Mini Cooper 998 Screamer Nut And Bolt Rebuild
#1711
Posted 24 November 2021 - 09:37 AM
#1712
Posted 24 November 2021 - 10:21 PM
Your very welcome and I'm glad some of the things I've posted are useful. These builds are not easy, it takes time and a serious amount of effort. What makes it more difficult is the poor quality parts problem and the "experts" that know very little.
Talking of poor quality parts, this is the result of the pot joints that leaked grease into the engine oil......
It's gone absolutely everywhere, in every nook and cranny. It's the molybdenum disulphide particles that's the problem. I need to get rid of it to prevent it blocking the oil filter again.
The result was this
Big end shells gone
Along with the mains
The shells are replaceable, but the crank was done by Rob Walker who has now retired
Fortunately, its OK
All this down to poor quality pot joints from Minisport
We live and learn.
Pete
#1713
Posted 26 November 2021 - 03:27 PM
I bet minisport are still selling them too !
#1714
Posted 27 November 2021 - 11:17 PM
I bet minisport are still selling them too !
I bet they are.
I have run into a problem with the gearbox. The input shaft is tightening onto the main shaft. It looks like the MED baulk ring is too tight on 4th gear, pushing it into the main shaft. I've dropped the gearbox off with a local guy who is going to look into it. Fingers crossed but he tells me that the gear kit is not a Jack Knight SC kit, as advertised, but a Leyland ST SCCR kit. I'm not going to complain about that.
I can't believe this build is still challenging me though.....
I'm cleaning the engine internals.... bolts, bearing caps etc with a combination of white spirit and celly thinners
It's slow progress but things are looking a bit better now
Pete
#1715
Posted 29 November 2021 - 03:26 PM
#1716
Posted 29 November 2021 - 10:41 PM
I'm glad you've got your mojo back Pete after all the downers you've had. It's been a very trying experience for you
It's been very dissappointing for me but I'm determing to sort everything out 100%
The plan is to make it a better car from what I've learned
This is the oil pump supplied by Retro Minis. I appreciate the engine suffered from lack of oil pressure for a short period, but this pump would have still been full of oil
I've ordered a new pump, main's and big end shells from MED
Onwards and upwards now with better parts...... I hope
Pete
#1717
Posted 30 November 2021 - 08:16 PM
I think the pump pulls unfiltered oil from the sump,debris in sump,trashed pump,Steve..
#1718
Posted 30 November 2021 - 08:21 PM
I think the pump pulls unfiltered oil from the sump,debris in sump,trashed pump,Steve..
Correct, it does. It's a terrible design.
#1719
Posted 30 November 2021 - 09:11 PM
The engine has done 1200 miles and the only debris in the oil was the moly from the pot joints. The filter was partially blocked and whilst the oil light came on at idle, revving it to about 3k gave 40 psi of pressure. That means the pump couldn't cope with the volume the engine demanded due to the restriction but I can't see it causing that sort of scoring.
Maybe I'm missing something?
#1720
Posted 30 November 2021 - 10:00 PM
Hi Pete, i have followed your project over the last couple of years and thoroughly enjoyed reading it , you've certainly been through the mill with some of the hiccups you've had .
Just for your info, on my build ,for the engine work i went to J and E Engineering services over in Rossendale (i live about a mile from Minisport) His prices are very reasonable and he won't do unnecessary work, when i took my engine parts over he gave me loads of advice .
Whilst there i noticed another A+ engine block on the floor and he then went on to tell me that he did work occasionally for Minisport , i told him of your woes , he sort of suggested that he had been the one to get drafted in to align the crank grinder up. His comments were that minisport had really taken their eye off the ball with the remanufacture work and there interest lies in all the hi tech machining work (brake calipers , hubs etc) and the guys in the engine re-work section ( which is now in the old scout hut ) are a bit neglected in terms of investment.
The guy at J and E is called John ,i would highly recommend him , he knows his stuff , gave me a tour of the workshop, i work as a precision machinist in the aerospace industry but i found it really interesting as he explained how he did stuff like balancing cranks and flywheel assemblies .
i'm a little behind yourself on my project, after seeing the copper gasket problems you've had i'm beginning to regret fitting one on mine! i had similar problems on my MGB with a copper gasket many years ago but was assured with the mini it was the way to go (we'll see) anyway good luck with the rebuild and hopefully all will be well in 2022
Kev
#1721
Posted 30 November 2021 - 10:01 PM
Whatever was blocking the filter must’ve gone through the pump?
Low oil pressure at idle isn’t a sign of a of a partially blocked filter but more too much clearance on the mains & big ends, thereby not providing the resistance to flow that allows the pressure to build. Obviously a faster engine speed means the pump is trying to shove more oil through that gap, so pressure will increase.
To put it another way, Aan engine doesn’t ‘demand’ a volume of oil, but rather allows a volume to pass. And excessive clearances (through poor machining or wear) allows too much volume to pass.
A blocked filter would cause high pressure if anything and then the pressure relief valve would open - you’d potentially see a fluctuating pressure on a gauge.
#1722
Posted 01 December 2021 - 05:53 PM
Whatever was blocking the filter must’ve gone through the pump?
Low oil pressure at idle isn’t a sign of a of a partially blocked filter but more too much clearance on the mains & big ends, thereby not providing the resistance to flow that allows the pressure to build. Obviously a faster engine speed means the pump is trying to shove more oil through that gap, so pressure will increase.
To put it another way, Aan engine doesn’t ‘demand’ a volume of oil, but rather allows a volume to pass. And excessive clearances (through poor machining or wear) allows too much volume to pass.
A blocked filter would cause high pressure if anything and then the pressure relief valve would open - you’d potentially see a fluctuating pressure on a gauge.
Yes, it was the moly. I replaced the filter and normal oil pressure was resumed despite the shells being damaged. I cut the old filter in two and it was caked in black, non magnetic particles.
The crank was ground by Rob walker and I checked the shell to crank clearance with plastigauge. It was spot on.
The blocked filter was causing the drop in oil pressure because there wasn't enough flow. A sufficient restriction will ultimately cause a loss of pressure.
Thanks for the replies. All interesting stuff
Pete
#1723
Posted 01 December 2021 - 11:33 PM
The engine has done 1200 miles and the only debris in the oil was the moly from the pot joints. The filter was partially blocked and whilst the oil light came on at idle, revving it to about 3k gave 40 psi of pressure. That means the pump couldn't cope with the volume the engine demanded due to the restriction but I can't see it causing that sort of scoring.
Maybe I'm missing something?
metal particles - steel, alloy and brass - will ultimately end up in the sump/gearbox due to the run in process. Sadly these go flying through the oil pump prior to the filter. My process is now to knock the cam in for 20 minutes and do a full oil and filter change. Then again after 100 miles (rings bedded in).
#1724
Posted 02 December 2021 - 09:55 AM
The only pump I fit is the AC Dodd 'Zero Tollerance' pump. Thomas Classic and Modern stock them.
#1725
Posted 02 December 2021 - 03:15 PM
Im running the KAD zero tolerance pump, impressed to be honest.
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