Classic Mini Cooper 12G295 cylinder heads. Absolutely everything you need to know, a complete guide.
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- Опубліковано 8 вер 2024
- Essential guidance on what to look for when buying a used classic Mini Cooper 12G295 cylinder head & information on other small bore A-series engine cylinder head castings.
I put a 1275 head on my 998 mini cut the block out a bit to clear the exhaust valve . It was a right little rev monster, used to go really well.😊
Yes a decent flowing cylinder head certainly makes the world of difference.
Nice work Phil, looking forward to more videos :)
MED Race Technologies thanks I appreciate it. I enjoy your videos to.
great video phil, i did have a 206 years ago, that got sold to a guy in hungary regards rich
Wouldn't have been much good on your 1380 anyway mate ! Ha ha.
Lots of information. Great video!
OvenproofJake thank you.
Very nice and helpful - cheers Phil! 👍🇬🇧
No worries glad you liked it.
Great work! Liked and subscribed and looking forward to more tech videos.
Classic Mini DIY thank you.
Nice one Phil! Definitely the head to get for a 998 turbo! They’re getting more and more expensive and hard to find now as you said.
I’ve got a 202 head at the minute that I’ve planned to open the chambers up a bit for a 998 turbo so will be looking forward to watching you work on the 295.
Excellent for a first video mate keep it up 👍
Mini Matt TV thank you, appreciate the positive feedback.
In the end I went with a modified 12A1456 pre A plus casting (my original head) modified by CST. It's got 31.75 inlets and 27.12 exhausts with completely reshaped chambers. This head is a better breathing head than a 295. It's inlet ports are smaller diameter but this aids gas flow as the 295 inlets are bordering on too large. It's got double valves springs, hardened seats it's the business.
The only thing that is a little odd is the inlet spring caps are higher than all the exhaust caps. This is apparently due to the collect groove being in a different position on the inlets. Although the spring seats have been machined/shimmed to ensure correct pressure. Have you ever seen this done Phil? Apparently it's completely fine.
Sounds like a good spec. People underestimate what can be achieved with those castings, the bigger port of the 295 isn't always an advantage.
The valves are fine as the spring height has been compensated for. Its not uncommon where different types/brands of valves are used.
Do you have to shim under the rockers as they are 1275 inlet valves on a 998? I'm pretty sure these are longer than 998 valves? Any advice would be great Phil. 👍
Hi Paul. If you use the 1275 valves you will have to shim the valve springs to correct the fitted height & the rocker geometry will need adjustment to optimise it, yes.
Really helpful video, thanks! What’s your opinion on using a 12g940 on a small bore engine? They seem far more plentiful (and cheaper) than the 295s :)
Rhys Lister if you go that route use the small valve version 33/29mm if it’s a road going car. Keep the standard size ports to, they’re more than adequate in size. Also be aware that the 1275 heads have smaller chambers than the smallbore castings so fitting one will increase your compression ratio by quite a margin.
You'll also have to pocket the block if you fit a 12G940 to a small bore engine. Just something to bere in mind 👍
@@OnlineHousehusband not necessarily. Have a watch of this:
ua-cam.com/video/rE9K1xspc68/v-deo.html
How thick is a standard unskimmed 12G295?
Hi Paul. 2.75” (69.85mm) is standard thickness.
@@TurboMinicom Brill thank you. So what is the most that can be taken off this head until it becomes unserviceable?