I feel that the most knowledgable people here on H-T reside in the FI forums, so I'm just going to ask a question regarding the new setup of my Integra.

Is 12:1 compression ratio too much for a B20B block, with stock B20B pistons/rods, B18C head, and 95 octane gas? I still have my link ECU so I can have it tuned perfectly, but people are telling me that while it will be quick, the pistons won't be able to handle extended abuse (if I was to go from 0-200km/h or something like that) and they told me that 11.5:1 would be more safer. What do you guys think? I need to tell the shop either today or monday on how I want it setup. Thanks

 

I think you'd have problems with the sleeves before the piston's.

 

Sleeves? Why should I?

 

I am having a 86mm all motor engine being built right now. I am going to run close to 13:1 compression with pump gas. Its quite possible, you need to back out timing and run the engine a tad richer. If you have 95 octane, then i would go at least 12.5:1.

About the b20 sleeves, they are supposively weaker than the stock vtec sleeves. I have never seen any solid evidence on this. I would say you'd be find if you are just going to overbore .5mm with the stock sleeves.


[Modified by boosted hybrid, 3:21 PM 2/15/2003]

 

had a friend with 12.5 (84.5) rollerwaves, stock rods and bottom, gsr head with spec b's. he never really finished tuning before he pulled and it sold his chasis. when he broke the bolck down to rebuild, found that he had cracked all 4 sleeves, not too bad, but any cracking is bad to start. he was running 93 octane, base timing was prob at 16

i have also heard that its better to use the vtec block than the b20 block.


[Modified by ronin, 12:28 PM 2/15/2003]

 

Tuning seems to be an issue with your friends problem, not his compression ratio. When i ran my built b16a with 11:1 compression on the street, i ran 8lbs through it. The dynamic compression ratio was through the roof in boost. I never experienced any problems, but the tuning was dead on.