Using 18 degree(or 15*) SBC heads on a LT1
06-29-2010, 01:38 PM
#1
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Using 18 degree(or 15*) SBC heads on a LT1
Besides using 18 degree specific pistons in the short block and 18 degree specific intake mainfold and converting over to reverse cooling, what else is required in using these heads in a LTx engine???
Do regular SBC/LTx headers still match up??
Can you still use regular HR lifter and roller rocker arms(in other words a conventional SBC valvetrain)??
Do you think flow number that these heads produce N/A makes the conversion worth it for high performance street???
I am thinking of going this route for my 383 LTx stroker build on my '95 Caprice instead of the usual 23 degree head Advanced Induction or Lloyd Elliot route that everyone seems to go.
One reason in prompting me in going this way is from an article in the February, 2009 online issue of Hot Rod magazine, Lingenfelter Performance Engineering built a 420ci small-block engine with a Bow-Tie block, a Callies 3.875-inch stroker crank, Oliver rods, and a Comp Cams roller. With 11.0:1 compression, 18-degree Chevy heads, and a Bow-Tie single-plane intake manifold fitted with EFI, this big-inch Mouse produced a stout 623 horsepower at just 6300 rpm.
Do regular SBC/LTx headers still match up??
Can you still use regular HR lifter and roller rocker arms(in other words a conventional SBC valvetrain)??
Do you think flow number that these heads produce N/A makes the conversion worth it for high performance street???
I am thinking of going this route for my 383 LTx stroker build on my '95 Caprice instead of the usual 23 degree head Advanced Induction or Lloyd Elliot route that everyone seems to go.
One reason in prompting me in going this way is from an article in the February, 2009 online issue of Hot Rod magazine, Lingenfelter Performance Engineering built a 420ci small-block engine with a Bow-Tie block, a Callies 3.875-inch stroker crank, Oliver rods, and a Comp Cams roller. With 11.0:1 compression, 18-degree Chevy heads, and a Bow-Tie single-plane intake manifold fitted with EFI, this big-inch Mouse produced a stout 623 horsepower at just 6300 rpm.
06-29-2010, 02:20 PM
#2
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Standard SBC heads or even "double hump" heads were bettered by the heads that are now called "vortec" heads. Those chambers were first developed on the LT1. So I doubt the SBC heads that do not have a "Vortec" style chanber will do any better.
06-30-2010, 01:07 AM
#4
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i dont know wtf speedy is talking about but you will in most cases make more power with 18 or 15 degree heads. there are a few 23 degree sbc heads that flow some serious numbers but they are huge bucks. i am pretty sure you can get any dart heads that are intended for a sbc made for an ltX but you have to order them straight from dart. thats what i have heard. but plenty of head porters have cnc programs for dart heads to make serious power. with the bowtie heads there is some homework that is involved with putting them on a certain setup to make them shine. but the same could be said for any head i guess. to get the most out of whatever its going to take more then buying them from summit and slapping them on your car.
07-01-2010, 05:52 AM
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Without getting into specifics:
LT1 or SBC headers wont work, you would end up needing to modify a set or have a custom set made.
Intake, again would either need one made or modify one that is out there for 18* heads.
You would need to have the 18* heads modified for the reverse flow cooling.
No these wouldn't be the best choice for a street car, 18* heads are going to shine at higher RPM's. - hence they are "race" heads.
FWIW doing a conversion like this EASILY cost $10K.
LT1 or SBC headers wont work, you would end up needing to modify a set or have a custom set made.
Intake, again would either need one made or modify one that is out there for 18* heads.
You would need to have the 18* heads modified for the reverse flow cooling.
No these wouldn't be the best choice for a street car, 18* heads are going to shine at higher RPM's. - hence they are "race" heads.
FWIW doing a conversion like this EASILY cost $10K.
07-01-2010, 10:50 AM
#7
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This is going into a daily driver not a weekend racecar. An LSx conversion is not as neat some people say it and as for the FAST setup I intend to use EFI Connection's conversion in using a Gen III or Gen IV PCM
07-01-2010, 12:15 PM
#9
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How about a set of SB2.2 Nextel Cup heads on a 396ci LT1? Check out this post from the Advanced Tech forum:
https://www.camaroz28.com/forums/sho...=Second+Street
https://www.camaroz28.com/forums/sho...=Second+Street
07-10-2010, 01:17 PM
#10
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i dont know wtf speedy is talking about but you will in most cases make more power with 18 or 15 degree heads. there are a few 23 degree sbc heads that flow some serious numbers but they are huge bucks. i am pretty sure you can get any dart heads that are intended for a sbc made for an ltX but you have to order them straight from dart. thats what i have heard. but plenty of head porters have cnc programs for dart heads to make serious power. with the bowtie heads there is some homework that is involved with putting them on a certain setup to make them shine. but the same could be said for any head i guess. to get the most out of whatever its going to take more then buying them from summit and slapping them on your car.
SBC chevy heads will not work on second generation blocks.
Second, as i mentioned, standard SBC chambers won't make more power than the LT1 heads since they brought about the vortec chambers. But were not called that. Next time do your home work before posting a WTF. DA.
07-10-2010, 04:10 PM
#11
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EFI Connection a better deal than you think
So with way better control and programming(with the LSx PCM) and hotter spark(the LS2 coil packs) with the proper control the EFI Connection Kit seems alot more cost effective than most realize.
07-10-2010, 04:23 PM
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There seems to be some confusion here. The 18-deg and 15-deg refers to the valve angles, not the "chambers". Generally, these are aftermarket heads. Shallower valve angles straighten out the runners between the intake ports and the valves, and improve flow. This has nothing to do with the various earlier Gen 1 factory heads, like the "double hump", "vortec", etc.
And Gen 1 SBC heads can be installed on the Gen 2 (LT1/4) engines, simply by blocking a couple of coolant ports and drilling some new ones. Very minor. The SB2.2 heads that I linked are shallow valve angles, and adapted to the LTx block. The engine was making 632HP NA on a non-optimzed tune.
And Gen 1 SBC heads can be installed on the Gen 2 (LT1/4) engines, simply by blocking a couple of coolant ports and drilling some new ones. Very minor. The SB2.2 heads that I linked are shallow valve angles, and adapted to the LTx block. The engine was making 632HP NA on a non-optimzed tune.
07-11-2010, 03:21 AM
#14
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Not only do you not know what I'm talking about. You don't know what you are talking about.
SBC chevy heads will not work on second generation blocks.
Second, as i mentioned, standard SBC chambers won't make more power than the LT1 heads since they brought about the vortec chambers. But were not called that. Next time do your home work before posting a WTF. DA.
SBC chevy heads will not work on second generation blocks.
Second, as i mentioned, standard SBC chambers won't make more power than the LT1 heads since they brought about the vortec chambers. But were not called that. Next time do your home work before posting a WTF. DA.
No, you're definitely the one with the lack of understanding.
07-11-2010, 08:25 AM
#15
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