[charlie66]

Originally Posted by Curious George

Thank you charlie66. I have Edelbrock D port heads, I think .040 gaskets, and not sure on piston height. Where is a good place to accurately learn more about tuning and reading plugs?

Knowing how your motor is put together is going to be the most help with out being there , so not knowing where the piston is at tdc makes it hard to give a guess on timing . If your piston is set in the hole then most likely the motor will not want the same amount of timing it would if it was at zero deck . I learned that with helping a member here over the winter when he was dynoing his engine. . Ill have to ask him where he ended up with timing. I think some where around 20 degrees or so. Not sure. He has round port e-heads and i think the piston is down .130. What fuel as you know will dictate timing as well. Being i have no real experience with aluminum D-ports i feel reluctant to say where timing will whind up. So reading the plugs in a trial and error process is going to be what you need to do.. But you need to make sure the air inlet temps are good as well as your AFR numbers at the same time. If there out of wack you will be wasting your time...

So if you're looking to learn more about reading plugs for timing this is the way i go about it: Ignition timing is directly responsible for the heat in the combustion chamber and therefore the color of the plug’s ground strap and the color of the first few threads on the outside of the plug. The ignition timing can be checked by looking at the color of the plug’s ground strap and the position of the "blue line" on the strap. The blue line really indicates the point at which the strap has reached annealing temperature of the metal. To help to understand this think of a bar of steel (ground strap) on a table that is being super heated with a acetylene torch at one of the tip ends. As the end heats up and the heat starts moving down the bar you will see a blue line across the bar at some point down the bar away from tip with the torch. This blue line reflects the temperature that is the annealing point of the metal. As the temperature increases the blue line moves further down the bar away from the torch. Similarly, the blue line moves down the spark plug ground strap as you put more heat in the engine.

If you are using a gold colored ground strap like with an NGK spark plug then not enough timing will show the ground strap as still gold or going light gray maybe with a few bubbles on it after a run. As you advance the ignition and put heat in the engine the plug ground strap will turn darker gray as well as the metal at the end of the threaded area. As the metal turns medium to dark gray you should start looking for the blue line (band) around the ground strap. Ideally, you want this blue line to be just below where the ground strap makes the sharp bend and above the weld. If you advance the ignition too far the blue will disappear off the strap and the strap will pick up rainbow colors (blues and greens). The next step beyond that is to start melting the strap from the tip end and detonation. When you are close to the correct timing then only change the timing by one degree at a time. If you ignition system has the capability of adjusting the timing of each cylinder independently (ICT) then you can use that feature to have the blue line in the same position on all the plugs. First, adjust the basic timing to get as many of the plugs to have the blue line just at the sharp bend in the strap. Now adjust the ICT to move the blue line to the same point on the remaining plugs. Once all the plugs read the same you can advance the ignition a little at a time to put the blue line just above the weld on the strap or whatever point gives you the best performance.

I hope this helps you some....

[er455]

Originally Posted by taff2

On my turbo 421 combo-7.5 to 1 compression, big plenum dual carb manifold, custom turbo cam- I run 42* initial timing! It starts easily with a separate starter/ignition switch set up and runs fine, I start pulling timing at 5psi of boost and at max boost of 18-19 psi(so far) its at 27 degrees. The footbrake launch and throttle response was vastly improved when I bumped the initial up from 32*. I religously read plugs (usually cutting a couple open) and all is good. I am on a C16 type fuel and use water/meth as a chemical intercooler.

Hey Taff got any pics on the 421 turbo motor ? Also what kind of time slips does it run ? Also Thanks for all the advice too....

[wreckmastr]

Originally Posted by charlie66

So if you're looking to learn more about reading plugs for timing this is the way i go about it: Ignition timing is directly responsible for the heat in the combustion chamber and therefore the color of the plug’s ground strap and the color of the first few threads on the outside of the plug. The ignition timing can be checked by looking at the color of the plug’s ground strap and the position of the "blue line" on the strap. The blue line really indicates the point at which the strap has reached annealing temperature of the metal. To help to understand this think of a bar of steel (ground strap) on a table that is being super heated with a acetylene torch at one of the tip ends. As the end heats up and the heat starts moving down the bar you will see a blue line across the bar at some point down the bar away from tip with the torch. This blue line reflects the temperature that is the annealing point of the metal. As the temperature increases the blue line moves further down the bar away from the torch. Similarly, the blue line moves down the spark plug ground strap as you put more heat in the engine.

If you are using a gold colored ground strap like with an NGK spark plug then not enough timing will show the ground strap as still gold or going light gray maybe with a few bubbles on it after a run. As you advance the ignition and put heat in the engine the plug ground strap will turn darker gray as well as the metal at the end of the threaded area. As the metal turns medium to dark gray you should start looking for the blue line (band) around the ground strap. Ideally, you want this blue line to be just below where the ground strap makes the sharp bend and above the weld. If you advance the ignition too far the blue will disappear off the strap and the strap will pick up rainbow colors (blues and greens). The next step beyond that is to start melting the strap from the tip end and detonation. When you are close to the correct timing then only change the timing by one degree at a time. If you ignition system has the capability of adjusting the timing of each cylinder independently (ICT) then you can use that feature to have the blue line in the same position on all the plugs. First, adjust the basic timing to get as many of the plugs to have the blue line just at the sharp bend in the strap. Now adjust the ICT to move the blue line to the same point on the remaining plugs. Once all the plugs read the same you can advance the ignition a little at a time to put the blue line just above the weld on the strap or whatever point gives you the best performance.

I hope this helps you some....

Great job explaining Charlie! A few pic's for example

[charlie66]

Originally Posted by wreckmastr

Great job explaining Charlie! A few pic's for example

Those plugs look good! Looks like you even have room for a little more timing if you felt the need to ...

Thanks Billy....

[charlie66]

Here is a pic of a plug that is very rich, and needs to take some fuel away , and a plug from a nice clean mid 9 second pass, this one was a little bit lean, added 1 psi fuel to it and picked up 3 mph. Note: Might need to take a bit of timing out of this tune up or use a colder plug, some deterioration on the center electrode however ground strap looked ok. It's also possible on this tune up that taking both fuel and some timing away might have been even better.

[charlie66]

Heres a desent video that explains it somewhat...



https://www.youtube.com/watch?v=8ckQf0J_FI0

[charlie66]

and heres a pic of one of my 4 cyl plugs on E-85 with 30 psi and 26 degrees of timing.. The others i posted earlier were on race gas with NOS..

[taff2]

er, it runs 8.90@163, (should be an 8.30) but very soft 60ft's off the footbrake as I couldn't get the car to spool up on the footbrake. I've fitted a transbrake now so hoping for a better 60ft,then I can turn the power up.
Here's a pic of the engine, it's somewhere under all those pipes,wires and tubes.

[Curious George]

Originally Posted by charlie66

I hope this helps you some....

It does, thank you.

[er455]

Originally Posted by taff2

er, it runs 8.90@163, (should be an 8.30) but very soft 60ft's off the footbrake as I couldn't get the car to spool up on the footbrake. I've fitted a transbrake now so hoping for a better 60ft,then I can turn the power up.
Here's a pic of the engine, it's somewhere under all those pipes,wires and tubes.

Very nice Taff car is flying for no aftermarket block very impressive..

[JSPONT]

Originally Posted by er455

Very nice Taff car is flying for no aftermarket block very impressive..

All the info in this thread and you compliment a car, and not the people who gave you some very good info??
Granted Taff does run fast on his own built parts but thought you wanted to know why your car is running poor?

[73 TRANSAM]

When I dyno"d my Turbo motor. I have a butler WP heads, fully ported Victor, Street roller cam, 8.75 to 1 and 482 IA2 combo. I made 570 hp @ 6100 NA on an honest dyno. I didn't maximize the NA as I have no plans on NA runs but I made 1265 hp @ 6000 with a blow thru carb on a 15 psi. Your combo made 550 hp vs my 570 hp but Im hoping I wont have a power issue on mine and so does yours. Good luck and I agree that you are not thanking the right guys that are giving you good info but hey what to I know. I do love TA!

[taff2]

And my post of how much timing I run, how much power I make, on a budget with factory iron heads and block (like the op's) is not helping? Post #62 may also show why he thanked me?

[er455]

What is going on with all you sensitive minded people ... I thought we were all grown ass men here , I compliment a guy and everybody else gets jealous? For the record I might not be the most political correct person but I am just a guy who loves Pontiacs and going fast , I have been turning my own wrench,s for over 35 years and was self tought way before the internet was around . Back in the days when all we had was hot rod magazines ... I do like the advise form other members to make sure I am doing something right the first time and the internet is fast and easy , for the record I have said thanks to everyone in this post (my post) at some time or another I am sure . Get over yourselfs ......

[er455]

Originally Posted by er455

Ok thanks guys .... I always thought that the reason turbo engines blew up was because they detonated and not because to much boost .. the Buick v6 is a perfect example the stock blocks have been 35 # of boost and if you ever seen the stock block and bottom ends they are very weak in stock form ....mine had a girdle and they have held together as long as they don’t detonate ... but I blew headgaskets from not having enough octane though . Also will a motor make more power on more boost and low timing or low boost and lots of timing ??

Notice how I started off this post .

[73 TRANSAM]

I have no beef with you Taff as I like what you have share in this forum. This forum is for sharing info, learning from it and also developing friends or acquaintance in the process. This is probably why no one post any more good info. But this is just my opinion and good luck on your turbo TA.

[Tom Vaught]

Originally Posted by 73 TRANSAM

This is probably why no one post any more good info.

I just read a lot of good info on spark plug tuning vs timing, Must have missed the lack of good info from people (not being there) somewhere along the way.

Tom V.

[JSPONT]

Originally Posted by taff2

And my post of how much timing I run, how much power I make, on a budget with factory iron heads and block (like the op's) is not helping? Post #62 may also show why he thanked me?

No TAff , you did help with your post, and were thanked. I just read a book on spark plugs, and one of the most bad azz Pontiacs around post his data log(most will never do that) then crickets.
I could give 2 chits I am just saying. The next time you post and maybe 2 or 3 people with some big knowledge on boost won't give 2 chits either and everyone can figure it out on there own.

Really what? Look at the time 2 guys spent in this thread to try and help you with a car that is running bad. I really do not care if you give credit. If I ask a question, guys will PM me with advise because of crap like that.
You are the sensitive one. I just stated what I observed, and was trying to let you know what it looks like. 73 Transam must think so too.
Carry on good luck with your car.

[er455]

Originally Posted by Curious George

Thank you charlie66. I have Edelbrock D port heads, I think .040 gaskets, and not sure on piston height. Where is a good place to accurately learn more about tuning and reading plugs?

Jspont Curious George is who ask Charlie about spark plugs not me ! so I did not say anything but did enjoy his explanation and knowledge on reading plugs so by you thinking I did not thank him is your mistake.. I start threads and other member jump on board with there own questions I don’t care that they jump in .I thought we’re all here to learn and help our very small community of turbo pontiacs , I think 73 trans am and Charlie can speak or type for himself so why do you feel the need to speak for them ??

[JSPONT]

I am not speaking for anyone, like I said, it is an observation, 73 I guess noticed it too. I really could care less if you ever fix your car.
It is a small community, I was trying to help you not make it smaller for yourself. That's all, good luck.