10 replies to this topic

[Patriot]

Hi,
just bought a 12g295 head to replace my 12g202 on my 1098, will the rockers and valve springs simply transfer over as the 12g295 head only comes with valves.

thanks

[Cooperman]

The valve springs & rocker shaft should be interchangeable between those 2 heads. However, if you are fitting or do ever fit a different cam you would need to check which valve springs are recommended by the cam manufacturer and then set the correct springs to the recommended fitted length.

[Patriot]

thanks, changing cam in the summer.

[Cooperman]

thanks, changing cam in the summer.

You will probably need to change the valve springs then unless you already have the recommended springs. Which cam are you going to install if you don't mind my asking?

Edited by Cooperman, 23 March 2013 - 11:00 PM.

[KernowCooper]

The rockers will change over, but the 12G295 had double valve springs where as yours has single valve springs, I presume your fitting the 12G295 as a upgrade ? are you still using the 1098 standard cam? If you intend to change the cam at a later date then you would need to change the springs.

As a matter of course how old are your current springs in terms of mileage, if they have covered lots of mileage I'd replace them while you have it apart

Just read your update, new springs now a good idea, depending on the cam even double springs as per the original spec on the 12G295, even though the 1098 is not such a high reving as the 998.

Edited by KernowCooper, 23 March 2013 - 11:03 PM.

[Cooperman]

The only concern with new double valve springs would be if the cam is still the standard basic 1098 (as in Morris 1100) cam. If the followers and cam are a bit worn the stronger springs could cause the wear rate to rise and the case hardening to fail. I've seen this on a high mileage cam/followers when much stronger springs were fitted. With a cam change then new springs and, of course, followers would be fitted as a matter of course. To fit a new cam to a 1098 the head needs to come off again, so the springs could be changed then, or now, whichever is thought best. A 1098 doesn't rev too much, so valve bounce due to soft springs is unlikely.

[Patriot]

intention is to install kent 266 cam, was hopefully going to retain existing springs untill I complete the cam can in the summer, then look at new set of springs.

thanks

[Cooperman]

Kent Cams recommend the VS2 valve spring for the 266. Remember, the MG Metro cam is virtually identical to the 266, so if you get the chance of an MG Metro one at a better price it would be ideal. In a 1098 engine the 266 is super as it peaks at around 5700 rpm and the 1098 can safely run to about 6000 rpm.

[Patriot]

many thanks

[KernowCooper]

I had a MG 1100 engine is a mini a few years back and it went very well.

[Cooperman]

I had a MG 1100 engine is a mini a few years back and it went very well.

So did I. It was an MG1100 unit with a 295 gas-flowed head, a 731 cam and a full 998-type exhaust.