Davey G

So, how is it doing now? How many miles on it?

UPDATE The car runs great, but I've had issues with rocker wear. The mechanic, who knows these engines, remains committed to finding the remedy. The cam is fine, the oil delivery is stellar with good pressure from idle on up. The head and bottom end are great. The only problem is the rocker wear, on new OEM rockers. Anyone else have a similar problem?

Well, I owe you all an update. I'm toward the end of break-in. Lot's of time was spent getting the inside fender/firewall welded up correctly and I also had some problems with the cam (not my fault or cost), so another had to be reground, along with lash pads. I end up with 10.3:1 compression (no detonation detected on 93 octane) with stock EFI so far, Stage 2 cam w/triple ground valves and Isky springs, 6-3-2 header, 2.5" exhaust. Man does she run now! It was already lowered with Eibach progressive springs and KYB struts, and has Brembo rotors/Toyota calipers w/ceramic pads. Interior is done stock except steering wheel and stereo. I did replace the headlight long ago, but now the other has a rock ding. Next will be some sheet metal work done on the floorpans, though it's been fiberglassed and is dry for the time being. Front airdam and rear spoiler needed. And I've got to get rid of those bumpers!

Still be careful on the lash pads. Do a wipe pattern on each rocker. Mine needed custom matched lash pads per rocker. Most because the new valve seats for the N42 head were not T-totally perfect in depth, so we corrected on the lash pad end of things.

Yes, even torque, though I did not expect that with the cam. But the minor porting matching the gasket voids and the 6-3-2 headers evidently helped that. The cam seems matched well to the build. Mr. Elgin of Elgin Cams did the regrind based upon the other specs we provided him. It's no race cam, but I like the differences compared to stock. Even from low rpm the engine pulls better, rolling on the power with more grunt. And if kept in higher rpms it comes on much quicker. Seems like a good combination for a street mod engine. I still have the 3:54 rear end, so at 70 mph I'm only running at 2500 rpm in 5th. A 3:70 or 3:90 rear end is in the future, but will have to wait for now.

Funny...and thanks!

I've run it up to 4500 rpm with no issues. I've got 700 mi to go before I consider it completely broken-in. From what I felt at 4500 I suspect I'll need to advance the timing to be good to 6000, but that may bring the detonation into the picture - only a prediction so far. It's been great in daily driving, but then I won't see much 6000 rpm in Houston traffic. Before the rebuild I had already redone all bushings and lowered the car with Eibach progressively wound springs, KYBs, and bump steer spacers. Sways bars are stock. It also got 15" 0 offset Koenig Rewinds with Yokohama YK580 on it. While not a race tire, these things really stick in daily driving, wet or dry. They give up some in hard race-oriented cornering to the track bred tires, but then I haven't had it on a track yet. Ride, traction, and noise are much better than the Michelin Exaltas. It is all coming together to my liking, making it one nice running, driving S30, just in time for fall driving. I'll let you know how higher rpm running goes.

I'll definitely let you know. Up to 3800 rpm it is great. I'll start playing with 4500 rpm in a few days.

I've rebuilt my engine for my daily driver '78 280Z after a lot of input from many, and lots of reading here. I decided on a N42 head (ports are gasket matched) on a N42 block with '75 intake and K&N induction, flattop pistons, .485/.270 reground OEM cam with Isky springs, triple grind valves and new Nissan rockers, Pacesetter 6-3-2 ceramic coated header, into a 2.5" MSA exhaust, all on stock EFI. The bottom end was refreshed with a polished crank and new crank bearings. It got a new oil sending unit, new timing chain kit, and new water pump. I've had the car back from the shop for 2 days and am pleased. I'm still 250 miles away from having it broken in - nothing over 3800 rpm, but it's running really well and no detectable detonation with 93 octane. After the break-in I'll change the oil and run up the rpms. I took the opportunity while the engine was out to repaint the engine bay, so everything came out. Good thing I did cuz I found a rusted/busted weld at the joint where the right inner fender and firewall come together, i.e. behind the battery. Had to weld in some metal from a donor, but it's strong now. I also had some key parts powdercoated at the same time - crossmember, engine mount metal, oil pan, intake, fuel rail, heat shield, timing cover, and of course the valve cover. I added a front strut tower brace and was surprized at the difference that made, so I'll add the rear one later. There are a few aesthetic changes to be done, but I'm almost there.

Engine is in the engine bay. I'm waiting on a distributor vacuum advance to arrive. I want to start the car with it installed before any tuning happens. Soon...

Yes, I've lowered mine 1.5" with spacers so as to not mess up the bump steer. I viewed the engine today with intake and header temporarily installed. The custom grind cam came back at .485/.270; should be good with the higher compression from the flattops with the header. I will powdercoat a few parts like the engine mounts and timing cover plate, etc. this week, so when they are back in a few days we'll be ready to put the engine into the car. May be starting the engine next week.

For now, but we'll see how she'll run. Maybe 2 weeks out.

Long time coming, but an update is in order. I upgraded the calipers to 4-piston. I also lowered the car by 1.5", and put 15" Koenig Rewinds on it. I've rebuilt (but not installed) the engine with flattop pistons using a N42 head that has had light gasket matching porting done. Also upgraded the cam (comes in today) to a .480 lift/.270 duration, of course with new rocker arms, lash pads and springs. Polished crank with new bearings. New timing chain and tensioner. New oil pump and water pump. It'll get the ceramic coated Pacesetter 3-2 headers and a 2.5" exhaust with high-flow muffler. I also sourced an N42 intake with the open runners so one can see the headers underneath. While the engine was out we removed all engine bay parts, did some welding under the battery tray, and painted black. New motor mounts. Crossmember, valve cover, fuel rail, and oil pan powder-coated. Front bumper comes off too. All comes together in next 2 - 3 weeks. Can't wait.

What octane rating are you running? 91? I'm having something similar built, but will be using 93 octane here in Texas, and won't need to pass smog. My requirement is that it run on pump gas w/o majorly retarding the timing. Anxious.

I'm in the Heights and drive a '78-280Z as my daily driver. I'm also a member of the Z Club of Houston. Let us know if we can help.

Got it running?

I've been driving my '78 280Z for about 1 1/2 years now during which time I have redone suspension, interior, a/c, sound, etc. There are some other cosmetics to go like an air dam and a new front bumper, but the thing has been running good. The key got stuck in the ignition, and while in to get that repaired I was informed I have a freeze plug starting to leak. I've always had a little smoke also, but it has increased as of late. So it looks like I have a rebuild soon (any other opinion?). All along I have planned to build more HP into it when I did the rebuild, but it is my daily driver, so I want it completely manageable, like stock flywheel, etc. So, with that said, if I want a good revving L28 with say 50 HP more than stock, what do I specify with the rebuilder?

Yes, I believe I have too steep of a rear end. 60 IS a stretch for 5th gear, and I try to not shift to 5th until 65+. When accelerating on the on-ramp I wind 3rd out to 65-70. I can tell the car likes those rpms, at least with the rear end I currently have. If traffic is cruising at 55-60 I am in 4th. MPH does not suffer from this type driving...it helps it. Sounds like better next steps would be a 3.90 - 4.11 rear end, lighter flywheel, and see where that takes me, and make decisions from there. I've learned a lot about the car in the year I've owned it. I am not concerned to keep the car stock like some over on classiczcars.com are; that's why I'm asking "next level" questions here at hybridz.org. I appreciate all the help from those who have owned theirs for much longer - thanks guys!

Tony D I agree, and have been doing that type tuning for a year now. Even the "Z specialist" mechanic says it's one of the best running stock 280s he's seen in a while, though we have not dyno'ed it. We've tweeked the timing, the AFM, etc. I have the stock cast iron manifold, the original downpipe, going into a stock sized (1.75" ?) newer pipe with only the stock resonator/glasspack, no muffler. Davey G

The 19 year old previous owner put the 5-speed in, saying it was from a 280ZX. I don't know how to verify that other than let my mechanic look at it. It's been a good transmission.

Wow! Seriously, Wow!

I knew I was asking the right guys. Sounds like I'm kidding myself to expect much with just bolt-ons only, though they would be well utilized with the other engine mods. The car will stay my daily-driver for the foreseeable future, but driving it daily with 200-225 HP would be more fun! So I'll plan on the engine mods come rebuild time. I'm sure I'll have some questions for you at that time. Thanks for the help and perspective. Davey G

Sorry, I should have qualified my question with "...and keep it NA."

The car was originally a 4-speed, but we dropped a 5-speed tranny in it during the refurb. What rear end came in a '78 with 4-speed tranny?

Yep, read the whole thread already. Braap is the man for engine builds! It was actually as a result of reading his EFI thread and Massive Headwork threads that led me to formulate my question - Without changing cams, EMS, pistons, valves, head gaskets, injectors, intakes, fuel rails, etc., what can I expect to get from K&N on the intake end and header/exhaust mods on the other end as far as additional HP? Maybe nothing, because the intake is restricted in the first place, the AFM measures flow and not mass and humidity coupled with a very limited EMS, and restricted by the smallish valves and without valve curtain relief work, porting, matched pistons to optimize squish on the peanut chamber, etc?