AydinZ71

@clarkspeed looking good, Clark! I have seen a few folks on here say the friction from PU bushings adds an undesirable static friction to the CA’s (and suspension) travel. Is that why you went Delrin? In my experience, delrin work-hardens so you might end up with a little bit of slop over time. Your bushing is pretty long though so the cross-axial forces should zero out the slop. Good luck, and let us know how she feels!! I am finally making my way to the front suspension and trying to decide between modifying my own adjustable LCA’s or buying them from these bolt-on dudes. My only reason would be to save time. Ok already bogged down on sheet metal replacement.

I personally would not run RTV. Quick search says it can handle 650f in intervals. You have probably seen pictures of them glowing red. The turbo manifold can get much hotter in some cases. I would stick to a metallic crush gasket. If you have issues sealing, I would have the manifold and head surfaces milled flat. you can try the RTV, but if/when it fails you will be back at it.

nice! In my experience, PH is the critical concern when you don’t want to strip metal plating. Not familiar with many over-the-counter chemicals that will strip plating unless it’s an acid/caustic. For example, Phosphoric acid (rust-most) is most commonly used to strip rust and non ferrous plating (like zinc) from steel.

true!!! Yeah... double edged sword. When driving though, the black would aid convection cooling as air flows over the surface, as the surface will radiate heat to the air stream. My mind is in “race car”, so no AC. I’m assuming the inside of my car will be warmer than the free flowing air around it. in general, this is going to have a really really minor effect. The body color makes the big difference since this effect how well the surface will absorb or reflect solar radiation. still fun to geek over.

I say leave it black. If you paint it while the asphalt (that’s what 3M undercoating is) is curing, the paint should stick pretty good. However, the whole purpose of the undercoating is as a sacrificial surface which is intended to be scuffed. Good move applying sealer first. I did the same, 2-component epoxy DTM sealer. Now you can spot the areas that will need repair in the future (I used white). On other areas less critical than the floor pans (above the fuel tank/cell) I used self-etch primer and applied the 3M material right on top. the other thing to consider is, black results in a higher radiative heat coefficient than white. For us who live in warm climates, this is a plus. The bottom of the car will radiate heat from the cabin. Best case scenario is a white car, with completely black undercoating. Doesn’t make a huge difference, but every bit helps. once cured, you can take a piece of steel to the surface and you will notice how much more resilient it is than paint (which chips). It will fade, but not break off in chunks how paint does. Make sure you don’t apply it too thick. If it goes on in globs, it is prone to chipping.

I like their seam sealer because it is a single component high solids epoxy that cures rock-hard. You can fill big gaps with it, and will bind really well to prepared steel. It is sand-able, and a good consistency to fill seams. It’s also non-porous and waterproof, like most epoxies. I don’t ever encapsulate or paint over rust. What typically happens is the margins of the seam sealer can rust, exposing the underside. Once water and air get under it, it’s useless and will again rust from the inside out. I'm sure there are other manufacturers, but the por-15 product is conveniently on Amazon.

Other option is to swap the fittings and hoses for PTFE (teflon) braided hose. The inner wall is more ridged on Teflon, and less likely to kink. Just an idea. Another idea is to use compression fittings with tubing. You can easily bend 3/8” steel tube with a cheap tool. There is quite a bit of vibration here, but anealed tubing should put up with it without cracking.

If it does not leak, you are probably OK. The oil drain is not under pressure. If you want to spend money, buy two 45 degree AN fittings. The ends should roughly be pointing at each other then. It would be right though, as the bends eat up distance.

yeah man I used to use weld-through primer a ton. Then I got sick of the smoke and just seam-welded everything. Anywhere I couldn’t, I used the por-15 seam sealer which is bulletproof. nothing wrong with weld-through primer! Do remember to wear a full respirator. Galvanic poisoning is no joke. Good luck, and it’s looking great! how about those funky green parts huh! Prices are competitive too.

@HS30-H is right. You wouldn’t be able to run this head on any of the classes in SCCA that run in “nationals”. Still, there are other regional road racing and vintage series races that have looser rules. More on the exhibition side, without a trophy 😂 Even for exhibition racing, the “cool” factor of running a DOHC L-series would get a lot of attention. HP needs would depend on the track, but given EP runs an L24 w/ SU’s, I think you will have plenty of power! The EP L24’s are in the 230-260hp range, but the torque band is limited to the higher RPM’s and typically run a redline 8-8.5k. No expert here, just spent a lot of time asking question from those who are. What I would be most excited about with this head is the potential for a broader torque band, and higher peak torque. The valvetrain will need to be super stable to run those high RPM’s though. You could test it on a block with pauter rods and forged pistons with valve reliefs, if you were interested in “stress testing” the head well past the OEM redline.

True At least not in SCCA. Can’t run it in ITS, EP. Not sure about the rules in Vintage racing. I have always had trouble finding the comprehensive rules for that. Still, I believe there are some exhibition track days, hill climb, time attack, etc.

Yeah I think your bang-for-the-buck on this head is NA. Once you are going forced induction, you can boost more to overcompensate the shitty flowing L heads. Clearly the DOHC will make more power at less boost, but I think the sexy factor is making big power in an NA application for road racing. Just my opinion

Very clean! Are you going to plug weld it, or seam weld the lap joint? If you want the OEM look, drill some 1/4” holes in the funky green part, and plug weld the holes to that base plate you primer-ed, then just grind it flush. That’s what I did. Used several clamps to hold the two firmly together.

Ah! They have a tendency to loosen up? Oh right... the expansion/contraction of the AL spacer. Yeah... that’s a good point. As the strut heats up, that AL will squish around the pressure points. I made a neoprene gasket for the gland nut/shock insert interface (seal-in oil around the insert) so that will eat up 1/32 of play. Il check the torque after I get her up and running. I bet after a few events she will seat well and stop loosening.

Updates: eliminated the rest of the cowl area, through to the drivers-side Pilar. Posting some pics and vids of me rebuilding the drivers side. next step is to install the tilton firewall-mounted pedal assembly. Then complete the cowl area. Steering column has been sandblasted and epoxy coated. Still on the fence on getting an aftermarket steering column. Just have not found one yet that has the features for the weight savings I was looking for. Thanks for following! IMG_6181.MOV IMG_6109.MOV IMG_6107.MP4 IMG_6160.MOV

@Leon @Derek thanks for that feedback! Sounds like the usual idiosyncratic, passionate folks like you said Not a bad thing at all, just important to keep ones patience. Il just be humble and listen more than I speak if I interact with them. The handful who were not-so-happy happen to be big-shots themselves. Let’s say... national champions. I can see how sometimes putting two high-achieving folks in a bucket may rattle around a bit. Derek, have you had any experience sleeving an L-series for better ring life or larger bore? At some point you are certainly eating into the water jacket, which isn’t great given larger displacement = more heat. I have heard of some sleeve material requiring an overall thinner cylinder wall, which can allow for larger displacement, better cylinder cooling, and longer ring life. Always curious to hear what kind of exciting ideas you have on the horizon for our L-series engines!

Wow this looks great!!!! Excited to see you test it out! What do you have in mind for monitoring the chain movement/reaction at various RPM’s (if any). Did you settle on the tensioner spring and cylinder design based on OEM oil pressure? How much more pressure does full oil pressure apply to it, and what is the significance of the check valve? You want to maintain the max tension when off? Can’t wait to see it running! what do you think of the Robello and ZCG folks? I have heard mixed things. Some say they are arrogant and dismissive but they could have just taken something personal. Not meant to be a shit-talking session. Just curious how they have been treating you.

@clarkspeed looking good! I didn’t realize a modified lower CA would be cheaper than aftermarket? AE claimed theirs are 3.5lbs lighter than OEM 🤷🏽‍♂️ I will weight then this weekend and get some data. Still, I think the mod to the OEM unit works and looks great! I also was unaware the rear LCA vertical supports needed reinforcing. I will have to look at that! They flex much? I have my sway bar mounted to them so maybe that will add some rigidity. why did you north the crossmember above the diff? Had clearance issues? I’m thinking if notching the front LCA crossmember so I can build-in some adjustability on the front diff mount.

@clarkspeed respect I have been bogged down for almost a year on rust repair, so I have had a huge amount of practice. Totally agree with you that it doesn’t matter on a race car. Sorry for hijacking your own thread by the way!! My work is a combination of structural and non-structural since rust has no bounds. Very excited to see how you progress!

I need to visit the chiropractor. My twin-idler gears are whining louder than normal recently.

I just found a cheap HF 12-point socket that would grab the square well enough. A set is like 8 bucks, so I don’t really care if I ruin them. I mean... if you have tried a bunch of stuff and it’s not working, it’s worth the time to just make the impact wrench work and get it off In 30 seconds if it’s accessible. @Mayolives it’s tight... just a matter of how much time you can invest to get it off. You could pull the diff in about an hour and use an impact wrench to loosen it, then put it back. It could always take you an hour to fiddle with it under the car and not succeed 🤷🏽‍♂️. Just a toss-up really. glad you were able to get it off friend!! Good luck with the car!

Thanks for all the input! I didn’t mean to hijack the thread and cause so much controversy 😂 I asked a few folks I know off-forum who race L-series, and they are aware of but don’t run the twin idler. Greg Ira for instance just moves the curved static chain guide to eliminate slack. They do however speak highly of the Kameari cam timing sprocket for its limitless adjustability. You would need to dyno the engine to get the most out of it if course, especially with a wild profile. thanks everyone for your input!! And sorry again to the OP

I’d love if someone could explain the purpose or advantage of the twin idler. I think it’s cool as hell. If it doesn’t serve a functional purpose though, I don’t think I would get it for the race engine. That noise indicates it is adding friction/resistance to the engine but I’m sure there is an up side! Does it keep the chain from fking up at high rpm?

@JMortensen looks good! I need to make one of those too. I am going to shop around for a spare (front and back) so I can fiddle with them on the bench. I don’t think there is anything wrong with not leaving a gap if your temp is high enough. You should get a nice Saturn shaped puddle right on the seam. My biggest issue with no gap is if the piece is bound on all sides, it tends to warp more since there is nowhere for the hot metal to expand. I suppose it’s like cooking. Something different works for everyone. I get a much flatter, even puddle when I leave a small gap. It’s all in the wrist movement and the duty cycle for me. I do Fraction of a second. Usually only burn through on OEM material where the material is so thin from corrosion. I swear it’s thinner than 20 gauge. I can fix holes pretty quickly though. Just build up the material around the hole, then fill-in. here is a vid of my technique, and a pic of how I fill gaps that are too small to create a sandwich piece for l. Certainly still a novice! IMG_6159.MOV

I agree with everything you have said I tend to go even bigger on the gap, 1/16. For me, this keeps the butt weld from binding as it expands. There is usually a “pinch point” where the expansion can bind and will sometimes need the cut-off wheel to break loose. The first few tack welds can be tough as they tend to “pull” the metal closer together. You see criticisms from time to time that makes you second guess your method, but after having this much practice I realize it’s just the nature of 20-gauge and rotsun metal. It would be interesting to understand what the quality of their steel actually is (analysis), because it certainly welds much more poorly then fresh modern cold-rolled mild steel. Lots of slag, off-gasing, splatter, and even the finished weld tends to be “duller” than virgin stock. Not that any of this mattered to Nissan since it was mostly resistance spot welded.