Roman

If I do some calcs for how much I've removed, being on the generous side at each step of the way it's something like 0.015cc per valve. Then maybe some extra off the bridge parts so lets say 0.1cc total per chamber or even double it to 0.2cc per chamber Then it's still only lost say 0.1 CR absolute max. So I'm still waaayyyy ahead of where I would be if I had to use the 13:1 pistons to get VVTI working. Or If I had to dig some valve reliefs into the pistons. So if it can breath only fractionally better at high rpm it's well worth the trade.

Thats a good point its likely grade 4.6 rod. It didnt shear the bolts though, they just came out from vibrations.

After what seemed like an infinity amount of hours doing some exploratory porting on my spare head, and getting comfortable with the various dremel tools and when best to use each shaped bit. I've decided I'm ready to do some porting on the proper head. One problem I needed to address first though. Has been that each time I have needed to get the valve springs fitted, the local engine shop has had to do it. And it's taken then weeks to get it done each time. Buying a generic valve compressor tool probably works fine, but I dont have any budget for that currently. So I did some measuring and printed a tool to work with a G clamp. Works good! I can get those son of a bitch tiny valve retainers in place by my self now. Time to pull things apart. Since I've done this all a few times now, it's pretty quick to get the head off. Quick inspection - No signs of detonation on the pistons, and the really nasty residue buildup from when I first got the motor isnt there anymore. The pistons look quite dark compared to before, not sure why. Perhaps just a bit of regular old carbon build up. Something funny I noticed while pulling things apart to get the head off. The alternator was only hanging on by the tensioner bolt. The main bracket had both of the bolts had come completely out. I'd noticed in the logs from the drags that the motor had been dropping battery voltage with more rpm, and it was worst in first gear. So it was obviously belt slip. I've bought some threaded rod so I'll wind some studs in and loctite them into the block. Then use some spring washers on the nuts. Hopefully that'll fix it. So progress on porting the actual head has been much faster than expected. Everything I've read about porting has said "Do one small part on one cylinder, then move to the others instead of doing 1 port all at once" I thought this would be massively tedious but it actually speeds things up a whole bunch. Because you get your technique good for that area then apply it 3x more. Then figure out how to do the next part. The main issue I need to avoid on this good head, is damaging the valve seat. I absolutely 100% want to avoid needing to get the seat remachined. Because of the time factor involved with getting someone to fix it. So I took 4x valves from my spare engine, and ground the faces down to be just about level with the valve seat. Then put these valves in place while I worked on each combustion chamber. This also made progress massively faster in this area, as I could get stuck in with a higher tool speed, without worrying about critical damage. I'm reasonably convinced that removing the lip around the seats in the combustion chamber, and the bowl area will be responsible for any/all improvements. Which is interesting because I'm pretty sure that most CNC porting jobs I've seen look like they're just hogging out the port from the port end. Rather than doing anything in the chamber. (wild assumption) I'm 50/50 on whether downsizing the injector boss will help much, seeing how it's a bit further up the port. However this is possibly laziness talking as it's quite time consuming. Will do it anyway while this is all apart. Here's some cross sections showing changes made in the chamber. Red is standard shape and green modified. Basically I gave up on trying to be stingy with material removal, and opted to do what I think will maximize flow at low lift for both intake and exhaust. Apart from the combustion chamber changes the exhaust side looks like it will definitely benefit from reshaping the roof at the transition of the machining to the casting in the bowl area, as it was quite gross. All that's left to do now is tidying up the ports from the port sides. Then spend a bit of time polishing the modified combustion chamber faces so there's hopefully no surfaces which will induce knock. Hopefully not too long and I'll have this all back together. Also good news, with Auckland travel restrictions lifting. I'm able to start getting my Hoist in place, in the shed. Once this is done, I will make a start on a better exhaust.

If you look at cars that need to run restrictors on the inlet, like FSAE or whatever. They basically all have super duper bellmouths/tapers on the pipes. Because getting the air as straaiiiggghhhttttt as possible is absolutely necessary when you're trying to fit as much as possible through such a tiny hole. So I think you're right @Yowzer in that a smaller runner would amplify the differences. BUT. If your runners are so small that it has a massive effect, then the first thing to do is make the runners bigger. (So long as you're allowed, which 99.9999% of cars are) As I dont think KPR has seen any instance of where smaller runners actually helps? Yet the gains from making them big are good, so long as the length is right. We live in a world where 1600 NA engines thrive on 52mm throttles and 3" exhaust, have the rules of physics changed since the 90s? Where this all would have been insanity? haha God I love that we have the technology to do all this stuff and the awesomeness of @kpr to test it all and break down myths that should have been extinguished 30 years ago.

The point of the swirl design was to see if having a capped end meant you could reflect a stronger wave. The idea of swirling it in sideways was that there is no straight accoustic path to the outside, its at 90 degrees. But there were no interesting peaks or troughs. I dont think its an issue with surface area of the slots, just that swirling the air in is hugely counter productive. Especially as it approaches the throttle plates that are trying to make the air go straight 50/50 under and over. You might end up with high air speeds around the side and none in the middle, and none if it helps get the air moving in the direction its meant to go. In summary: A++ will submit more silly designs in the future

It doesnt even have a tacho Nah the rods are straight, but on one side of the block they come reeeeaaallll close - most aftermarket rods you need to grind the block to make them fit. JUN conrods are actually a bit banana shaped so they fit without needing this. But those are like 4x as much so yep, die grinder it is. haha

Due to overwhelming peer pressure I decided to set the rev limited to 9100rpm and see what happens Horsepower has peaked earlier but its still worth holding the gear so you drop down closer to peak HP Keep in mind fuel, ignition and vvti angles have fallen off the end of all of the tables haha. So not optimized. Let me explain what it sounds like: fucking excellent. I've added a 9k rpm column to my fuel table, and then adjusted VE values to suit results. It's not falling right on its face, at 8500rpm showing 107.5% VE, now at 105.2% So once stronger rods are in I cant see any good reason not to keep going even past that

Yeah, good point! Although, to be fair I've stopped having problems with the crank bolt coming undone since doing it up tighter, and using some loctite haha. If the crank had a keyway in it, I bet I never would have had problems in the first place. Just a cheaper shittier design this way. It's quite smooth at high rpm though, it doesnt feel like it's going to explode into a billion pieces. Like I cant quite explain it, but some motors happily do high rpm but dont sound happy about it. It quite happily revs out and feels/sounds like it wants to keep going. Not a particularly scientific conclusion but there you go. haha

Yeah! Must something like that. Says in toyota stuff that it's done for sake of more torque. Also some of the above stuff is incorrect because I just read its got a 12mm offset not 11. D'oh. Will be the same but more exaggerated I guess. Also, gash expansion is an interesting typo to make

Here's some afternoon diagrams to go with the morning graphs @yoeddynz So while I was trying to figure out the VVTI situation, I was trying to think if the crank being offset in the block helps give piston clearance for vvti (piston accellerates away from TDC faster?) The crank sits 11mm further towards intake side of the engine, relative to the centreline of the bore. I just finished some of the drawings to take some measurements from to try understand whats going on with this. So there's some weird shit that goes on as the piston accellerates at different rates depending on if its coming down or going up. (when rotated clockwise) When the crank is laying flat at 90 or 270 deg, the piston is a different distance up the bore for each. On the way up, it's 6.962mm higher by that time, than the way back down. Then also, the crank angle at which the rod is perpendicular to the crank, happens at an earlier time on the combustion stroke than compression stroke. It happens at 21 degrees above horizontal instead of 12.44 degrees. Maybe there's a better gas expansion ratio at this point, of the gas expanding relative to the combustion chamber volume expanding. So more force can apply on the crank. Or something else dunno. Either way it's weird shit. Also some weird shit happens around 90 deg of crank travel on the combustion stroke. Where the rate of accel does weird stuff. I'm guessing this is also something to do with having the piston exert more force on the crank at that position.

KPR's 10k rpm comments are in reference to... well... doing 10,000rpm I have no idea what would be the next weakest link. These rods come with ARP bolts and they state they are 9k capable / 600hp rated. It's all just guesses at this stage, there isnt a well established group of people revving Prius engines to 9k haha. It seems Thailand has the most love for turd polishing 1NZ motors. But the language barrier makes things tricky. And yeah the thing with porting the head is that you can increase flow but if you are already at 100% VE then you're not magically going to stuff 30% more air into the engine. But the thing is, fuel table generally indicates where the most airflow happens which relates to peak torque. So even when this starts to nose dive, you're still gaining horsepower. This is fuel map from an old tune on beams motor: The big hump of peak VE is at around 6500-7000rpm then drops off pretty sharply - but still makes best power past that point. (Weird wobbly shit on the graph is thanks to MAP as load source and possibly weird exhaust related harmonics with massive ports) Then look at the prius one If someone showed this to me without the rpm scale, I'd be thinking "Where's the other half of your fuel map? It's not what I would have expected at all.

Nah it will be fine* *until it isnt

I'm in a Facebook group chat about Toyota stuff. Obviously these people have no idea who they are dealing with

Speak of the devil Disregard low end grunt, acquire 9000rpm

Haha yes, I agree. Also it's been enjoyable driving it with the airbox on at night time, because I'm not doorting some poor rural persons kids awake from 3km away haha. So I'm not at all keen on a loud exhaust. Can hopefully keep it reasonably quiet. With my Carina I was surprised how rowdy it wasnt with only straight through mufflers. I'd originally flanged the rear one so I could swap for a chambered muffler to keep it streetable. But didnt need to in the end. See how it goes.

I'm onboard with KPR's school of thought / observations, that beyond the extractors and a short segment after that, the rest of the exhaust is just gas transport. Nothing to do with tuned length, velocity, etc helps. Even on his near stock 20v, removing the exhaust after extractors gave gains. So yes this will get a 3" pipe at some point, haha. Adding a restriction or back pressure never helps. With the porting vs exhaust situation. If you look at the big dick swing K motors with custom heads etc, and they will hugely favor the intake side valves, even at the expense of crappy positioning for exhaust side. So I think porting will help to some extent even if I have a stink exhaust, IF it's allowing a higher amount of fresh air to be captured at higher rpm. I found a chart from someone who ported a 1NZ head. So the maximum lift cams you can get for a 1NZ are 9.5mm lift, that equates to 0.37" on the chart. So if you look at what an unported intake side flows at 9.5mm as is, its about 160cfm. With ported intake side, you now reach 160cfm at about .25" or .26" which is about 6.6mm lift. So instead of having that peak flow value at the impossibly fractionally small amount of time that the cam sits at full lift, you've now broadened it, and this goes all the way down the chain embiggening the flow capability of your cam at all lift values. Which is valuable in this case because I cant actually get any cams bigger than 264 deg 9.5mm lift. On the other hand, it's still possible that this is going to achieve nothing until I've sorted the exhaust. But that's fine too, because exhaust will definitely happen, just not yet.

The next most logical thing to do on this car, power wise, is leave it alone and just drive it the exhaust. However I'm a bit road blocked on that currently, for a variety of reasons. So I've been having a think about leaving it alone and just driving it what else I can do for free/low budget. So its time to just drive it give a head a tickle up and see if it makes any difference. The following is best guesses with no actual testing or proof. So take with a grain of salt. The "bad" news about porting a 1NZFE head seems to be that most of the tutorials that I've seen, work to address problems that dont exist with a 1NZFE haha. Because a modern factory casting/machining/port design are quite good to begin with. If they were shit, I probably wouldnt be seeing 8500rpm already. The intake port side is very steep and has an awesomely shaped short side radius. The valves are decent size for displacement, and the bowl area can be tidied up a bit but isnt the worst thing I've ever seen. There are some casting marks to tidy up but they're not incredibly dreadful. I am thinking the areas that will show tangible improvements on a 1NZ head are: -Deshrouding the intake valves, on the combustion chamber face. So removing the slight lip that exists from the machining process. This should hopefully give better flow when the valve just comes up off the seat. So I guess it's kinda like having a slightly longer duration cam for "free" as your useful airflow starts at an earlier amount of lift. However need to be careful to minimize the amount of material lost, or compression ratio starts to drop. So I dont think I will do the exhaust side, as there's less benefit when the flow direction is reversed. (For a turbo motor I'd do the whole lot as losing a smidge of CR isnt detrimental in the same way) I'm thinking that this will either be marginal to the point of being completely pointless, or possibly the most important change of all. Then in the intake port, smoothing out the transition from the machined bowl area into the cast area. And reducing the size of the injector boss protrusion. Then also narrow up the divider a bit, but maintain a rounded nose on it. I'm not sold on the idea of knife edging. I doubt there are going to be any massive gains here. Maybe nothing at all. But even the tiniest improvement cylinder filling at 8000+ rpm equals potentially a tangible difference. Either way it's something fun to learn about and it's "free" in that all it really costs is a whole lot of time. Haha. This is a junk head (RIP 2NZFE) which I've been practicing on so far, I managed to cut right through the injector boss seat from inside the port... But now I know how far I can go without issues. Will be fun to see if it makes any difference once I've done a proper head. But it's heaps of work. Definitely earning those 1.5 horsepower gains haha.

Yeah that's worthwhile! It's amazing how all that stuff can add up, and you have a supposedly light engine drowning in accessories weight.

Good effort! The more I look at the yellow car, and the more I've looked at that other thread and seeing these IRL. The more I'm convinced you probably own the least dented one on the planet

They must be ramen the air in

Assuming some of the shorter ones will be on extensions, and since this is kinda like horse racing I'd say: 1. It's Ramen men, hallelujah 2. big straight blue lagoon 3. big white badonkadonk 4. green swirly boiz 5. smaller than average, white, but an arse like a jack hammer 6. blue screw drivers If we could get all of the dyno plots overlayed and slowly increasing rpm then get someone to narrate over the top like a horse race please

second place is the first loser (to noodles)

In reference to the start of this discussion, which was my car heat soaking (or at least, the IAT sensor heat soaking) at the drags. It's a very simple thing to replicate. Because I can just go for a drive with lots of airflow, do a full throttle run. Then leave the car to sit idling for a significant period until the IAT gets high again (with IAT sensor set to observational only, not changing tune) Then do another full throttle run straight away. Then monitor the percentage of difference in Lambda value of the two runs, and the two idle speed conditions. This will show what the "Real" heat soak value is at each end of the spectrum. Thinking about things a little more though. Since my motor has very high compression, I think it's likely that the heat of compression is probably considerable. So the IAT being 20 or 35 deg probably doesnt make too much difference. From a knock perspective, perhaps IAT isnt that relevant. If that is the case, then it's just adjusting the fuel trim by a % that's needed, based on observational result. Calculations are good for giving a starting point, but observation gives you the sum of all variables, some of which you cant calculate for. From my drag runs, with goal AFR of 12.8:1. In the third gear runs I was just slightly richer of this target. In the first gear runs with heat soaked IAT sensor, I was sitting around 13.2:1 So a definite indicator that the air coming in was cooler than IAT was reporting, so skewing the airmass result. TL;DR: Unplug IAT next time hahaha

Arent you double dipping by multiplying the axis by both MAP value and VE?

Yeah to had to swap in the guts from a later model speedo to make it work. Was from an st202 celica or something like that. The odo came with it, and I lost my trip meters. The tacho worked just with the addition of a resistor, from memory.