Plugs orange, should I alter sequential?

Tuning concepts, methods, tips etc.

Moderators: jsmcortina, muythaibxr

Post Reply
rithsleeper
Helpful MS/Extra'er
Posts: 93
Joined: Sun Jul 26, 2015 7:57 am

Plugs orange, should I alter sequential?

Post by rithsleeper »

I have a MSX3 on a 383 sbc stroker with a meduium cam set up to run 7K rpms. This is a 95% duty road track engine. As you can see from the picture I am pretty sure I have my initial timing advance set too high. My engine was running a bit hotter than normal when I swapped to the "initial timing table generator" that MS2 has when searched on google. Pictured this is cylinder 1,3,5,7 and my finger is pointing to #1. I'm much richer in the rear cylinders so I was thinking about dialing my tuning back but also trying to use the trim tables. Maybe 5% fuel added to Cyl 1, 3% to #3, -3% to #5, and -5% to #7. Just to get the ball rolling and get better accuracy from my Wideband that is mounted in the collector of this side of the engine.

Whenever I go to find a place to begin with tuning I just can't find stock tables or an assortment of ignition tables with similar engine setups. I'm trying to get the best street tune I can before going and dropping the $500 dyno fee and end up having to go back again for a second tuning session.

Anytime I ask for a reference timing map people say, "I would just look at the stock curves for a sbc" or "just find the table for a stock ______" but I can't find anything even close to stock tables for ignition. I type into google, "stock ignition table 1989 corvette" and I get jack diddly.

Just for reference of what kind of engine it is, SBC 383
cam card is shown below, 1.6 rockers, TPI mildly ported Miniram II, AFR 210cc Competition heads, CR ~11:1. Running Torco mix with 93octane gas making ~95 octane.
Image
cam card.jpg
cam card.jpg (16.53 KiB) Viewed 622 times
Attachments
383milecamTPIminiram.msq
(262.92 KiB) Downloaded 29 times
turbo conversion
Super MS/Extra'er
Posts: 1281
Joined: Thu Aug 19, 2010 6:22 pm
Location: White House, TN USA

Re: Plugs orange, should I alter sequential?

Post by turbo conversion »

The orange color is probably caused from the fuel additive.

Every additive (octane) I have used colors the plugs.

David
1976 Datsun 280Z L28ET Garrett GT35R T3-T04E stage3 50 trim 63 A/R housing custom grind cam 2000-6000 rpm 440cc injectors intercooled 18 lbs. boost
3" exhaust turbo back LC-1 o2 sensor Hallman manual boost controller EDIS 6 ignition batch fire 60mm throttle body 5 spd T5 borg warner 3.54 lsd
spitnl
Helpful MS/Extra'er
Posts: 39
Joined: Tue Feb 21, 2012 3:57 am

Re: Plugs orange, should I alter sequential?

Post by spitnl »

Search for engine number instead.
L98 engine I believe?

However I'm not sure the stock advance will be anywhere near what your engine needs.
Your engine is not stock and you have changed a lot.
I would do a search or ask on a chevy forum what maximum advance people are running with your AFR cylinder head and factor in camshaft and compression.

I do agree that the plug colour is likely caused by the fuel additive.

Further keep in mind that the #1 cylinder might not always be 5% lean over the entire rpm and load range.
Are you running multiple wide bands?

Have you flowed each injector to check they are all even?

Fred
rithsleeper
Helpful MS/Extra'er
Posts: 93
Joined: Sun Jul 26, 2015 7:57 am

Re: Plugs orange, should I alter sequential?

Post by rithsleeper »

The injectors are brand new from fuel injector connection so I have no reason to suspect anything is wrong with the injectors. The opposite side of the engine looks identical. pretty bright orange like the same color if you have a heavily rusted part and run sand paper over it a few times and turns that lighter orange (pics look darker than it does in real life).

Thank you for the advice on the plug color. I was wondering why (if it was so hot or lean) I was still getting blackish coloring on the rear plugs also.

From what others have said on the corvette forums, this is common with this intake since the rear of the intake tends to get short changed in the air department.

I only have 1 wideband but I have welded bungs on every single primary so I could potentially swap it to each cylinder. Adding a second wideband would be another $100 which I'm not opposed to if that would help. Just one more thing to wire in.... UHG I'm so sick of all the wiring. I feel like that's all I've done for the past year and a half.

My thought on the percents were to get it a step closer and then start putting the wideband in each cylinder and driving to see a pattern and extrapolate close to what each other cylinder would be doing. This seems like a very long process to tune each cylinder individually and then on top of that, then go to the dyno and have them tune each cylinder individually would cost well over $1000. I'm a poor teacher, my funds don't take me as far as some.
tryingbe
Experienced MS/Extra'er
Posts: 196
Joined: Tue Sep 05, 2017 3:19 pm

Re: Plugs orange, should I alter sequential?

Post by tryingbe »

I have one wideband o2 sensor for my 4 cylinder engine.

Wouldn't you want at least widebands for each of the the two bank of 4 cylinders?


How are you monitoring knocks?
Last edited by tryingbe on Sun Nov 05, 2017 10:01 am, edited 1 time in total.
1985 Dodge Omni GLH Turbo MicroSquirted 367whp http://www.msextra.com/forums/viewtopic ... 04&t=67324
spitnl
Helpful MS/Extra'er
Posts: 39
Joined: Tue Feb 21, 2012 3:57 am

Re: Plugs orange, should I alter sequential?

Post by spitnl »

If the injectors came as a matched set you're OK in that area.

I did a quick search on the AFR 210 head and ignition timing and I would set the max timing at 29 degrees to start with.
Don't be surprised if the part throttle timing it likes is quite low, you have fast burning chambers and high compression.
Low numbers with ignition timing at max power doesn't necessarily mean low power, it just means your engine is efficient.

That does look like a long process.
I'm still building my MS3X sequential v6 turbo car, going to run 4 lambda sensors to speed up the process and get better accuracy. (1 to read overall engine AFR and 3 to switch between banks)
Like you I thought I could swap 1 around, but after doing some reading I decided to go for 4.

Have a look at this engine running 8 lambda sensors in closed loop and notice the trim per cylinder doesn't stay the same over the rpm range.
https://www.youtube.com/watch?v=6kQGp-fHuFc
Last edited by spitnl on Sun Nov 05, 2017 10:55 am, edited 1 time in total.
jsmcortina
Site Admin
Posts: 39585
Joined: Mon May 03, 2004 1:34 am
Location: Birmingham, UK
Contact:

Re: Plugs orange, should I alter sequential?

Post by jsmcortina »

Do remember that on many engines difference in AFR per cylinder are caused by air-flow differences rather than injectors.

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
spitnl
Helpful MS/Extra'er
Posts: 39
Joined: Tue Feb 21, 2012 3:57 am

Re: Plugs orange, should I alter sequential?

Post by spitnl »

That was what I meant, but if your injectors also differ from each other and you're not compensating for it then there's no point in trying individual cylinder trims.
Sorry if I wasn't clear enough and thanks for clarifying, James.
kaeman
Master MS/Extra'er
Posts: 643
Joined: Sun Nov 06, 2005 12:31 am
Location: NORTHERN CALIFORNIA

Re: Plugs orange, should I alter sequential?

Post by kaeman »

I found that when I used fuel additives, I had the orangish colored plugs, I quit using the fuel additive and retuned my timing to just run premium pump gas, I contacted trick flow, to get a recommended max timing for best power. I have different colored plugs like you are showing, but its the difference in air flow in my intake manifold runners. Have you made a hard pass and killed the engine then read the plugs? I know my buddies at the dragstrip kill the engine at the 1/4 and coast off the track so they can get accurate plug readings, evidently the idling on the return lane doesn't give the same results as the hard pull. Your engine may actually be running closer than you think under load and going rich on the rear cylinders during idle .. Just a thought.
64 el camino, 383 SBC, 11.7 to1 CR, accufab tb/rhs intake, 44lb injectors, trick flow heads, xr292r solid roller cam, belt drive camshaft, dry sump oil system, 2400 stall, turbo 350, spooled 9 inch, strange axles, 3.89 gears, dual wideband, full sequential fuel/cop, MS3x using 1.4.1 code.
rithsleeper
Helpful MS/Extra'er
Posts: 93
Joined: Sun Jul 26, 2015 7:57 am

Re: Plugs orange, should I alter sequential?

Post by rithsleeper »

I'll have to try the hard pull and coasting.

I realize the air flow is the inconsistent part. It's why in the beginning I stated this is the problem with this tunnel ram that others have experienced. The only option is trying to widen the rear runners to compensate but I don't think that would be wise at this point. Very difficult to come back from. I'm very limited by hood clearance.

Tearing down this engine is getting very tiresome. I've done it so many times for different problems. I'd be doing some welding to build up a tiny bit of the rear runners or touching the head which afr specifically says dont do it.

I'll ponder I guess. Try the hard pull first.

I'm not monitoring knocks. I can't because I would have to tune a knock sensor first. Can't do that with the setup not even having a baseline first. 29* seems awfully conservative from anything I've read but I didn't think it was possible to predict it based on the head itself. Thought it was all just a try and see kind of thing and then hit the Dyno and find where makes best power cause a knock would happen after the best power peaks.
Post Reply