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Midway through a “basically” similar build (w/434 sleeved LS3) w/ my 2,995lb C5.
Ported/blended 12 degree BR285’s, Ported MSD, Compression 11/1 ish for pump gas, headers and a massive lift cam (.720”/.675)
Curious if anybody is running anything similar and what kind of results/driveability they had after pro-tuning. Any vId clips , etc....
The cubes and heads will manage the cam lift .720"/.675" cut on Hardened 8620 Alloy (made for extreme/high spring pressures). All supporting mods....drive train,fuel,cooling,suspension, (AP Racing) brakes,underway as well.
It is being built at my request to be able to be driven by my wife or “a valet” despite the power potential. I wonder if 700hp (on engine dyno) is possible/ or if 10.9 is possible on street ET’s while maintaining street manners. I will let ya know soon but that’s in the works so I am fired up.
If you're only looking for a 10.9, you can reach that easily with a warmed over stockish LS7.
If you're going to limit yourself to a MSD. ported or not, I'm not sure if your combo will be able to take advantage of .720/.675 worth of cam with the associated duration....... most big cubed LS's peak at 6300-6400 with this intake.
10.9 is just minimum where I want it to be and I am certain that traction will be the limiting factor given the build and gear. I got the factory C5 Zo6 speedlines just to get that extra 2 inches or so of tire without going aftermarket.
I am sure it could probably go way way faster but it damn well better hit 10.9 and have the A/C blow cold. I just want that 10 second slip man and a valet or my wife to be able to park it (Mcloud RXT w/MGW shifter).
Anyway, I also want it 100% streetable in traffic so that’s where the compromises and decisions come in. Like why it is 4.155/4.00 to swallow up more cam (.720) and air. Anyway these AHP Archangel heads are supposed to shine over >.700 lift so there is that too. Having a hard time even guessing the HP on it and the heads should be finished sooner than later.
I will update the thread when the car is completed over at AHP. They are basically rebuilding the entire thing because it sat for a long long
They were trying to dial in something from Texas Speed but some issues led to the possibility of moving to Yella -Terras. I have not received an update and am pretty much running on blind faith at this point.
They were trying to dial in something from Texas Speed but some issues led to the possibility of moving to Yella -Terras. I have not received an update and am pretty much running on blind faith at this point.
Yikes !!!! Do you still have the option of selecting a different head package ?
The lift specs that you posted alone usually requires a significant rocker setup for such high lifts.......you don't want to skimp in this area if you want valve train stability, especially at higher RPM's.
No, the issue was quality control from a vendor. These guys have everything dialed in to a T, everything is being triple checked and tested which is a source of the delay. Their quality control and testing is like nothing I have ever seen, They want their best foot forward on this build and given the lift, yeah the rockers need to be perfect. 2126LSR Johnson lifters too.
No, the issue was quality control from a vendor. These guys have everything dialed in to a T, everything is being triple checked and tested which is a source of the delay. Their quality control and testing is like nothing I have ever seen, They want their best foot forward on this build and given the lift, yeah the rockers need to be perfect. 2126LSR Johnson lifters too.
Good luck
I didn''t take any chances with valve train stability...Crower shaft's for my heads.
AHP is using Brodix porters castings for their Archangel heads from the pics posted and the markings on the castings . They run stud mount traditional rockers.
AHP is using Brodix porters castings for their Archangel heads from the pics posted and the markings on the castings . They run stud mount traditional rockers.
Wow those are nice, is there any downside to shaft mounted rockers ?
(I never want to touch the engine or think about). .
Other than initial cost and purchasing a head designed to use them (or machining an existing head's rocker pedestal to accept them), there are no downsides IMO.
I'm running the Brodix BR7 BS 275 heads which are designed for them...needed the stability and control for my big hydraulic cam and it's intended power band.
Very cool, big heads, large cam....same direction I am going.
How is your driveability, idle, etc... with that in top on an LS7 (?)
Do you run a lot of lift and/or is it duration ?
My duration is nothing crazy — odd as it may seem.
It's not installed in the car yet.....scheduling engine dyno time for the middle of the month.
My heads have the smaller port than yours....275cc intake.....keep the velocity up while still flowing over 410 cfm at .720+ .
My cam is larger than yours, and I'm a bigger motor too.....testing intakes and throttle bodies during dyno runs to see what it will take to feed it
Wow that is crazy. The cash outlay is a MF for this stuff. My main thing is daily drivable so we will see. Anyway, I do not know what my ports actually are but they are closer to 275, if that ( I was guessing when I started the thread back in March). It has been a long road. But yea port velocity is obviously king (and proper valve/machine work, valve train, cooling)). I had one of the first sets of the AFR 205’s on another build long ago and that introduced me to that concept.
I grew up near Katech and have toured their facility in a professional (OEM) capacity. I had a close friend who worked there and he used to score me their used race-fuel cans they used for races w/GM . They were killer garbage cans for the garage man.
Anyway good old luck with your build.
Last edited by Mirek Again; 05-03-2019 at 07:06 PM.
I didn''t take any chances with valve train stability...Crower shaft's for my heads.
+1 for Crower shaft rockers. I've got them on my engine and I too have Brodix porter castings done by another shop. I'll be sure to check back once I get some miles on her.
Quick questions for those in the know...at which point does sleeving a factory block become better and cost effective to just go with an aftermarket block like Dart, rhs, or lsx? Just curious, id think an aftermarket block from jump on a build like this would bring alot more to the table for similiar costs. Correct me if im wrong tho. Just curious
If you are staying n/a resleeving an alum 5.3 is the most cost effective and lightest... otherwise if you plan to spray/boost it the 6 bolts per cylinder head style aftermarket block is better.... Stay away from the RHS block as they have had many issues with porosity/leaking in the blocks. LSx iron block weighs an additional 130lbs+ over a factory aluminum.....
Building a big cubic inch n/a motor that really works is $$$$$$. Killer cylinder heads and aftermarket rocker arms alone are big coin.
If you are staying n/a resleeving an alum 5.3 is the most cost effective and lightest... otherwise if you plan to spray/boost it the 6 bolts per cylinder head style aftermarket block is better.... Stay away from the RHS block as they have had many issues with porosity/leaking in the blocks. LSx iron block weighs an additional 130lbs+ over a factory aluminum.....
Building a big cubic inch n/a motor that really works is $$$$$$. Killer cylinder heads and aftermarket rocker arms alone are big coin.
I wanted reliable max LS based displacement and to keep the motor over-square (4.155 bore / 4.00 stroke).
I did not want the LSX weight penalty either, this led to the Darton sleeved LS3.
I originally kicked around doing a 454 but landed on a 434 bulletproof build for the long-term.
Not running spray or boost either, just a weekend car to drive up the coast to wine country with the wife, **** like that.
04-17-2019, 02:42 PM
