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The LS series heads combustion chambers are far more efficient than the older designs. Hacking up a new set of heads from a $14000 engine seems idiotic to me.
 

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Jmark said:
Hmm, sitting here with my mouth zipped shut!!!! LOL
If I weren’t so foolish, I would do the same!


I haven’t had an opportunity to do any work on the LS7 engines; I personally
don't know anyone that has one. It’s an excellent high performance engine
that responds well to modifications so I’m told.

I do plenty of work on the LS1, both production and aftermarket heads. They
respond to porting and the grooves very well.
 

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Discussion Starter #8
To automotive breath:


So do you think it's possible to improve upon stock LS7 engine using the grooves?
 

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Red, what in gods green earth is the current issue you have with the stock LS7 head that I know for a fact will run 12:1 on pump gas from Cleveland to Little Rock Arkensas in 95 degree heat and stop and go traffic AND makes well over 500 SAE corrected flywheel horsepower with about 27 degrees of total timing, with the AC running.

Grooves in this type of cylinder head will do no good. It is a superb head as is. Not a cylinder head you'd want to hack up.

Do yourself a HUGE favor one day and go to a car show and spend some time at the GM Performance Parts trailer and exhubit area. Many times they have their LS cylinder head engineers there. They are a wealth of knowledge and have always been willing to share information.
 

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Rick WI said:
Red, what in gods green earth is the current issue you have with the stock LS7 head that I know for a fact will run 12:1 on pump gas from Cleveland to Little Rock Arkensas in 95 degree heat and stop and go traffic AND makes well over 500 SAE corrected flywheel horsepower with about 27 degrees of total timing, with the AC running.

Grooves in this type of cylinder head will do no good. It is a superb head as is. Not a cylinder head you'd want to hack up.

Do yourself a HUGE favor one day and go to a car show and spend some time at the GM Performance Parts trailer and exhubit area. Many times they have their LS cylinder head engineers there. They are a wealth of knowledge and have always been willing to share information.
Not to mention 28mpg to boot.
 

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What's wrong with taking a good head and making it better? I don't know of any head that can't be improved. Cut the thing up and see what you can do. :thumbup:
Bob
 

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Where is the data showing grooves in a head make any improvement. Oh never mind, we have been through that discussion 8 friggin thousand times.

I think you are making a huge assumption that a groove is "a good thing"

Mark Steilow had his Camaro on Power Tour. He has an LS7 in it. He shaved the head and it's running 12:1. I know Mark and I know his good friend Jody, who was also driving the car. No issues running pump gas.
 

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Discussion Starter #16
To automotive breath:

No, I don't have LS 7 engine yet.

Even if I did, I would want to run it stock (at least till the warranty runs out) for two reasons:

1. This way, I won't have to worry about voiding warranty.

2. Also, it will give me enough time/opportunity to evaluate the stock LS 7 performance/mpg so that I can use it as a base to judge if the groove will make a difference.


To some of you:


Sorry if I caused you unnecessary aggravagtions.

I had no idea that Somender Singh's groove would create so much controversy.

P.S. Yes, the groove is beautiful looking.
 

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What would you do if a crack formed along one of those grooves and ended up trashing one (or both) of those expensive CNC machined heads?
 

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leldai73 said:
are the grooves just cut in with a swiss file? or is there some sort of
complicated tooling involved
milleldai,
I cut the grooves with a 1/16" ball end mill parallel with the deck surface. I
then widen (to 1/8") and deepen the opening into the chamber roof with a
hand held file.

Red Grant,
One of my many current projects is to modify a Chevy 5.3L truck engine for
reductions in fuel consumption and emissions. I know someone that grooved
a stock truck with outstanding results. Keep in touch and I'll let you know
how it goes. I hope you get your LS7, it is an awesome performance engine.
 

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I don't mean to hi-jack but I'm considering doing this to my 383 that has yet to be assembled. I have a set of 906 vortecs that I will running on this engine. the compression will be right around 11:1. Now Im thinking of a two groove setup with the grooves aimed at the spark plug with the grooves making about a 60* angle to each other. This engine is planned to be a mostly street engine I'm looking for a little cushion zone to run pump gas without pulling tons of timing.

what are your thoughts?

oh and some specs
.535/.540 lift
242/[email protected]
300/310 advertised
113 lobe separation
106 intake centerline

pistons are flattops
 

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foxman267 said:
I don't mean to hi-jack but I'm considering doing this
to my 383 that has yet to be assembled. I have a set of 906 vortecs that
I will running on this engine. the compression will be right around 11:1. Now
Im thinking of a two groove setup with the grooves aimed at the spark plug
with the grooves making about a 60* angle to each other. This engine is
planned to be a mostly street engine I'm looking for a little cushion zone to
run pump gas without pulling tons of timing.

what are your thoughts?

oh and some specs
.535/.540 lift
242/[email protected]
300/310 advertised
113 lobe separation
106 intake centerline

pistons are flattops
Your combination is ideal for the modification for two reasons. The camshaft
overlap causes reversion and excessive exhaust residual gas in the chamber
at low RPM. In addition 11:1 compression is pushing the limits with a 23
degree iron head engine.

With the grooves you will find a much improved idle quality and outstanding
off idle throttle response. These circuits will be much easer to tune with no
need for over rich mixture to mask poor combustion. This alone will result in
a reduction in fuel consumption. No choke is needed and warm up time is
reduced to little or nothing. Spark plugs and oil will run noticeably cleaner.

I have been doing numerous heads with a two groove layout like in the first
picture, it works great. With your combination I would consider a third groove
similar to the pent roof head shown.



 
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