moving up to a 1098

[David W.]

I have a 1098 engine available, and my 948 is starting to lose compression. I've scoured the forums searching for compatibility, and here's what I've come away with:
If I put my 948 back plate, flywheel and clutch on the 1098, I'll get along fine.
I wasn't able to find clear advice on using the 1098 back plate, flywheel and clutch. I gather there will be interference inside the bell housing due to the "taller" clutch. But might that be offset by the thicker back plate?
Also, will the clutch fork fit with the "taller" 1098 clutch even with the thicker back plate?
Thanks

[philthehill]

If you do not have the 1098cc gearbox the easiest way to utilise the 1098cc engine is to use the 948cc rear engine plate, the 948cc flywheel and the 948cc clutch cover.
The down side is that the 6 spring 948cc clutch is not really up to the power output of the 1098cc engine and may well slip under the application of power.
If you can obtain a 948cc 9 spring clutch all the better as it will cope with the 1098cc engine.

If you utilise the 1098cc rear engine plate, the 1098cc flywheel and clutch cover - the clutch will foul the inside of the 948cc gearbox bell housing.
The shape of 1098cc bell housing is different to the shape of the 948cc bell housing so as to accommodate the larger 1098cc clutch.

As regards the clutch release arms and pivots see the attached link below.
http://gerardsgarage.com/Garage/Tech/TO ... arings.htm

Using the 9 spring clutch cover the original 948cc clutch lever and mount can be used.



I hope the above is of help in resolving your quandary.
Phil

[David W.]

Just what I needed. I'm only driving around town in a very flat area, so I'm not worried about the 948 clutch, although I'll look for a 9 spring up until the moment of i installation.
Thanks very large!

[David W.]

And 10 minutes later, there was one on Ebay, and I bought it.
I'll sleep well tonight.

[philthehill]

Well done.
The 9 spring clutch cover was used on a variety of vehicles including the early Triumph Spitfire (1147cc & 63bhp) and the Reliant Kitten.
I recently purchased a NOS 9 spring clutch cover (below & listed as Triumph Spitfire) for use on a modified 948cc 'A' Series of which the power will be comparable plus to the 1098cc engine.
Below is a photo of a BMC Special Tuning XSP racing engine fitted with a 9 spring clutch cover which has the 6 yellow springs and three blue springs the same as the Triumph Spitfire so I am sure that your 9 spring clutch cover will cope.