Houston...we have CONTACT! UPDATED 09APR

Well, changed plugs...no problems now on any of the cylinders. Went with Bosch Platinums.

Nice thing is they seem to be almost perfect range for the car. the flat part of the plug has light black soot, and the prong is perfectly clean and porcelain is still perfectly white. I'll take a picture next week since I'm leaving for the weekend.

Slade
 
Slade, glad to see you got it all worked out. I'm running the Bosch Platinums too.

As for your CR, I suspect you are a bit higher than 9.5 with 48cc chambers. My engine worked out to 9.5 with 52cc's.

On another note, just wondering how the OZ head compares to the trips, since you've had a bit more time behind the wheel now?
 
I'm working on putting that together.

I'm working if I'd be able to eventually use your roller tipped rockers...hmm

Slade
 
Slade,

Since this issue is resolved, thought I’d ask one more question.
What is your deck height?
I was checking the Compression Ratio calculator, and with a 48 cc combustion chamber, .025 Head Gasket Compressed Thickness, and a deck height of .025 I get a Compression Ratio of 9.5:1, assuming you still have the stock dished pistons. Did you switch to flat tops? With a deck height of 0, I’m getting a C/R of 10.1:1 :shock:
 
If that's the case Don, then perhaps we need to reconsider the pump gas versus compression ratio issue again. :roll: Especially if he only used 92 or 93 octane gasoline.


-Chris
 
I assumed my deck height was stock. I am using stock dished pistons, thin head gasket, and had the same calculation you had of 9.5:1 CR. I've been running 92 with no problems with ping.

I actually never measured my deck height. I guess it'll go unknown until I get it rebuilt.

Slade
 
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