Davey G Posted October 3, 2013 Share Posted October 3, 2013 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. Quote Link to comment Share on other sites More sharing options...
madkaw Posted October 3, 2013 Share Posted October 3, 2013 So no mods to the stock FI? When you get into the power it might get interesting. Quote Link to comment Share on other sites More sharing options...
78zstyle Posted October 4, 2013 Share Posted October 4, 2013 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. . Interested to see how this works out.. Quote Link to comment Share on other sites More sharing options...
s14kouki10 Posted October 4, 2013 Share Posted October 4, 2013 Nice, I'll keep an eye on this. My setup is the same except I have a different cam. Hope it works out Quote Link to comment Share on other sites More sharing options...
Davey G Posted October 4, 2013 Author Share Posted October 4, 2013 (edited) I'll definitely let you know. Up to 3800 rpm it is great. I'll start playing with 4500 rpm in a few days. Edited October 4, 2013 by Davey G Quote Link to comment Share on other sites More sharing options...
Davey G Posted October 18, 2013 Author Share Posted October 18, 2013 (edited) 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. Edited October 18, 2013 by Davey G Quote Link to comment Share on other sites More sharing options...
Domzs Posted October 18, 2013 Share Posted October 18, 2013 Where are your caps for brake master ? It's not a good idea to have brake fluid sitting out in the open , moisture is bad . . Good looking engine . Quote Link to comment Share on other sites More sharing options...
s14kouki10 Posted October 18, 2013 Share Posted October 18, 2013 Nice, is there a noticeable difference in horsepower gain from before and after the rebuild? Quote Link to comment Share on other sites More sharing options...
Davey G Posted October 18, 2013 Author Share Posted October 18, 2013 Where are your caps for brake master ? It's not a good idea to have brake fluid sitting out in the open , moisture is bad . . Good looking engine . Funny...and thanks! Quote Link to comment Share on other sites More sharing options...
Davey G Posted October 18, 2013 Author Share Posted October 18, 2013 (edited) Nice, is there a noticeable difference in horsepower gain from before and after the rebuild? 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. Edited October 18, 2013 by Davey G Quote Link to comment Share on other sites More sharing options...
Davey G Posted March 10, 2015 Author Share Posted March 10, 2015 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? Quote Link to comment Share on other sites More sharing options...
madkaw Posted March 10, 2015 Share Posted March 10, 2015 Lots of issues reported here-what's your issue.? Quote Link to comment Share on other sites More sharing options...
NewZed Posted March 10, 2015 Share Posted March 10, 2015 It's been a year and 4 months. Most say that new OEM rocker arms don't exist anymore, unless you found some old stock. Many people report ruined cams also, so your finding that only the rocker arms are bad is odd. You haven't really described the problem either, just "rocker arm wear". Need details. Is it visible, or is it supposed from valve lash change? How is your mechanic going to "find" a remedy? Different arms, different oil? Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.