BRAAP

Hmmm… Factory ’77 Z cars came with the N-47 head which has a round EXHAUST port WITH liners. As far as I am aware of, Nissan did not offer a round EXHAUST port L-6 head without the liners on production cars. Either you are looking at the intake ports of an N-42 head, (square EXHAUST ports), you just didn’t see the liner, (previous owner could of removed the liners, but not likely), or you have a VERY rare and exotic L-series cylinder head that requires you immediately remove that cylinder head, carefully package it up and ship it directly me here at Rusch Motorsports for further LONG TERM inspection, testing, and evaluation… If the latter, let me know I’ll give you our shipping address…

Drax, If you set up many cams, you may as well just purchase a complete set of the available lash pads as it will expedite cam set up time. If you don’t want to purchase all of them, then for starters, I would get.150-.220 which should get you by for 90% of the street and mild to moderate race cam set ups you will run across. If you need to set up a cam that needs thicker than .220, you can always just snip pieces of .010”, .020” and .030” feeler gauges/shim stock and just stuff those pieces between the lash pad and valve stem itself. Feeler gauges are pretty cheap, under $5 for set of Craftsman, or keep a sharp eye at garage sales.

Yasin, Sorry, there is no PM from you in my inbox. Try E-mailing me… braapZ350@hotmail.com

Please don’t be sorry for your questions. That is what this forum is all about. Asking questions and sharing our experiences so that others may benefit and build upon our experiences. For the EDIS to work with Mega Squirt you will need all the parts in the bottom pic I posted. 1) Control module. 2) 36-1 trigger wheel to mounted on the crank. 3) VR sensor to read the 36-1 wheel. 4) and the coil pack. Once you have acquired and installed those items, I “think” the programming portion within Mega squirt might be easier for the EDIS than it is for the Dizzy configuration, though I have no “actual” experience using a Dizzy with Mega Squirt on an L-series, so this is just my guess at this point….

We get our lash pads directly from Nissan/Nissan Motorsports. We use only genuine Nissan L-series rockers as well. The rockers we supply with our cam kits are brand new “NISSAN” Rockers. There are some aftermarket NON Nissan rockers that should be avoided at all cost. Those NON Nissan rockers look similar to the Ford Pinto style rockers and are garbage. They will wipe out a cam in very short order. I have spent many an hour on the phone with Dave Rebello of Rebello racing engines, and both he and I are on the same page in regards to L-series cams and rockers. We both agree that used NISSAN L-series rockers are just fine with new cams even if they are from a different engine, as long as the rockers are in good shape, i.e. no divots or noticeable visual wear. This only applies to NISSAN rockers, not aftermarket rockers. We both have seen some reground Nissan rockers that we would never run our engines, so beware of some reground rockers. If you plan to reuse used rockers, just buff the wiping surface and the tip surface and you are good to go. Dave even uses used rockers on his full tilt GT race engines and claims ZERO cam/rocker failures! No matter anyone else’s opinion on this subject, the fact that Dave Rebello uses used rockers on his full tilt GT race engines with ZERO failures should be testimony enough! As long as the wiping pattern is checked and there is adequate oil supply to the rocker-cam interface and the rocker wiping surface is in “good” condition, AND the cam is a known good quality core, (typically new Nissan cores or reground NISSAN cores fall into this category, aftermarket cams are hit and miss in regards to durability), you will have no troubles even with big lift cams using really stiff valve springs. FWIW, with all of our cam kits that we sell, we include brand new Nissan Rockers. For my own personal L-series, engines, I just dig through my used rocker stash, (just as Dave Rebello does for his GT race engines, so don’t throw away your old rockers. If they are in good shape, Dave Rebello and myself will take them off your hands…), but for our customers who purchase a cam with their custom Rusch Motorsports L-series cylinder head, we include brand new Nissan Rockers. For our cams, we use Rebello reground NISSAN cams for our cam kits. We use new rockers in our cam kits not because the “new” rockers are better, but because it gives the customer the piece of mind that their rockers are new. For some, that makes all the difference. Hope that helps, Paul Ruschman Rusch Motorsports

Okie dokie, just one more… This one, installed on my partners L-28ET with the engine set WAY back in the chassis, shown here in its raw aluminum stage just prior to getting ceramic coated.

Ditto what Pete said. I’m also sporting the 2nd option with NO distributor. MSnS-E, v-3.0 running a Ford EDIS module from an Exploder, coil pack from a Dodge Intrepid, VR sensor and 36-1 tooth wheel from an Escort… Runs great…

I couldn't of said it better, (or at least in fewer words.. LOL)

Yasin, Glad we were able to help out. The wipe pattern looks great. In looking at your margin on the back side of the rocker, the .170 pad is as far as I’d push the wipe pattern for a street engine. Just make sure and check that the rest of the rockers have similar patterns, and if they do not, just juggle lash pad thickness so that they all end up having similar wipe patterns. Take care, Paul Ruschman

So you “need” 10:1 comp ratio in your L-series eh? You are planning to run at least AV gas or race fuel right? Off the top of my head, I don’t know how much material needs to be shaved from the E-88 for a flat top piston L-24 to achieve that comp ratio, but if it ends up retaining its open chamber design, it will rattle like a Dodge Cummins even with 92 Octane premium. If you are planning to run race gas, then why not take full advantage of the fuels detonation resistance and run 12-13:1? If you are planning to run pump gas, do yourself a HUGE favor. What “little” power gain would be had by raising the comp ratio to 10.1, will be lost and even more power lost due to the amount of ignition timing you will have to back out to keep it from rattling. If the E-88 head is your only option with pump gas, leave the comp ratio alone where it is and spend your money on chamber reshaping, mild port work, mild cam, free flowing exhaust, lightened flywheel, quality ignition parts, etc. The Datsun L-series with open chamber heads or dished piston does NOT like even 9.5:1 on pump gas. Good luck, Paul Ruschman

Cam selection for multi valve engines is a little different than for a 2 valve design, well at least the lift and duration specs are different for a given power band on similar displacement 4v vs 2v designs. Sorry I couldn’t be of much help on this one… You might try the S-13/14 forums. There has to be an S-13/14 forum out there that has a few “honest” knowledgeable KA24DE guys on it?... Good luck…

Yasin, Sure did. It was nice talking with you again. Glad we could be of assistance.

JSM pretty much covered it. Any more angles than 3 is pretty much splitting hairs. Since every single head that goes through our shop gets multi angle seat work, we will only cut 3 angles if the customer request this, otherwise we try and give them 5 angles but sometimes the intake or exhaust seat may only get 4 angles, other variables at work for different applications dictates that. In the near future we will be offering radius seat work which offers the ideal seat geometry, but again, n a mild street engine on the dyno, the power gains will be negligible at best. The multi angle seat work is just one of those “attention to detail” items that most high end shops cover to give their customers every last bit of performance.

Yasin, Glad we could help. If you need anything else, just let us know.

Yeah, that is the back side. The back side is a little easier to mark yet harder to read once installed, i.e. be a contortionist bent around the front of the engine with the little mechanics mirror or from underneath the car using a little mechanics mirror. The front side would be easier to read, but is a little tougher to get the marks lined up and as close to each other as possible. I think Mortensen is alluding to the fact that marking the front would be a more ideal approach and I’d have to agree.

Uh,.. hmmm.. well.. “How do you set the timing without a timing light?” Sorry to be the bearer of bad news here but there is no real way to actually KNOW where your ignition timing will be within 10-15 degrees or so without using an actual timing light. You can get it within 10-20 degrees of the desired fire off point, but that is it. You may even get lucky and get it set right where you wanted it though the odds are not in your favor. Sorry. You need a timing light, even you have to borrow one. That is the only way to verify your ignition timing is ANYWHERE close to where it needs/you want it to be. Good luck

Pete, GREAT pics. Thanks. It sounds like your ground electrodes possibly got so hot they were essentially melting and depending on which way the ground electrode was facing, up or down, (plug index), dictated which way the ground electrode “fell” as it went elastic. If this is the case, you’ll need colder spark plugs. You should be running at least a 7 or an 8 heat range in NGK speak. If the ground electrodes did get so hot they were essentially melting, 2 heat ranges colder would be a good starting point. Of course, with a much colder plug, that means all the time the engine is running and you are NOT working the engine, the plugs will be carbon fouling as they won’t be in their heat range till you have been standing on it for period of time.

Oliver, In regards to “looking” for cracks the crank would need to come out any way, so in that case, just have a machine shop magnaflux it as the mag will detect cracks that we can’t see. Looking at your pics of the damper, there is a good chance that your crank is ok. It looks as though the rubber is just “starting” to fail, so the inertia ring should still be damping at least a little bit. Definitely swap it out for a known good one and if you install a used one, witness mark it. I just use a chisel to witness mark as it wont rub off. Good luck,

By using a thinner lash pad “AND” maintaining the recommended lash clearance, that will automatically raise the rocker pivot to achieve that same valve lash adjustment. I.e., to retain the same lash clearance at the cam, a thinner lash pad means a raised pivot, and vice versa.

Yes. It is smearing, (a downside of the Prussian blue, just make it a real thin coat or use a sharpie as Mortensen suggested), but there is so much Prussian blue on both side of the rocker that the smearing isn’t “covering up” any possible “over wipe”, if you will. Your wipe pattern is just fine, run it. You could cheat it back little bit, but you wouldn’t “feel” any gains that would come from it. In looking at those pics, it appears that you could safely go with a .020” thinner lash pad if you were inclined to cheat the rocker ratio.

If that engine is original, most likely the block has the dished pistons and if so, then keep the N-47. For an N/A application with the OE dished pistons, the standard Z car N-47, the N-42 or the E-88 are really your only options. The P-90 with those pistons gives you nothing in the way of performance unless you add boost as it will drop your compression ratio “below” 8:1. If long term performance enhancements are in your future including an engine rebuild, then I recommend you keep the P-90 and keep a sharp eye for a set of the European flat top pistons. HTH,

I hate being the bearer of bad news but there is a chance that your crank is now junk if indeed the inertia ring did separate from the hub of the damper. This is NOT good. When the rubber goes away, the damper is NOT doing its job, i.e. the inertia ring is not “damping” the twisting forces that are taking place within the crank shaft. Depending on how long the engine has been ran like this or how “hard” it has been ran, the crank could be junk. I’ve seen this MANY times with the L-28. If you caught it early enough, there is a chance the crank is just fine, but… One example is a fairly new mild race engine to be used primarily for open track days. The crank magged good when the engine was originally assembled, owner wanted to use his used damper. The damper was witness marked and he was instructed to monitor that witness mark after each event and if the marks were no longer aligned, the engine was NOT to be started again until a new damper was installed. Typical end user, he didn’t check the witness marks even once. The inertia ring separated from the hub, who knows how many laps he ran with it like that at Thunder hill, it wasn’t many. The crank was removed and magged out of concern and sure enough, over half the rod journals were spider cracked at the radius as well as a few of the main journals. Another crank was then installed with a NEW damper, that engine is doing very well today.

We can source valves, springs, stem seals, gaskets Clevite 77 rod and main bearings, etc. Also, I recommend you use the Felpro Viton stem seals as they will last much longer and also allow for more retainer to seal clearance for a larger cam. Speaking of larger cams, are planning to go to larger cam in the in future? For prices on the parts you need, post us at the address listed below with the items you need, (any “over” and “under” sizes that apply as well), and we can send you a itemized quote for those parts. ruschmotorsports@hotmail.com Thank you, Paul Ruschman The Viton Stem seals as installed on a P-Rieths custom N-42 head…

First off, EXCELLENT write up SHO-Z. Rztmartini, Hmmm.. I’m not sure I understand your question, i.e. possibly you are meaning something a little different than the terminology you used? I’ll take your question at face value and try to answer it as best I can. The short answer to your question is a resounding no. An intercooler is good and will help keep the intake charge cooler/ i.e. air charge will be more dense for a given boost level, but the oversized injectors and Mega Squirt? No. Injector size and the controlling unit that opens and closes the injectors, (i.e. the EFI ecu), will not overcome lack of squish/quench/poor chamber design or even band-aid the ill effects caused by the lack of squish/quench. By using oversized injectors, this will allow you to run pig rich, which will reduce the combustion temps and help to keep the detonation demons away, but it only helps a little and induces other issues such as fouled spark plugs, cylinder wall and piston ring wash down, more frequent oil changes due to fuel contaminated oil, etc. In short, running an engine pig rich to keep detonation down is not the best route around a poor chamber shape or too high a static compression ratio. You should size your injectors to the amount of horsepower the engine will produce, not size them to compensate for poor chamber design by running the engine pig rich. Also,I have seen a few posts on this forum claiming that just by switching from the OE EFI to Mega Squirt, detonation was reduced or eliminated. Those are FALSE claims. There were other variables at play that the people making those claims just were not aware of. Mega squirt, in of itself, has no special abilities to remove or reduce detonation over the OE EFI. The job of the ECU is to send a timed electrical pulse to the injector, (the injector is nothing more than an electrical solenoid which unseats a pintle, disc, ball, etc to allow fuel to flow through it). The electrical signal that comes from the ECU, whether it be OE ECU or Mega Squirt, use the same electrons to open close the injectors. No magical detonation reducing electrons are produced by the MS controller. With Mega Squirt, it is easy to run the engine PIG rich as stated above, but the OE EFI can also be ”fooled” and made to run pig rich as well delivering the same result. The OE EFI computer and Mega Squirt are just controllers that are opening and closing the injectors which are just electrical solenoids. The ECU has NO magic in it taking detonation away. Now the intercooler is a help on many levels and is good idea. To wrap this up, the L-series is prone to detonation at lower static compression ratios than most other engines for a few reasons. Unfortunately, this is an issue that we are stuck with, especially if you use the OE style dished pistons even with a squish head. Our only realistic options in overcoming this short fall with the L-series is try to and achieve that ideal optimum squish and keep the static compression ratios a little on the soft side of average. To get the ideal squish “AND” a decent comp ratio with an L-series is costly as it usually involves custom pistons.