Gen 5 LT1 L83 L86 heads

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In-Tech
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Re: Gen 5 LT1 L83 L86 heads

Post by In-Tech » Wed Nov 08, 2017 7:42 pm

Carnut1 wrote:
Wed Nov 08, 2017 6:24 pm
After you get your first electric bill you will never want to use that bench again!
Haha, yup, could get interesting. I will be programming my own microchip to control it and datalog all the data so hopefully reducing run time to a minimum. I will be using a GM computer to log barometer, map before(between supercharger and electronic throttle) and after supercharger, Mass air flow to over 1500 grams per second as well as air temp before and after the supercharger...All the while letting the GM computer handle all the calculations, GM spends millions of dollars and many many thousands of man hours developing these computers and it would be stupid of me to try to build it when I can buy a computer for a couple hundred bucks.
I have a couple that are slightly damaged. Been thinking about trying a set on a ls3, plugging the injector boss. Headers are the hang up as far as being able to use shelf stuff. Id like to see how they stack up to the earlier heads. They look better in several ways.
There are a few sets of L86's on ebay at times fairly reasonable and will probably pick up a set soon, I am just hoping to find one to cut up first. Yes the heads look really good in several ways and the flow numbers don't match the hp levels say flow/hp x/y verses the LS3 flow/hp x/y is quite different. Meaning the new heads make good power with substantially less flowz (can I say that? \:D/ ) Sure, the direct injection and higher compression does make a difference but can't believe it's as much as I'm seeing. I do have a L83(5.3) coming that I will be doing some cam development on, cam cores are the problem so far. If all goes well I will be running that with direct injection and associated computer as well as plugging the direct injection and using LS3 style computer and port injection just to see what the difference in power is. That will tell us how much the DI is helping.

Anyhoosit, again, if anyone runs across a junk L86(6.2L) head, I would love to have one. [-o<
Heat is energy, energy is horsepower...but you gotta control the heat.
-Carl

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Re: Gen 5 LT1 L83 L86 heads

Post by CGT » Thu Nov 09, 2017 11:15 am

In-Tech wrote:
Wed Nov 08, 2017 7:42 pm
There are a few sets of L86's on ebay at times fairly reasonable and will probably pick up a set soon, I am just hoping to find one to cut up first. Yes the heads look really good in several ways and the flow numbers don't match the hp levels say flow/hp x/y verses the LS3 flow/hp x/y is quite different. Meaning the new heads make good power with substantially less flowz (can I say that? ) Sure, the direct injection and higher compression does make a difference but can't believe it's as much as I'm seeing. I do have a L83(5.3) coming that I will be doing some cam development on, cam cores are the problem so far. If all goes well I will be running that with direct injection and associated computer as well as plugging the direct injection and using LS3 style computer and port injection just to see what the difference in power is. That will tell us how much the DI is helping.
Very cool. I'd be like to know what you come up with. Sounds like your going to busy. I haven't messed with the E92 PCM yet.
"How or Y do you think I get all this $hit, I read all of you all builds and desktop dyno them with all the correct info and I've got your build."

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Re: Gen 5 LT1 L83 L86 heads

Post by In-Tech » Thu Nov 09, 2017 12:00 pm

Hiya's,
I have only gone so far as to suck the program out of a L83 E92 and have a look around, lot's to learn. Shhhhhhh i'm gonna rent a truck and strap it on the dyno for a few days and play and get more comfortable :-#
Heat is energy, energy is horsepower...but you gotta control the heat.
-Carl

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Re: Gen 5 LT1 L83 L86 heads

Post by JodyB » Sat Mar 24, 2018 3:14 pm

Very interested in this. I bought a set of l83 5.3 heads to look into crossbreeding with the cheap 4.8/5.3 gen3&4 bottom ends. Holley hirams make carbs or port injection a possibility. Big question is cam cores. The in&ex valves were switched, and the rear cam bearing was moved back to make room for the fuel pump ecc. How far?

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Re: Gen 5 LT1 L83 L86 heads

Post by JodyB » Sat Mar 24, 2018 3:17 pm

Rhs had a lt ls hybrid head meant to bolt on a ls block. One would assume a cam core was in the works since they are under the same group as comp cams?

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Re: Gen 5 LT1 L83 L86 heads

Post by JodyB » Sat Mar 24, 2018 3:21 pm


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Re: Gen 5 LT1 L83 L86 heads

Post by JodyB » Sat Mar 24, 2018 3:25 pm

Any chance of some halfassery to deal with the moved rear cam bearing and use an gen5 lt style cam?

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Re: Gen 5 LT1 L83 L86 heads

Post by JodyB » Sun Mar 25, 2018 8:58 pm

https://docs.google.com/file/d/0B_jE2-I ... piVG8/edit

Something great for a read. Development of the direct injection lt engine.

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Re: Gen 5 LT1 L83 L86 heads

Post by JodyB » Sun Mar 25, 2018 9:07 pm

Head bolt dowels were moved from the bottom to the top corners. No big deal to drill the gen3/4 block. Gen 3/4 headgakets wont work. Gotta get some gen5 gaskets and have a look.

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Re: Gen 5 LT1 L83 L86 heads

Post by CGT » Sun Mar 25, 2018 9:46 pm

JodyB wrote:
Sun Mar 25, 2018 9:07 pm
Head bolt dowels were moved from the bottom to the top corners. No big deal to drill the gen3/4 block. Gen 3/4 headgakets wont work. Gotta get some gen5 gaskets and have a look.
I have layed the 2 gaskets on top of each other. Everything appeared the same other than the holes for the small bolts.
"How or Y do you think I get all this $hit, I read all of you all builds and desktop dyno them with all the correct info and I've got your build."

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Re: Gen 5 LT1 L83 L86 heads

Post by CGT » Mon Mar 26, 2018 12:24 pm

Resized_20180326_111439.jpg
5.3 gaskets. L83 on the right LC9 etc on left
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"How or Y do you think I get all this $hit, I read all of you all builds and desktop dyno them with all the correct info and I've got your build."

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Re: Gen 5 LT1 L83 L86 heads

Post by JodyB » Mon Mar 26, 2018 8:54 pm

Image

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Re: Gen 5 LT1 L83 L86 heads

Post by JodyB » Mon Mar 26, 2018 8:59 pm

Image

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Re: Gen 5 LT1 L83 L86 heads

Post by JodyB » Mon Mar 26, 2018 9:02 pm

Image

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Re: Gen 5 LT1 L83 L86 heads

Post by JodyB » Mon Mar 26, 2018 9:04 pm

Last two images were the new lt block with the new rear cam bearing position.

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