Carbon build up, affects on FI motor?
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From: MD
Carbon build up, affects on FI motor? I did a Compression check on my motor when changing the plugs out and my compression tester read 160 psi on all 8 cylinders (it seemed a little high). I started wondering about carbon build up and its affect on compression. My a/f is at 10.0:1 until i can get time to tune it again. There might be build up in there If this is true then that would definately explain why i have to run -9 degrees of timing for 5 psi and it still tends to set off the KR to about 3.x
Whats a good way of De-carboning the engine (i dont have cats to clog up)?
<img src="graemlins/gr_chug.gif" border="0" alt="[chug]" />
[ January 27, 2002: Message edited by: G ForceSS ]</p>
Whats a good way of De-carboning the engine (i dont have cats to clog up)?
<img src="graemlins/gr_chug.gif" border="0" alt="[chug]" />
[ January 27, 2002: Message edited by: G ForceSS ]</p>
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From: Gilbert, AZ
Re: Carbon build up, affects on FI motor? MCCC. Mopar combustion camber cleaner. Any local mopar dealer (dodge, chystler, ...) parts department should have it. About $8 a can. Follow the instructions on the can. The stuff works wonders for removing carbon from combustion cambers. On DSMs, people have noticed it get rid of knock.
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From: Barstow, Ca.
Re: Carbon build up, affects on FI motor? [quote]Originally posted by G ForceSS:
<strong>I did a Compression check on my motor when changing the plugs out and my compression tester read 160 psi on all 8 cylinders (it seemed a little high). I started wondering about carbon build up and its affect on compression. My a/f is at 10.0:1 until i can get time to tune it again. There might be build up in there If this is true then that would definately explain why i have to run -9 degrees of timing for 5 psi and it still tends to set off the KR to about 3.x
Whats a good way of De-carboning the engine (i dont have cats to clog up)?
<img src="graemlins/gr_chug.gif" border="0" alt="[chug]" />
[ January 27, 2002: Message edited by: G ForceSS ]</strong><hr></blockquote>
Besides raising compression, excessive carbon can also cause glowing "hot spots" which may lead to preignition when fuel/air enters the cylinder.
My 8.5:1 Supra motor has compression in the high 150's, what is the static compression ratio on your motor?
160 psi sounds like an OK number, unless you have checked it since new using the same gauge and noticed an upwards trend in the numbers
<strong>I did a Compression check on my motor when changing the plugs out and my compression tester read 160 psi on all 8 cylinders (it seemed a little high). I started wondering about carbon build up and its affect on compression. My a/f is at 10.0:1 until i can get time to tune it again. There might be build up in there If this is true then that would definately explain why i have to run -9 degrees of timing for 5 psi and it still tends to set off the KR to about 3.x
Whats a good way of De-carboning the engine (i dont have cats to clog up)?
<img src="graemlins/gr_chug.gif" border="0" alt="[chug]" />
[ January 27, 2002: Message edited by: G ForceSS ]</strong><hr></blockquote>
Besides raising compression, excessive carbon can also cause glowing "hot spots" which may lead to preignition when fuel/air enters the cylinder.
My 8.5:1 Supra motor has compression in the high 150's, what is the static compression ratio on your motor?
160 psi sounds like an OK number, unless you have checked it since new using the same gauge and noticed an upwards trend in the numbers
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Teching In
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From: MD
Re: Carbon build up, affects on FI motor? Static Compression is 10.2:1
I know its has to have carbon deposits since everything else including the plugs are carboned up. There is always the traditional water mist into the engine or trans fluid to clean the chamber. I was hoping there is a better more effective way.
Unreal, do you have to poor that can into the tank? I don't have very much luck with fuel additives. though this one may work. <img src="graemlins/burnout.gif" border="0" alt="[Burnout]" />
I know its has to have carbon deposits since everything else including the plugs are carboned up. There is always the traditional water mist into the engine or trans fluid to clean the chamber. I was hoping there is a better more effective way.
Unreal, do you have to poor that can into the tank? I don't have very much luck with fuel additives. though this one may work. <img src="graemlins/burnout.gif" border="0" alt="[Burnout]" />
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From: Gilbert, AZ
