C/Head

[jtd.75]

Can anyone tell me if a 1098 cylinder head will fit a 948 engine and if so whats req. is it a straight foreward swop or not.

[bmcecosse]

It will fit just fine - has slightly larger inlet valves and better porting, however - it has bigger combustion chambers and therefore the compression ratio will be down. If the car is just for pottering about then it will be fine - if you intend it for serious motoring then you should get the head skimmed by 60 thou to bring the CR up to a decent figure. If you can also fit the camshaft from the 1098 engine - you will then get virtually the power of the 1098 engine (48 bhp, gasp!) - but at about 10% higher revs of course because it then will be pumping the same air flow as the larger engine at the lower revs.

[jtd.75]

has anyone more imput to my message re swop 948 over to 1098

[Shawn]

I think BMC said it all - I'm doing the mentioned swaps on my spare engine - just finished cleaning up the head yesterday - have to get it skimmed first.

[jtd.75]

Thanks Shawn

[jtd.75]

hi bmc if i was to use the 1098 c/h on the 948 engine would i be able to still use all the other bits that i used for the 948, like the exhaust manifold, and the tappit push rods in other words a straight swop.
jimmy

[wanderinstar]

Don't think Jimmy believed you Roy, till he got it confirmed by someone else.Ian.

[jtd.75]

Hi wanderingstar , not sure what you mean could you please explain as the old grey matter is not what it use to be since i retired.

[picky]

jtd.75, The head from the 1098cc engine will fit the 948cc engine without any modification or other parts needed. You will of course need a set of new gaskets to complete the job. With the 1098cc head the engine will not be very powerful, but if you have the head skimmed, which takes some material off and makes the engine compress the air and fuel more, you will get more power.
hope this helps, any more questions then just ask!
Tim

[ian-s]

hi bmc if i was to use the 1098 c/h on the 948 engine would i be able to still use all the other bits that i used for the 948, like the exhaust manifold, and the tappit push rods in other words a straight swop.
jimmy

YES !

[paul.kissick]

You have to skim 60 thou of the cylinder head to get a good compression ratio

[paul.kissick]

You have to skim 60 thou of the cylinder head to get a good compression ratio

sorry thinking on somethin else

[jtd.75]

Thanks Picky, that was very simple and I understand that now. BMC has been a great help too in replting to my pms

[wanderinstar]

Jimmy,
Sorry if I got it wrong, but it just seemed that you didn't believe what Roy said until Shawn confimed it. A sentiment echoed by many on here. However there seem to be a few doubters coming round to his way of thinking, slowly.
Ian.

[picky]

no problem jtd.75
Picky

[bmcecosse]

Try to get it skimmed jtd - it will be so much better! Try asking at local garage - they must use some kind of machine shop - a big lathe will do it provided it can 'swing' the head ! However - it's obviously not ideal because of the interrupted cut. A vertical mill is the best way !

[jtd.75]

hi wanderinstar, i have always found what is simple for one guy is difficult for another. And going by some of the comments on here on some of the things they get upto with there beloved car is amazing, with all the mods they do to it. Its not that I doubt anybodys word at all far from it I have learnt a lot from you guys out there.
Thanks to you all.
Jimmy

[Cam]

Jimmy,
Sorry if I got it wrong, but it just seemed that you didn't believe what Roy said until Shawn confimed it. A sentiment echoed by many on here. However there seem to be a few doubters coming round to his way of thinking, slowly.
Ian.

Ian, maybe Roy is slowly coming round to the 'doubters' way of thinking!

[bmcecosse]

Errr - NO ! I don't think so ! You can rely on me for sound low-cost advice anytime - don't hesitate to ask.

[Cam]