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Ok ok, #2 didn't even make it onto the engine stand, but it sounds more dramatic when I lead with that shocking statistic.
So backing up. Thursday the 18th, #1 rod bearing starts telling bad knock knock jokes. Finding the jokes unfunny I pulled it that night/friday morning, established with Kpower that the oil pump was shot and ordered a new one, and began the hunt for a replacement K24. That same Friday I had found one in a junkyard about an hour from me, already out of the car and ready to be delivered. 2009, 120K miles, $540 delivered to me, great, dandy, $500 K24Z3's are still alive.
That junkyard is one of the most poorly run yards I've dealt with. Not only did it take them till Wednesday the 23rd to actually deliver it, the motor itself was junk. It *almost* made it onto the engine stand before I realized that there was a substantial amount of rust in the intake ports. I slapped my 3' breaker bar on the front of it and tried to turn it over, to find it was seized solid. Even with the plugs out I couldn't get it to budge. It probably was a good running motor when pulled, but it must have been stored outside, or had water dumped on it at one point(they had removed the intake for some reason, so the ports were fully exposed, not even tape).
All the intake ports were bad, but I think this sums up how shot that motor was: \
Yeah, even the valves were seized in place.
I'm still trying to work with that yard to get them to come pick up their scrap motor, but I have been verbally promised a refund. Failing proper action on their part, I can always do a chargeback and defend it with an ample papertrail.
Ok, so strike one. The day after finding that one was toast, I paid way to much goddam money for a Z3 from another local yard. Just shy of $1100 for a 2010 with 132K miles. If Z3 prices don't come down by the time I need a new motor I'll honestly look into building my own header and fitting an A2. If I'm going to pay four digits for a motor, I might as well get the one that has all the VTEC and makes a extra 20whp.
Anyway, this motor wasn't nearly as clean inside as my old one. It was pretty obvious the former owner was definitely all about those 20K mile oil changes. There was also some water in the oil, I think from one of the valve cover ports not having been capped while it was sitting.
Thursday the 24th I bring the newest addition home. Turns over, I can hear it build compression, still had an OEM starter bolted to it, and a very intact wiring harness(lots of spare connectors I'll definitely be saving!)
Friday/Saturday/Sunday I put it in the car as I have the time. I didn't take any photos this time around as I was just focused on getting it done. I did timelapse it as a personal little project.
As the insides of this motor were a little sludgy, so I made sure to fill it with only the top tier good stuff:
Yeah I really did put that stuff in, but I only left it in for initial startup/coolant bleeding, then I dumped it all out and put real oil in. Since the oil pan, valve cover, timing components, and VVT/VTC solenoids were reused, I'm uber paranoid about old bearing material contamination. I cleaned them all thoroughly and ran the non-electrical stuff though the dishwasher, but was still worried, and it was justified as there was about a dime's worth of glitter that came out of the rear sump. With the fresh oil I also added about a quart of ATF... I remember hearing somewhere that it helps break down oil sludge or something, idk sounds like snake oil to me, but I had some left over from the daily so dumped it in. I'll be changing that oil/filter inside the week anyway.
Anyway, she's in, she runs, pulls good. Didn't make any changes to the tune and she fired up after 5-10 seconds of cranking. Didn't do a compression test yet as I'm dead tired.
Over this next week I'll try to run about a tanks worth of gas though it to make sure this one doesn't also have an affection for bad knock knock jokes. This weekend(April 1-3) I'm headed down to Roebling Road for a NASA event. Am I very uneasy driving it down there 4 hours, running all weekend, and driving back on a car that hasn't been track tested yet, and was only just installed into the chassis? Hell yeah I am, but what's life without a little spice and threat of four figure tow bills?
This weekend(April 1-3) I'm headed down to Roebling Road for a NASA event.
I'll be at the event too and looks like we're in the same run group (HPDE 3). Towing the car down Friday afternoon. Let me know if you need any help with bringing stuff to the track, I'm in Dacula and have some spare space in the truck.
Have you thought about using the Honda Accord K24Z3 with 190hp and slightly lower compression? I wonder if the insides are as stout as the Acura TSX version of the engine. Some, like me, may be ok with 10hp less. They do run a lot cheaper than the Acura version.
I'll be at the event too and looks like we're in the same run group (HPDE 3). Towing the car down Friday afternoon. Let me know if you need any help with bringing stuff to the track, I'm in Dacula and have some spare space in the truck.
I'll be in HPDE4, but I'll definitely keep an eye out, so come say hi! I'm headed down Friday, but don't really know what time at this point and might be caravaning with some others. I appreciate the offer though.
Originally Posted by bimmerboy
Have you thought about using the Honda Accord K24Z3 with 190hp and slightly lower compression? I wonder if the insides are as stout as the Acura TSX version of the engine. Some, like me, may be ok with 10hp less. They do run a lot cheaper than the Acura version.
I honestly had forgotten the Z3 comes in anything other then the TSX, so no, I had not considered it. A quick car-part.come search shows them hovering around the $850 mark, with some extremely low 10K mile engines in the $1500 range. I don't know that the $200 cheaper motor (between a $1000 TSX motor or $800 Accord motor) is worth it for loosing 10-25whp, but I'll have to file this information away for later.
Damn man. Seems like some of these go in and run strong and others are like a couple engines down the road. I guess that's the commuter car junkyard engine game huh.
Thankfully my weekend down at Roebling was *mostly* uneventful and trouble free.
My old PB with a BP powered miata was a 1:23.10, set on Hoosier takeoffs. I went this time with the goals of:
1: Don't blow the engine please god let the engine survive
2: Dip into the 1:18's, which is about where some other Kmiatas are hanging out at,
3. Get a TT signoff for future NASA events
4: Don't blow the engine
Running with NASA in DE4 I was able to get some clearer laps then a more open HPDE event, which was nice. First session out on a damp track I clicked off consistent 1:20's on RC-1's so I knew the car was about in the right ballpark.
Second session out on a fully warmed and dry track I knocked out a 1:18.1, and could have dipped for the 17's if I wasn't held up in the final corner the lap before.
Because this was my first time out with an Aim Solo, I wasn't completely aware of the buttons I was pushing, and managed to erase all the data/times logged from day 1(there's a whole story about that and my AIM being loaded with only EU tracks since I bought it from the UK, but suffice it to say I was doing a lot of button pushing on that thing that I shouldn't really have had to).
The lap was caught on the gopro at least, even if the gopro decided to not record any audio.
The day after I loaded the tank with E85, but the track wasn't quite as fast(no one in any group went faster) and I only managed to do a 1:18.8. This one I DID save the data from, and the gopro DID decide to capture audio for.
The second to last session of Sunday I started having fuel pressure issues again. In the corners it was dropping to ~30PSI, and eventually was barely holding 40PSI on the straights. The day before it had held pressure great down to the last gallon, so with half a tank I knew it wasn't fuel starving. I pulled in and it was only holding 55-58psi at idle(set to 60psi) so I called it quits there and skipped the last session. Some quick and dirty troubleshooting in the paddock points to the FPR being the issue AGAIN. Gah these Aeromotive FPR's are apparently garbage. Don't buy them, I'm not buying another one.
I dialed in the setscrew to bring it back to 60psi base pressure, but the entire way home it fluctuated from 58-53psi in cruise. I haven't had the time to take it apart and see if there is something obvious in this FPR that's causing the pressure loss, but I somehow doubt it.
But other then that... the car and engine held up great without any real issues. Its an absolute riot to drive with the extra ponies and makes all the annoyances I've dealt with so, so worth it. Down the looooong straight the high HP cars would only pull 4-5 car lengths on me instead of 10, the extra 15mph picked up from the K really coming in handy. I had previously worried that I would be front limited in grip, but actually found it was the rear I was struggling to keep a handle on. I added some angle to the second element and dropped the rear ride height down 1/4" to help calm it, but it was still a bit looser then I would have liked, as demonstrated in the first clip here:
I came away with a handful of issues and bugs to fix, but the only major issue is the FPR failure. If I don't find an obvious cause when I take the aeromotive apart I'll seek another, much cheaper solution that won't cost me another $300 to fix when it dies every other week.
Oh, and I was approved for TT once they saw I was SCCA TT approved and had a handful of NASA events to my name. I don't know when I'll be able to put that to use, but the option is open to me now.
About two weeks from now I'm heading to Kentucky for the Pine Mountain hillclimb. At this point its unsure weather I'll be driving the car up, or putting it on a friends trailer and codriving it with him, depending on the state of his own car.
Make sure its not the pump going out or a pickup issue. I've never had an issue with an Aeromotive regulator on track or drag cars, so getting back to back failures doesn't sound right. Make sure you're buying through an authorized dealer - there are a lot of fakes out there that are difficult to identify unless you know what you're looking for. Aeromotive even put out a briefing on it a few years back.
Yeah I don't know what to think about that fuel pressure issue anymore. I took apart the regulator, cleaned/inspected everything, reset base pressure, and it holds pressure perfectly again, zero issues.
Anyone see anything noteworthy inside there? This was before I wiped everything down with a clean rag and re-assembled it.
And the order of assembly:
The only thing that I can come up with is perhaps the tank isn't venting, and the return line is backing up, causing the pressure to drop... no, actually writing that out, that doesn't make any sense either.
Perhaps heat in some way though? When fuel starve was the worst on track it was afternoon, ~80* out, and everything would have been pretty heat soaked... doesn't explain why it still dropped some pressure on the way home however, ambient dropped down to 60* and we made an hourish stop for dinner around dusk that everything would have cooled off during.
I tried clamping off the return line in paddock, the pump built 80PSI almost instantly so I'm inclined to say its not a pump/filter/line issue. I'm just dumbstruck as to what it could be. My fuel lines are pretty far away from the exhaust and under any nearby coolant lines, so I don't think fuel boiling is a concern? Fuel feed/return circled in red, that's at least a 5" airgap between the exhaust manifold and fuel lines.
I have the same regulator. Been driving around with a 10amp fuse for my aux fuel pump relay, knowing it was suspiciously low, but it's never blown, apparently I have to upgrade that. Attached is a video of me pinching the return line. FP is on "S01". Hits 125psi (FP internal bypass) before the fuse blew. Yours should be doing the exact same. You have an issue inside the tank.
If the pump isn't taking a dump, maybe there's debris in your tank that's blocking the screen, and settling back into the tank when its been shut off for a while? My money would still be on pump taking a dump, though.
I solute the death of your generic $0.05 single use fuse and appreciate its life well lived in the name of science.
Get you some of these type two solid state fuses. They cut power during a short, then restore it(assuming the short source is gone) once power cycled. They also make a type 1 that constantly tries to reset itself until the short is gone, no power cycle needed. More expensive then your generic fuses, but honestly not badly priced for what you get, and the fact you only need the ones installed+ 1 or 2 extra for peace of mind.
I have a 25amp fuse on my fuel pump, so its not going to trip on just an overpressure. But it shoots right to 80PSI once the return is clamped off.
IIRC, the pump I had in previously was a "TI Automotive" pump stamped on it, and it would pop the relief around 120PSI. The one currently installed is branded walbro, and from what I can see online, 85PSI is where the OG walbro pumps have their relief valve set.
Log pulled with the car idling, and me pinching off the return line right at the regulator.
Originally Posted by Supe
If the pump isn't taking a dump, maybe there's debris in your tank that's blocking the screen, and settling back into the tank when its been shut off for a while? My money would still be on pump taking a dump, though.
I checked the tank when I was doing the swap and it was clean, but it looks like running E85 freed up some crud. I'll have to make a note to run/pump the car dry at some point and clean the tank out again. Still, nothing large or numerous to get though a fuel sock and clog anything...
My initial thought was pump as well, as its easy and... just makes sense. But its happened with both my legit(afaik) pumps, and both pumps hit their pressure reliefs easily with the return clamped off.
Originally Posted by Boosted Falcon
Another possibility is how or lack of proper tank ventilation. Could it be drawing a vacuum?
just a thought.
I thought of this one initially as well, as the initial issue popped up when ambient temps were their highest. I didn't have any pressure venting when I poped the gas lid, and after thinking about it more, would a pressurized fuel tank cause a loss of pressure? If the tank backed up so much that the return line couldn't dump fuel back in, then the return would back up, and pressure would increase... right? Or am I missing something there?
I can't find anything wrong on the pump assembly either. Clamps are all tight, that little bit of rubber line isn't obviously split, the sock is clean and had to have the gas in it squeezed out.
And of course, the issue still hasn't cropped back up during some street driving, so its probably going to wait till I'm on a record breaking flier at Road Atlanta to rear its head again.
My money would still be on pump taking a dump, though.
Yup, yall were right after all.
Issue cropped up again on a hotter day, dropping pressure the more it ran. Pulled the pump assembly again, still couldn't find an obvious issue, even changed that little bit of rubber line that lives in the tank to see if it had a split only apparent under pressure. No dice.
Frustrated, I left the tank lid off and ran the car like that so I could peer into the tank and see if something was leaking. As soon as the pump primed fuel sprayed out of the top of the tank with ample force to dust my interior with fuel. It seems the relief valve on that pump is partially stuck open. Weather something inside the pump failed, or somehow debrie got past the sock and into the pump during a low fuel run I can't say. Also don't really know why it only does it when warm/half empty tank, maybe whatever is jammed in the relief valve is swelling and causing it? Anyway, pump swapped out for the spare, pressure restored. Passed a full tank though it yesterday up in the mountains when it was fairly hot out, ran it down to less then a gallon, held pressure great. Hopefully that's the last of that issue.
Curly you were living on the edge with your 10amp fuse on the pump, no wonder it popped during an overpressure.
I grabbed an amp meter from work and went though to see what everything pulled out of curiosity. It turns out I severely overbuilt the wiring, not that that's a bad thing. At idle it pulls 14amp(9 of those are the fuel pump). Low beams(hellas) pull 13 amps, high beams(LED's) pull 5amp, and all interior items(USB charger, interior light, driver fan, Pi dash) barely pulls 5amps, brake lights pull 5amps. I didn't check the cooling fan load, but it has a 25amp breaker that has never popped, so even if you assume it pulls 20amps(doubt, its probably half that once the initial load settles), the maximum the car would pull is ~60amps, and I built it to be comfortable holding 90amps.
Little late, but a few exterior photos from the NASA weekend at RRR. Did not realize how low my splitter was with the track wheel/tire setup mounted, its no wonder all my splitter wear plates were obliterated after two days.
Next weekend (April 23/24) is the Pine Mountain Hillclimb in Kentucky. About a 5.5hr drive one way. Will be caravanning up with one other NC Miata. Honestly not looking forward to the drive up, and from memory of last year, the course is very un-friendly to Miata gearing with several first gear hairpins that torquey FWD/AWD vehicles just eat up time in. Hopefully the Kpower helps claw some of that time back, but I feel like there are quite a few people that will expect this car to be at the top of the times and I'm not so sure its going to be all that competitive, especially if the caliber of cars this year matches last years.
Glad to hear it was the pump after all and everything's running smoothly. Good luck at Pine Mountain, I haven't been yet, but will one day once the SB2.2 swap is finished in the RX7. Definitely a tough crowd. I thought the southeast guys had some ringers, but the Aubeles and the rest of the PHA crew are downright fast (and not to mention, have more than a few screws loose. No scared drivers in that bunch.)
Curly you were living on the edge with your 10amp fuse on the pump, no wonder it popped during an overpressure.
I grabbed an amp meter from work and went though to see what everything pulled out of curiosity. It turns out I severely overbuilt the wiring, not that that's a bad thing. At idle it pulls 14amp(9 of those are the fuel pump). Low beams(hellas) pull 13 amps, high beams(LED's) pull 5amp, and all interior items(USB charger, interior light, driver fan, Pi dash) barely pulls 5amps, brake lights pull 5amps. I didn't check the cooling fan load, but it has a 25amp breaker that has never popped, so even if you assume it pulls 20amps(doubt, its probably half that once the initial load settles), the maximum the car would pull is ~60amps, and I built it to be comfortable holding 90amps.
So I actually know this, I have no idea why/how I got a 10amp fuse in mine and it never blew. I've wired a few AiM PDMs into various vehicles with similar Walbro or AEM pumps, and you can monitor current draw on all power outputs. Typically I can run lift pumps (next to no pressure) on a 10-15amp circuit, and the main feed/surge tank pump on a 15-20amp.
Soooo Pine Mountain Hillclimb.
Based on my experience from last year, I knew this course did not favor momentum cars at all. There are several very tight horseshoes in the lower half of the hill that really kill speed and force you to start all over again, while trying to climb uphill. FWD or cars with lots of low end grunt really do well here for the reasons just stated.
I didn't want to burn up good rubber fighting for last place, so I mounted some old tires to burn them up before they fell apart on me. Some 4 year old 245 R7's. As a bonus I could use them to see if I needed to roll/pull the fenders in the future without being worried about the tire getting sliced up.
Mmmmm those are some big boys. Mounted on a 9.5" Konig wheel.
In hindsight, I was not *as* outgunned in class as I had expected, and the old hoho's stuck even worse then I thought they would. I felt like the car was constantly on ice, even when the course was warm and I actually got good heat into the tire. There was more then one moment when the car unexpectedly snapped on me and I thought I was headed off, but she came back in one piece. I think if I had stuck with my 245 RC-1's, I would have had a solid shot at a 4/5th place finish, for which they do hand out a trophy for(22 people in class). An actually fast tire and I think I could have easily fought for top 3 in class. Oh well. Always next year, as we were given news over the weekend that Pine is confirmed though 2024, as well as some major sponsors(Summit Racing!) had come onboard to help fund/grow the series.
Fastest run of the weekend was a 1:55.2. Official results haven't come out yet, but I think this will place me around 8th in class(out of 22) and probably mid 20's overall(90 entries).
I actually had zero mechanical issues all weekend, although during one run I tagged a hay bale with the edge of my splitter and tore the splitter fence off, but that shouldn't be too much hassle to repair. I actually had more damage happen to the car on the drive home then I did on course. During a fuel stop on the return I had to reverse a few feet. Tired and not paying super good attention, I didn't realize my tire trailer had jackknifed to a hard 90*, and it bent the **** out of one of my endplates. I bent it back to the condition below to get it home, but its beyond salvaging, so I'll need to make new ones.
This isn't a huge loss as a few of the bolt holes for these endplates had started to wallow out and they were starting to get some wiggle to them. The aluminum I had used was too soft and it fatigued quite rapidly. I would have needed to replace them at the end of the season anyway.
On a brighter note, I received many compliments about how the car sounded. So even if it wasn't the fastest, at least it sounded good I guess?
Finish sure seemed to love it:
Little bit of a break now in the season... I'm going to try to hit up Road Atlanta in early June as my first NASA TT event, but that's still only a maybe. I am signed up for the Jzilla HPDE event at Road Atlanta late June, so one way or another I'll be able to get this car on Road Atlanta soon and see if I can break into the low 1:30's.
Glad to hear the car held up well. Looked like the hill bit quite a few cars with at least one rollover. Watched a few sun-washed videos, do they put a chicane on the straights to kill speed? Just curious what sort of peak MPH you hit there.
Glad to hear the car held up well. Looked like the hill bit quite a few cars with at least one rollover. Watched a few sun-washed videos, do they put a chicane on the straights to kill speed? Just curious what sort of peak MPH you hit there.
The bridge right after the chicane is a state historic landmark of some sort. Apparently its super old and they are unable to repair it if any damage were to occur. We were all told last year that if anyone touched it at all we would not be invited back. Thus the chicane to get the speed down, and the ample amount of water barriers surrounding the entrance to the bridge.
The video I posted above has speed data pulled right from the AIM. I think top speed on the course for me was low 80's. It's a mostly 2nd gear course with only brief moments in third(4.3, 5spd, 8k redline).
03-27-2022, 11:27 PM
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