Xnke

They can't straighten it? I have straightened a few of them, got them to under 5 thousanths warp before cutting. It is detailed in How To Modify Your Nissan/Datsun OHC, but i think it's in the How to Rebuild as well. Definately don't settle for a warped head, it'll only cause you grief. Have them CC the chambers, cutting 30 thousanths off my unshrouded N42 dropped the chamber from 46cc to 42cc.

Hey, if i'm wrong i'm wrong, But I did truly think that it was you who had said that Tony. Either way, without a damper or flywheel mounted, the harmonics are at those points mentioned. Tony is correct, the point has been made that the pistons are the limiting factor for speed and power in a stock bottom end, anyway.

Seriously, chill out guys. The japanese use japan-made cams because they are in JAPAN. We normally use US-made cams because we are in the US. That's all there is to it. No, there is no magic. BRE made advances in these engines by trial and error and HUGE budgets. Kameari made advances in these engines by trial and error and HUGE budgets. Sunbelt made advances in these engines by trial and error and HUGE budgets. Wako made the same advances, with similar budgets. We have looked at a LOT of eye candy in this thread. It makes power. It has shown some of us what a "Japan" style port job looks like. It shows us what a "Japan" style engine block looks like. Again NO MAGIC. There are two different methods to producing high-power engines, it appears. "Massive Ports, Radical Cams, And Ridiculous RPMS" seems to be the method they prefer in japan, they are not looking for wide power bands and streetable power, they are looking for power in ridiculous excess and that's exactly what they get. The other method is Building for Torque, Not RPMs. This happens a LOT more in the US, because MANY of these cars are set up for pump gas, driven on streets with traffic, and tend to "conform" to the V-8 way of thinking. You get your low-end and mid-range torque, and you get your low-end and mid-range power. Shooting for middle ground always ends up missing to the low side.

That's pretty cool Tony, but it was YOU who initially informed me about the crank breakages happening due to harmonics that were believed to be in that region, prompting the tests when I had access to dynamic balance and torsinal deflection measuring equipment capable of balancing objects to 20,000RPM, and showing twists on the order of fractional millimeters end-to-end The data showed the big harmonic peaks at those aforementioned points, and again in the 12,000RPM region. it also showed just how damn flexible these cranks are! I don't recall exact numbers right now, but the amount of twist end-to-end was visually apparent with the strobe. That, and folks who were reportedly cutting ~6mm off the tail of the crank, and running 10-12lb flywheel+clutch assemblies in order to reliably run 9-10K RPM in the Japan scene to avoid breakage on/near the #6 rod journal Maybe I'm just paranoid.

7000RPM is a pretty good redline for the stock-internaled L motors, any higher with a non-prepped crank and you will risk crank breakage. There are some tricks you can use to go higher, but at all costs don't let it hang between 7200 and 7500, if you are gonna run through that range get through it as fast as possible. There are two wicked harmonic peaks right there, on the L24 and L28 cranks. The stock cast pistons are pretty decent, and will hold up to 7000RPM without too many problems. Good quality lightened cast pistons, in an N/A engine that sees realistic piston speeds, will hold up fine with a good tune. Do the math and you will know if you've got realistic piston speeds, and check with your manufacturer to find out what is recommended for your components.

Make sure you keep the rockers with the mating cam lobe, otherwise you will get a little wear, if not more than a little wear. For a given cam, as long as the cam doesn't change, the rockers don't change, then keep the rockers paired with their respective cam lobes and you shouldn't have a bit of trouble. PS, you only get jumped on when the cost of doing it right is not that much more than doing it cheap...I know, I used to take the cheaper route every time till i realized that it wasn't actually cheaper in the end.

The injector position doesn't make that much difference. Look at the GM TBI manifolds, the injectors are all in front of the throttle plates. Millions of engines out there and they all ran fine. Yes, there are more ideal solutions. No, it probably isn't that big a deal under 300-400HP.

I am thinking that the L24E Maxima motor has a 17lb flywheel, as opposed to the 24lb flywheel that was on my L24. Either that, or that maxima L24E had a lightened flywheel on it, as I pulled it from the junkyard.

If you have to ask if your tools and experiance are good enough, I'd take it to a shop. I have done lots of valve guides, did mine in the head I'm running now. But I also broke a bunch of them learning how to do it, and it's not fun to remove them once you've broken them down inside the hole. Before I was comfortable doing the job, I probably did three practice heads worth of them. Once you get the new one pressed into place, you have to ream/hone the inner diameter to meet specs, 95% of the time, in my experience. You will need a valve guide removal mandrel, and an air hammer. Make absolutely certain you scrub the head and valve guide really really good, and you need to strip the entire head and heat it in an oven or with a torch very evenly, so as not to warp it. SCRUB the junk off the port side of the guide, anything left on the guide will score the bore that the new guide will seat in. Slip the mandrel into the guide, and carefully let the air hammer knock it out, being sure to not put any side loading on the guide or it WILL break off. Then you're **** out of luck, half the time, and have to take it to the machine shop anyway if you don't have another mandrel specially suited to remove the broken guide. Installation is done the same way, with the air hammer and practice, and then you ream/hone the guide to size.

2500$ is not really that much money to spend on the car, if you have any rust at all. read up on the rust problems, check the car thoroughly and then decide. for 2500$, I'd go with the SBC V8 swap. It is a lot of work, and you won't be able to afford to pay someone else to do it. 2500$ will disappear pretty fast in labor costs.

Guess you didn't search for the oft-mentioned EFI bible. That, and the problem is very likely corroded or loose connectors, probably at the ECU. They are notorious.

Drain the tank, put in fresh gas. If it's sat for years, the gas is no good. if it's sat for a year, the gas isn't any good, at least in my area.

So it's an L20A, non turbocharged, from '77. I'm thinking that the injectors are 160cc units, but don't quote me on that. TonyD or Alan would know, I'm sure. Also, hoov100, the L20 =/= L20A =/= L20B. L20/L20A are L6, L20B is L4, and the L20B came fuel injected in some markets, in the HA510.

You don't need to do the leaded/unleaded conversion. You have a P90 head, it already has steel seats. You don't need to do anything to the engine, as long as it ran fine when you left it. Drain the oil, change the filter, change the oil. Pull the spark plugs, and put about a teaspoon of oil in each cylinder, let sit 20 minutes, then put the car in first gear, and rock it a bit if the engine is stuck. If engine moves freely, put in neutral and give the starter a chance to spin it up with no plugs, listen for bad noises. Do a compression check, run down to the local autoparts place and see if you can rent/borrow/buy a compression tester. For a P90/F54 block, assuming the P90 came factory assembled to the F54 block, You already have a turbo engine, and thus should see 120-160PSI compression, roughly. You're not looking for an absolute number so much as that the cylinders are within 10% of each other. Put in new plugs, fill the float bowls of the carbs with fresh gas, and crank'er over. A year is not too bad to leave one of these engine sitting, as long as the throttle plates were closed and the exhaust was on the car. No need to get the engine rebuilt if all that was wrong was that it was simply setting for a year. If you can't get it to fire over, check for spark, then check to see if your timing is correct. The SU's usually don't have too many problems unless they are just worn out.

that graph is not right...The Torque and horsepower curves have to cross at 5250RPM, due to the way horsepower is calculated. I think your dyno operator screwed up, or the machine is not setup correctly, or some other major error. Barring that, you're right, it's a weird curve, for sure.

Strip the L16 down to a longblock, and two guys can easily lift the engine in and out of the car. Wouldn't want to do it all day long, but it's not that heavy.

Found out the cam was ground with the wrong index, so installed as it is it is 2* retarded to start, then i was off a tooth for another 9*...11* retarded total. Got another compression tester and checked compression again, it was 130lbs, before moving the cam. Old compression tester has been marked and thrown out...inaccurate readings. Advanced the cam the 9* from the slipped tooth, checked compression again, 155lbs. Nice increase! Advanced the cam to the #2 position, compression jumped up again to 177lbs per cylinder. Now we're cookin! And it now doesn't take 22* of timing advance to get it to crank over and run!

Ok, so I have had my engine together for a while, run it for about an hour total, and have put two miles of running on the clock. I have followed the break in I've always used, namely, accelerate to about 50mph, then let off the gas and let engine braking slow the car 4 or 5 times, thus, using the engine vacuum to pull the rings against the cylinder walls. It's always worked well for me, in the past. However, I believe I may have installed my cam wrong, I think that the cam timing is retarded too much. The engine runs fine, however cranking advance is 20*BTDC, less than 18* and it will pop out the carbs every time. The cranking compression is only 90PSI. Every cylinder is exactly the same, but this engine was built with a 9.5:1 compression ratio. I should see something along the lines of 180PSI. My cam is a Delta Camshaft regrind, and when I installed the cam I installed it with a new timing set, and set the dowel and chain up for the #1 sprocket position. Everything seems to point to a retarded cam timing: the large amount of advance needed, the low cranking pressure, and the fact that the engine doesn't really wake up till about 4500RPM. Am I on the right track here, or barkin up the wrong tree?

You should probably call them up and ask them for info on the part number. That seems like it was a 300F lobe profile; but may have different lobe centers or something, thus, the different part number.

Schneider Cam; Grind 300F Part Number: 17038 Grind Number: 300F Intake Duration (gross): 300 Exhaust Duration (gross): 300 Intake Duration (.050â€): 256 Exhaust Duration (.050â€): 256 Intake Valve Lift*: .560" Exhaust Valve Lift*: .560" Lobe Separation: 106 Intake Valve Lash: .010" Exhaust Valve Lash: .012" RPM Range: 4000-8250

All of them. If you're paying a shop to do it, it'll cost like 40$ more, because most of the work is in the disassembly and reassembly. If you are doing it yourself, you might as well do them all because like i said, the work is in the disassembly and reassembly.

that is the PCV tube, and you shouldn't really be able to pull that out of the block. It connects to the PCV valve in the intake manifold, as the last poster suggested.

I'm currently looking at the same thing, but I still need the rotary motion of the SU throttle set-up. Even with my SU's, the part throttle modulation is touchy, and with the twin 50mm TB's its gonna be even more so.

Your spark issue is caused by not understanding how the EDIS system works. You only need one EDIS module. You only need one EDIS coil pack. The practical rev-limit on the EDIS-6 module is 8,400RPM. There isn't really a confirmed rev-limit, because there are some modules that have been run up to 12,000RPM with no issues, and some quit above 8400RPM.