turbogrill Posted September 13, 2016 Share Posted September 13, 2016 (edited) Hi, I am planning to build a race car engine for my 280zx endurance Chumpcar racer. It's all amateur hobby racing and nothing professional, still it would suck very much if it breaks during a race. I am doing this 50% for power and 50% for reliability. I am a beginner hobby mechanic. I got all the OHC Nissan books My goals: - 100% for 10hours without blowing up several times a year. - Usable range 3500 - 7000 RPM (To keep cost down and keep some reliability) - 200HP crank (but 250 would be fantastic) Engine will consist of the following: - Megasquirt fuel only (can't do timing due to race regulations) - Race camshaft (Schneider 284-92F is a good candidate, 284/292 (236/244 @ 0.05"). 488/.504 lift) - MSA Headers - F54 block - N47 head (worth spending $650 for a Lonewolf porting?) - Some exhaust (2"?) I have a F54 block that comes with pistons but no head. This is what I plan to do: 1. Replace piston rings 2. Replace main and rod bearings 3. Replace all gaskets 4. New waterpump 5. New oilpump 6. New cam springs 7. New rocker arms 8. Should I get new pistons (block comes with pistons)? 9. Should I get a new Timing kit? Is there anything I should add to my todo list? Does the cam make sense? Is there something that is specially hard that I should leave to a professional? First time I ever mess with engine internals. I am not super tight on budget but forged pistons is way out of my budget. Many thanks Edited September 13, 2016 by turbogrill Quote Link to comment Share on other sites More sharing options...
JMortensen Posted September 13, 2016 Share Posted September 13, 2016 You don't need forged pistons for the kind of rpms you're planning on. If they aren't damaged, I'd reuse the stock pistons. Spend the money on a valve job. Loose bottom end + tight top end = hp. You might want to do a reground cam vs Schneider. I really like their springs, but their cams seem to have a habit of losing a lobe. Might be due to new oil formulations, but the other possibility is the cams are too soft, in which case a reground stock cam is a good option. Quote Link to comment Share on other sites More sharing options...
HuD 91gt Posted September 13, 2016 Share Posted September 13, 2016 (edited) You won't reach your hp goals without the port job. Edit: Didn't realize he was aiming for 200 at the crank. RTFQ Edited September 14, 2016 by HuD 91gt Quote Link to comment Share on other sites More sharing options...
JMortensen Posted September 13, 2016 Share Posted September 13, 2016 200 crank hp? I think that's a reasonable goal without porting. Quote Link to comment Share on other sites More sharing options...
Andreas Posted September 14, 2016 Share Posted September 14, 2016 200 crank hp will not be a problem to reach. I have just dynoed my new engine and its not perfectly tuned. It made 180 whp, dont know what crank hp that is but i guess around 220. N42 +1mm block with flattops and a E88 head with no port job. Tripple 45 Msa stage 3 cam Quote Link to comment Share on other sites More sharing options...
turbogrill Posted September 14, 2016 Author Share Posted September 14, 2016 200 crank hp will not be a problem to reach. I have just dynoed my new engine and its not perfectly tuned. It made 180 whp, dont know what crank hp that is but i guess around 220. N42 +1mm block with flattops and a E88 head with no port job. Tripple 45 Msa stage 3 cam Nice build. Care to share the curve? Curious to she how the power is delivered. Quote Link to comment Share on other sites More sharing options...
Andreas Posted September 14, 2016 Share Posted September 14, 2016 (edited) Here you go: Edited September 14, 2016 by Andreas Quote Link to comment Share on other sites More sharing options...
turbogrill Posted September 14, 2016 Author Share Posted September 14, 2016 That has to make some heads turn in Sweden! (What does the local P1800 fanatics say?) I assume the all that salt vägvärket pours must eat the poor Z cars. Our 1980 280zx is rusty as it is, and it's in Texas! Quote Link to comment Share on other sites More sharing options...
Andreas Posted September 14, 2016 Share Posted September 14, 2016 Yes, They are rare cars here. Of the 25ish cars that sold new here in 1973 (only year here) there arent many left. As you say, they like salt on the roads here in Sweden(are you familiar to sweden?) Quote Link to comment Share on other sites More sharing options...
clarkspeed Posted September 14, 2016 Share Posted September 14, 2016 Easy peasy. Do you need to run on pump gas? You can do a lot better with some serious compression and different head. Otherwise the N47 is fine for pump gas. Build engine like the book and verify every single tolerance. Stock flat top pistons are fine. Shoot for a little over 10:1 compression. The higher you go, the more octane boost you will need to keep the N47 from pinging on 93. Pocket port clean up the head so there is a smooth blend into the valve seat. Good valve job. Balance out the rockers/lash pads. Use the most open intake/throttle body set up you can afford and port match manifold to gasket to head. Run 2.5 or 3 open exhaust with a good header. If 2.5 use mandrel bends, if 3 muffler shop bends are fine. Personally I would go with a milder cam to keep from moving the power band up and try to keep the rev limit around 6500-6700. Quote Link to comment Share on other sites More sharing options...
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