Roman

I already have. Got the Kelford springs and titanium retainers in there. Will be interesting to see how the factory cams can go when able to spin up a bit higher.

The 2GR heads will be best, since they have huuuugggggeee valves because of the much bigger bore (94mm bore vs 83mm 4GR) So as a result the valves are 7-8mm bigger diameter which is crazy. If you put a 2MZ crank into a 2GR then you end up around 2.9 litre with a stroke that "should" allow 10 or 11k rpm. I guess the thing is, first I just need to get a motor together and see what happens when it runs. It is entirely possible that there is some insurmountable issue with the valvetrain (or whatever) so arguing semantics over which motor will do 11,000rpm is irrelevant when the whole thing explodes at 9000 anyway. Haha. God I love wildly speculating though

I had another good look over everything last night, and I couldnt see any issues. All of the piston pins move freely no problem. Even on the cylinder that went kaboom, the remaining end of the rod swings around on the crank no prob. No signs of any cracking or anything else on the remaining 3 that I can see. But yeah need a dye test to know for sure. And imagine what a pity it would have been if I listened to the formulas, and missed out on the most fun I've ever had in a car haha. There definitely does seem to be a sensible upper limit to mean piston speed though, even absolute screamers like the bike motors and Alfa DTM cars all seem to stay below 5K ft/min. Piston and rod weight will play some part, the fact that 1NZ rod and piston is so light is likely a big part of how it managed to go for so long without issues. So I might not be able to push the limit quite as much with the heavy stuff in the V6. A mate has a K24 that he's revving to 9k rpm - 99mm stroke so that's 5800 ft/min, bloody hell haha. Here's a pointless graph for you today @Stu

Yeah would need to use 3GR block, 2MZ crank and 2MZ rods. Or you'd end up with the piston sitting way too low in the block. Then you might get lucky and find that 3GR or 2MZ pistons work and give an acceptable CR. The 2MZ piston has a dome on the top, where as 3GR/4GR are dished with weird DI stuff on top of piston. So hopefully would be able to mill them down to a good CR if they are "too high" rather than the opposite. But who knows.

Dont you worry, I'll more than make up for it when the engine is running. Haha

So even more stuff matches up. Both have: 22m gudgeon pin 56mm bigend 61mm main journal. Welllll shit. Thats another item on my pickapart quest list then. 2mz guts!

The 5GR motor has been brought up a few times in this chat - the unobtanium China only 2500cc short stroke GR motor. Well ive found out some interesting stuff. The GR series of motors shares a considerable amount of dimensions with the previous MZ v6s. They have identical bore spacing, bore offset, and stroke length between various versions of each. This would solve the mystery of where the 5GR crank comes from - Its a bunch of left over 2MZ cranks shipped to China to build cheaper 2500cc non DI GR engines with 3GR blocks. It would also make sense for why it was a 2005 year only engine -just an end of line bitsa, as the 2MZ cranks would be the only ones left unused by the GR series. 3gr bore x stroke: 87.5 x 83 1mz bore x stroke: 87.5 x 83 5gr bore x stroke: 87.5 x 69.2 2mz bore x stroke: 87.5 x 69.2 1mz cyl spacing: 105.5mm 2gr / 3gr / 4gr cyl spacing: 105.5mm If this is true. Then the ultimate combo would be a 3GR block (cheap and easy to get in NZ) and a 2MZ crank which I could likely find at pickapart or just buy a motor. This wouldnt exceed 5000ft/min piston speed until a smidge past 11k rpm. So this might be version 2.0 motor one day if that works.

What is also cool, is that someone asked me if I could send them a file for the ITB adapter. Sure. So they had some CNCd And they've also made some 14.9:1 pistons. How good! And this is all going in a tube framed EP80 time attack car for a European hillclimb or autocross or something series. It still looks like cams are the bottleneck though, but it will be interesting to see how it goes with the higher CR and presumably some race gas.

Hi, just a thread ressurection to cover off a bit of a post mortem on the first motor. I covered some of this earlier but I finally pulled the motor fully apart a couple of days ago. (FYI @GregT and @VitesseEFI ) So what do we know for starters before I pulled the motor out? Well, theres a big hole in the block. But unknown level of carnage inside apart from that a rod is broken. So my first thoughts were, yep, finally the skinny 1NZ rods have caught up with me. Which is why I had some forged rods set aside for fitting at some point. However, when I took the head off the engine. It was interesting that on this cylinder the piston was just parked at TDC. It hadnt hit the head at all - no damaged valves or anything. The only damage was some block debris that got sucked into an adjacent cylinder, and put a little dent in the piston top. So I was expecting to pull out the whole piston, with a little bit of rod dangling off the bottom. So when I tapped it out, and this is all that came out, I actually laughed so hard. Oh man! Totally unexpected! Then looking down the bore, there was just a small part of the rod left swinging around on the crank. Gudgeon pin AWOL but possibly in the sump. Oil filter and housing both AWOL. So some of this isnt consistent with idea of the rod breaking first. For starters, if the rod broke first I'd expect to see the gudgeon pin and a small part of the rod still hanging from the piston. Looking at the piston there are two types of damage, some areas where they have been bashed by the rod or gudgeon pin. Where it looks dented in. But then other areas where it looks powdery - this is cast alloy breaking or being pulled in half. Then looking at the block, there are some clues about what happened too. Since the piston was just happily parked at TDC it makes me think that what likely happened is this: Piston approaching TDC, decelerating. Rod starts yanking the piston back down. Piston says "no thanks" piston cracks, top stays at the top held there by the rings. Now the lower half of piston, full rod, and gudgeon pin are swinging around unsupported. On one side of the block, you can see where there is a notch that clearly shows the width of the rod flapping around smashing stuff... But a little bit below this, is a hole a little wider than the gudgeon pin... So I think the unsupported rod flopped over, got pushed hard against the bottom of the sleeve/bore. Then the only direction it could go was out the side. Then it had no choice but to smash through the block. Then either on the way out or the way back in, the gudgeon pin and top of the rod broke off. Then the remainder of the rod was free to flail around, which is why there's a vertical notch higher than the wide gudgeon pin sized hole. The piston has holes in it to return oil from the bore that the rings scrape off. So these were a weak point, broke partially across these. Being a 4 stroke engine there are two times approaching TDC where this could have happened, on the compression stroke or exhaust stroke. Can we tell which? Well, can have a good guess. When you do a compression test, you might get like 200psi or 150psi on the gauge... thats a value from the compression stroke. So on the compression stroke at TDC it's actually holding the top of the piston in place with 200psi or whatever before any combustion has happened. Then also since you have an ignition event happening earlier than TDC, it's already building some pressure from that too. So unlikely to happen on this stroke. On the exhaust stroke though, especially if you have good extractors. There is no ignition event building pressure. The only resistance on the way up, is the exhaust gas trying to push out the exhaust. At or close to TDC there can be close to absolute vacuum above the piston. So you've got 200psi less force trying to stop the top of the piston from coming off. So this makes me think it likely happened just after TDC on exhaust stroke. When I pulled all of the pistons and rods out, there wasnt really any extra information to be gained about the one that was damaged. But I thought it would be interesting to look at the other three. I've not measured anything up, or pulled anything apart. But a visual inspection doesnt show anything immediately wrong with the other three. 1NZ motor still makes me amazed at how tiny everything is - Undo the rod caps with a 10mm socket. Undo the main caps with a 12mm socket. Haha! Which is not saying something against it. This is the whole reason this motor went as well as it did. Everything is CRAZY light. Nothing is bigger than it needs to be. And the end of the rods have small dowel pins in them to align the cap as well. Real race car shit. The main point of trying to figure all of this out though. Is that if the piston failed first, then there's no point fitting aftermarket rods (which I already had) So in that respect it was disappointing to see that the piston seems to be what broke. As aftermarket pistons cost a lot. I'm not sure if there's too much more I can discern from these remaining pistons/rods as I dont have any decent measuring equipment etc. However it might be interesting to do a dye penetrant test on a piston and see if there's any hairline fractures etc. I'll buy a kit at some stage, and post up if there's anything interesting showing up.

Yeah they do make roll cages out of it. I'm not sure to be honest, I've just heard it tends to crack or shrink a lot from welding and it causes issues. Since this is a flywheel that if all goes to plan it is going to be spinning at a fairly silly rpm. I'd rather not take too many chances with it. Buuuuttt yeah maybe I should have an ask around. I might go get a second flex plate/ring gear from pickapart and just bolt all that up. At least that way I can know if the motor can crank over or not.

Its damaged the back face that mates up to the crank. Its just dug one side a bit too deep.

Rethinking my throttle situation a bit more. My e-throttle ITB setup on the echo worked well with a printed manifold, because the throttles were a single solid assembly. So there was no force applied to the manifold apart from the hanging weight. For the BMW throttles it is back to a two bolt flange on each throttle, and each throttle trying to twist itself off in various ways like the 20v throttles do. Also, it's very important that I have each bank of throttles perfectly(ish) aligned. So it seemed like life was unnecessarily hard having 2 separate manifolds. So I printed a big single one as a test fit to see how far off I was... the port spacing was about spot on, but a few of the bolt holes needed moving slightly. So I started from nearly scratch again, modelling a big slab looking thing. The idea is that it will have a layer or three of carbon flat over the top, and the bottom. So I wont try carve out the shape at all, simple is better. I've cut some channels into the underside, that will link all of the throttles together. A layer of carbon will seal this all off. Then I will tap into it for brake booster / IACV / PCV / whatever. So all that messy stuff will be tucked up nicely on the underside and come out the back. I'm gonna use recessed M8 cap screws to bolt it down to the heads, as bolts end up too close to the throttles. Hopefully this ends up strong enough to work as a printed part, and easy enough to make. Even if I do end up wanting to make a final part from alloy, it's good to have a reasonable scheme for making prototypes. This will be too expensive to get printed on the MJF machine via 3rd party though. Maybe for a final one. Another benefit of this is that I dont need everything bolted onto the motor to figure out the linkages, can work on it on the bench. The total assembly height is only 35mm though, so it would be feasible to cut most of this out of a big slab like my sump. So this might be a project for Dad's CNC one day. But the port geometry is very difficult, would need hand finishing as you cant reach a lot of the areas with a 4 axis machine. If I do that, I'll cut the shape down to just have a lot of ribs between throttles and remove most of the material, as it would weigh heaps like this. It looks like my flywheel got damaged beyond repair when the cutting tool caught it in the mill. My understanding is you cant really weld chromoly safely so dont think it can be built up with material then skimmed flat again. So will have to look at other options again. It might be feasible to skim it down further, skim all of the outer part off beyond what the clutch plate needs. Then run a standard flex plate behind it. No stress though, shit happens - chalk it up to the learning budget.

Oil squirters Here's my thoughts - if they werent there, dont go out of your way to fit them. If they are, then sweet. The 3 Banger GR yaris motor has 3 under piston oil squirters per cylinder. And each piston of that motor about the same power as 3 5M pistons, so the maths checks out!

100% definitely watch this one, great vid @yoeddynz

You're right, it was a great video and I love the amount of effort he goes to on these vids. I think what I meant was that the first video felt like he was really onto something and had unlocked the secret to the cool sound. That we could all try apply to our engines... But then left a cliff hanger on the actual results. But then second video was more like deconstructing all of the reasons or theories for why all of the stuff from the first video didnt work. So was disappointing in that regard, but still awesome/funny content. However, there are still a few good datapoints for GR motors on what sounds good.

Ahhh pity that his V12 didnt end up sounding any good. Cool that he's working to still develop it though. That's the only way to make NA engines do what you want - by suffering. haha Video wasnt quite as a cool as the first one, but sometimes reality comes and punches your theory in the face haha. I saw another video on youtube where someone did a front facing 6-1 on the Honda J series V6. By my ear it didnt sound any better or different than the 3-2-1 setup. Maybe just when you have to make the pipes so damn long to make it work, it doesnt work anymore.

Oh shit! Been waiting for this vid to drop for ages. Watching now!

Just because I'm using a shit engine doesnt mean fertilizer is going to help! Or does it

Gotta think big my man - Forget about some jiggly anime. We could fit the entire MSpaint dick pics thread on there

A little progress Unsolicited general Life update Things have been a bit frustrating at the moment. It felt like I was right on the precipice of having the motor firing up, and on a roll after getting the sump fitted. However seemingly simple things have been getting complicated and house related stuff has also been sapping my time/energy/life. I dont think there's any chance of attending oldschool drags in this car now, just dont have enough time left. Current goal is just to try get my car moved to my new house. Just getting the car movable has been surprisingly time consuming. A few years ago I was planning a fairly decent overhaul of a few things on this car. Swapping SW20 rear brakes for MX5 stuff, swapping booster setup for a pedal box, redoing fuel lines and front calipers etc. So I ended up pulling some stuff apart, figuring it'd be coming out for good. So I didnt bother putting bolts back in the right place and all that. Which I'm usually fairly good at. So, I've chewed up a massive amount of time just looking for bits which is annoying. I managed to get the handbrake working, after lots of rummaging through boxes etc to find parts. Still need to spanner check a lot of the suspension stuff. New intake stuff This has also been a lot more complicated and time consuming than expected. I've definitely pushed my timeline back a whole lot by swapping throttles. I ordered some fuel rail extrusions, 12mm rod, and some bearings. I've finalized the drawings to drill new fuel rails and actuator rods and have done a few test prints before chopping anything up. For the fuel setup, I was initially wanting to feed into one fuel rail, link to the other, then have an FPR on the back of the second rail. However its too crowded up front to link the left and right banks together. So I'm going to use the Corvette fuel filter with the built in FPR, to make it a returnless setup. That will split to feed each bank and have a pressure dampener on each rail. I'll mount a fuel pressure sensor near the tee, to see if there are any weird things happening with having the FPR down the back. However that's how a lot of cars do things now, so hopefully it's fine. I've decided it'll be a good idea to have some support plates that link each bank's rods together and hold them straight etc. As each bank tries to pull itself in towards the center of the vee when rotated against spring pressure. I'm just going to run a cable pull setup as it's seeming a lot more complicated to get an e-throttle setup working for now. It might still end up a dual e-throttle setup, as this will actually make balancing the left and right banks a lot easier. Do it digitally rather than mechanically. I'm going to drill the fuel rails and rods on my dads manual milling machine, which has encoders on it to output X and Y coordinates. So it's easiest if all of my dimensions are relative to a zero point on the parts. Hopefully get some of this done tomorrow night when I'm up in Auckland. With some printed mockup parts on the engine it's looking like this. My throttle pull wheel thing will go down the back of the motor instead, as it's already quite crowded up front. Annoyingly, for whatever reason the BMW TPS's stick out quite far off the end throttles. However I'll keep both of them, as it'll make it easy to diagnose if I've got any bank to bank imbalance for whatever reason. It's been finnicky to get right. But once I've got the new rods drilled, it will be a lot easier to test etc. As it all binds up a little currently as the linkages arent spaced apart properly. Although it's all been a pain, the amount of room to the bonnet that I've gained, will make all of the extra trouble worth it. The final version will have the pulley arrangement fully enclosed so there's no chance of it getting jammed up with stuff falling in somehow. These linkage rods I've got are no good, they'll vibrate the ends loose easily by the looks. So I might end up loctiting the threads to the exact right lengths. Or find some better ones. Digidash fuckery part deux After a lot of frustration troubleshooting this LED screen, which would only display some of the lines on the screen. I found that my Teensy board was the actual issue. Replaced that, then it started working properly. It doesnt look so great on photo/video but the appearance in real life is ssweeeeeeeeet! And it's super bright too, and the boot time is almost instantaneous. So I've started working on some basic graphics for it. Fuck knows why there's a radar looking thing there, but there ya go What I have learned from previous efforts, is that any time spent adding some structure and scalability to things pays dividends really quickly. All of the stuff shown above is movable/scalable in real time. To generate one of the vertical bars on the screen, I just need to run this line of code and it generates the borders, level, colours etc. VerticalBar(6, 25, 25, 30,0,100, temp); Where the values are: VerticalBar(Xposition, Yposition, Width, Height,Min value,Max value, CAN Variable); Then for the indicators, its just like: IndicatorLeft(10, 7, 1); Where the values are X position, Y position, and 1 or 0 for on/off. So if I have some context sensitive screens, where some of the features need to move around. It's incredibly easy to reposition them. I could even move them around in real time, for whatever reason. One thing that is great about how these LED screens work, compared to the Nextion LCD screens I have been using in the past. Is that the LCD screen, there was an onboard (slow)FPGA and (slow)processor which handled graphics stuff. So it was cool that you could load fonts and bitmaps etc to the screen itself, and using a GUI to design things on your PC it would just load all of the graphics, fonts etc. Then you just had to send it serial commands to update values or whatever. However the problem was, any time you send a command (for example, update the temperature value) It would start that command, pause the unit while it refreshes/rewrites all of the relevant pixels. Then when finished it would send an Ack command back over serial to say it is happy to accept the next command. The problem is that even the smallest quickest command has quite a high overhead in write time. So if you want to update 10 things at once on the screen, you end up waiting while the stack of commands sequentially run. So it ended up that whatever you could do to minimize the amount of pixels that updated, paid dividends. But it was annoying, and ultimately a bit too slow. The refresh rate was too slow to have anything like a shift light or shift bar as part of the screen. With this LED screen instead. The only onboard hardware is essentially a few buffers which hold the current RGB value of each pixel. Whether you're updating anything or not, It rewrites all of the lines over and over from the buffer at a very high rate. Instead of sending each separate command, like to update the temperature value. Then requiring a confirmation that each command has finished. My controller board (Teensy 4.0) has a copy of the entire screens RGB values stored in RAM. So any update you make, first happens just to update these values in RAM. Meaning you can absolutely stuff it full of changes and there's no external communication, it's near instantly changed. Then when have changed everything you want, it sends the whole screen's new image over. Whether you have made 1 pixel change, or all of them. It's exactly the same speed either way. So essentially, complexity is free. which is super awesome, and means I can have as many layers or stupid animations or star swipe or whatever the hell else. Any animations or generative graphics can be scaled and reapplied etc as much as I like and it'll have almost zero impact on performance. If I use the Teensy 4.1 arduino board, which has an onboard SD card. I can load bitmaps or GIFs onto it to display on the screen as well. Basically, in conclusion, I've found a digidash option that is an animated, low res version of MSpaint. Who'd have thought that in the year 2023 there are such glorious technologies available for those of us wanting to draw pointless low resolution graphs in real time. Living the dream!

I'd have thought that whatever the load source, you'd just have slightly different VE numbers at low throttle with it disconnected?

But higher differential fuel pressure is better fuel economy

I'd go a step further and not bother putting vac on the FPR at all. As there's no real point in reducing fuel pressure for NA setup.

If you advance the ignition timing and the engine wants to make more power, but it cant because it knocks - then higher octane fuel will help your motor make more power, by allowing more ignition timing without knock. If you advance the ignition timing and the engine makes same or less power, with no knock. Then a higher octane fuel wont do anything. If you just switched fuel to something different with no other changes, it's unlikely you'll make any more power. Unless you're using partially oxygenated fuels (like E85) or nitromethane or whatever. hah. I'm fairly sure that back in the day, when MSNZ banned avgas for racing (or something similar, paraphrasing horribly probably) Everyone had a big sook about it, but then retuned their cars for 98 octane and found they made the same or more power anyway.

Generally a waste of time compared to 98 octane pump gas. The only reason I can see to use it would be if there's some specific reason you need leaded fuel. Like some janky old valve seats or whatever.