When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I can't believe still nobody is making cast iron turbo manifolds (other than banks) for the SBC.
I found that importers are making (cost effective) cast iron turbo manifolds for pretty much every engine you could imagine, yet none for SBC.
I did see that the stainless single turbo kit got redesigned. I actually got a good laugh at this. I'm not sure if you guys recall, but back in 2013 I modified a set to work with my AFR heads due to the header hitting the plug:
Looks like they did a redesign to resolve the issue:
They also moved the wastegate flange to the back of the log, which makes sense because it's closer to where your down pipe would be. Yet another issue I found with the old design, you had to run a small tube that was really really close to the strut tower.
I'm tempted to pick up another set of these to play with, but I really would prefer a cast iron turbo manifold..
Everyone and their MOM, wants Pretty over Function/ Performance.
Little do they know that Pretty does NOT last long.
I use nice OEM Cast Iron Manifolds... cut them up, and Fab what I need to Fab
(When a Customer is on a Budget. they work great as long as they are not Chinese Fake Manifolds).
Now, I prefer to use 0.120"-0.125" Thick-Wall Stanless Tubing.
It is a huge Bitch to try and Bend... Small Mandrel Bent Sections can be Purchased... or make lots of Pie-Cuts.
This stuff does very well with the Heat.
I also use 0.220"-0.225" Material in trouble areas with excessive heat.
Lastly I Ceramic Coat inside and out.
Everyone and their MOM, wants Pretty over Function/ Performance.
Little do they know that Pretty does NOT last long.
I use nice OEM Cast Iron Manifolds... cut them up, and Fab what I need to Fab
(When a Customer is on a Budget. they work great as long as they are not Chinese Fake Manifolds).
Now, I prefer to use 0.120"-0.125" Thick-Wall Stanless Tubing.
It is a huge Bitch to try and Bend... Small Mandrel Bent Sections can be Purchased... or make lots of Pie-Cuts.
This stuff does very well with the Heat.
I also use 0.220"-0.225" Material in trouble areas with excessive heat.
Lastly I Ceramic Coat inside and out.
Image below:
Been doing a lot of reading on and off over the years. I've put together the following list of pros and cons of cast iron turbo manifolds:
PRO:
Better construction, more longevity
Better bolt engagement, better for supporting large turbos
Better spark plug access since tighter bends can be achieved
More back pressure, turbos tend to spool 800rpm sooner
CONS:
Reduced flow when compared to large tube race manifolds
Slightly lower peak HP
I think for a street car it's a more durable, better product. Which surprises me that nobody makes them. Hooker makes some really nice cast LS turbo manifolds, and of course off-shore manufacturers make them for just about every engine combination.
Yet the only ones I've seen for SBC are old ACCEL manifolds from 50 years ago, or Banks. very strange.
I thought about just making another set. But I'd prefer purpose built manifolds..
Meh. Most mild steel headers last a long time in my experience. As long as its not a dd in constant rain and salt weather lol. Most turbo cars are good weather street fun toys so it works fine. Stainless does too it seems when welded correctly. I seem to hear more about stainless crackng than in mild steel and maybe thats due to improper tig weld or 18 ga material? Idk
a cast manifold kinda limits what you can do with the system as far as placement goes and clearance. Assuming you mean turbo direct mount to it. Given sbc is in a ton of vehicles with varying chassis constraints making specific manifolds may not be cost effective since most just go lsx since its a better boost motor. Maintaining plug clearance and having downpipe clearances makes it more difficult I think
now a cast log type manifold with just a forward facing vband connection could be nice. Either up and forward or down and forward style like you see in a lot of turbo headers. Could hopefully have good plug clearance and freedom to mount turbo anywhere. But the charge pipe to turbo will need to be mild or stainless steel again…so only half the advantage i guess? A fabbed sch 10 pipe manifold would be fine for durability aspect but be heavyy
always thought there would be a market for it but when the market did put out some kits like bbs designs, cx racing or whatever other china kits out there, doesnt seem like many are doing them. Seems like 90% are ls swapped fabbed kits or someone with a built sbc with a fabbed custom setup that benefits from headers.
Meh. Most mild steel headers last a long time in my experience. As long as its not a dd in constant rain and salt weather lol. Most turbo cars are good weather street fun toys so it works fine. Stainless does too it seems when welded correctly. I seem to hear more about stainless crackng than in mild steel and maybe thats due to improper tig weld or 18 ga material? Idk
a cast manifold kinda limits what you can do with the system as far as placement goes and clearance. Assuming you mean turbo direct mount to it. Given sbc is in a ton of vehicles with varying chassis constraints making specific manifolds may not be cost effective since most just go lsx since its a better boost motor. Maintaining plug clearance and having downpipe clearances makes it more difficult I think
now a cast log type manifold with just a forward facing vband connection could be nice. Either up and forward or down and forward style like you see in a lot of turbo headers. Could hopefully have good plug clearance and freedom to mount turbo anywhere. But the charge pipe to turbo will need to be mild or stainless steel again…so only half the advantage i guess? A fabbed sch 10 pipe manifold would be fine for durability aspect but be heavyy
always thought there would be a market for it but when the market did put out some kits like bbs designs, cx racing or whatever other china kits out there, doesnt seem like many are doing them. Seems like 90% are ls swapped fabbed kits or someone with a built sbc with a fabbed custom setup that benefits from headers.
Everyone does seem to be jumping on the LS bandwagon. Lot of guys putting 6.0's into their cars it seems as well.
The new truck I just ordered is coming with a 6.6 direct injected motor. Wonder when those are going to start popping up in hot rods too.
But anyway, I have a good SBC power plant. I'm not really ready to do the LS switch yet.
i will probably be selling a set of the cx racing third gen headers soon. they wouldnt work for me, had to do the standard straight foward ones.
That's a pretty clean set up. Nice.
I'm putting this in a second gen. This is the boosted engine that came out of my thirdgen. It needed a home and it wasn't a good fit for my Convertible, so I decided to buy my '79 Z28 back since the guy I sold it to 12 years ago hasn't touched it.
Going to be a blow through sniper EFI since I have a brand new one on the shelf.
So.. I've been convinced to change directions on this.
I was talking to some folks on another forum, and I'm just really impressed with the 5.3 truck motor, single vs7875 with the hooker cast manifolds. One guy is running a stock 5.3 with just a cam and this turbo setup and is running 9.7 @ 140mph in the quarter. Most of the SBC guys are running big high end builds to achieve those times.
So I think I'm going to put the 412 SBC in my '68 convertible and leave it naturally aspirated, and get a used 5.3. Probably use the terminator ECU to manage it.
I know factory 400 blocks could have thin cyl walls or weak around the main webbing but they have held some power. 9 sec power shouldnt be to hard. My buddy did break the main webbing in his 400 block with a high 9 nitrous combo. But nitrous is harder on a motor in a sense.
i would think a 4 bolt 350 block should easily do 9 sec power in a thirdgen. But likely need atleast rod and piston upgrade. Stock crank is iffy, might as well throw a cheap eagle or scat forged crank in it. But marty did it with the grenade so idk
I know factory 400 blocks could have thin cyl walls or weak around the main webbing but they have held some power. 9 sec power shouldnt be to hard. My buddy did break the main webbing in his 400 block with a high 9 nitrous combo. But nitrous is harder on a motor in a sense.
i would think a 4 bolt 350 block should easily do 9 sec power in a thirdgen. But likely need atleast rod and piston upgrade. Stock crank is iffy, might as well throw a cheap eagle or scat forged crank in it.
I've always been a little nervous about pushing this block. It's a 2 bolt 400, which is "stronger", with a forged crank, scat ibeam rods, and forged pistons. My machinest always told me not to push factory blocks past 500hp unless doing steel caps. Didn't do that with this block.
I do like the idea of "throw away" 5.3's though. They ae so cheap to buy, even if I blow one up, who cares? If I blew up the 412 and it ruined my AFR210 heads I'd be awfully sad.
Right. Theres always that. Are 5.3’s still cheap? Are ls supplies drying up yet lol
I forget what state you are in, but up here in New Hampshire the trucks usually are rotted and off the road long before the engine is dead.
I usually see anywhere between $500-1200, depending on miles, and right now you can buy about 5 different complete 5.3 trucks for under $1500 if you wanted to.
There is an additional 18 on car-part.com, from junk yards.
When you consider the fact that I literally paid over $3,000 last month just for a few piles of dirt, it's not a lot of money lol.
I need to do a little more reading so I understand the differences. David's is an L33. Not sure the difference between that and the other 5.3's offered.
Thin-Wall Steel Tubular Headers (for use with Turbochargers) do not really have a longevity issue (unless they are simply garbage).
The main issue (performance losses) is actually the loss of Heat in the Pipes (not good for the Hot side of a Turbocharger System).
Although it is less crucial in this application... Flow is lost with rough/ unported Cast-Iron Manifolds.
Hot gaseous exhaust compound expansion (Not Flow per se) is really what drives the Exhaust-Wheel (after all it is a Gas Turbine).
As @anesthes said, there are pros and cons (Of course) between Cast-Iron Manifolds and Steel Tubular Headers.
The absolute best option that I have Found after a few deacades of being in this Business...
is Thick-Wall (0.1200") Stainless Tubing with Internal Ceramic-Coating (external in addition also helps keep the Heat in the Pipes)...
as well as Thermal-Wraping on the outside.
Engine displacement/ Cylinder-Wall thickness:
People were overly concerned with the 6.2L (L92/ LS3) regarding Forced Induction.
As someone who has found the Cylinder-Block Power Limits of these Engines (many, many times).
You do not have to be concerned with the the Cylinder Walls...
Even with 0.500" Head Studs and O-Ringed Decks; the Head-Gasket is going to be the "weak link" and Fail first.
Windowing the Block is also a contender, when hitting the power limits of these Cylinder blocks.
A 6.0L or a 5.3L (with thicker walls) does have it's advantages (increased cooling, and reduced Main-structure movement)...
But the only way you will see a Cylinder-Wall failure (even on a 6.2L) is from Detonation or a mechanical issue.
LSx cores (excluding 7.0L Cores) will be plentiful for a very (VERY) long time to come.
I have somewhere between 500 and 600 Cores in storage.
The biggest hit to Core availability has been from businesses (Like Texas Speed) who Machine the Cast-In Cylinders out of the Block...
Re-sleeve them, and add $2,000 on to the cost of the Core.
True heat in a turbo system is where turbine power is derived. However most front mount systems, turbine sizing and housing AR are more crucial in my experience. Front mounts usually already have lots of heat. Lots of turbo options out there now, matching turbine and compressor is fairly easy to do and maintain good spool and make power.
my “mid” mount ended up being more laggy than anticipated, and that has alot to do with heat, although efforts to wrap and hold heat in the piping has not done much. So with less energy available, likely need to downsize turbine size and housing AR much more than front mount. But some downsize pipe size diameter in effort to boost velocity and the kinetic energy aspect.
i have done the housing AR thing and picked up a lot more response. But on a short header and feed pipe in a front mount, i dont think you lose much with a tubular design, and maybe even benefit from much less weight which all adds up and can be important for track times. If you are into that thing. Street car, not as big a deal
True heat in a turbo system is where turbine power is derived. However most front mount systems, turbine sizing and housing AR are more crucial in my experience. Front mounts usually already have lots of heat. Lots of turbo options out there now, matching turbine and compressor is fairly easy to do and maintain good spool and make power.
my “mid” mount ended up being more laggy than anticipated, and that has alot to do with heat, although efforts to wrap and hold heat in the piping has not done much. So with less energy available, likely need to downsize turbine size and housing AR much more than front mount. But some downsize pipe size diameter in effort to boost velocity and the kinetic energy aspect.
i have done the housing AR thing and picked up a lot more response. But on a short header and feed pipe in a front mount, i dont think you lose much with a tubular design, and maybe even benefit from much less weight which all adds up and can be important for track times. If you are into that thing. Street car, not as big a deal
For a Mild Street-Car Build (Under, 1,200 HP)...
I completely agree with you.
I generally do not build anything that produces 1,000 HP or less.
These Days 85% of my builds are usually in the 2,000 HP to 3,500 HP range for "Drag Week" style Cars...
Or full Tube-Chassis/ Pro-Mod/ Funny Car Vehicles in the 5,000 HP to 8,000 HP range.
The other 15% are usually 3rd-Gens (the occasional 4th-Gen) in the 1,200 HP to 1,800 HP range.
These Days 85% of my builds are usually in the 2,000 HP to 3,500 HP range for "Drag Week" style Cars... Or full Tube-Chassis/ Pro-Mod/ Funny Car Vehicles in the 5,000 HP to 8,000 HP range.
whats your shop called? Where you located?
so you dont use typical 16 ga tube for any of those? Its all .120 wall? How heavy do those headers come out to be?
You guys are so far off the charts in regards to what I'm aiming for lol.
I'm looking to make around 600/540 crank HP. From everything I'm reading, junkyard 5.3 with a summit stage 2 turbo cam, some pac springs, and a vs7875 makes 800+hp.
I think the cast LS turbo manifolds will work great for my application. I think this is going to work out great. I could probably even use a cheap gt45 and hit my target HP.
Which actually is a great question - if I'm looking for quicker spool, would the GT45 or a T76 be a better option than the vs7875 ? More than 650 crank HP on a 4 speed stick is going to be just silly, plus I'm not putting a cage in the car.
Yeah it should but wont make as much power as the turbine should back up to quickly
i was lighting up a t70 very quick on my rear mount 305 tpi when it still had cat on the car lol. Once I straight piped the cat i lost spool and had to tighten housing ar
Yeah it should but wont make as much power as the turbine should back up to quickly
i was lighting up a t70 very quick on my rear mount 305 tpi when it still had cat on the car lol. Once I straight piped the cat i lost spool and had to tighten housing ar
Forgive me if I'm misunderstanding, but if your target goal was only 600-650, would you go with the turbo that spools quicker and has less potential, or the one that spools slower and has more potential?
Quicker spool but i dont think the t76 would do 600 on a 412. Too much backpressure. It may do it on a stock 5.3. But the 7875 is proven and doesnt have much issue spooling either so it would be abit more efficient. The gt45 68-69mm compressor could get near 600 as well on a 5.3 and is cheap. Similar turbine size and probably tick slower to spool than a .96 t76.
so you dont use typical 16 ga tube for any of those? Its all .120 wall? How heavy do those headers come out to be?
It was in Manhattan... I retired last year.
It was called "CrO³me Engineering Services" (unlisted, and I only took Customers by appointment).
I was going to immediately open a New Business... it was going to be My Son's first Business (But he has developed some serious Health issues and has been hospitalized for that last year and change).
So I now have a different new Business (Just Electric and Harnessing work) called the "Quick Connect" (out of a new Building that I had built at home in CT).
Forgive me if I'm misunderstanding, but if your target goal was only 600-650, would you go with the turbo that spools quicker and has less potential, or the one that spools slower and has more potential?
Again, 4 speed manual car.
I assumed you'd want quicker spool?
-- Joe
Why not just build 600 HP to 650 HP normally aspirated?
I'm looking to make around 600/540 crank HP.
-- Joe
not to derail the direction of the thread, but i think i would just stick a 76mm on the 412 and call it a day. toss some ebay headers on there and finish out the hot side. should be reliable at that level too i would think.....
on top of what he already has now, maybe… looking at a bigger better head package, and cam, and single plane. Resell the current stuff it could be done but lose alitte mannerisms
-$1,600 for stock CNC LS3 Heads.
-$400 for a Camshaft.
-$400 for Valve Springs, Retainers, Locks, and Seals.
-$200 for 3/8" Pushrods.
-$300 for SP Intake Manifold.
-$600 for weight-matched Forged Pistons and Rings.
Yea he would need a free LS3 engine to start out with. lol
amazing how cheap the LS stuff has gotten. even cnc head porting. i had a pair of heads done about 15 years ago with a "homeboy hookup price" and it was $1200 i think back then.
For his goals though i think he could just get a cheap borg turbo or something like that. it would be way more docile, make way more torque, and still make the same hp as a 650hp n/a setup.
not to derail the direction of the thread, but i think i would just stick a 76mm on the 412 and call it a day. toss some ebay headers on there and finish out the hot side. should be reliable at that level too i would think.....
I was thinking about doing that, but the SBC in my '68 convertible smokes a little bit (50 years old) and I'm swapping the body over to a new frame this winter so I figured why not just put the 412 in the '68 and do an LS in the z28. Especially since it's set up with the sniper already, probably fits the whole '68 theme better.
I was thinking about doing that, but the SBC in my '68 convertible smokes a little bit (50 years old) and I'm swapping the body over to a new frame this winter so I figured why not just put the 412 in the '68 and do an LS in the z28. Especially since it's set up with the sniper already, probably fits the whole '68 theme better.
-- Joe
junkyard 5.3 with 76mm turbo would probably work good
Call around to the GM dealers in your area...
ask the parts manager if they have any cores for sale (meaning GM did not want them back).
I have seen them as cheap as $400.
Also for no real reason... Trucks Engines (like the L92) are about half the price of a Car Engine (like the LS3).
L33's are cheap, I can get low mile L33's for $1200 all day.
It's the "other stuff" that drive the price up, like the fbody oil pan, conversion mounts, management system, etc. But I have been wanting to try the Holley terminator X on a car so this might be a good project.
The 412" SBC made good power with the vortech T-trim, but the more I think about it I'm probably going to have to rebuild the 350 in the '68 Convertible, which always end up spiraling out of control and costing more than a junkyard L33, so I might as well just use the SBC I have for that car. It's about 450hp naturally aspirated so with the 4spd and 3.70 rear end it should wake the car up.
08-16-2022, 08:29 AM
