No, an Accusump would not have saved that engine. A better thought out tuning plan done with a real dyno capable of steady state testing might have. I suspect however that the real problem was pushing an essentially unknown bottom end beyond its limits.
Continuing to do pulls and driving it home when it's obviously unhappy about something is also a recipe for disaster.
I don't believe an Accusump can save a motor.
It won't eliminate the air introduced into the system if the pump gulps air.
Air has no lubricating properties and must go through the motor to escape the oiling system.
An Accusump may allow a motor to last a couple of heart beats longer but it will eventually fail.
In reply to bentwrench :
The idea behind an accusump is that the air never enters the oiling system.
I also don't love the accusump idea because it also will slow down pressure increase when you snap the revs up suddenly (as you have to get the accusump up to pressure, not just the oil system). I'd rather work to prevent the pump from sucking air in the first place.
In reply to rslifkin :
As far as I understand that's not how they work. On mobile, lemme try and find a link.
I'm also seeing a lot of dogging on the guy behind the YouTube channel without actually knowing much about him or his channel. He ran his car @ 220+ hp for 40k miles before he upgraded the turbo and went of the big number. His approach to modifying cars is methodical - I'm pretty sure he went into this knowing it would go boom (in fact he pretty much says this). His channel is full of quality information and videos for miata and turbo folks in general. Not just some shmuck who threw an ebay turbo on a miata and expected to DD @ 300hp.
**edit
Here's the postmortem that I hadn't seen yet. Fun disection!
https://youtu.be/F_Ua8hM8D2A
bentwrench said:I don't believe an Accusump can save a motor.
...
https://grassrootsmotorsports.com/forum/grm/track-miles-equal-how-many-road-miles/145555/page1/
From this thread.
Streetwiseguy said:...
Engines on a left turn biased track were good for several thousand miles, but I discovered that a right turn biased track drops the crankshaft life to an hour or so.
I have an accusump now.
...
I can't seem to find the link for explaining how they worked (precharged, etc). I have read several accounts on here swearing by them. (and apparently Lotus Elises come with them stock?)
https://grassrootsmotorsports.com/forum/grm/learn-me-accusump/49454/page1/
Anyone considered the possibility that the 'low momentary oil pressure' was rather just an electrical spike that overrode the sensor signal?
I'm not convinced the motor actually experienced low oil pressure.
bentwrench said:I don't believe an Accusump can save a motor.
It won't eliminate the air introduced into the system if the pump gulps air.
Air has no lubricating properties and must go through the motor to escape the oiling system.
An Accusump may allow a motor to last a couple of heart beats longer but it will eventually fail.
Unless you have a dry sump system with a good deaeration tank, the oil going through the journals is more of a foam anyway. This is why HLA-equipped engines will have clacky lifters after a good run. The oil got turned into a froth and the HLAs are full of air that needs to work its way out.
This is also the reason for deep sump oil pans. It's not to run 9 quarts of oil, it's to make the oil four quarts lower so it stays away from the crank, cutting down on the foaming. (Not eliminate, but cut down anyway)
Here is an interesting video if you are a dork. Video camera looking at a clear section of valve cover in a Porsche 928. The oil exiting the cam caps is lightly aerated, and you can tell when he is cornering because the lightly-aerated oil turns into a light foam.
In reply to Knurled. :
You can also run an anti-foaming agent in the oil to help also. The easiest is just a larger sump (bigger pan).
I endorse the Accusump. I used one on my unopened 230k mile 1MZ-FE V6 that I put into a grippy MR2 and beat it ruthlessly on track. GRM had much less success with that same engine on track in a Camry, and it was their experience that convinced me to not even do one track day without one on that engine.
At best, it will give you a few seconds of reduced oil pressure when you would otherwise be dry. It's still a crutch for other oiling issues...keeping the pickup submerged at all times is the key to keeping a wet sump engine alive over the long term.
One of the teams I race Lemons with has one on their Chrysler 420a, along with a LOT of other cheaty oiling tricks (windage tray, crank scraper, electric scavenge pump and high capacity oil pan,) and we are STILL unable to maintain oil pressure on right-hand sweepers. And that engine needs bearings every other race.
I've always had Accu-sumps in my race cars, but they will not help on Dyno-Pulls, so, NO--an Accu-sump would not have saved that motor in the vid.
In reply to Tyler H :
Why not go home brew dry sump for your Lemons team? Billzilla made a 2 stage dry sump oil pump from two SBC oil pumps and a pulley. Should be in budget.
Someone needs to alter the old rotary turbo meme to "Boost goes in, rod bearings go out."
He found the edge of survival for the rods, and just stepped right over that edge...
Dr. Hess said:In reply to Tyler H :
Why not go home brew dry sump for your Lemons team? Billzilla made a 2 stage dry sump oil pump from two SBC oil pumps and a pulley. Should be in budget.
Kinda like a fuel cell -- easier in concept than execution. Plus it's not my car, so it's a shared decision. I imagine when they swapped the intake and exhaust side on the 420a head casting for the Talons, they skipped the R&D the original car got. Oil has to be going somewhere, and I'm betting it's in the head. I recommended tapping the top left side of the head and running a braided hose back to the oil pan. Next to free and what harm could it do?
Lotus Twin Cam motors use a hole in the bottom of the head and a rubber tube external to the block to drain it into the (Ford) sump.
You'll need to log in to post.
