My friend just bought a motor from a local performance shop. Fully built bottem end. sleeved, high compression forged pistsons, forged rods, balanced, rebult head. and the list goes one. the motor is an h23 vtec, but it dosnt run right, and its pinging like hell. I did a compression test and on my compression tester the compression was 305, 295, 300, 305. I thought my tester was bad so i tested my car (h22, just put down 215 whp 1 week ago at a dyno) i tested 190,195,190,195.

What is the minimum gas requirements to keep it from pinging. he was running 91, and i told him i wouldnt run anything lower than 101. We were also running my p13 with rc 440 injectors. What gas must He run at a minimum? Also anyone know what the compression ratio of the pistons would be to yield that high of numbers?

 

wow have fun killing gas =]

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JoN2DaSoNz &raquo;</TD></TR><TR><TD CLASS="quote">wow have fun killing gas =]</TD></TR></TABLE>

Higher compression gives better gas milage.

Sounds like he needs to go back to that shop and get some more info. What pistons are in there? The shop should know the comp ratio and fuel requirement...

 

thats what i told him, but all they told him is they are 11.5 cp pistons, but i dont think its 12. Im thinking they were 12.5:1 h23 pistons. so with the h22 head that would bring it up past 13:1. I dont really know though.

 

it depends on the stroke....

what Crank/Rods?

 

It has h23 crank and rods, micropolished crank, and forged rods.

 

anyone have an idea of how high the gas octane i would need to run in order to keep it from pinging?

 

highest you can get and run some meth injection for peace of mind you can get the cheap kit cuz its n/a

 

is he still running stock cams?

 

yes. stock head just just rebuilt.

 

ID run at least 95....but as high as I could,untill the pinging subsided.

 

i am having the same problem
the static compression is very high
when he puts in aftermarket cams it will be fine.
i have my dissy retarted all the way.
i am looking into getting a dyno tune this week
just retard the dissy untill you can take it to the dyno, he will be just fine

 

it is still pinging like crazy with the dizzy retarded all the way. would it even be safe to drive to the dyno. We are going to put higher octace gas in it to see if it goes away, but i told him not to even drive it until we get the pinging problem fixed.

 

get a p28 & crome and find a tuner.i dont think the p13 can run the injectors properly

 

What are you using for fuel management. I would run 93/94.

ask the shop what they were using before. (ignition system, fuel system, octane fuel)?

 

sounds like you jumped into something you dont understand........

 

run race fuel.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 98vtec &raquo;</TD></TR><TR><TD CLASS="quote">sounds like you jumped into something you dont understand........</TD></TR></TABLE>

I didnt jump into anything. I installed the motor for a friend, and im trying to help a friend get answers to some of the questions he has. None of this is for me. All of MY cars with motors I built are running just great, and produce great numbers for what i have done to them. So dont jump in my thread talking **** like that, either contribute or GTFO.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by alterdcreations &raquo;</TD></TR><TR><TD CLASS="quote">get a p28 & crome and find a tuner.i dont think the p13 can run the injectors properly
</TD></TR></TABLE>

Got a p28 with neptune right now. Just waiting for the tuner to come to town, then it will hit the dyno.

thanks everyone that had something productive to add.

 

you could allways try and tune with E85.... thats like 106 octane.....

 

e85 is not an option. It is not availalbe within about 400 miles of me.

 

As a temprorary band-aid for the detonation you can dump in a couple gallons of toluene from a hardware store paint department. It's got an octane rating of 118.

FWIW if those pistons are 11.5:1 in an H22 swapping the H23 crank/rods will push it another point or more.

Toluene and then P28 + tuning ASAP before detonation blows the rings, kills the bearings and ruins the head gasket.

Pirate

 

oh snap... i forgot about toluene..... search google and there are a few sites with the ratios to make normal gas whatever octane you want (Up to 118 octane) with toluene..... you can find it at most paint supply stores....

 

A very good tune on pump gas should be enough to get by without pinging. I would not drive it till its tuned.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PirateMcFred &raquo;</TD></TR><TR><TD CLASS="quote">As a temprorary band-aid for the detonation you can dump in a couple gallons of toluene from a hardware store paint department. It's got an octane rating of 118.

Pirate</TD></TR></TABLE>

next time i head to the track i will be sure to have some of that
but kulrevon is right, i wouldn't drive or start her untill a tuner is present, trust me is worth it to wait.
good luck with her