Careless

I was looking for something unrelated to this thread and stumbled on your blog somehow... and then clicked the main page link and saw the vid- so I had to come back here, thinking i was the first person to see it and had to spoil the good news with a subtle hint like "Derek has some 'splainin' ta do." just awesome, Derek. i think i speak for a lot of us when there are those who say taking on something like this is a waste of time, or it will "never work" and all that jazz- but that's all people like us are trying to do here, is waste time doing fun, interesting, and challenging things- and I think you made the best of it as far as cars and Datsuns go in particular. I feel like it's a really proud moment for the Datsun Z fans, too. It's how I'd imagine the way a certain number of people felt when they saw the OS Giken heads become "available", or when photos of the LY heads started to surface, and that someone, somewhere, somehow, something was breathing other-wordly new life into the Z car. Just its existence and the fact that it's operating now makes me really happy. congrats on not giving up and seeing it through and sharing the process with us in fine detail. any paypal account I can send a beer (or non-alcoholic beverage) to? or perhaps put it towards an adapter plate to give it a 6 speed trans? hehehe

or perhaps a 3 litre v6 that is now a 1.5 litre V3/6 ... depending on how good you are at sleep wrenching. lol

all the removable parts. You'd need a tumbler about 4 to 5 times the size of a common industrial sized one in order to get the action needed to support and lift an engine block through vibratory motion. I don't think it would be too feasible. the media and burnishing compound cost alone would be a mortgage. and getting all the media out of the crevices of a block would be more work than it's worth.

I'd post in this thread, but I don't want to disrupt the flow with photos of my own work- but you should see what a fully assembled vibratory tumbled L24 looks like. I can shows ya if you'd like. Best tool once you work out the finishes attainable through testing various mediums and compounds/burnishing fluids. Some media will get you as close to the "virgin casting" look on the inside of most engine parts that aren't exposed to the elements, like the inside of the timing chain cover.

I don't need to buy or have the intention of buying something to point out a part of the project that I feel could use some more love and attention on the next go-around. This is a discussion forum. We discuss things here. If that's not the case, then why are hundreds of people posting in this thread? Are they going to buy it too? Why are you so offended by my opinion, anyways? Are you buying?

valve cover looks great.. but that font & typsetting.... blehhhh

which head are we talking about here? 1100HP LY Datsun head? not questioning truth/existence. would genuinely like to read about its applications where 1000hp would be necessary in racing for whatever class it was in.

I may be nitpicking here, but I would have used some red scotch-brite sanding belts and a couple of squirts of elbow grease to wipe the mandrel bending lines/marks from the tubing before welding them up. It ends up looking 10 times better, and prevents it from looking like it is made out of mild-steel exhaust tubing. I know it can be done post-weld, but then you lose the colouring at the weld joint- which is attractive to most people looking at welds and manifolds in particular. Eventually the tubing will end up looking a somewhat uniform brown colour across the entire length of the manifold if it's 304SS due to intergranular corrosion- but the process of treating the tubes to some belt sanding will make it look reeeeeeeeal nice for photos. you could try putting some tape over the welds and do it afterwards if you think I'm on to something. Or not. I'm a block of text on a forum, not a cop! Some 321 tubing would make 'em look real right n' purdy for a lot longer if it's not going turbo However, K motors respond amazingly to turbo- so I expect this manifold to change at some point... right, Derek?

FWIW, Formula 1 engines have (at least since the mid 80's) used between 240-400 grit paper finish on the ports. Most commonly around 320g- both FI and NA engines alike. A far cry from laborious dimpling process, accomplished by using a 1/8 shank ball-end burr on a pencil grinder. (They get reaaaaaaal violent when you start using them to reach far into the port). If you're going to attempt this, try your best to find a 1/8 ERICKSON collet grinder. It is much better than the "pinch" style collets, especially for extended bits. From my reading/research... port size/shape/floor is where 90% of your focus should go, as F1 engines also have virtually no SSR on the intake ports, and slight SSR on the exhaust ports, which are a lot smaller than the intake ports as well. However, Larry Wildmer @ endyne (theoldone.com) has created CNC programs that leave the ripples in the ports, and his work is some of which I used to follow the most whenever there were updates. Not sure how he's doing now. There are finishes that I have seen on many different engines- and everyone says theirs is the best for <insert reason here>, but I tend to look at F1 as a good place to begin- and they've proven that shape is more important than finish. You can achieve a good "smooth" type of paper finish using a variety of cross buffs rather than paper. The advantage to smoothing out the port during the porting process, regardless of final finish, is that it gives you a much better look at the port shape and unevenness or undulations as you progress, and it is a necessary porting tool, IMHO. Look at photos of cross sections of your particular port castings, and go from there. Finish is something you can worry about after, TBH. Also, from the heads I've taken apart- I've noticed that two of the ones that had polished exhaust ports, as well as the ones I have on my engine stand right now on my VG33ET have soot that can be easily wiped off with a little scrubbing with one's finger (I use someone else's finger whenever possible ). The polishing is most likely a lot more "self cleaning" than a rough surface that gives peaks/valleys for carbon to bond to. Think about it, you roughen things up to allow adhesives to bond better- why wouldn't you at least polish/320g+ your exhaust ports?

preferably off the intake manifold (after the throttle body) unshared from any sort of valve that diverts vacuum to another device. It will not matter much as long as it's tapped in before the vacuum device/valve, but having it run to the manifold on its own line is ideal.

you mean an oxide type media?

Well it wouldn't have anything to do with the machining of the valves, as it could be accomplished by making a secondary trough around the head, like a rectangular riser- also with a 2mm o-ring. Just looks really nice. Reminiscent of the cool flat-head ford's with offenhauser covers. Some LZ20B's were sprayed Dark Crystal Black, while some had the Datsun Dusty Blue colour.

casting my vote for "trough" around the head (since it's too late to cast it now), and LZ20B style cam covers, complete with metric acorn nuts. casted 4-bolt cam gear covers are a desirable aesthetic as well.

Heresay, and BS. If that were to make any sort of sense, or have any performance advantage- I would run the smallest pads on the largest brake calliper I could find and out-brake everyone with this new secret performance trick, borrowed from the 60's and 70's. Sorry, but it just doesn't make sense. The only reason why earlier 240mm Z31 discs held better than any 250mm disc were due to the AFTERMARKET options only being available in 240mm option because the 1984-1986 models, turbo and non-turbo alike, were equipped from factory with 240mm assemblies. This is stated in the 1984-1986 FSM on page CL-10. It is identified as Clutch Disc Model 240TBL, and Clutch Cover model C240S. When the 1987 Z31 300zx came out with the uprated FS5R30A transmission, Nissan sized them up by 10mm. The N/A models remaining @ 240mm like their turbo and non-turbo predecessors. This is stated in the 1987-1989 FSM on page CL-10. It is identified as Clutch Disc Model 240TBL, and Clutch Cover model C240S for the non-turbo, and 250TBL / C250S respectively, for the turbo model with the beefier transmission. It is not cost-effective for a company to make new templates and produce new discs for an extra 5mm on either end of the disc. For no other reason is the 240mm available through aftermarket suppliers who manufacture clutch assemblies with higher holding capacity. Nissan upsized their units because they did not increase the harshness of the clutch engagement- they kept it relatively the same as the 240mm version by equipping the unit with more friction area, but using the same friction compound. For an aftermarket setup, the extra 10mm is almost negligible. If I handed you a box of 250mm clutch discs and put one 240mm in there, you would never know the difference, even if you went sorting through them. The hub splines on virtually all Nissans are the same too, so any 240mm disc from a Z31 will work on a Z32/33/34 provided the center spring/hub is the same depth, and the friction pads are of the same thickness. The FS5R30A is the predecessor to the Z32 RS5R30A, and is virtually the same, internally. Thus the Z32 engines backed by MT transmissions are all equipped with 250mm discs. Also, the FS6R31A is fitted with a 250mm clutch disc from factory in the Z33/34 because it is the successor to the R30A series transes. The added 5mm on either end of the disc does not contribute a HUGE amount, but you can use a 250mm flywheel like a Fidanza, or SouthBend Clutch, and you can buy a 240mm or 250mm disc, and pressure plate. Someone correct me if I am wrong, but the Fidanza flywheel should accept both 240 and 250mm discs and pressure plates. You will get the increase in clamping load from having an uprated pressure plate, you will get the increase in friction surface due to the extra 10mm overall disc OD (which is not anything to write home about), and you will get the increase in holding power through use of better friction material like "Feramic" button type pucks- which, combined with the increase in clamping load, is the most important part of the assembly, and the part that makes the biggest difference. The main reason why there are many 250mm options nowadays is most likely because Nissan does not use the 240mm disc on any higher powered vehicles now as a low-cost/low-model option, so now it doesn't make sense for them to go "backwards" so to speak, and since the flywheels are different heights, different bolt patterns, and the ring gear offset is in a different place, they had the chance to redesign everything @ 250mm with no 240mm option. I would try the South Bend Clutch option, as I have used their old "stage 4" model, which is equipped with a 350z pressure plate, and a 250mm disc, and it should be fine on your "Rhino" 250mm flywheel. It's also very drivable. You can use your current setup. It should work fine... but 400hp out of a VG30/33 makes gobs of torque. Don't expect a stock pressure plate to make full use of the uprated disc friction pads. If anything, it will slip and glaze the pads too easily, and then you're left with three pieces of junk rather than one.

I have a better idea. I'm driving an RB30 block to vancouver in the coming weeks. I have a R30A transmission from a Z31. It is missing the bellhousing. I can bring that to you if you're willing to buy it. You would just have to take the bellhousing from your RB26 and put it on the Z31 gear casing without all this fancy welding business. it is nearly identical to the RB25 transmission. I believe the only differences between the Z31 VG30 and RB25 transmissions were the bell housings. PM me if you're interested. Transmission shifted pretty good before I took the bell housing off to sell it to someone who needed it.