Created: March 23, 2017
Any aluminum head will have advantages in lighter weight and better cooling due to aluminum being able to shed heat better than iron.
Created: April 25, 2014
Most motors will go at least 80,000 miles before "needing a valve job"! But what are the signs? How do I determine if I really need it? Do I do it myself or pay a local machine shop.
Created: January 15, 2014
Valve stem seals: The o-ring style seals are used on the early small bore heads, most later heads use the umbrella style. As an engine wears, the clearance between the valve stem and guide increases; as this gets beyond tolerances the car will tend to smoke under deceleration (when you take your foot off the throttle). Good valve stem seals will allow for greater wear before the smoke becomes intolerable.
Created: October 10, 2011
Call them cotters, collets or keepers, these little items are often overlooked during a head rebuild. If yours are worn and need to be replaced, make sure you order the right ones. Minis used three different versions over the years.
Created: February 03, 2011
The engine build I recently covered in previous Mini Magazine issues developed into a bit of an ongoing 'project'. During a discourse with the editorial staff at Mini Mag, it was decided the build feature presented an ideal opportunity to demonstrate just exactly what such an engine build is capable of in days where it's generally believed you have to have an all-singing, all-dancing 1380cc engine to have an enjoyable road burner - leaving those with very limited budgets a little depressed.
Created: July 24, 2006
Last time we started building a small-bore engine for maximum power. But there is no point having a good engine and putting the wrong head on it. I'm going to use the 12G202 head, as these are the best to modify for our purposes. They are a bit smaller than the 12G295 or 12G206 heads, which gives you a bit more metal to play with when grinding. As far as a standard head goes, you can't go past the 12G295 or 12G206.
Created: January 28, 2006
Fastener Retention Overview There are three methods that can be employed to determine how much tension is exerted on a fastener; using a torque wrench, measuring the amount of stretch, and turning the fastener a pre-determined amount (torque angle). Of these methods, use of a stretch gauge is the most accurate.
Created: February 09, 2004
This addendum to the Cylinder Head section was fueled mainly by pictures of combustion chamber shapes and folk's excitement at what they could possibly do for them. It is also prompted by the 'new isn't always great' teaching. So what's in these varying and dramatically different chamber shapes?
Created: October 27, 2003
Detailed description of the numerous cylinder heads as built by Mini-Tec
Created: July 03, 2001
Ben Howes 8 port has been at various shows this year, and was good enough to bring it down to Mini Spares' open day, with New Mini Spares 8 port fitted.
Created: May 16, 2001
The specter of 'unleaded fuel only' - instigated in UK on January 1st 1999 and seemingly from decades ago across the rest of the world - seems to be forcing more and more folk into frightened, panic orientated action.
Created: May 01, 2001
Whatever else owners do to their Minis by way of interior/exterior modifications or none at all, a very large proportion desire and search for an increase in engine performance.
Created: April 13, 2001
Material choices for guides are down to two distinct types - cast iron and bronze. Yes, cast iron. NOT steel as described in many adverts and by vendors. Never have been, never will be. These are as fitted to the various A-series cylinder heads as standard in all applications.
Created: October 19, 2000
Many moons ago, the standard performance valve shape was the then-ubiquitous 'penny-on-a-stick' profile. For the very good and simple reason it minimised airflow obstruction by having the least amount of material in the way. Very plausible, and a design that many have stayed with to this day
Created: January 30, 2000
A selected range of modified cylinder heads are available to suit a wide variety of applications. All port and chamber modifications are carried out by experts to current state of the art specifications. Therefore, actual specifications may alter slightly as gas flow and port velocity efficiency improvements are developed. Where large bore heads are used on small bore engines (i.e. 12G940 casting on 948/1098cc block), it is necessary to check full lift of exhaust valve, and pocket the block as necessary.
Created: January 30, 2000
Everybody has their own opinion on this subject. The most experienced people will tell you that the best way to maintain your engine performance is to accept the fact that valve jobs need to be done 2 or 3 times more often than rings and bearings! And this data base was concluded when leaded gas was the norm! Now that unleaded is all you can get, valve jobs are needed even more often! The purpose of a valve job is two fold; first the valve seats. The impurities in the air and gas often get trapped between the valve and the seat in the head; under worst conditions stopping the valve from closing, but more commonly being smashed enough to allow just a little seepage of hot gases.
Created: January 30, 2000
This kit has been produced by Mini Spares to reduce head gasket problems on performance orientated engines, especially those utilising large over bore sizes. Standard type head studs and nuts are mass produced which unfortunately compromises the specification of the end product. Worst affected are the threaded portions which create problems during torque-down; thread deformation, stud distortion and possible stretch, off-square seating of the nut to head and so on.