• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

1098cc stock compression numbers?

Share this page

Luke_Healey

Luke_Healey

Jedi Trainee
Offline
I've been digging through the Haynes manual and may have missed it, but I'm looking for the stock compression number for the 1098cc engine (warmed up..)

I have en el-cheapo compression tester, but out of curiosity I hooked it to my Sprite and pulled the following numbers from the following cylinders- 1:180psi 2:190psi 3:190pdi 4:190psi.

I'm just curious if that seems healthy or weak? It's higher than anything else I'm driving, that's for sure /bcforum/images/%%GRAEMLIN_URL%%/wink.gif

Thanks for any info.
 
Though comparable, don't compare compression readings with compression ratio. Readings are done with a larger chamber volume (it includes the volume inside the gauge) and with carbon buildup in the chamber. Gauges can also easily be 50% wrong. Suffice to say that the readings are on the high side of engines today, while low readings would be around 100 to 120. More important is the deviation of the cylinders, and yours are good.
 
Man, you good. Those are excellent numbers.
 
It could be the big layer of gunk on top of the pistons too /bcforum/images/%%GRAEMLIN_URL%%/wink.gif

Yeah, typically what I'm looking for is a weak cylinder or something indicating valve or ring problems. I was pretty happy to see her puffing away seemingly healthily.
 
Put a half a tablespoon of oil in each cyl and check it wet. this will seal the piston rings and let you check valves. Especialy the low one.
 
Back
Top