4.3L VORTEC V6 PERFORMANCE. SHORTY VS LONG TUBE HEADER TEST-WHICH ONE MAKES MORE POWER & TORQUE?
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- Опубліковано 8 лют 2025
- THE OTHER GUYS. HOW MUCH POWER DOES THE GM 4.3L V6 MAKE? DO SHORTY HEADERS WORK? SHOULD I INSTALL LONG-TUBE HEADERS ON MY 4.3L V6? HOW MUCH POWER ARE LONG TUBE HEADERS WORTH? WHAT WORKS BETTER, SHORTY OR LONG TUBE HEADERS? SHOULD I UPGRADE MY 4.3L V6? CHECK OUT THIS VIDEO WHERE I RAN A 4.3L V6 THAT WAS MISSING MORE THAN A FEW COMPONENTS TO MAKE A COMPLETE MOTOR. I PURCHASED THE NECESSARY COMPONENTS AND STUCK IN ON THE DYNO TO COMPARE SHORTY HEADERS TO LONG TUBE HEADERS ON THE V6. WHICH DESIGN MAKES MORE POWER AND HOW DID THE HEADER CHANGE ALTER THE AIR FUEL RATIO OF THE CARBURETED V6?
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I agree 100% we need more aftermarket support for the 4.3. A hand full of cams, a couple of intake manifolds, and limited ignition options make this a hard platform to adopt.
why v8 swap it
@@overbuiltautomotive1299 Because most of us that choose to run the 4.3 is due to weight or packaging restrictions. SBC doesn’t fit in everything unfortunately.
Honestly the 4.3 v6 is great, stock it can take 500-600hp to my knowledge, and get decent gas mileage...although now I'm more interested in the newer lv1 and lv3 4.3 v6 which is based off the newer LT engines...I know one guy did a lv3 swap in his buick grand national after a prominent company for 3.8 buick engines completely botched the machining on the 3.8
I would love to see more videos on the 4.3 V6
Personally, I'd love a greater aftermarket for the 4.3. Like better heads, cams, efi intakes, etc.
But, I wish the LV3 4.3 was more common. If it was, id rather just have one of those
I built my 4.3 with a lunati cam, self ported heads, dropped biggest valves you can possibly fit in there. Sits around 350hp mark
I would love to see more v6 parts.
Agreed.
I put one of those in a 64 nova with a 1/2 ton truck 5 speed 20 years ago. It was fun
What was the parts setup for this? I want to do this same package. Where do I find engine, trans, and clutch etc? I just want a carb and points ignition. Thanks
Well, Crane has a good steel billet cam, but they're in Australia now. Glad I got mine before they left.
My 4.3 has flat top pistons, it's zero deck, the heads are milled, and it has 1.6:1 rockers.
No way to dyno it, it's Vortec EFI.
Oh, it has Hedman long tube headers.
Those were certainly some unexpected results, this was a fun test. I'm looking forwart to seeing more. It would be great if there was more parts availability for this platform in the way of more aggressive camshafts and heads
I think this thing could be rowdy! A cam and a turbo would probably go a long way to getting this thing to make 700hp. Good job Richard! I’m pretty sure I’ve watched every one of your videos!
I’m still waiting for the V10 Ford Triton vs Dodge Magnum shootout!
It would be great to see aftermarket support for the 4.3l beside Amazon turbo kits and marine intake manifolds. Can’t wait to see your videos on the Comp Cam for the 4.3 as well as any other content you plan on for the 4.3. Keep up the great work and I really appreciate your videos!
30 years ago I had an ‘81 Malibu with a 229. A gearhead friend of mine and I swapped on that manifold, a Holley 390 vacuum secondary, and a Comp “260” flat tappet cam with some 1.6 pro magnum rocker arms. Turns out we got lucky and didn’t coil bind the valve springs. Anyway i remember the 1st time going for a ride and him manually shifting the TH350. My 19 year-old self was thoroughly impressed. I think Hooker made a set of headers for that application back then but I think now all you can get is circle track stuff.
Yes. I always want to see more. Thanks for what you do. 😊
I have a 4.3 with the Brodix heads, longtube Headman headers, a cam, and a holley 500cfm 2 barrell. Getting it all sorted in my S10 and may get it to a chassis dyno this year. Cant wait to see what you come up with.
Note that Brodix heads with angled plugs have major clearance issues. I am running header flange spacers to get the primaries away from the plugs.
Interesting results. You know, in theory both practice and theory are the same. But in practice, they are not! Yes to more Chevy V6 but would really love to see the LFX (60 degree V6 with DOHC)
I've been wanting to see you revisit the 4.3! Love to see more!
This video is causing alot of deep thoughts in the shop right now. Our shop lead is saying its a matter of the stock cam and timing in the mid range more to 🤨follow
Absolutely i'd love to see more performance parts for the 4.3! I's a stout little engine!
It's good to know this is about the power level I'd see in my boat with that manifold. Looking forward to the swap from the 2-bbl now.
As far as parts, it'd be nice. I know guys used to call up comp and ask for the sbc extreme marine cam but for a 4.3 and they'd put the lobes on a 4.3l core no problem. The biggest issue I think is that there are enough differences with the 4.3l over the years it's difficult to have parts as certain blocks use different pieces. Unlike a 350 where it's always the same there are some annoying differences.
Aftermarket 4.3 heads, and an intake manifold designed to bolt a M90 roots blower straight to it. That would be awesome.
Don't know if it'll flow enough judging but this video my 500cfm carb is a little small for it
The gen 5 eaton m90 is good for about 400-450 hp depending on airflow mods and pulley's and whether 91-93 or e85...id be more interested if they can come up with a 2005-2014 gt500 supercharger adapter or even terminator cobra m112 adapter...that way there's no need to spin a m90 to the moon and back to reach above 400hp
Would love to see more videos on the 3/4 350
Wondering if the 180 degree turns to accommodate the flipped header affected power output?
Would love to see how much power you could make with the 4.3 I ran one for 20 years in my work truck and even pulled my horse trailer to work getting wild cows up. Great motor!!
Need to do more testing on these. Turbos and prochargers!!
THANK YOU, SUMMIT RACING!!!!
TOTALLY AWSOME VIDEO RICHARD. PLEASE CONTUINUE TO SHARE YOUR TRUTH.
This test was done many years ago using an oversized carb along with Comps biggest offshelf cam at the time the 280HR and the V6 ended up just under 300hp if my memory serves me correct.Pretty sure a V8 with th same mods would of made 100hp more but if you already have the V6 in something small like an S10 it might be worth hopping it up a little
Resonance in tubes tuned exhaust .
I enjoy the 4.3 content. I'd love to see a couple more cams on that stock build.
Yes, affordable aluminum heads and cams would be a game changer
I echo the comments from others regarding the extra pipe and U's on the long tube. True test would be to turn the shorties around and run the exact same "exhaust" post headers. Technically, you changed two things here instead of just one. Resonance in those tubes could account for AF weirdness.
tube length does not change AF
Yes yes I have sheet metal intake I been looking for parts for years
WOW!!!! THE SHORTY HEADERS WERE WORTH THE INVESTMENT.
Love to see aftermarket parts for the 4.3. So many have been made but so little in available parts.
I'd really like to see more performance oriented LT based V6. it seems to me like a 3/4 6.2 could do at least very close to as well as a 5.3, while being significantly smaller and lighter
see the LV3 vids
@@richardholdener1727 I've seen them - I've watched most of your videos for years now - but I wish they made a proper hipo V6 with bore matching LT1 as well as head flow etc
Interesting results. That's exactly the opposite of what I'd expect.
It would be cool if there was a TPI style intake for these, instead of that spider injector stuff. Or maybe a tunnel ram...
agreed
Are you familiar with the marine intake setup for these?
Love the testing
Thanks, Richard.
Im ALWAYS interested in seeing performance V-6 stuff. Im sure that 4.3 could make 300hp with a cam and heads. Especially heads. Maybe adapt the turbo setup from a Buick? Same basic bottom end, isn't it? Hell, I dont care. Its all fun!!
I would like to see more on building lthis engine. I'd balance the rotating assembly, deck the block, grind a hydraulic roller cam for the aluminum heads and a single plane, and Holley injection. If this engine is to be turbo charged, better pistons and rods will lead to a reliable 500 + horsepower engine.
Why build the school bus exhaust system? If it was simply to get the exhaust blowing towards the rear of the room, just turn the dyno cart around, it has wheels for a reason. Yes, you would have to reposition some wires and hoses but that's still easier, and cheaper than buying and building a 15' exhaust. One last thing; is that a 2 1/2" to 2" REDUCER on the end of the transcontinental pipeline! The increased exhaust back pressure would explain the AFR
you are incorrect in your assumption that the dyno can be turned around quickly and easily-the exhaust took a just few minutes
Yes, to all that.
Would love to see a full v6 engine build. I'm wanting to build a racing v6 engine for next year bump n run season and would love to what makes big gains in hp and torque
I like the 4.3 i wish it had more support. I really wanted to put in my 65 el camino possibly with turbo, but i got gifted a 283 standard bore block, so i went with that.
It looks like 2 possibilities intake manifold and or header manufacturer , if intake manifold by edelbrock performer rpm might make a difference or header by Doug thrones hooker etc isn't alot of options probably but the 4.3 is sadly underestimated have a friend of a friend with a chevy chevett with 4.3 running 10's on bottle and high 11's on motor and whenever hearing at idle you think it's v8 powered, definitely is a sleeper, love the videos hats off to you for all this unthinkable testing you it's alot more than powernation and many other automotive performance platforms that's been around along time, especially when you did some honda engines, (Bseries man myself) raised around chevy's but fell in different generation my old man always tell me I'm wasting my time with a 4cyl, pass away before honda era, on side note which was something else raised around is Vw air cooled motors they are also under estimated but don't see them in wreck yard either, good video/info my man.
What I assume is a wetflow issue is less likely the heads than intake manifold and or carb. I would think this kinda video would be way more interesting with dyno data included. Bsac, bsfc, A/f, water temp and maybe a air turbine reading.
Wondering if you turn the shorties backwards like the long flow would the numbers be a bigger difference
I would love to see anything at all for the 4.3l and yes I would buy affordable performance heads
If that engine has the aluminum rocker brackets, you can run 1.7 LS rockers on it in place of the stock 1.5 roller trunions.
I have a older v6 performance book that refered to the 4.3 as a semi even fire motor. I will have to check a motor to see.
If so, it will need individual cylinder timing.
Reason for second timing mark on harmonic balencer. #2 and #1 cylinder.
I have a 1997 s10 with 4.3 that I want to hop up. would love to see more videos on the 4.3. Cam change, port factor heads, test the brodix heads. would like to see it with fuel injection....
I would love to see a 4.3 Vortec with a comp 260ahr and nitrous wet kit and see how it compares to the turbo set ups.
Would love to see 300 hp out of a 4.3 liter. Correct cam and aluminum heads should do the trick easily. Once that is done then I'll want one!
We would like to see various cylinder head and camshaft testing on the Vortec 4.3 Liter! I personally would like to see you fabricate an intake to accept the Eaton M90 (L67)!?!
In the past I floated ( and was poo pooed ) the idea of a long header on one side of a V motor and a short on the other to see if this flattens out the power curve. Supposedly, some NASCAR motors in the 90's / 00's used headers with unequal length per bank ( meaning cyl 1 3 5 7 had unequal length and 2 4 6 8 did as well. No info as to if they paired tube length with cylinder firing order bank to bank.
the cup guys have header length and design scienced out-and none of them use shorty headers
Affordable aluminum heads!!!!!! PLEASE!!!!!!! These engines are way underrated. More cams and some more affordable stroker kits as well would be sooo awesome. I know so many people that would build the hell out of a 4.3v6 if only they had good aluminum heads.
No aftermarket heads though is what turns everyone I know off about 4.3.
Definitely 💯 agree with more cams and heads and I wish they made a TPI intake for the og 4.3 the 3/4 350 because I have one in my s10 and it’s a great little engine for having 240,000 on her and she still gets sideways all the time lol but I want more low end and I’m thinking about putting a marine two barrel carburetor intake and cam on it, but I’m not sure if it would help. I would love to see a test with a two barrel intake in carburetor set up and maybe a mild boat cam for a daily driver application love this motor, but I’m still tempted to put a 5.3 I have in it lol but it’s got a glass 4L60E in it so yeah lol
I have a vortec 4.3 and a vortec 4200 the 4.3 is great for towing, I don’t know if something is bad with my 4200 it’s supposed to be more powerful but the 4.3 beats it because of it’s low speed torque and towing uses a lot less fuel
Richard find someone to grind the base lobe of the cam and increase the lift / duration or if you can get a custom one made
I'm very interested in what the 92 to 05 stock cam shaft does in that engine It can be gotten from melling Then start in on the other cam shafts
Before you change cams, try some 1.6 rockers, my experience is that they can bring 25 hp at peak
25 seems like a lot for rockers-but easy enough to test
@@No1414body I’ve done 1.6 rockers in my 4.3 that has a comp 268/454 dur and lift cam and maybe seen 10hp difference if that much. Mine is .040 over flat top pistons port matched heads to a edelbrock 2111 intake Sanderson long tube headers and a Holley sniper efi. I’ve got it in a 48 Chevrolet flatbed dually that weighs 5,600 lbs and it pulls it around pretty good
@@richardholdener1727
I'd agree, I don't think my 1.6:1 rockers are going to gain me 25HP. Maybe 1/2 that.
I think lunati makes a Cam for the 4.3, would love to see the difference from lunati and comp cam
My question would be what effect did the longer post collector pipe have on the torque curve..
I'm wondering if the crankshaft is forged? I'd like to see the results with the stock heads ported vs some good aftermarket aluminum heads with and without a cam upgrade. I'd also like to know how much it weighs with and without aluminum heads. So, it's 3/4 of a 350, then?
has anyone ever sat down and ran the numbers on the heads available for the 4.3? you've got z,w,x engines all part of the vortec engine family comp cams has at least 3 different off the shelf cams available and you can custom order grinds through them(i had one)now its been 20 years since i built this engine but at the time the guy i had port my z code heads(original) told me he tested them at 163cfm stock and after slurry porting was able to achieve 225cfm he flow ported the edelbrock tbi intake to the heads and ported the shorty headers to match, it had a big block tbi body with a small block fuel pods on top all port matched together. sorry i never had the chance to put it on a dyno (just wasn't available back then) but what i did come up with was a spunky little s10.
Another point is that this is an odd-fire V6. Does that make a difference in how the headers act? I would think so.
this is an even fire v6 (split pin crank)
@@richardholdener1727 well, dang. I got myself confused. Seems like some of the older ones are odd-fire, but quite honestly I thought the split pin is what made it that. I am seeing different information now. I guess I got too used to my good ole' 6G72 with a firing order of....wait for it: 123456
I would like to see charts after porting the exhaust ports... If you haven't done that already
4.3 V6 PERFORMANCE 101
Collector design on the long tubes limiting low end torque possibly?
I would like to see some intakes for a reasonable price
Shorties might increase cylinder pressure at low speed?
Please push for aluminum heads and maybe a better intake🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏
Do you have a video out about how to make a turbo system work and what you need, a turbo for du mm ies for lack of better words
Are those 1 5/8 or 1 3/4 primaries? V6 can be an odd duck but very rewarding when done right!
Don't think the length of pipe and 90s made a difference over the shorties?
I’ve been thinking about cutting up a set of speed master aluminum sbc heads and seeing if I can make them work on a 4.3
Do some testing on the 4.2l ford v6
SUGGESTION: MORE 4.3 CHEVY V6 IN SOCIAL MEDIA.
Only reason I swap sbc in s10 is no affordable aftermarket parts for 4.3
Man you gotta get a mic that can handle high spl in the dyno cell. Maybe try plugging in a pair of headphones as a microphone? I tried putting some airline earbuds in the engine bay once and they worked as a high spl microphone, but sounded... like airline headphones (real bad). So maybe a decent pair of headphones would work as a high spl mic in a pinch?
Can't even tell what the engine sounds like.
Try a set of sanderson cv97 they will clear everything and be a more equal length
SUGGESTION: ALUMINUM CYLINDER HEADS!!!!
PS - a stroker crank is first order in priority. Then we can talk about heads, etc.
cam, then heads, then intake, then boost, then displacement
@@richardholdener1727 the stock crank is good to about 500. The various turbos on the internet show this to true (for example Finnegan's rotsun). the crank is first to go as you get into ~500 territory, especially easy with boost and current parts.
SUGGESTION: LOW PROFILE OIL PANS!!!
@RichardHoldener- I would ❤️ to see what BigDogs Porting, could do with these stock cast iron heads(w/bigger valves, plus milled, for more compression 9.75 to 10 to 1), BigDogs Ported carbed intake, BigDogs ported shorty headers, & a custom speced hyd. Roller cam by BigDogs Porting, to match this combo! It would be Awesome, if the 4.3 could get some chop, from a high overlap custom cam( with dur. @ .050 being around 220° int., & 228° exh.) , around .500 Lift, with a 110° Lobe Sep. Angle. Power band of around (3,000 Rpm to 6,500 Rpm) This thing, with a 3,500 to 4,000 high speed tq. Converter, drag tires, & matched Rear gear ratio, in a 3,000 Lbs. race wt. Ride would be a "RIPPER"!
HCI go a long way
Richard please run with/without balancer !!!!
How many HP it cuts from engine?
do you mean balance shaft? because you should keep the balancer/damper in place
@@richardholdener1727 yep
Above cam shaft
U can simply unbolt its gear
Balance shaft will holds in place by front ball bearing
It lubricates at rear (sleeve) so cant be removed without blocking rear oil passage
Any chance you could run some stock manifolds on the same setup?
I suspect you were getting different A/F from cylinder to cylinder. Your 02 sensor was most likely on one header out. Probably a combo of the heads and intake. Just a guess.
THE AF METER WAS IN THE EXHAUST-SAME SPOT ON BOTH-CHANGE WAS THE HEADER CONFIGURATION
@@richardholdener1727 I know. The air fuel was wonky on both.
Stupid question but never tried 3800 and 4.3 same bolt pattern?
@@keithsmith9889
No
I know it's off Subject but have you ever thought about doing a big bang with a 6.2? Just to see if the block goes first or if it's a rod or something. There's always debate on iron block 6.0 vs all aluminum 6.2 block. Just curious
The alum (5.7L, 6.0L and 6.2L) blocks will not support the power levels of the iron blocks or the alum 5.3L blocks.
@richardholdener1727 that's what I assumed but I had to argue with some internet professionals 😂
@richardholdener1727 you said once that you couldn't run a 09 3.9 v6. Was just curious why. I'd love to see one with a turbo on it. If I had a transaxle to hold it I'd turbo the one on my rail buggy lol
Didn't Roadkill put a turbo 4.3 in the Rotsun? It's been a minute since I've watched it but I was thinking that's what they used. A turbo off a diesel and ran it till it decided it didn't like keeping all those parts in it. I remember it was a Chevy V6 just can't remember the size.
they did
@@richardholdener1727 Think it would be interesting to know just how much power that engine can make. I know the old 2.8L V6 was tough as hell. I knew a guy who had one and used to beat the crap out of that truck. He would rev it way past the redline all the time. If I remember correctly he went through 4 or 5 clutches because he was always trying to do burnouts by revving the engine up and dumping the clutch. Yet despite all the abuse that 2.8L made it over 250k.
Long tubes look like they had 3" pipes. Lost scavenging on the little V6 hence the torque loss.
Is Scavenger effect the difference in the headers?
that should help power
Can you let us know how much timing was used.
34
Could it be harmonics ?
Have oregon camshaft grind some custom cams.
Is there a method to know if short 1.875 headers or long 1.625 would be better
LONG TUBES HAVE MADE POWER BETTER THAN SHORTY ON EVERY OTHER TEST-I STILL THINK THERE IS A PROBLEM WITH THIS TEST
Dual planes have the runners above and below each other, that's a divided single plane.
it really is 1/2 and 1/2-meaning not a great design
@@richardholdener1727 Seperated by 240 degrees at least.
Those headers did what I have been told headers do for over 20 years, shorties for bottom end, long tubes for mid/top end. The AFR at the top end change didn't surprise me either. I am guessing that gooder scavenging of long tubes over short tubes is created the stronger signal. I wonder if smaller high speed air bleeds on the secondary side would help.
I think a 300~325hp 4.3 in an S10 would be super fun, so yeah, gooder heads and cams would be cool to see. Maybe there isn't much V6 demand because there isn't much V6 support...
If you think shorty headers do better down low-then you haven't seen any (of the many, many) other dyno results. This was extremely unusual-enough so that I feel there is a problem with the test
I bought my son an H3 hummer, and I'm looking to install a 4 3. I'm looking forward to the next video
What happened to that Bowtie 2 piece intake that you show on the engine at 0:30?
COMING-BUT IT IS FOR THE EARLY (NON VORTEC) HEADS, SO HOLES MUST BE DRILLED IN HEADS
@@richardholdener1727 Awesome!