2003-08, Oil gallery plugs

Here's something unusual that cropped up a little while ago that I've never commented on before - main oil gallery plugs/bungs.

I'd been conversing via e-mail with a guy that was experiencing weird oil flow/supply problems with his performance street engine. Initially he'd been blaming it on the supposedly superior oil pump he'd bought. He sent it to me; I inspected it and found it to be in perfect health with no signs of causing the issues in hand. Firstly there was a claimed total oil drain down from the pump causing lack of initial supply on start-up for a few seconds, and then repeated crank bearing failures when used in anger (i.e. at high rpm for protracted periods). Unless there is something drastically wrong with the oil pump and fitment - cracked pump body, non-flat mounting surface, mounting bolts too long, split gasket, etc. - it will not drain down simply because the inlet and outlet ports are above the centerline, near the top of the pump as it is mounted to the block.

Lubrication - Oil pumps

Essential to the well being of every engine is its oil pump and oil. Much in the same way as the heart and blood is deemed relatively important to us humans! It's also another of those greatly misunderstood and, unfortunately, misrepresented subjects connected to engines.

An alarming number of so-called A-series engine specialists would have you believe that once parting with a veritable bundle of your hard earned readies on that mega motor, what you really need to keep it in good health is a high-pressure/high-flow oil pump. Seems a sensible consideration - except in the A-series world it's impossible. Oh, there are pumps that will give better flow rates than others, but high pressure? Absolutely not.

Oil pressure is regulated by the relief valve in the block of an A-series, not in the oil pump as with say a Ford. Yeah, you know - the one that gets jammed, causing heart failure as you believe your crank bearings have dissolved, and is a pig to get out.

Lubrication - Oil, what it does and how

It's criminal. Folk spend fortunes putting together super-sonic motors, only to skimp on the oil they use. Why? Oil's oil right? Wrong. Even if it's a standard engine, it deserves TLC considering it's extremely hostile working environment.

Oil is literally the engine's life-blood. The opening few sentences are astonishingly true. Oil isn't there just to prevent all metal components within an engine fusing together in the first few seconds of running, creating a total melt down of Chernobyl proportions. It's an intricate blending of chemicals to protect the engine as a whole.

The most commonly uttered statement about engine wear is most wear occurs within the first 10 minutes from start up when cold. True if cheap chip fat oil is used.In performance and race engines, a considerable amount of wear is created by heat, load, speed, and pressure. Again, cheapy oil won't give protection here.

SU Carbs - Dashpot oil

This subject is a regular message-board poser. Many of us have touted our preferences and discoveries whilst playing about over the years.

One problem with trying to deal with it on the message board is the sheer volume of information offered and available against the time availab

Classic example - the MG Metro. Its adventurously sporty cam makes for a slightly lumpy idle. This increases idle speed emissions, so Rover use manifold-sourced vacuum to increase idle speed ignition timing via the vac advance. It is a little on the thin side, but the whole engine tuning data for each engine is based on using this oil. Used as such it works very well, especially where economy is the main goal and the car is driven very sympathetically.
ATF - 'automatic transmission fluid'. A very good substitute where the genuine SU dashpot oil isn't available for use in STANDARD spec engines.

C-AHT54 CENTRE OIL PICK-UP PIPE - FITTING INSTRUCTIONS.

Oil pressure loss caused by oil surge can be experienced under hard cornering. To alleviate this it is essential to fit a centre oil pick-up pipe.Mini Spares' continual research and development program has seen advances in pick-up pipe design, replacing the original ancient design conceived by Abingdon ST some thirty-plus years ago.

HPS5 – IN LINE OIL PICK UP MAGNETIC TRAP WITH FILTERHPS6 – IN LINE OIL PICK UP M...

FITTING INSTRUCTIONS

Mini oil pumps are susceptible to premature failure caused by excessive large particle contamination of the oil, mainly metallic debris created by the gearbox. The situation is not helped by the oil getting to the pump before being filtered. Mini Spares has developed components to help minimise this problem, including these in line magnetic oil traps. Their design allows easy fitment, as the adapter simply replaces the standard oil pick up pipe blanking plate on the back of the gearbox. It’s position in the oil supply gallery necessitates frequent removal of the trap to clean collected particles out, more so for the filtered version. Failure to do this will cause premature failure of the pump and possibly engine bearings.

There are no hard and fast rules for this periodic maintenance as vehicle usage will determine debris build up. Obviously a carefully driven road car will not need as frequent attention as a race car. Certainly clean it at e...

C-AEG410, C-AEG411, C-AEG412, C-AEG413, C-AEG414, and GLP110MSSUREFLOW OIL PUMPS...

PLEASE READ THESE INSTRUCTIONS FIRST

The pumps are thoroughly cleaned when assembled, so only priming the pump is necessary prior to fitment. A precautionary testing of the pump prior to priming is recommended - merely turn the rotor using thumb and forefinger engaged on the pump drive. It should turn freely. If it does not, it will be necessary to strip the pump down to make sure no debris is causing the problem. Make careful note which way up the annulus fits and ensure it goes back the same way. Prime the pump with preferably engine building lubricant (less likely to drain away before start up is effected).

If not properly primed, oil pressure may not be obtained; crankshaft and bearing damage may result.

Make sure the retaining bolts do not bottom out in the relevant tapped holes in the block before securely clamping the pump to the block. Any air leaks caused by using bolts that are too long will cause oil pressure deficiencies, drai...

C-AHT54 Centre oil pick-up pipe.

Since the inception of the newer design of this essential component, literally hundreds, if not thousands, have been sold and used. Some folks have been suspicious of the filter gauze, believing it to be too fine and therefore restrictive in flow.

Others have questioned the 360 degree, straight cut-off end, suggesting it may cause ...

Historical Article - Nov 1991 - MINI SPARES PERFORMANCE OIL PUMPS

MINI SPARES PERFORMANCE OIL PUMPS

The requirements of modern automated mass production of commercially available oil pumps has necessitated the opening up of manufacturing tolerances to help rapid assembly.  As a majority of the internal components are close to – and in many cases exceeding – their maximum tolerances the oil is recirculating within the pump rather than being passed to the engine.  This results in a rapid drop in oil pressure under arduous conditions such as racing.  To solve this problem all internals and cases are machined in matched sets and built by hand to Mini Spares’ exacting specifications.  This new range of pumps is available for the different drive types.  As the original pump has always been more than sufficient for the Mini engine (some ...

Historical Article - Nov 1991 - MINI SPARES PERFORMANCE OIL PUMPS

MINI SPARES PERFORMANCE OIL PUMPS

The requirements of modern automated mass production of commercially available oil pumps has necessitated the opening up of manufacturing tolerances to help rapid assembly.  As a majority of the internal components are close to – and in many cases exceeding – their maximum tolerances the oil is recirculating within the pump rather than being passed to the engine.  This results in a rapid drop in oil pressure under arduous conditions such as racing.  To solve this problem all internals and cases are machined in matched sets and built by hand to Mini Spares’ exacting specifications.  This new range of pumps is available for the different drive types.  As the original pump has always been more than sufficient for the Mini engine (some ...

Historical Article - April 1994 - Pumping Oil

Pumping Oil In the last issue, I cited that there are many questions, side issues and problems that regularly occupy "Br time. On reflection, the following must be one of THE most popular, so more than a side issue is pertinent. Or more precisely, questions appertaining to their performance. For many other engine types, tuning companies offer both high capacity and/or high pressure oil pumps. This is a very relevant, and indeed praiseworthy option to the standard equipment types. Especially when one considers such bizarre facts as original Ford/Lotus twin cam pumps only supply 40psi of oil pressure.

Lubrication - Oil, What it does and how it works

It’s criminal. Folk spend fortunes putting together super-sonic motors, only to skimp on the oil they use. Why? Oil’s oil right? Wrong.

SHOCK ABSORBERS

Technical lowdown on shock absorbers,what to look for and what to buy Having introduced the fairly unknown Kayaba (KYB) range to the mini market in 1997 I am still amazed how gullible people are when buying cheap dampers. I have tried every type popular type available in the last 35 years, Armstrong including their adjustables, Girling, lockheed, Koni, Spax., Avo, Bilstein,Monroe,Boge,Gabriel and GMax The best to date were probably the very expensive special design Koni adjustables that we had built for the Monte Carlo rally. I also used the spare set on my 8 port car. You get what you pay for? For a non adjustable, Bilsteins rate highly although like the Koni specials are expensive, but you get what you pay for. The essence of a quality damper is to upgrade performance by using more sophisticated higher quality component build in the valving, piston, rod and seals etc along with a performance upgrade to improve the cars road holding.

Primary Gear - Bush Replacement

With the cost of new primary gears spiralling ever upwards, and the availability of good, serviceable used ones, fitting new bushes to existing gears is becoming a more common solution. For some reasons for bush failures and rectification to stop it re-occurring, see article Primary gear - Bush problems. Since there is no useful information given in any of the workshop or DIY manuals on this subject, following is my approach to dealing with the issue. The first thing to get to grips with is which bush is which. This has added an element of confusion to many conversations I have had with folks on this subject, so - the FRONT bush is the one nearest the engine block, the REAR bush is the top-hat one nearest the flywheel. This is because the front of the engine is actually the radiator end - quoted in 'in-line' engine-speak. The REAR bush is the same on all primary gears - be they for small or large bore engines. The FRONT bush is different for each though; the small-bore one is smaller

Idler Gear - Setting End Float

A fairly crucial part of how the idler gear operates is its tolerances and running clearances. part numbers: 22A1545, 22A1546, 22A1547, 22A1548, 22A1549, DAM4822, DAM4823, DAM4824, DAM4825, GUG705563GM, AAU8424, ADU6033, CCN110, 2A3643, 22A152, 53K547, Terminology: DTI - Dial Test Indicator End float is a continual problem as folk either ignore it through ignorance or lack of accessible information on how to do it, or belief special tools are needed. Also, later factory assembled engine units (from about 1992 onwards) were built up using whatever shims and thrust washers were available, since Rover were not making regular orders for all shim/washer sizes due to the forthcoming end of production. Consequently, many units left Rover with incorrect (usually too big) clearances. The idler gear was no exception. Too tight a clearance and the idler gear will either seize solid when it gets hot, or destroy the thrust washer thrust faces in the comparably soft aluminium gearbox and t

GEARBOX - Up-Rating Drop Gears

The standard drop gears are fine for practically all road use - almost irrespective of power output. part numbers: DAM9373, C-STR123, C-STR124, C-STR30, C-STR30A, C-STR30T, C-STR30TA, C-STR230, C-STR240, C-STR250 Terminology - Drop Gears - Transfer gears (primary, idler and input gears) Large-bore - Refers to anything based on a 1275-type unit Small-bore - Refers to anything based on 850/998/1098 units Despite what many folk believe - they are more than strong enough, and will perform perfectly well if correctly set up. That means getting the idler and primary gear end floats right, and using new bearings for the idler gear at each re-build. Simply following the methods outlined in the relevant workshop manuals will achieve these simple goals. There are two problems with standard drop gears - the main one is the helical cut of the teeth, the other a very limited selection of ratios. The helical-cut teeth are essentially power absorbing - both from increased metal-to-metal c

Gearbox - Up-rating diffs and FDs

There’s a good selection of straight-cut final FDs available. Examine the FD table, and using information from

'Gearbox - Final dives, standard' and 'Gearbox - Formulae for car speed, etc.'

you can assess which would best suit your usage. Bear in mind that they’re noisy, make sure you select one that’ll fit your diff unit, and also consider that using drop gears will allow fine-tuning of the ratio where necessary. See

'Gearbox - Up-rating drop gears'

Gearbox - Up-rating diffs, FDs and ancillaries.

part numbers: C-BTA166, C-BTA167, DAM6624, BTA101, 2A7062, DAM5071, DAM6027, RPS1418, C-AJJ3385, C-22A1731, ...Read more

Primary Gear – Bush Problems

Although not of immediate interest to many road-runners/street-burners, mainly accorded to the racing scene, it seems to be a perplexing problem to a very large number of folk around the world, and has burned up plenty of telephone time.

part numbers: 13H2934, LUF10005, CE12, 22G109, DAM8889, DAM8887

With the cost of new primary gears spiralling ever upwards, and the availability of good, serviceable used ones, fitting new bushes to existing gears is becoming a more common solution. For some reasons for bush failures and rectification to stop it re-occurring, see article 'Primary gear - Bush problems'. Since there is no useful information given in any of the workshop or DIY manuals on this subject, following is my approach to dealing with the issue.

The first thing to get to grips with is which bush ...

GEARBOX - Syncro vs 'Dog' engagement

NOTE

; A 'high' or 'low' ratio gear is in reference to it's performance, not it's numerical number. To illustrate - a 'high' FD ratio will give 'higher road speed', but will have a numerically low figure. A 'low' FD ratio will give lower road speed, but have a numerically high figure. part numbers: C-AJJ3371, C-AJJ3319, C-STN39, C-AJJ4014, C-STN76, C-STN77 A by-product of this will be reduced acceleration capability on the 'high' ratio, increased acceleration capability on the 'low' ratio. The main gearbox gears work in the exact same way. Cog swapping Elsewhere we've considered what alternative standard production ratios are available - but that still leaves you with the power-consuming and limited-ratio alternatives helical tooth type gears. Not desirable in a competition orientated car. The solution to this comes in the form of several types of straight-cut gear sets (teeth are cut at 90 degrees across the gear as opposed to the angled helical type).

GEARBOX - Close-Ratio Conversion Pre-A+ Gearbox

As outlined in the 'Gearbox - standard production gearbox types' article, it is entirely possible to change the common 4-syncro gearboxes to the helical close-ratio set-up as used in the Cooper S, 1275GT, 1300GT, and some early MG Metros providing the right parts can be sourced. And you don't already un-knowingly have the close-ratio kit fitted! Part numbers are detailed at the end.

The other pre-requisite for this conversion is that it can only be applied to the early, pre-A+ type mainshaft gears. That's those that have the square-topped teeth as supposed to the distinctively pointed A+ profile. This is because despite being endowed with A+-type fittings for the mainshaft end and layshaft, the conversion gears have the pre-A+ tooth profile. This is not to say that the conversion cannot be put into an A+ gearbox casing - it can and is detailed in the relevant article.

What is essential to understand is that the pre-A+ second and third mainshaft gears are going to be