My buddy has a 95 del sol, d16z6, automatic. he recently spun a rod bearing and is having his motor rebuilt, my question is he is going to have 12.5:1 cp pistons on basicly a stock motor he said hes having it bored .040 over and a mild cam but thats it. I told he that was a very bad idea but he still doing it but what do u guys think. o he will be using the stock ecu no chip. just a vtec controller that hes gonna set at 3800 (hes a big time ricers but bare with me) what consequences should he expect and what can i tell him to do to at least het him 6 months or so out of the motor.

 

just run premium gas.

 

but even with 93 octane it seems like no chip no tuning and 12.5:1 cp would just rip that motor to shreds

 

probably should get a tune... that's quite a bump in compression

 

I assume he is converting to manual as well? 93 octane should be fine for him.

He will need tuning. I wouldn't expect the motor to last more than 6 months untuned (on a stock P28 I would think), especially if he is beating on it.

 

ummm, if he is running the stock ECU with overbore, cam and 12.5:1 CR, his motor will either NOT run or run like ****. Also dose he have an IHE? if not he should seriously consider that since he engine will be craving a lot more air then the stock setup will allow.

And Depending on the tune he may still get pre-detonation with 12.5:1. Most of what have read has said you should not go any higher then 12:1 unless you are using race gas.

 

using high octane gas, and using a adj cam gear is fine for the bore and compression ratio, its when you swap cams he will need a tune since the new cam has high lobs and his vtec engagement will be different and to set the best vtec engagement point is to run a dyno with vtec unhooked then put vtec on around 3500 and once both dyno's are complete take the sheets and put them together where ever the lines cross each other is where the vtec engagment should be set to.

 

isnt gonna work hes gonna melt his pistons faster than he knows what to do with leaning out bad

 

The only way it will work is to run racing fuel,($11.00 a gallon) and have ecu chipped and tuned to get the most fuel through out torque curve.
Ive got a d16y8 with 12.88 to 1 compression with p29 pistons and tuned ecu and crower stage 2 cam. Thats the only way i got to work. Cooked 3 sets before i got it to survive.