier, I would've never sent them to Delta. So as a note to others, DO NOT send your rockers to get reground at Delta. They will ruin perfectly good rocker arms. I ended up getting 6 prepped rockers from Rebello as well. I bet this saved me a lot of hearache (right, Jim? ). Plus, once we were done, we chowed down on some pizza. I really couldn't have asked for a better experience! Standing over the shoulder of an expert L-series builder while he played with my head (who's going to make the first joke?) was a delight. I'm taking a food break right now. I've got the head installed and the next step is to time the cam. Once that's done I'll check valve-to-piston clearance. If everything is good, I'll break it down and finally work on assembling the engine. Looks like having the engine in the car this weekend may still be a possibility.

Thanks! It's really a bit loud for my taste but you gotta have at least one loud car in your life, right?

I'm not going to dwell on P/H clearance too much, unless Braap or 1 fast z feel like retracting their claims. If it was safe from the factory, I assume it'll be safe with .004" taken off the block deck. Guess we'll find out, eh? Got the .263" lash pads that were supposed to be correct for my cam, but of course they are not. I'll be scrambling to determine correct lash pad thickness tomorrow, as I need shorter ones. My guess is .240" should be just right, but I'll probably just bite the bullet and cut up some feeler gauges to be sure. I'll also be looking for a local shop with a surface grinder but will probably have to resort to turning them on a lathe...

Jim, you're right that .022" is very tight. I should've said that I'm aiming for .022-.025", so .022" would be the minimum. I got the numbers from the guys that have built way more engines than I have: http://forums.hybridz.org/topic/58127-best-way-to-achieve-piston-to-head-clearance/ I'm anticipating being OK with the OEM gasket but I'll let you guys know how the numbers pan out. I definitely have confidence in getting the car to idle smoothly, THAT I do have experience in! I'm looking forward to JCCS, but first will be the wedding on the 31st and a trip to Hawaii afterwards...

It's relative motion, whether the sleeve moves or the bushing moves there's always going to be movement between the two. What you don't want is axial preload on the bushings, for reasons that were already mentioned.

I just hope it runs at all! Good point on the piston rocking, although I'd hope that the piston doesn't rock enough to make .010" worth of difference! Thanks for the tip on the copper gaskets. If I were proactive enough, I'd order one right now just in case. However, $125 for something that I might not use is a little hard to swallow. With that said, I'd probably opt for a .043" gasket as that would give me a very nice .022" piston-head clearance which is just about what I'm shooting for with the Nissan gasket. Are you guys using a copper gasket, Jim? Yes, I considered the elasticity of the putty as well, hence my thoughts of trusting the numbers from the dial indicator. Those should be dead-on. The putty will not be used for piston-head clearance checks.

Here's my reasoning: if stock deck height is .021-.025" above the block as Braap said and I run a Nissan gasket, why would this be a dangerous scenario? I would of course like to err on the side of caution so I guess we'll see what the numbers are.

I highly doubt that made sense to anyone... Again, read the exhaust sticky. This is a technical site so please leave the conjecture to yourself.

Making some progress... I banged in the core plugs, a much bigger pain-in-the-ass than I expected. Busted out some turbo head bolts that I got for Christmas or a birthday present years ago and did some clearance checking. I used an indicator and a bracket attached to the head to get some relative measurements regarding gasket compression and piston-to-head clearance. The head was torqued down with a previously compressed Felpro gasket that Jim sent me. The indicator was then zeroed and all bolts loosened. The number on the indicator then represented how much the gasket was compressed. The indicator showed .021". I measured the uncompressed gasket thickness as 1.5mm/.059", meaning compressed gasket thickness is .038" or .97mm. I also double-checked myself with the indicator by reinstalling the head but without the gasket. The indicator read .0385", so within .0005" of the calculated value. I then triple-checked that using clay aka Silly Putty. Before the head was torqued down with the Felpro gasket, I placed the clay in one of the cylinders. The engine was rotated once with the clay inside. I measured the clay by slicing it in two with a fine blade and using the depth gauge of my caliper. The readings I got were .7-.8mm, or .027-.031", which should directly represent the actual piston-to-head clearance. That's way off from my other measurements and calcs, which I trust more. I'll probably use the clay for piston-to-valve checks but I'll rely on the indicator for piston-to-head numbers. Using the .038" compressed gasket thickness, I get piston-to-head clearance of .017". Yes, that is pretty dang close but I'll be using a Nissan HG in the final iteration so I'm hoping for another .004-.008" from that. I will, however, use the indicator to measure compressed thickness upon final assembly to be sure. In other news, I got a few parts the other day. My order of Nissan head dowels, wire-netting (PCV vent), and radiator hoses came in. Here's the wire netting compared to some old stuff I harvested from one of my other blocks. Obviously it's new and clean but I also like how the wire is soldered to the netting instead of just being wrapped around it. I've got some lash pads on order, should've bought those a while ago. Progress is being made and if I don't have the engine in the car this coming weekend then I've screwed something up. As far as I can think of, the only thing that isn't figured out is the fuel routing in the engine bay and the exact plans on the exhaust.

That may just be the most awesome V8 swap ever...

Read up on how exhaust systems work before posting nonsense please: Exhaust Tube Sizing

Your "mechanic" is guessing... With all that said, do you prefer to spend $75-100 on a leak down test, or thousands on a rebuild, or hundreds on a used engine which will then require lots of TIME to pull the old one out and install the used one? That will cost a lot of money if you're not doing the pulling and installing yourself. DO THE VALVE LASH ADJUSTMENT FIRST! Then check compression again, and perform a leak-down test if compression isn't satisfactory. Gollum does well to point out that the oil burning could easily be caused by worn valve stem seals.

Like I said, do a valve lash check first, before doing ANYTHING else. Maladjusted valves can cause low compression. If it turns out to be a valve sealing issue (determined with a leak down test) then a head rebuild is in order. I have a receipt somewhere but from memory, my head rebuild was ~$250-300. However, this is only for parts and machine work as I'm putting the head together myself.