Kinkstaah

But.... the reason I want to run a 60 weight is so at 125C it has the same viscosity as a 40 weight at 100C. That's the whole reason. If the viscosity changes that much to drop oil pressure from 73psi to 36psi then that's another reason I should be running an oil that mimics the 40 weight at 100C. I have datalogs from the dyno with the oil pressure hitting 73psi at full throttle/high RPM. At the dyno the oil temp was around 100-105C. The pump has a 70psi internal relief spring. It will never go/can't go above 70psi. The GM recommendation of 6psi per 1000rpm is well under that... The oil sensor for logging in LS's is at the valley plate at the back of the block/rear of where the heads are near the firewall. It's also where the knock sensors are which are notable for 'false knock'. I'm hoping I just didn't have enough oil up top causing some chatter instead of rods being sad (big hopium/copium I know) LS's definitely heat up the oil more than RB's do, the stock vettes for example will hit 300F(150C) in a lap or two and happily track for years and years. This is the same oil cooler that I had when I was in RB land, being the Setrab 25 row oil cooler HEL thing. I did think about putting a fan in there to pull air out more, though I don't know if that will actually help in huge load situations with lots of speed. I think when I had the auto cooler. The leak is where the block runs to the oil cooler lines, the OEM/Dash oil pressure sender is connected at that junction and is what broke. I'm actually quite curious to see how much oil in total capacity is actually left in the engine. As it currently stands I'm waiting on that bush to adapt the sender to it. The sump is still full (?) of oil and the lines and accusump have been drained, but the filter and block are off. I suspect there's maybe less than 1/2 the total capacity there should be in there. I have noticed in the past that topping up oil has improved oil pressure, as reported by the dash sensor. This is all extremely sketchy hence wanting to get it sorted out lol.

I don't know it is due to that. It could just be due to load on track being more than a dyno. But it would be nice to rule it out. We're talking a fraction of a second of pulling ~1 degree of timing. So it's not a lot, but I'd rather it be 0... Thicker oil isn't really a "bandaid" if it's oil that is going to run at 125C, is it? It will be thicker at 100 and thus at 125, where the 40 weight may not be as thick as one may like for that use. I already have a big pump that has been ported. They (They in this instance being the guy that built my heads) port them so they flow more at lower RPM but have a bypass spring that I believe is ~70psi. I have seen 70psi of oil pressure up top in the past, before I knew I had this leak. I have a 25 row oil cooler that takes up all the space in the driver side guard. It is interesting that GM themselves recommend 0-30 oil for their Vette applications. Unless you take it to the track where the official word is to put 20-50w oil in there, then take that back out after your track day is done and return to 0-30.

(it is a brand new ported mellings pump) I suspect the lack of pressure is due to the leak. It was *not* that low in other logs of oil pressure in the past. It wasn't that hot either, but not far off.

Yeah the rule of thumb with an LS is 7psi per 1000rpm. That is decidedly not enough at 6800rpm. I mainly looked for the scenarios where knock started to be picked up and it was later in the session when things were hotter, and oil was thinner, and the pressure was lower than it should be. (i.e very horrible). I am hoping with thicker oil (I was running Penrite ten tenths 10-40, the manual specifies 10-30) that does not leak that it's much improved at that time!!! I am using Project Mu Club Racer CR pads. I'm also using the Project Mu 335C fluid. The symptoms imply that it was fluid that boiled, but no bubbles seemed pretty weird to me when I bled it today. I want to try Castrol SRF as it has a much higher wet temp but, well, I have new Project Mu fluid lol... so I should at least use that. The pedal on track was really noticable. It went from basically normal feeling to instantly near-floor. The car did pull up as before, it was just very much nearly at the floor before the brakes engaged. At that point I pretty much decided the day was very done, it did *kinda* come back during that very slow cooldown lap into the pits. Felt perfectly fine driving home.

Went over my datalogs on a whim and noticed a worrying combination of events. High RPM High Temperature Low Oil Pressure Knock Retard I bought some 10w-60 because I actually think this will be better going forward given track temp is 125C and 10-40 will actually be thinner in those environments. I know I had a leak but it's not entirely sure how much pressure loss can be attributed to that. The knock retard does correlate with all of the above. When it's not present oil pressure is higher. And by 'low' I mean at 6800 RPM the oil pressure was recorded as low as ~35psi pretty constantly. Which is obviously very not good. I'm hoping that thicker oil that ISNT LEAKING will result in a bit more pressure when I need it. Also in the last session I got a very spongy break pedal. I bled the lines as the car is on jack stand right now with the wheels off and I noticed... no air in the lines? Maybe the tiniest bit of tiny frothy bubbles for the first 0.1 seconds of bleeding the whole car? The breaks did come back to me after I backed off (and felt fine driving normally). Doesn't appear to be any leaks anywhere that I can see. Any thoughts on that?

I agree with you WRT the hard top. MX5's may be one of the better looking soft tops but I cannot think of ANY car, EVER that looks better with a soft top vs a hard top (or a designed roof). At all, ever. I also feel this way about the C5 Vette, the Z06 looks horrible compared to it's original form, it has an exaggerated version of the differences you're talking about.

I am well aware as I did rant at him to buy a MX5, buy the 2.5 before he DIY'ed it, etc as well as do things to the holden. He will obtain a ND. It's the best of both worlds. They look great in person, definitely the best looking one. Just a matter of time now.

I used to do that (sills with rubber jack block).. ... then I got side skirts, and there's no way for the jack to actually work there, the jack pad itself on the jack is too big. Is the answer to use a... smaller (?) jack? Hmmm.

The obvious answer here is get a ND2/3 RF with the Targa top. The red is nicer, too!

This is the only point I can access with any floor jack and my car is SUV height - What's the actual suggested alternative here? I have also driven up on blocks in the past, but lets say you have a problem and the car is on it's wheels already and can't be driven up/off anything? Not a huge fan of bits of wood being spat in random locations either (it hasn't happened, but what-ifs occur) Perhaps I would also really enjoy having a quickjack :p Time to google quickjacks.

Neg, the top one is actually for the front. The sizes are 18x10.5 +18 and 18x11 +32. I measured many times but I'm sure I'll have problems as this is the thread for problems.

Welp, good to know. Will have to wait awhile until steady hands with drills and taps are available. In other news, these just arrived! I will weigh them for posterity. Edit: 11kg each (or 10.9/11.1 depending on what my scale decides over multiple tests, the 18x11 don't seem to weigh noticeably any more than 10.5)

Thanks folks - I've saved a few links and I'll have to think of potential cable/adapters/buying fittings. First step will be seeing if I can turn the curren abortion of a port into something usable, then get all BSPT'y on it. I did attempt to look at the OEM sender male end to see if it IS tapered because as mentioned you should be able to tell by looking at it... well, I don't know if I can. If I had to guess it looks like *maybe* 0.25 of a mm skinnier at the bottom of the thread compared to where the thread starts. So if it is tapered it's pretty slight - Or all the examples of BSPT vs BSPP are exaggerated for effect in their taper size.

How do you propose I cable tie this: To something securely? Is it really just a case of finding a couple of holes and ziptying it there so it never goes flying or starts dangling around, more or less? Then run a 1/8 BSP Female to [hose adapter of choice?/AN?] and then the opposing fitting at the bush-into-oil-block end? being the hose-into-realistically likely a 1/8 BSPT male) Is this going to provide any real benefit over using a stainless/steel 1/4 to 1/8 BSPT reducing bush? I am making the assumption the OEM sender is BSPT not BSPP/BSP

..this is the current state of that port. I appreciate the info help (and the link to the Earls thing @Duncan). Though going by that it seems like 1/4 then BSP'ing it and using a bush may work. I don't know where I'd be remote mounting the pressure sender... to... exactly. I assume the idea here is that any vibration is taken up by the semiflexible/flexible hose itself instead of it leveraging against the block directly. I want to believe a stronger, steel bush/adapter would work, but I don't know if that is engineeringly sound or just wishful thinking given the stupendous implications of a leak/failure in this spot. What are the real world risks of dissimilar metals here? It's a 6061 Aluminum block, and I'm talking brass or steel or SS adapters/things.

I'm not quite understanding or I'm missing steps here, (I appreciate people are trying to inform my brain but I am of the dumb, especially today) - All I want to do is mount the male BSPT of the OEM sender into the system somewhere without it snapping the adapter via vibration. The Nissan sender has a male 1/8 BSPT output. The block has a (very destroyed) 1/8 NPT input. I'm not really sure how a lathe assists with that, and also don't know anybody with a lathe, nor specifically what I would want to buy. I'm not really sure how adding additional adapters creates a better, more leak proof resilient seal here.

Yea I mean I know it exists, but finding (specifically) female BSPT to male NPT (i.e, to plug a Nissan OEM sensor into a 'standard' NPT port) was truly difficult. I don't think I'll recreate the setup I had in the past unless it's (possibly?) advisable with a stronger T piece made of steel, but who knows if the aluminium threads in the block become the next weak point etc. Given it may need to be redrilled out and something tapped into it, it'll need to be Female BSPT to the something that ends uo coming out of the side of the block.

I'm actually not sure - I think it was "Stealth Performance" (It really is near impossible to find a FEMALE 1/8BSPT to 1/8NPT male at ALL) but having the thing leveraged on a 90 degree angle on a small aluminium fitting is not too smart. Also in not too smart, I've drilled out the center of the broken fitting so there's maybe 0.00001mm of thread to bite into, so yeah. I may have to get it drilled/tapped/plugged entirely. Given I could conceivably tap a thread/adapter/pressure line in any point in the oil system I suppose it's feasible to run a line to the Nissan Sensor to keep the dash working. Do these exist in AN fittings and the like? Like an AN fitting that has a NPT (or other?) thread as well for putting a sensor in?

Well GTSBoy, prepare yourself further. I did a track day with 1/2 a day prep on Friday, inpromptu. The good news is that I got home, and didn't drive the car into a wall. Everything seemed mostly okay. The car was even a little faster than it was last time. I also got to get some good datalog data too. I also noticed a tiny bit of knock which was (luckily?) recorded. All I know is the knock sensors got recalibrated.... and are notorious for false knock. So I don't know if they are too sensitive, not sensitive enough... or some other third option. But I reduced timing anyway. It wasn't every pull through the session either. Think along the lines of -1 degree of timing for say, three instances while at the top of 4th in a 20 minute all-hot-lap session. Unfortunately at the end of session 2... I noticed a little oil. I borrowed some jack stands and a jack and took a look under there, but as is often the case, messing around with it kinda half cleaned it up, it was not conclusive where it was coming from. I decided to give it another go and see how it was. The amount of oil was maybe one/two small drops. I did another 20 minute session and car went well, and I was just starting to get into it and not be terrified of driving on track. I pulled over and checked in the pits and saw this: This is where I called it, packed up and went home as I live ~20 min from the track with a VERY VERY CLOSE EYE on Oil Pressure on the way home. The volume wasn't much but you never know. I checked it today when I had my own space/tools/time to find out what was going on, wanted to clean it up, run the car and see if any of the fittings from around the oil filter were causing it. I have like.. 5 fittings there, so I suspected one was (hopefully?) the culprit. It became immediately apparent as soon as I looked around more closely. 795d266d-a034-4b8c-89c9-d83860f5d00a.mp4 This is the R34 GTT oil sender connected via an adapter to an oil cooler block I have installed which runs AN lines to my cooler (and back). There's also an oil temp sensor on top. Just after that video, I attempted to unthread the sensor to see if it's loose/worn and it disintegrated in my hand. So yes. I am glad I noticed that oil because it would appear that complete and utter catastrophic engine failure was about 1 second of engine runtime away. I did try to drill the fitting out, and only succeeded in drilling the middle hole much larger and now there's a... smooth hole in there with what looks like a damn sleeve still incredibly tight in there. Not really sure how to proceed from here. My options: 1) Find someone who can remove the stuck fitting, and use a steel adapter so it won't fatigue? (Female BSPT for the R34 sender to 1/8NPT male - HARD to find). IF it isn't possible to remove - Buy a new block ($320) and have someone tap a new 1/8NPT in the top of it ($????) and hope the steel adapter works better. 2) Buy a new block and give up on the OEM pressure sender for the dash entirely, and use the supplied 1/8 NPT for the oil temp sender. Having the oil pressure read 0 in the dash with the warning lamp will give me a lot of anxiety driving around. I do have the actual GM sensor/sender working, but it needs OBD2 as a gauge. If I'm datalogging I don't actually have a readout of what the gauge is currently displaying. 3) Other? Find a new location for the OEM sender? Though I don't know of anywhere that will work. I also don't know if a steel adapter is actually functionally smart here. It's clearly leveraged itself through vibration of the motor and snapped in half. This doesn't seem like a setup a smart person would replicate given the weight of the OEM sender. Still pretty happy being lucky for once and seeing this at the absolute last moment before bye bye motor in a big way, even if an adapter is apparently 6 weeks+ delivery and I have no way to free the current stuck/potentially destroyed threads in the current oil block.

Whoops!

Perhaps the answer is... more jacks!* *proper jacks must be used.

I read this and thought "ah! I will do this scissor jack on the tow point thing!" I just use my floor/low profile/costco jack and lift the car up by the tow hook itself, then slide jack stands under. Never thought about using scissor into floor jack combo :p

Ah! I actually managed to snag a lightly used set.... that aren't so suitable for me right now. They don't work on a GTT without some cutting or creative heat moulding. I thought about reselling them myself cause I didn't want to murder them, but it looks like I'm probably going to attempt to murder them/melt them because I may as well. @GTSBoy @PranK can somebody close this thread?

You have a knack for photography my friend. It makes the 86 look like a complete bucket. The 34 went with you to Europe and back. It's special. (we all feel the same about our 'shitboxes' that every bystander seems to absolutely love)

If you like - I have the STL files so I can email em. There's a couple of gotchas (i.e the holes are not threaded so you might need/will need) to utilize some M3 melt-in threads for some of the points. However if you want to be super accurate, and are willing to remove your calipers and your SHOCKS it's a really good tool. You also might need to scale the part that measures the tyre width a bit wider. It defaults to a 7.5in tyre and I mean who is running that. Luckily with the magic of CAD this is very easy to rescale.