Twin Turbo LSX Datsun 280Z
04-10-2015, 03:41 PM
#681
Launching!
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I can relate to this. I bit the bullet and went with the aftermarket block for the 260Z even though my goals are lower than yours. "1000 hp+ all day long" is the internet catch phrase for stock junkyard builds.
04-10-2015, 03:43 PM
#682
But when driving surely it wasnt as low as 9psi ? Is that what was logged ?
When my cam bearings walked a few years ago at an event I lost pretty much all oil pressure. I only had a mechanical gauge at the time.
As I reached the finals I raced anyway, probably only had around 2-3psi at idle, rising to maybe 10-15psi at the top end.
I then drove 300 miles home.
Really...all things considered the engine was in very good condition when I pulled it apart. Even the bearings. So I dont see a single low load low psi incident doing much harm if any.
Move forward 3 years with a block with crappy line bore work done. I raced most of last year with poor oil pressure, 40-50psi when coldish, less when warm. Even less when racing/warmest. Probably idled around 10-15psi for most of that year.
When racing and oil was hotter and under more load it really was down as low as 10psi at max rpm/load.
After a year of that plus normal driving in between, the main bearings were fucked. Really fucked. Rod bearings bad, but less so.
Some light piston/bore scuffing but not terrible.
I contribute the damage mainly to the bad machining work for the main caps that was done locally, but also down to the cog drive I had on my blower in 2013 which is bound to have hammered the crank a fair bit and where some of the damage was initiated.
I've a brand new block I'm putting together at the minute, no idea how long it will last..it's all good about from them ******* oil squirters I insisted upon. There really isnt any room for them ! ****.
When my cam bearings walked a few years ago at an event I lost pretty much all oil pressure. I only had a mechanical gauge at the time.
As I reached the finals I raced anyway, probably only had around 2-3psi at idle, rising to maybe 10-15psi at the top end.
I then drove 300 miles home.
Really...all things considered the engine was in very good condition when I pulled it apart. Even the bearings. So I dont see a single low load low psi incident doing much harm if any.
Move forward 3 years with a block with crappy line bore work done. I raced most of last year with poor oil pressure, 40-50psi when coldish, less when warm. Even less when racing/warmest. Probably idled around 10-15psi for most of that year.
When racing and oil was hotter and under more load it really was down as low as 10psi at max rpm/load.
After a year of that plus normal driving in between, the main bearings were fucked. Really fucked. Rod bearings bad, but less so.
Some light piston/bore scuffing but not terrible.
I contribute the damage mainly to the bad machining work for the main caps that was done locally, but also down to the cog drive I had on my blower in 2013 which is bound to have hammered the crank a fair bit and where some of the damage was initiated.
I've a brand new block I'm putting together at the minute, no idea how long it will last..it's all good about from them ******* oil squirters I insisted upon. There really isnt any room for them ! ****.
04-10-2015, 03:57 PM
#683
9 Second Club
I do not believe it will have done any real harm, as it certainly didnt on mine when the cam bearings walked.
Obviously there is some debris in the oil, so harm has been caused somewhere, but I dont think it is because of the low oil pressure.
But I'm still not understanding. You said the mechanical gauge read 9psi for a brief time. Has the engine ever replicated this oil pressure since that time ?
Is it a regular occurrence ? as you seem to say it runs higher than that normally ?
If it was me, being the lazy person I am I'd just continue to run the engine an keep an eye on pressure. If it starts to get worse, or you're finding more debris in the oil then pull it.
04-10-2015, 04:04 PM
#684
lol, my point was more about running the engine with low oil pressure for a very short time.
I do not believe it will have done any real harm, as it certainly didnt on mine when the cam bearings walked.
Obviously there is some debris in the oil, so harm has been caused somewhere, but I dont think it is because of the low oil pressure.
But I'm still not understanding. You said the mechanical gauge read 9psi for a brief time. Has the engine ever replicated this oil pressure since that time ?
Is it a regular occurrence ? as you seem to say it runs higher than that normally ?
If it was me, being the lazy person I am I'd just continue to run the engine an keep an eye on pressure. If it starts to get worse, or you're finding more debris in the oil then pull it.
I do not believe it will have done any real harm, as it certainly didnt on mine when the cam bearings walked.
Obviously there is some debris in the oil, so harm has been caused somewhere, but I dont think it is because of the low oil pressure.
But I'm still not understanding. You said the mechanical gauge read 9psi for a brief time. Has the engine ever replicated this oil pressure since that time ?
Is it a regular occurrence ? as you seem to say it runs higher than that normally ?
If it was me, being the lazy person I am I'd just continue to run the engine an keep an eye on pressure. If it starts to get worse, or you're finding more debris in the oil then pull it.
Yeah sorry i never specified. So i made a half *** pass. As I'm heading back to the pits i notice the mech gauge at 0, I immediately pull over and shut it down. After realizing what i did I fired it back up and checked oil pressure via Holley (34 psi.) When i finally got back to my camp it was down to 9 and the pan showed close to a quart of oil.
04-10-2015, 04:09 PM
#685
9 Second Club
Yeah sorry i never specified. So i made a half *** pass. As I'm heading back to the pits i notice the mech gauge at 0, I immediately pull over and shut it down. After realizing what i did I fired it back up and checked oil pressure via Holley (34 psi.) When i finally got back to my camp it was down to 9 and the pan showed close to a quart of oil.
Presumably you logged the run and broken line incident on the Holley ? How did oil pressure etc look on the log ?
ie the two havent always read the same ?
The debris didnt look good, but at this point I think pulling the motor would be a bit premature as long as pressure is still fairly good and steady.
04-10-2015, 04:59 PM
#689
9 Second Club
04-10-2015, 05:02 PM
#690
So whilst the broken line leaked some oil causing the mechanical gauge to read incorrectly, sounds like the engine always had decent pressure as indicated on the Holley ?
Presumably you logged the run and broken line incident on the Holley ? How did oil pressure etc look on the log ?
ie the two havent always read the same ?
The debris didnt look good, but at this point I think pulling the motor would be a bit premature as long as pressure is still fairly good and steady.
Presumably you logged the run and broken line incident on the Holley ? How did oil pressure etc look on the log ?
ie the two havent always read the same ?
The debris didnt look good, but at this point I think pulling the motor would be a bit premature as long as pressure is still fairly good and steady.
04-10-2015, 06:22 PM
#692
9 Second Club
Pressure readings should really be the same.
If I'm using the likes of a mechanical gauge for in car reference, I like to calibrate the ecu pressure sensor manually and to the same scaling as the in-car gauge so they always read the same.
In some ways that is not the correct way to do so, but if there is only a small discrepency between in-car gauge and the ecu sensor reading, it's no big deal.
It just means that numbers I see when I'm driving will be reflected when I view logs so I'm not trying to figure out why there are differences.
This applies to any pressure reading whether boost, oil, fuel etc
04-12-2015, 04:39 PM
#694
Pulled the trans and got the oil pan Down far enough to get my hands and my phone inside. I can't get the pan conpletely down without dropping the crossmember.. No thanks. I ran my hands through every corner of the pan and took about 30 videos and I can't find a single piece of bearing material or even a gold flake for that matter. I'm just going to run it like it is and keep an eye on the oil pressure. If it starts to drop I'll yank the motor and either throw a forged crank shaft in it or replace the bearings, sell it and find a block that can hold 1500hp and be done with it. At this point, 40psi hot idle pressure is fine by me. Hell 25/30 is fine by me.
Super magnum goes in next week and it's off to the drag strip to start practacing for bayou drags. In hoping to make a 9sec pass before then.
Super magnum goes in next week and it's off to the drag strip to start practacing for bayou drags. In hoping to make a 9sec pass before then.
04-15-2015, 11:54 AM
#695
Teching In
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Getting some cosmetic stuff done while I'm waiting on the motor. Shouldn't be long now, just talked to Eric and the cam tunnel is being bored out a little. Couple bearing where spun. I also need a new cam as my 228r took a beating. Any suggestions are welcome, I have t decided between PAT G/LIL John/Martin
Here is the front bumper. I decided to bring the front end up to date. I already have projectors/HID's so this was the likely move. No more big *** ugly amber turn signals.
Here is the front bumper. I decided to bring the front end up to date. I already have projectors/HID's so this was the likely move. No more big *** ugly amber turn signals.
Man car looks awesome ! IF you don't mind me asking where did you get your LED blinkers and what did they cost. Thanks
04-18-2015, 02:13 PM
#699
