1098 pistons

Post by **turbominor** » Mon Dec 29, 2003 2:35 pm

Any one know how big the dish in standard 1098 pistons are ( eg 3 cc)

Engine code is 10v if that helps!

Post by **stormin** » Mon Dec 29, 2003 9:05 pm

Hi Iain,
It all depends on which pistons you have, thereis a high compression one and a low compression one!
The HC will have 6.9cc dish and the LC 12.3 dish. If your engine is from a late car then it is likely to be the HC type.
I confirmed the size of my piston dish by pouring water into it from a cough medicine cup!! not entirely accurate but near enough.
Are you doing a rebiuld or what?

Stormin

Post by **turbominor** » Mon Dec 29, 2003 9:16 pm

Hi Stormin,

thanks for the good answer, shall poor some oil on the piston and see how much i use.

Not rebuilding, just trying to work out the compression ratio when i fit a 1300 head. As turbos and big compression's dont go togeather

Post by **rayofleamington** » Mon Dec 29, 2003 9:30 pm

i once rebuilt a 1098 Van engine - the pistons were heavily dished comapred to the normal ones, so I always thought the low compression ones were easy to spot.

Post by **turbominor** » Tue Dec 30, 2003 1:19 pm

Hi Ray

can you have a look at the picture and see if they look heavily dished to you

( was taken just after the head came off, so things look much better now!!)

Post by **rayofleamington** » Tue Dec 30, 2003 7:18 pm

they look very much like standard pistons.

Post by **turbominor** » Tue Dec 30, 2003 8:47 pm

Cheers Ray

6.9cc it is then, of to visard for some 'a' level maths then.

Will post some pictures of the body shell tomorrow, as she has just been released from the body shop, a covered in 2pack black

Post by **rayofleamington** » Thu Jan 01, 2004 4:54 pm

they certainly look correct. That's quite a find! - (however it doesn't say if they are oversize)
Have the block been overbored? Also - are there any wear ridges at the top of the bores?
If you have notieable wear ridges, it doesn't mean there is a problem - 'A'series engines can keep running happily with ridges up to 1mm but if you change the pistons, the rings may then knock into the ridges causing damage.

Post by **stormin** » Thu Jan 01, 2004 8:23 pm

Hi Iain,
Just looked at the pistons on E bay they are the LC ones they may suit your purpose, I cant remember what Vizard said about CR's for turbo's but you dont want it high for sure.
Sounds like a nice paint job you've had done, I was thinking about Black WHEN I get round to spraying my rebiuld.
Cheers
Stormin

Post by **turbominor** » Fri Jan 02, 2004 9:14 pm

cheers guys, I emailed the chap and they are +20thou, shame as i have a newly honed and rebuilt block.

Worked out I get 9.2:1 with the 12g940. so back to the original head.

Any one want a good unleaded 12g940 let me know!

Post by **rayofleamington** » Fri Jan 02, 2004 9:47 pm

Any one want a good unleaded 12g940 let me know!

yes please
how much?

ps - what bore size is your block?

Post by **turbominor** » Fri Jan 02, 2004 9:49 pm

Hi Ray,

my block was new about 6000 miles ago, so standard size, and has just been honed and had new rings fitted.

Cost me £35, so yours for that, or if you have a working unleaded 1098 as a swap

Post by **rayofleamington** » Fri Jan 02, 2004 9:56 pm

I have a (very) well worn 12G940 that I was going to recon, but for £35 it'll save me plenty.
Sorry - don't have any unleaded standard heads - I had one once but it got sold with the car.
I'll drop my details on a PM
many thanks,
Ray.

Post by **turbominor** » Fri Jan 02, 2004 10:10 pm

cheers ray, look farward to meeting!