#7 Always Broken
09-15-2010, 11:37 AM
#21
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Wouldnt having EGTs on #7 and #8 help to make sure the combustion process is not getting too hot? If you base your tune off #7 and #8 there shouldnt be an issue with detonation, given the rest of the cylinder will be progressively more lean/rich but you will have a much smaller chance for detonation.
Does that makes sense?
Does that makes sense?
09-15-2010, 12:01 PM
#22
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Wouldnt having EGTs on #7 and #8 help to make sure the combustion process is not getting too hot? If you base your tune off #7 and #8 there shouldnt be an issue with detonation, given the rest of the cylinder will be progressively more lean/rich but you will have a much smaller chance for detonation.
Does that makes sense?
Does that makes sense?
On the other hand, I dont think it can be detected with EGT since a hot spot in the cylinder head triggers early detonation. How does a hot spot alter EGT, I dont know, but my guess is it probably doesnt.
However if we didnt have taper seat plugs, we could have used a CHTG to look for a change.
Cheers
09-15-2010, 12:04 PM
#24
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09-15-2010, 12:19 PM
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In early testing I put 4 wide bands in each header, flipped the intake around and could never find any tuning issue with #7 that varied from cyl to cyl. Coolant problems seemed the culprit as the LS6 transfer tube change is when the problems started coming around. The steam vent tubes need very little flow as they really just clear air that can be trapped in the head causing hot spots in the rear combustion chambers.
The LS series of engines has many coolant issues that can cause problems in higher hp engines or long duration run type engines. Everybody that is working with these engines has different approaches to fix these problems, all of which probably have merit. The basic flow path in the engine is not very good for sustained high power, or short burst extreme power engines.
Kurt
The LS series of engines has many coolant issues that can cause problems in higher hp engines or long duration run type engines. Everybody that is working with these engines has different approaches to fix these problems, all of which probably have merit. The basic flow path in the engine is not very good for sustained high power, or short burst extreme power engines.
Kurt
09-15-2010, 12:26 PM
#28
I woudnt think the crossover tube has any cooling affect....its just a vent.
And cleaning out my stock intake last night (off the engine) I blew it out with an air hose... through the throttle body the majority of the air went out the back ports. The back ports are going to run leaner because of air flow characteristics of the manifold. It wasnt designed to have air pushed into it.... it was designed to have air pulled into it. .....2 totally different flow concepts.
And cleaning out my stock intake last night (off the engine) I blew it out with an air hose... through the throttle body the majority of the air went out the back ports. The back ports are going to run leaner because of air flow characteristics of the manifold. It wasnt designed to have air pushed into it.... it was designed to have air pulled into it. .....2 totally different flow concepts.
09-15-2010, 12:57 PM
#29
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In early testing I put 4 wide bands in each header, flipped the intake around and could never find any tuning issue with #7 that varied from cyl to cyl. Coolant problems seemed the culprit as the LS6 transfer tube change is when the problems started coming around. The steam vent tubes need very little flow as they really just clear air that can be trapped in the head causing hot spots in the rear combustion chambers.
The LS series of engines has many coolant issues that can cause problems in higher hp engines or long duration run type engines. Everybody that is working with these engines has different approaches to fix these problems, all of which probably have merit. The basic flow path in the engine is not very good for sustained high power, or short burst extreme power engines.
Kurt
The LS series of engines has many coolant issues that can cause problems in higher hp engines or long duration run type engines. Everybody that is working with these engines has different approaches to fix these problems, all of which probably have merit. The basic flow path in the engine is not very good for sustained high power, or short burst extreme power engines.
Kurt
Did you detect any success in adding the additional coolant crossover?
Thanks for the input.
Cheers
09-15-2010, 06:45 PM
#32
Also address the cause Great info and research so far on keeping the rear tubes.
Another approach also aimed at the cause in a boosted engine is to maximize cooling and lower intake charge temps.
I personally have a 74 camaro I am installing my LQ4, turbo 400, 3.73 gears, 75mm turbo, air to air intercooler and meth injection. For now using stock 317 heads. This will be a street/strip car with a lot of strip use (mostly 1/8th mile).
So for a car that also sees street time I would go air to air intercooler and meth injection. A strip only car I would go air to water intercooler as we know it is 14 times more efficient than an air to air intercooler. For strip only use I would even go air to water intercooler and meth injection.
Also use the biggest radiator that is practical for either use.
My strategy is to maximize cooling in all these areas at the same time to not only address the symptoms, but also more of the cause. I personally will be running the rear tubes, air to air intercooler, meth injection, and a huge radiator. This is instead of just running an air to air intercooler and calling it a day like a lot of guys do. My .02 cents.
Hpbob1
Another approach also aimed at the cause in a boosted engine is to maximize cooling and lower intake charge temps.
I personally have a 74 camaro I am installing my LQ4, turbo 400, 3.73 gears, 75mm turbo, air to air intercooler and meth injection. For now using stock 317 heads. This will be a street/strip car with a lot of strip use (mostly 1/8th mile).
So for a car that also sees street time I would go air to air intercooler and meth injection. A strip only car I would go air to water intercooler as we know it is 14 times more efficient than an air to air intercooler. For strip only use I would even go air to water intercooler and meth injection.
Also use the biggest radiator that is practical for either use.
My strategy is to maximize cooling in all these areas at the same time to not only address the symptoms, but also more of the cause. I personally will be running the rear tubes, air to air intercooler, meth injection, and a huge radiator. This is instead of just running an air to air intercooler and calling it a day like a lot of guys do. My .02 cents.
Hpbob1
09-15-2010, 09:09 PM
#35
09-15-2010, 09:59 PM
#36
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What's the difference. I have only seen people tap the flat spot over the upper hose outlet which seems like it would be the same as tapping the upper hose. I guess I am just asking, which one is BEST. I don't care what's easier or faster
09-15-2010, 10:25 PM
#37
09-15-2010, 10:51 PM
#38
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reverse flow? what about converting the ls1 heads for reverse flow a la lt1? Would this eliminate the cooling problems seen in higher hp and boosted applications?
seems like it might work better than having your tubes tied
seems like it might work better than having your tubes tied
09-16-2010, 11:11 AM
#40
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I thought the coolant entered the head, travelled down to the end of the head, them dropped down to the jackets and back out.
Can anyone confirm this?
Cheers