As an automotive tech, I gotta jump in on this. If your timing chain is on the back of the block, it means the engineerings give a **** about what they're designing, and are at least trying to improve.

As for the K-motor, am I reading this correctly? A stock turbo K's limits are about the same as a built turbo BP? Ignoring ye old turbo stud issues...

 

This falls right into the age old "mechanic vs engineer" battle. Yeah timing chains at the rear probably makes great sense from a design standpoint, but are a nightmare and disaster from an end user serviceability standpoint. And as a mechanic... You know which side of that fence I'll stand on.
Depends on a lot of things, but a stock K with a smaller, rapdly spooling turbo setup should probably be kept at or around 400whp/400tq to remain reliable and non-block venty.
I've seen K's with much larger, slower spooling turbos make 600whp reliability.

 

Probably best to use less aggressive timing than the map I posted. I found cracks on my stock sleeves on 3 out of the 4 cylinders. I only had like 10 hours of run time. My tune had a very mild boost ramp and made 395whp on a dynojet. My engine was bored for a 87.5mm piston. I bought a ramey racing sleeved short block, so hopefully my engine issue are done now.

 

Bare block, freshly painted. Bored out .5mm to 87.5, cleaned, decked, line honed.



Perfectly balanced crank installed on ACL main bearings. Plastigageing to confirm the machine shop's measurements.



Everything checked out, doused in assembly lube, applied sealant where needed, bedplate on, mains torqued



Wiseco 87.5mm pistons assembled on Eagle rods with King rod bearings and ARP bolts. #2 was too tight on the wrist pin. Since I had to make a trip back to the machine shop anyway to pickup the head, I took it back to them for a quick polish and it slid home smoothly after that.



Kpower windage tray interfered slightly with the ARP rod bolt on #1. Pretty sure this is a long known fitment issue, nothing chopping a small hole in the baffle doesn't fix.


Closeout photo of new pickup, windage tray, and modified oil pump installed, torqued, and ready to be sealed up


Ummm... yup. No comment your honor.



Hottanks are miracle machines. Last time I saw this head it was yellower than 70's wallpaper, stained with years of weathering and 30k mile oil changes. Now... its factory fresh. Skimmed, cleaned, pressure tested, valve job, In/Ex supertech bronze valve guides, Ferrea valves, supertech dual springs and Ti retaining hardware.





ARP headstuds, new headgasket, fingers crossed I don't regret not opting to sleeve this thing.



Cam towers and stock cams in, more red juice liberally applied.



And that's where I left it for tonight.




I'm waiting on a rear main seal. I herp derped and forgot to order some minor items, RMS was the only thing I didn't have spare of on hand. By the time it shows up this motor will be well assembled and ready to throw into the car for startup and breakin.

 

Gah damn! Just a bit of a step up from the last one eh? Stoked to see it fire again.

 

Wow, haven't checked this thread in a bit and holy moly it really blew itself apart! You've been hard at work props man!

I'm personally not a fan of sleeved blocks as I saw some issues with sleeved motors (granted this was ~20 yrs ago, maybe things are a bit better now). This was on old honda B series motors. One was a golden eagle sleeved block (don't know if they're still around) and another Darton. One sleeve sunk a bit after the engine ran and the other would leak coolant from the water jacket into the crankcase. If you can avoid sleeving I think it's just one more failure point to avoid. Perhaps this is a non-issue these days, Jeremy Allen is local to me and supposed to be top notch, but I'm very skeptical of sleeved blocks. The OEM Honda steel sleeves are cast into the block have "ribbing" (yes for pleasure ). I cracked an oem sleeve on my old b18c back in 2003 and have a piece around still. Aftermarket sleeves are press fit and can shift more easily (I think).

That's a lot of boost and power you were pushing. The K24 has cast pistons right? At ~500whp I'd think anything that's slightly off could be trouble. On my F22, I know people can make 5-600whp easily on the stock motor, but most of these guys are just doing straight line racing which is simply much less stress on everything only being short bursts. I'm making almost 400whp on my turbo s2k, and originally built it to be a track car, but puzzied out as parts/motors/chassis are expensive these days. There are some turbo s2k track cars but most seem to be only ~450whp mark, no more. Honestly at >500whp I gotta wonder how often/how many hours you can expect a motor to last on track. This is where I start to wonder if more cylinders is the answer as it's spreading out the "load."

I completely agree. Germans do some stuff, which may make the engineers happy, but is a pita in the real world and unnecessary.

 

I snapped a picture of the old sleeve I keep in my toolbox. It's a good reminder to not do stupid ****. My integra was running great. Built motor with .5mm overbore wiseco pistons, eagle rods, stock sleeves. Running 1.1bar on pump gas, t3/t4 50 trim. The car started missing on the highway a bit that night but on the way home someone pulled upto me at a stoplight and started revving at me. Of course I knew the car started missing but said F it. Spinning first and 2nd, shifted into third, and giant cloud o smoke. The sleeve let go. If I wasn't a retard I would've never raced that idiot but that's what happened. :( In your early 20's you do dumb ****.. lol Sorry for the rambling.

 

@SlowTeg Pretty sure sleeving tech has improved. I've seen tales of a few botched jobs, but the vast, vast majority of high HP(800-1500hp levels)K24 builds are sleeved. I think CSS is currently the go to for sleeving, and the installed steel sleeves are much, much thicker then your toolbox ornament appears to be. The entire cylinder area of the block is completely milled out on a CNC machine and one piece sleeves/block guards are pressed into place. It's not just a steel liner pressed into a bored out aluminum chamber, its effectively a completely new set of combustion chambers fitted to the OE cast aluminum block.


Few catch-up items before I get into the good stuff and forget about them.
Shifter itself was great. Tight, notchy, felt just as good as my old shifter. Two issues. One, due to the slight tilt on the transmission(the Fisch bellhousing adapter assumes you maintain the original ~10° of the K24. The Kpower mounting does not), the completely vertical, normal 3rd gear position was... 5th, first was tilted very heavily towards the driver, and 3rd was imperceptible between the two.
Second... The shifter was actually a little too close between the gears for my liking. It took some slight concentration to land the desired gear, instead of being purely natural.

I fixed both these issues by chopping the shifter handle off the base, welding on about 1.5" of height, and giving an angle to it so it now sits perfectly vertical on the neutral position. The resulting additional leverage and natural position has GREATLY improved the shifting feel and driver comfort. Once painted and with the tunnel cover in place, you can't even tell the shifter was modified from an aesthetic view.



I've been wanting to do this for awhile, but didn't have the ***** to drill a hole in the turbo manifold till now. Finally manned up and destroyed a bit drilling though that solid piece of stainless. EGT added so I can monitor combustion temps and shut things down before things get too spicy.


I stole this trick from a buddies timeattack car, and replaced my terrible amazon knockoff fake carbon side mirrors with cameras. 130° field of view on each, much less drag due to only having a small camera in the airstream, and was fairly cheap to do. While these 720p displays are not exactly crystal clear, they will be plenty to see anything alongside in the paddock or track.










Timed, valve cover on, rod bender bolted up, ready to be mated to the transmission and installed.




And shortly later, installed in the car. The days of being able to have this engine go from engine stand to installed for fireup inside an hour are definitely gone, even with my efforts to keep assemblies unboltable and modular, but its still doable in under 2.5-3hrs or so.


And as of yesterday morning... we have successful light off. Few minor hiccups during initial heatcycle, but nothing that wasn't able to be remedied quickly. Made terrific oil pressure, reached and held operating temp, and is the smoothest idling engine this chassis has ever seen, K or BP. Fully balanced rotating assembly ftw. Now to drop it on the ground, take it out and start breaking it in on the street.

The wastegate is wired FULLY open because otherwise I just wouldn't be able to help myself...

 

Honda motor, blind spot cameras just like the new Hondas… what’s next?

Seriously, the camera idea is badass. Bet the line of sight allows you to keep your eyes closer to what’s happening in front of you while “checking your mirrors” as well.

Oh, yeah, and I guess it’s cool your new engine is running too. Congrats dude, that was a quick turnaround all things considered!

 

I'd like to think technology has improved, but not necessarily. Maybe the machinists that install sleeves are simply better/more careful/tighter tolerances, but the closed deck sleeves haven't fundamentally changed from 20+ yrs ago. I never said sleeves don't work and aren't stronger. Of course a sleeved motor can make a lot more power, I was just saying it adds another failure point (if you don't need it). The point about the picture of the sleeve I posted is that the steel liner is not just a straight piece of steel. It has "ribbing" that holds the sleeves tightly in place and is cast into the aluminum block/water jackets with aluminum surrounding it and is MUCH less likely to move/shift than aftermarket sleeves (which are "only" pressed in place). It's irrelevant how "strong" a sleeve is if it shifts a tiny bit and pops a headgasket. The weakest link is obviously not the sleeve itself (on a sleeved block).

Anyway, nice progress on the build.

 

Excited to see this thing start ripping again! I feel like I should know this, but is that a g25-660?

 

Yessir, G25-660, .92AR. Love this turbo, comes on super early, and should still make killer numbers up top.


Had a handful of minor issues during the initial heatcycle and subsequent 50mi break in, but nothing directly motor related. Coil pack died, loose ground, misconfigured trigger setting throwing VVT errors, blah blah blah. Didn't immediately spin a rod so I'm happy.
Did 50mi or so of WOT --> high vacuum coasting to fully seat the rings, then dumped the break in oil and put real oil in. Another ~50mi or so for my own sanity, then re-installed the wastegate and gave it some positive pressure.

Also had my oil pressure sensor fail while oil priming the engine(why is it not building oil pressure??). The sensor seems to have internally failed and allows oil to freely gush though it into the connector, and then onto my garage floor. I tossed a harbor freight gauge on there as a temporary measure until I got the parts in for this:


The line insulates the sensor itself from the insane engine vibrations that kills sensors(to date, 2x TPS sensors, 1X oil pressure sensor). I've been warned this could happen with directly mounted sensors but kinda stuck my head in the sand about it till now.
Unfortunately since that sensor was both my oil pressure and oil temp, temp is waaaay off due to the static oil in the line not heating as quickly as block oil. Coolant could be at ~190* for half an hour and oil "temp" will barely approach 120*. I might add a pan or turbo feed temp sensor at some point in the future for more accurate readings.

Both my exhaust mounts broke 3rd or 4th time out. This is not the first time this has happened, I guess the weld area is just too small in relation to the vibration it sees.


So for the forward mount I wrapped the mount halfway around the exhaust, giving it a ton more weld area/strength then before, and for the rear I didn't weld it to the exhaust at all. Just bent up this compression mount that wraps fully around the pipe. This results in some more rattleage then before as my DIY exhaust hugger mount isn't perfect, but physically prevents the exhaust from being able to fall off even if the forward mount fails. Both mounting bolts get safety wired, otherwise they rattle out within an hour or so of drive time.


Speaking of vibrations, I hate having the motor half solid mounted. Every shift under power feels like something is going to break from the shock load(having a mostly solid mounted diff probably doesn't help this feeling). The vibrations and harmonics at certain RPM's are headache inducing. Next opportunity I get I'm probably throwing the OG rubber Kpower/GM mount back in there and wrapping it in heat reflective tape to try and keep it alive. Or maybe I'll make a new mount that incorporates a traditional poly bushing. But the solid mount feels so incredibly bad to drive with, and I've had to crossdrill and safety wire an additional dozen bolts on the chassis to keep things in place.

Also had an alternator die *again*. If I add this one to the count for the 2023 season(since its seen maybe a week's worth of drivetime in 2024), I think that's four alternators killed for one year. Gets really annoying dropping $1K worth in rebuilding alternators, plus having to swap them in and out, per season. Frustrated, I threw everything at fixing this somewhat common problem.
OEM Crank pulley replaced with a smaller drive Fluidampr. Alternator pulley replaced with an MPC underdrive pulley. Bosch Alternator replaced with an OEM Denso.
By my calculations, the OEM pulley setup was spinning at 20800RPM when engine RPM was 8K.
With the underdrive pulley and Fluidampr, now it should only see 11700RPM when engine RPM is 8K.
This should be the ticket to much longer lasting alternations in the bedro-- err, on the track. Honestly if I could get a full season out of a single alternator, I would be thrilled, as doing a yearly alternator rebuild/swap in the off season is much easier than doing it trackside.




The extended shifter was great. Until it wasn't.


Whoops. Apparently the cast aluminum of the shifter does not like being welded to+ the extra leverage of the taller shifter, it kept snapping at the weld joints I had added. This happened twice on me even when I went "fine I'll just add MOAR WELD"
Third time it broke on me I added extra plates for and aft to help reinforce it and add more weld area. If it breaks after that I'm moving to a different shifter.



Annnnd that's the important things. Right now I have the car on wastegate(~200kpa) and it hauls. Probably have 2-300 miles on the new motor, and nothing has gone catastrophically wrong with it, it isn't smoking, and catchcan isn't overflowing. So far all wins.

I have a dyno day scheduled for the 14th. Plan is to turn it up until the turbo runs out of breath, I run out of *****, or motor runs out of will to live. Or maybe some combination of all those. Either way it's gonna be fun.
If it survives the dyno then I'm immediately signing up for a TT event at Road Atlanta in early December. It's been over a year since I've been on track and the itch is itching hard. I wanna drive this thing full **** flat out in 5th and not worry about going to jail already.



https://www.youtube.com/watch?v=BXwI...ature=youtu.be

 

Looking good!

A suggestion for exhaust mounting: My exhaust is essentially solid mounted, and I tried a few different things that didn't work. When I did the K swap, I picked up some high-temp vibration damping mounts from McMaster-Carr. I'm not pushing turbo temps, but so far they've worked perfectly. I'm using p/n 4403K661

https://www.mcmaster.com/catalog/130/1696/4403K661

 

Never thought about remote mounting the sensor like that, but I've been wanting to move mine off the block on my car for a while now and that seems like a pretty simple way to do it. Mine's hanging off a brass T right now and I'm always a bit worried it's going to crack at the worst possible moment. I always thought about getting the T moved over to the firewall, but the frame is an interesting idea.

 

I'm sure you've considered this already, but wouldn't a flex joint be a worthy consideration for the exhaust mount failures? I'm assuming packaging is challenging for that, but if everything is solid, you aren't giving the system room to thermally grow which will create challenges at the stress riser locations (your welded tab mounts). The flex joint would also provide vibration isolation.

Creative solution on the oil pressure sensor, but I can see why it is having challenges on accurate readings. The line is acting as a cooling mechanism for the fluid, just like OEM NA/NB power steering lines.. The turbo feed seems like a wise location for vibration isolation and the fastest reacting measurement if that's what you're most worried about. The pan would have a slower reacting oil temp measurement as you'd be measuring the moving average of a larger volume of fluid and I'm not sure you'd gain much from a vibration isolation perspective over the OEM location.

Best of luck with the dyno day in a few days!

 

I have the same turbo on my honda.. It's not a K, but an F22. I like it as well, but am a puss and just pushing 9 psi. It's gotta be fun with double that in a miata.

Nice! I remote mounted my oil pressure sensor on the chassis similar to yours on my honda. I had one sensor die after many years and just replaced it about a year ago. Depending on the sensor, having it hanging off a tee just seems to be asking for problems (especially a brass tee, I'd at least get a steel one). Those combined pressure/temp sensors are nice but you need flow for temp, and about the only place I think you can get flow and pressure would be off of a sandwich plate. The temp is off because you're just waiting for the oil sitting in the line to heat up and it's not circulating. I like the oil pan for oil temp simply because that's what most people and OEMs use, so you can have an apples to apples comparison.

I'm not sure if I missed it somewhere but I'd def try to incorporate some flex in the exhaust system. If it's all solidly mounted it just puts a lot more stress on everything imo. Same with the motor mounts, a little give is always good as you pointed out. I can't imagine the NVH in your car.

Good luck man! It's impressive the amount of work you've gotten done in so little time!

 

How things have changed since the beginning.

 

So it just dawned on me that this is you. Now we follow each other on instagram, but as far as that I don’t think I’ve ever talked to you. Not too sure what the point of you DMing me to say this is all about? Not like your turbo K swap (that probably makes more power than my stock LS) is a BP like Emilio, so I’m just a little confused. Care to elaborate or just **** talking to **** talk?

 

I had picked up some donut style isolators when I rebuilt the exhaust last time. There simply wasn't space add them due to proximity to the body and ground. I do like that style of mount though, I might try to use something like that(or maybe a normal style poly mount) as a motor mount.
There is a 4" braided flex pipe in the wheelwell that helps to isolate the downpipe/engine from the chassis sections. It can only do so much when the engines solid mounted.
Literally the definition of scope creep haha. Started out with much lower goals.
No **** talking was intended, that was a legitimate congratulations. I remember when that record was set and was surprised it stood this long considering the caliber of cars we have now.
I've been following you/your car since your V1 almost took the Laguna Seca record a few years back. My remark was intended to highlight the differences in the two, not disparage your laptime.
Sorry I didn't respond to your PM, I get many PM's on various platforms and simply forgot to respond.

 

We’ll chalk it up to lost in translation of the internet then I suppose.

But just for laughs, my brother and I are going to dig out this spare roller I have out back and build what I’m going to call v2.16. Just to keep the naysayers shut up, it will only have a cage that doesn’t extend into the engine bay. High strung turbo 1.6, factory glass and a dash. So that way when that car goes and runs faster than the old records I’ve already beat I won’t have to hear anything about “tube chassis” ****.