What's been the breaking point?

[d112crzy]

manifold design will play a big role...

the better flowing.. the easier it will be to achieve 400whp (not saying its ur goal) but.. thats roughly what the stock stuff can handle.. for how long? who knows..


if stock rev range is kept.. i dont think nothing too crazy would happen.. probably cracked ringlands would be my first guess as what would happen.. seeing as how it would(i hope) have a good tune..thus.. detonation would be kept to a minimum..

detonation = one of the sources of snapping rods like toothpicks.. they cant handle 20+psi and a pre-ignition ontop of that..


back to the manifold talk.. not only will you achieve good numbers with something that can flow worth a damn.. but.. youll be able to keep egts down.. (protect them ringlands) and also make power as a plus


race gas would be smart.

also.. what turbo are you planning to use when you attemp this??



OT(I swear we have been talking about egt's all week.. lol)

Detonation will break ringlands before it breaks anything else.... If a rod snaps is because there is too much power going through it and/or insufficient oiling.

[HondaBob]

manifold design will play a big role...

the better flowing.. the easier it will be to achieve 400whp (not saying its ur goal) but.. thats roughly what the stock stuff can handle.. for how long? who knows..


if stock rev range is kept.. i dont think nothing too crazy would happen.. probably cracked ringlands would be my first guess as what would happen.. seeing as how it would(i hope) have a good tune..thus.. detonation would be kept to a minimum..

detonation = one of the sources of snapping rods like toothpicks.. they cant handle 20+psi and a pre-ignition ontop of that..


back to the manifold talk.. not only will you achieve good numbers with something that can flow worth a damn.. but.. youll be able to keep egts down.. (protect them ringlands) and also make power as a plus


race gas would be smart.

also.. what turbo are you planning to use when you attemp this??



OT(I swear we have been talking about egt's all week.. lol)

Lol, the EGT woes...

I am building a tubular top mount (hopefully) whit a PTE SC60 turbo.

This motor will eventually be built.. at that point I'd like to get serious, and no point fucking around with any BS on the setup. Just do it right the first time (minus block)

[kantkillkeenan]

Im actually looking to do the same build. See how much i can get with the F22

[yardiexd40]

What direct relationship is there between high egt's and breaking ringlands? How hot do you think the combustion chamber temps are during combustion?

[MRX]

What direct relationship is there between high egt's and breaking ringlands? How hot do you think the combustion chamber temps are during combustion?

Think about it from this perspective: If you retard the timing too much the fuel that is ignited, although late, still gets ignited, correct? Well, think about the time it takes for the a/f mixture to explode under optimal conditions (perfect spark timing, pressure, and flame travel). Whether the mixture is ignited, at say 25* as opposed to 14*, doesn't change the amount of time it takes for combustion to start and end. This is called "burn time."

However, in regard to egt's there becomes a problem because if the mixture takes the same amount of time to completely burn and you are running retarded timing then you are igniting the mixture late, in reference to the piston's physical position (tdc).

If your piston is on its way down, your exhaust valves are going to be opening immediately proceeding or at the time of bottom top dead center. The a/f mixture, having been ignited late, is still exploding once the valves are open causing exhaust gas temperatures to raise due to the flame travel still not being completely done burning the a/f mixture. The piston is literally forcing the flaming mixture into the exhaust ports.

This is gravely important if you think about of the speed at which the pistons are traveling. The pistons travel so fast that for the time it takes the mixture to burn, the piston may be already on it's way back up to complete it's cycle. This means the explosion is pushing the piston down as the crank is forcing the piston upwards; Two opposing forces. This results in a loss in power and in some cases broken or damaged parts. Our weak point are our ringlands.

Its not necessarily the egt's, its the cause of the egt's that's the problem. The egt's are the indication that the timing is too far retarded or too far advanced. The combustion chamber can get past, i'd say, 1500+* F for gasoline engines. Possibly hotter. But exhaust gas temperatures are much lower than the chamber temperatures because of the distance it has to travel as well as the exposure to already combusted particles and the air in the exhaust stream.

[WiKKeDV16]

you da motha forkin man..

glad to see you more active around these parts

[dbsharp]

my bad yall, I was on yard's computer. I didn't think abuut who's name In was posting in. Funny how alcohol makes you forget that shit.

On a side note, ERROL IS the fucking man.....
And you all can expect to see big things (dyno graphs) from his build, IF he sticks around these parts long enough for me to help him complete it (and tune it, well retune it).

[wed3k]

Think about it from this perspective: If you retard the timing too much the fuel that is ignited, although late, still gets ignited, correct? Well, think about the time it takes for the a/f mixture to explode under optimal conditions (perfect spark timing, pressure, and flame travel). Whether the mixture is ignited, at say 25* as opposed to 14*, doesn't change the amount of time it takes for combustion to start and end. This is called "burn time."

However, in regard to egt's there becomes a problem because if the mixture takes the same amount of time to completely burn and you are running retarded timing then you are igniting the mixture late, in reference to the piston's physical position (tdc).

If your piston is on its way down, your exhaust valves are going to be opening immediately proceeding or at the time of bottom top dead center. The a/f mixture, having been ignited late, is still exploding once the valves are open causing exhaust gas temperatures to raise due to the flame travel still not being completely done burning the a/f mixture. The piston is literally forcing the flaming mixture into the exhaust ports.

This is gravely important if you think about of the speed at which the pistons are traveling. The pistons travel so fast that for the time it takes the mixture to burn, the piston may be already on it's way back up to complete it's cycle. This means the explosion is pushing the piston down as the crank is forcing the piston upwards; Two opposing forces. This results in a loss in power and in some cases broken or damaged parts. Our weak point are our ringlands.

Its not necessarily the egt's, its the cause of the egt's that's the problem. The egt's are the indication that the timing is too far retarded or too far advanced. The combustion chamber can get past, i'd say, 1500+* F for gasoline engines. Possibly hotter. But exhaust gas temperatures are much lower than the chamber temperatures because of the distance it has to travel as well as the exposure to already combusted particles and the air in the exhaust stream.

not even an engine builder and he knows more than me.

[d112crzy]

He's a tuner, he HAS to know this shit to be a real tuner. I don't know many engine builders that really know the internal events better than a tuner does.

[d112crzy]

Think about it from this perspective: If you retard the timing too much the fuel that is ignited, although late, still gets ignited, correct? Well, think about the time it takes for the a/f mixture to explode under optimal conditions (perfect spark timing, pressure, and flame travel). Whether the mixture is ignited, at say 25* as opposed to 14*, doesn't change the amount of time it takes for combustion to start and end. This is called "burn time."

However, in regard to egt's there becomes a problem because if the mixture takes the same amount of time to completely burn and you are running retarded timing then you are igniting the mixture late, in reference to the piston's physical position (tdc).

If your piston is on its way down, your exhaust valves are going to be opening immediately proceeding or at the time of bottom top dead center. The a/f mixture, having been ignited late, is still exploding once the valves are open causing exhaust gas temperatures to raise due to the flame travel still not being completely done burning the a/f mixture. The piston is literally forcing the flaming mixture into the exhaust ports.

This is gravely important if you think about of the speed at which the pistons are traveling. The pistons travel so fast that for the time it takes the mixture to burn, the piston may be already on it's way back up to complete it's cycle. This means the explosion is pushing the piston down as the crank is forcing the piston upwards; Two opposing forces. This results in a loss in power and in some cases broken or damaged parts. Our weak point are our ringlands.

Its not necessarily the egt's, its the cause of the egt's that's the problem. The egt's are the indication that the timing is too far retarded or too far advanced. The combustion chamber can get past, i'd say, 1500+* F for gasoline engines. Possibly hotter. But exhaust gas temperatures are much lower than the chamber temperatures because of the distance it has to travel as well as the exposure to already combusted particles and the air in the exhaust stream.

The piston travels up as it's compressing air. If the timing were correct, it would fire a few degrees before it reached the top(depending on rpm). If the timing were retarded, it would fire just as the piston started going down already. If it were super retarded(what it sounds like you're explaining), it would have to be in the negative or around 0 for it to still be burning once the piston starts going back up for its exhaust stroke. IMO, your explanation is a little on the extreme side.

High EGT's mostly come from not enough air. If you don't have enough air, you're more than likely either running too rich and/or don't have enough ignition timing. Even if you have the correct a/f ratio down, you could have too little timing still causing those high EGT's. Adding timing will make for a better burn and lower EGT's because there is no unburnt fuel left for the next combustion event, which could cause predetonation.

I'll expand more tomorrow.

[MRX]

D112 is speaking about the relations of air/fuel mixtures and egt's. But I'm going to try to keep the things separated so we aren't repeating the same thing in two different threads. We have further talk of this in this thread if you wish to learn more about the topic:

http://www.cb7tuner.com/vbb/showthre...71#post2133771

[chessboxer]

He's a tuner, he HAS to know this shit to be a real tuner. I don't know many engine builders that really know the internal events better than a tuner does.

That is the VERY first thing we cover in all of our training seminars.

Then we break down an engine to look at it as an air pump, the guys at EFI 101 do the same thing.