ajg193 Posted June 27, 2022 Share Posted June 27, 2022 Remember to add a touch of titanium Quote Link to comment Share on other sites More sharing options...
Roman Posted June 27, 2022 Author Share Posted June 27, 2022 Even if i was a casting master, and i know absolutely nothing about it. There would be no benefit if current pistons are at the strength limit of cast material without forging. And there's no way to DIY forging as best I know. Machined from billet might be an option, or see if anyone sells unmachined forged blanks that are close enough. However I'm also not sure how much stronger billet would be. Quote Link to comment Share on other sites More sharing options...
Spencer Posted June 27, 2022 Share Posted June 27, 2022 Will be easy to get whatever piston you want made for this if you have $$ (like $1500-2000 at a guess) we will need to up the kitty moneys though lol 2 Quote Link to comment Share on other sites More sharing options...
Roman Posted June 27, 2022 Author Share Posted June 27, 2022 Yeah the lads in Thailand sell forged pistons in whatever CR you request. Up to 15:1 But they're pretty spendy. (Compared to rest of project) heh However my Dad has ordered a 4 axis cnc that will arrive probably in a few months. Pistons and/or rods might be feasible projects eventually. But start with some easier stuff while learning. Could maybe do a cnc port job as well, not as well as a 5 axis but would be cool. But gonna be a learning curve. 8 Quote Link to comment Share on other sites More sharing options...
shrike Posted June 27, 2022 Share Posted June 27, 2022 39 minutes ago, Spencer said: Will be easy to get whatever piston you want made for this if you have $$ (like $1500-2000 at a guess) we will need to up the kitty moneys though lol Wonder if there is any off the shelf option from another motor Or anything fun on aliexpress Was it ca18 pistons in a 4k or something like that, maybe it was Honda ones I can't remember "Rzcrew Garage - Forged Pistons 76.5mm - 8:5 to 15:0 Compression Ratio - Toyota - 1NZ-FE - RZ-FP-1NZ-FE - 8:5.1-75 - RZCrewEurope – RzcrewEurope" https://www.rzcreweurope.com/products/rzcrew-garage-forged-pistons-76-5mm-8-5-to-15-0-compression-ratio-toyota-1nz-fe-rz-fp-1nz-fe-8-5-1-75?variant=18299895775343 15:1 605euro :p 1 Quote Link to comment Share on other sites More sharing options...
Roman Posted June 27, 2022 Author Share Posted June 27, 2022 Oh yeah so about $1000nzd, not too bad I guess. Maybe closer to 1300 after tax and shipping. But 15:1, sweet I can run it as a diesel too haha! Yeah it looks like Honda D16 motor, Suzuki vitara motor, and 4efte are possible similar options with similar pin and bore size. But people normally put the strong vitara pistons in the d16 motor and make 400hp. But the horsepower load on a cast piston is different to the rpm trying to pull the piston apart. 1 Quote Link to comment Share on other sites More sharing options...
GARDRB Posted June 27, 2022 Share Posted June 27, 2022 22 minutes ago, Roman said: But 15:1, sweet I can run it as a diesel too haha! Flexfuel, diesel or methanol 3 Quote Link to comment Share on other sites More sharing options...
h4nd Posted June 28, 2022 Share Posted June 28, 2022 On 26/06/2022 at 17:04, Roman said: Either way, it might be a good idea to drill some tiny chamfers on the oil holes next time for stress relief. But I'm not sure if you can get a drill anywhere near it while the piston is intact. So, hopefully the rods are the problem and not this haha. A old-style Dremel with flex-shaft is only about 18mm around the handpiece. Set a ball end tool in there miiiight reach? (Jobmate dremel clone flex shaft is poor, avoid.) Or do it reeeally slowly with one of these? https://www.aliexpress.com/item/4000126830373.html Quote Link to comment Share on other sites More sharing options...
h4nd Posted June 28, 2022 Share Posted June 28, 2022 1 hour ago, shrike said: Wonder if there is any off the shelf option from another motor Or anything fun on aliexpress 1 hour ago, Roman said: Oh yeah so about $1000nzd, not too bad I guess. Maybe closer to 1300 after tax and shipping. But 15:1, sweet I can run it as a diesel too haha! Yeah it looks like Honda D16 motor, Suzuki vitara motor, and 4efte are possible similar options with similar pin and bore size. But people normally put the strong vitara pistons in the d16 motor and make 400hp. But the horsepower load on a cast piston is different to the rpm trying to pull the piston apart. Or CBR 1000 from '04, at $89 (if 17mm is a reasonable height for yours?) https://www.aliexpress.com/item/1005003624664740.html 1 Quote Link to comment Share on other sites More sharing options...
GARDRB Posted June 28, 2022 Share Posted June 28, 2022 At what amount on the give a little will you go for hayabusa?? 1 1 Quote Link to comment Share on other sites More sharing options...
Roman Posted June 28, 2022 Author Share Posted June 28, 2022 Ahh wow never considered bike pistons! I will have to get out one of the remaining intact 1nz pistons and measure it up haha 1nz piston has a compression height of 27.5mm (top of piston to centre of pin) Ideally find something with a slightly higher number so I could machine the top to get the compression ratio right. If the compression height number is lower, it will drop CR too much. Might be worth buying one of those pistons to have a look though. I'd need to press out the bronze bush in the rod and refit one for a 17mm pin instead of 18mm. Or hone the pistons to suit 18mm pin. But I'm guessing the bike one will be strong enough and probably lighter. 1 Quote Link to comment Share on other sites More sharing options...
h4nd Posted June 28, 2022 Share Posted June 28, 2022 Maybe near these numbers: https://rzcrewgarage.com/products/cp-pistons-kit-11-5-1cr-75mm-bore-toyota-1nzfe-sc7447-sc7447 Specifications: Manufacturer Brand: CP Pistons Part Number: SC7447 Compression Ratio: 11.5:1 Bore (mm): 75 ( STD) Stroke (mm): 84.7 Rod Length (mm): 140.8 Pin Diameter (mm): 18 Compression Height (mm): 27.6606 Block Height (mm): Piston weight (Gr): 226 Replacement Parts: Pin: 708-2250-15CP1C Rings: CPN 2953 Locks: 708 050 SWL Quote Link to comment Share on other sites More sharing options...
Roman Posted June 28, 2022 Author Share Posted June 28, 2022 23.5mm compression height on the bike pistons. Bummer Quote Link to comment Share on other sites More sharing options...
Roman Posted June 28, 2022 Author Share Posted June 28, 2022 1 hour ago, GARDRB said: At what amount on the give a little will you go for hayabusa?? Nah. I just need to buy Hayabusa pistons, Hayabusa rods, Hayabusa crank, Hayabusa block and head. Then I'll have the world's fastest 1NZ 1 2 3 Quote Link to comment Share on other sites More sharing options...
RUNAMUCK Posted June 28, 2022 Share Posted June 28, 2022 After you window the block on your next engine, the round after that of give a little should stretch to forged pistons. Quote Link to comment Share on other sites More sharing options...
Muncie Posted June 28, 2022 Share Posted June 28, 2022 Brian crower has some rods and other bits on clearance on the website for around $250us was looking for buick stuff. Have a gander 1 Quote Link to comment Share on other sites More sharing options...
Popular Post Roman Posted July 2, 2022 Author Popular Post Share Posted July 2, 2022 Thanks to everyone that pitched in some bucks for a new motor! I closed the page after there was enough to buy one. So thanks an incredible amount. Will have the money through some time next month, so will buy a motor when I can. Hopefully I wont let you all down somehow. I've been doing a bit more nerding with the piston/rod situation. I've been thinking that maybe one day I might be able to CNC a piston from billet, so drew one up with all of the important dimensions as per a standard 1NZ piston. I've made it so that all of the internal piston geometry has no overhangs that you couldnt machine from a vertical tool head. So it looks like it would be possible to machine this in 4 main operations. But I also have absolutely no bloody clue how much extra complication there is in real life to do this. However while doing this, it got me more thinking about how universal pistons and rods potentially are. The only things about a rod that need to be correct are the big end diameter matching your crank, the pin hole matching the piston, and the overall length matching the piston and rod's combined height to top of the block. So the main things I've needed to look for are: 43mm big end, 18mm piston pin, 140.9mm rod length if using standard pistons. The 1NZ has quite a long rod, so although there are some other Toyota engines with a 43mm big end and 18mm pin (4EFTE) they have much shorter rods. Around 130mm or there abouts. Early 4AGE have a 43mm big end as well, but also shorter rods and I think they had a 20mm pin. There were some non Toyota engines that had a 43/18 combo, but rods too short. Since I'm potentially looking to use a bike piston which has a lower compression height (center of the pin to top of piston) I need to find a rod that's a little longer than 140.9mm to make up the difference. The GSX1000R pistons look really nice and light, and they're cheap and normally do 11,000rpm. Buuuutttt the piston top to pin distance is 4.16mm shorter than 1NZ pistons. So to run those with no other changes I'd need a rod around 145mm long. However, despite a caffinated internet binge until 2am. No luck. The only rods that are longer than 1NZ with the correct sized big end that I've found are from a Honda L15A motor. Which is the 1500cc engine out of the Jazz etc. These motors have a smaller bore and an even longer stroke, and have a 149mm rod. (Wow!) and a matching 43mm big end and 18mm pin. MaxSpeeding makes rods for these motors as well. The problem with a 149mm rod is that even with the shorter bike pistons they would stick out the top of the block by about 4mm which is too much to be able to machine off the top safely. However this rod might work for a 2NZ crank in a 1NZ block setup. For some mega revs. The long rod setup, for a 1NZ piston needs a rod which is 152mm long. So that's 3mm difference than what I get with the L15 rod - Meaning if I can find a piston with 3mm larger compression height, it would be bang on. 1NZ compression height is 27.6mm D16 Honda motor is 29.5mm 4EF(T)E is 29.9mm D15B honda 30.7mm So a 1NZ block, 2NZ crank, L15 rod, and a D15 piston would be 0.1mm taller than the original 1NZ piston deck height. Hah! These pistons have a flat top on them, so still might end up with a good compression ratio. So this has been a fairly pointless exercise in terms of finding any better pistons or rods for the 1500 setup. If pistons want to keep flying apart I'll just have to save up some bucks for forged 1NZ pistons. However it would be interesting if this 1300 combo could be chucked together for cheap-ish. 16 3 Quote Link to comment Share on other sites More sharing options...
ajg193 Posted July 2, 2022 Share Posted July 2, 2022 Aren't pistons not actually cylindrical? I thought quite often they are a bit bigger diameter in the middle or something. Could make it a bit more difficult to machine without a lathe or millturn machine Quote Link to comment Share on other sites More sharing options...
tortron Posted July 2, 2022 Share Posted July 2, 2022 They are tapered. Because they don't heat up evenly. Crown will expand more than the skirt *oh yeah, the bit in the middle. The taper sort of tapeers back in to the bottom, so you have a surface/ring that takes the thrust against the cylinder wall. Probably a bit of tuning in getting that right and getting a good sealing, long milage piston at many many rpm. You could ignore it for something that's getting rebuilt every few runs Quote Link to comment Share on other sites More sharing options...
Roman Posted July 2, 2022 Author Share Posted July 2, 2022 Interesting! Did not know that. Will take some measurements when I've pulled out one of the more intact pistons haha. 1 Quote Link to comment Share on other sites More sharing options...
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