31 replies to this topic

[matthewjtovey]

Hi

Im looking at putting a 1275 head (12g940) on my 1990 Mayfairs 998. Ive found so far that i will need to pocket the block. However, i can find no where how you actually do that!!

Could someone walk through the steps for me please.
Also can this be done while still in the car or does the engine have to be removed?

Any photos of the process would be great!

Thanks

Matt

[MRA]

Do you mean like this one....

[attachment=113568:IMG_0784.jpg]

Well this one was done on our CNC mill

It depends on how good a job you want ? some people have apparently used a dremmel, however accuracy will be sadly lacking

[dossy]

What is pocketing? In lehmans terms!!

[MRA]

It is the offset machined sections or cut outs on the top of each cylinder, these are to clear the exhaust valve of the 1275 cylinder head (12G940) when used on a small bore engine such as a 998 etc...

[mini 4o]

What is pocketing? In lehmans terms!!

hi
just means making space in the block for the valves to go up and down, as the 998 and1275 head have different spacing(lehmans terms)
Imo not worth the trouble, fit a complete 1275 and go
John

[matthewjtovey]

Do you mean like this one....

[attachment=113568:IMG_0784.jpg]

Well this one was done on our CNC mill

It depends on how good a job you want ? some people have apparently used a dremmel, however accuracy will be sadly lacking

Thanks for the photo and info! How much roughly would this cost to do properly? If the engine was still in the car when taken to the machine shop.

[PhilipGCaldwell]

its usually 60 Earth pounds

[dossy]

makes sense, thanks for that! i have a 998 but im hoping to upgrade to something bigger, so i dont really want to get too technical with modifications if im not keeping it!

[PhilipGCaldwell]

makes sense, thanks for that! i have a 998 but im hoping to upgrade to something bigger, so i dont really want to get too technical with modifications if im not keeping it!

stick to 998 much more fun, and more reliable

[benb12]

makes sense, thanks for that! i have a 998 but im hoping to upgrade to something bigger, so i dont really want to get too technical with modifications if im not keeping it!

stick to 998 much more fun, and more reliable

I know you love your small bores but you need to explain why you think a 1275 would be less reliable! I've had absolutely no reliability issues with mine.

[MRA]

I have no issues with my 1380 turbo engine either....

[PhilipGCaldwell]

998s are bomb proof

[MRA]

Do you mean like this one....

[attachment=113568:IMG_0784.jpg]

Well this one was done on our CNC mill

It depends on how good a job you want ? some people have apparently used a dremmel, however accuracy will be sadly lacking

Thanks for the photo and info! How much roughly would this cost to do properly? If the engine was still in the car when taken to the machine shop.

It will cost a lot more than £60 if the engine is still in the car when you take it to the machine shop.... and that is assuming that they will even bother to do the job, taking engines out is not normally associtaed with machine shops.....

[benb12]

998s are bomb proof

No more "bomb proof" than a 1275. If you can't explain why a 998 is so much more reliable than a 1275 then don't make the claim!

[dossy]

1380 turbo is what i want!!!!!