280 psi in each cylinder = what compression?

[khai_tuan_nguyen]

Originally posted by Calesta@Sep 1 2004, 12:01 PM
Ignition timing maps?  There's a lot more to timing than the base measurement.

[post=384731]Quoted post[/post]​

Is ignition timing with the distributor?

What other factors determine timing besides cam and distributor?

Obviously I don't much. So here is the story. I had the p72 obd2 ecu and had to turn dist timing to 14 and cam timing at factory to stop it from pinging it still pinged. I got p28 ecu and hondata s100 and obd2a-1 conversion. We kept cam timing factory and even adjusted distributor timing as low as 0 and it still pinged.

What are some other possibilities for the pinging and what are other possibilites to stop it besides the lower compression pistons and race fuel?

What am I mnissing

Thanks for the patience.

Khai

 

[exospeed*com]

HOLD UP here.

Compression Test Results wont get you the Compression RATIO of your motor.
The TEST results just gives a reading to tell the condition of the rings and valve sealing as well.
IT DOES NOT equal any compression ratio of the pistons of any kind.

Low compression reading under 150 or so can mean bad piston rings or also bent valves. a higher reading at high 100 and over 200s mean that the rings are sealing well and the valves are also.

 

[khai_tuan_nguyen]

Originally posted by exospeed*com@Sep 1 2004, 12:24 PM
HOLD UP here.

Compression Test Results wont get you the Compression RATIO of your motor.
The TEST results just gives a reading to tell the condition of the rings and valve sealing as well.
IT DOES NOT equal any compression ratio of the pistons of any kind.

Low compression reading under 150 or so can mean bad piston rings or also bent valves. a higher reading at high 100 and over 200s mean that the rings are sealing well and the valves are also.

[post=384753]Quoted post[/post]​

Isn't it possible to have really high compression pistons and it should read like 3xx, but because of bad seals it only reads 2xx? Also what does this mean in regards to what Calesta and I were talking about.

Remember I am learning. Thanks for bearing with me.

Khai

 

[phunky.buddha]

Yes, that is possible- but as said earlier, there's really no way to tell what your compression is based on the compression test. It's a test, not a measurement.

Ignition timing maps are in your ECU. The distributor timing is just the base timing, that's it. It's the base timing that your ECU works off of, and everything on the ignition map run off of that.

 

[khai_tuan_nguyen]

Originally posted by Calesta@Sep 1 2004, 05:30 PM
Yes, that is possible- but as said earlier, there's really no way to tell what your compression is based on the compression test. It's a test, not a measurement.

Ignition timing maps are in your ECU. The distributor timing is just the base timing, that's it. It's the base timing that your ECU works off of, and everything on the ignition map run off of that.

[post=384885]Quoted post[/post]​

Ok I think I get this part of it now. The guy tuning my car was explaining this to me. My distributor timing was at 20 degrees (base), but he supposedly changed it with hondata (almost down to 0).

Is this what you mean Calesta?

In other words you can set your dist timing to anything as long as the ecu knows where that point actually corralates to.

If this is correct than my original question still remains:

The timing (not just the base, but the hondata) was set almost to 0 and it still pinged. They believe my compression (280psi) is too high to run on 92 Octane pump gas.

Calesta mentioned it is probably something else. What else could it be?

Remember I also put some race fuel of 112 octane mixed 50/50 with 92 octane and its not pinging any more. Could this be a sign of anything?

What determines the pinging, detonation, the overall compression (measured through the spark plugs etc. which takes into account seals etc etc.)

OR

the compression of the piston 12:1 12.5:1 13:1 etc.


KHai

 

[phunky.buddha]

Yes, that's what I mean. You have the base timing, then you modify from there. You don't want to just arbitrarily set your base timing somewhere though, because you can only vary your timing from the base so much.

Compression too high, no. You can do it.

What else? Could be anything... take it apart and find out.

What determines pinging? Tons of stuff that only YOU can know at this point. There's no way anyone online can tell you what's wrong with your engine. You're just going to have to take it apart and find out on your own.