Cathedral Ls Heads Vs LS3 Head Dyno Test

[@gordongrimes2797]

Eric some friends and i did track testing in california at a desert track from a door car to a dragster small blocks [earley 1990s] every test done with a 1050 dominator picked up ET and at least 3 MPH.this was before the better carbs of today 6464 dominator.heads where not what they are today. every body said the carb was to big for a sbc.WORNG. used an adapter on a 4150 manifold.Thanks for performing this test. love the videos.

[@mack8940]

the best ls3 combo i saw ran the cid 4500. it picked up big numbers over all the others

[@v8packard]

I love Dominators. The difference between the heads might be more pronounced with cams that are optimized for each head.

[@BDauto86]

Very interesting, thank you for sharing Excellent job on the 243s, those numbers were very good

[@chevyrc3623]

I shared this video to a couple of guys who like ls to show how your ported cathedral did and sweet that's awesome how your ported head did

[@davidreed6070]

Eric you have always put out good information.

[@rickyfulks6656]

Awesome torque numbers Eric

[@brianholcomb6499]

I’m glad you pointed out what the cost was! Those LS3 heads do really good when you have the compression up! People also seem to forget about the deck thickness & material! I know it’s an enforcer, so probably cheaper material! But most think an aluminum head, is an aluminum head! There are huge differences if you plan on using a power adder! Factory heads start moving way sooner!

[@jeffwooton7138]

Glad I waited to post till the end. You answered most of the questions I had. I just wonder about the possibility of overscavenge on the LS3, and not making power with the carb swap. Just spitballin' here.

[@BN-pi3jk]

Love your tech heavy vids!

[@johnbernhardt9705]

Great work like usual but I would love to see equal compression ratios!! Thank you!

[@tonym6854]

Excellent test. For the street i think cathedral port is the way to go. I have a similar build with TEA ported 799 heads but with a Mamo ported LSXr/102 combo. Wish i knew the torque numbers. Also i imagine that a dual plane on your test mule would have even more impressive torque numbers. Great job 👍

[@michaelparadisis4076]

Great test.

[@rogergm92]

The community says thanks. Thanks!

[@terryenyart5838]

Appears the 243 are more efficient . Nice job on the exhaust flow!

[@lcxu1051]

I'm going to say due to the smaller CSA of the 243 heads the port volisity is up more than the afr heads. That with the compression ratio difference is why the 243 heads stayed with the AFR heads and out preformed the afr heads down low untill the head became more port efficient in the upper rpm range where the afr head took over with the little bit extra flow and larger CSA

[@johnzeek4731]

I would say that too but he measured the volume and it was the same.

[@lcxu1051]

@johnzeek4731 there is a difference between taking meterial out from the right area and wrong area. The start of the 243 port flow is just above what the engine will require at that rpm. Where the afr head is well above what the engine needs so port volisity and ramming affect of the port suffers till higher in the rpm range when the engine requires more airflow. If the afr head had bowl and throat work done to it. It will improve more in the top end but I feel it still won't match the 243 head as it will still have a better port volisity compared to the afr head especially when the engine requires that in the lower rpm. Not to mention the port discharge coefficients of the 243 head over the afr head.

[@WeingartnerRacing]

Not saying that this won’t happen but on the sbc when i used a ported head that ended up being larger by 20cc it was up everywhere even down low.

[@lcxu1051]

@WeingartnerRacing if you take the metal out of the right areas make the port larger that will work. But if you take it out of the wrong areas and make the port larger. It will be bad for flow.

[@deankay4434]

Eric, In the regular guy world, LS-111 (Vortex iron block truck) engines with stock cathedral intakes are disappearing fast. With out any modifications other than cam for grocery getters with some headers, using OEM EFI, intakes are not abundant, even with E85 injectors, could a non-racing product pickup or car expect to see maybe 20+ HP gain and extra torque using a comp motorhome / grandmas grocery getters performance? Just curious. I have less money in my pockets now while still married 44+ years as she still spends on kids & now grandkids. I guess my time came & went. So living cheap. Thanks Eric now, and your exhaustive efforts to do the cam shootout! My hat is off to ya! 😊

[@lauriegregorylgregory6315]

great work eric,love it, but that half pointin compression is alot and would chng. enforcers #s.

[@DSRE535]

Nice job!!!! Yeah one thing for anybody that builds engines or deals with a lot of used parts cleaning everything up takes up way too much time unless you have a pretty serious machine. what do you do after these heads have been ran to get them cleaned up for the customer? blasting cabinet really makes them look like crap, and doing it by hand takes way too much time but anyways lmk, thank you!

[@yepyep340]

GOOD STUFF!

[@ClaudeMayer-ek9mk]

Great job Eric

[@realazliving]

If you look at the average torque and hp numbers on your chart it’s interesting. I already knew the graph would show the 243s are a great all around street head from that.

[@davidwickboldt712]

In 226 years we still don't fully understand the the internal combustion engine. So we get unexpected testing results.

[@terryenyart5838]

I don't believe I've ever removed a head without carbon build-up to some degree, unless it was eating coolant. Then it's dishwasher clean😮

[@patrickoleary6379]

Eric, to me, the valve size tells most there. Also,the air speed is more important than we are thought to think. From talking to diff serious head guys,(devs and more), the air speed is one of the most important metrics, and I have found that to be pretty true. I’d be really interested to see the air speeds n the 243s, I would seriously bet, until it goes turbulent, they’re more managed, and more suitable for the turn. Wondering if that’s why you didn’t show the 243s speed, I don’t blame ya if that’s the case. Just thought I’d throw that in there. Good vid as always!

[@WeingartnerRacing]

I didn’t take the measurements because it’s for a customer. I don’t need to do it when I know what I need to do when I’m porting the heads.

[@patrickoleary6379]

@@WeingartnerRacing ya absolutely Eric….I figured it wasn’t needed. I have def found, if you can manage the air speed properly to make that turn, even if it looks a lil funky, it will out perform something a lil more conventional, with more spread out and higher/lower numbers than wanted….. didn’t mean to come across as sounding like you were being misleading, it came out wrong….. obv ya know what it needs to look like. I assume that’s the real perk of the wing sometimes, it helps to manage the speed, and give that bit of a directional change. Haven’t played either them much myself. When I used to mess with small scooter engines, guys would hog the ports way out and kill the speeds. They never believed me that I was using a much smaller port design, with proper speeds and a good custom ground cam ( at that point cams were very limited and I believe still are). I was able to make almost 12 hp out of a gy6 50cc engine with a 52mm bore and stock stroke. Most guys weren’t getting past 10hp. That was the most drastic Percentages I’ve seen, obv as almost 25% more was a hell of a lot from proper port and esp intake elbow. They would make or break the characteristics of the engines. I must’ve went thru 10 of em before I found the right size/shape. Darin has said before some numbers about the slope of the walls, and in retrospective, had I followed those guidelines, I couldda saved a lot of time.

[@patrickoleary6379]

@@WeingartnerRacing another interesting tidbit, I also used WAYYY oversized carb on that engine. It actually was for a 200cc Honda engine, that was tuned in perfect for my application. Everyone told me it wasn’t gunna work, it was gunna be a dog off the line, and sure I guess it killed a lil throttle response under 3k,( with a stock engagement around 2000rpm), but the clutch didn’t engage till almost 4, as it was spun to 11,500. I can honestly say, it was a beast off the red light. Most 600s couldn’t keep up to 60mph.

[@dondotterer24]

I'm guessing the 243 has more air speeds? And tweaking the cam specs and using the split intake manifold. It's going to make some impressive power! Great job!

[@timothybayliss6680]

Right on

[@DARRON40]

very good

[@jonsetzer9556]

Start making the high speed bleeds in the carb a little bigger it’s gonna clean the engine up and make more power

[@WeingartnerRacing]

The afr is on point at wot.

[@LynnTwinCustoms513]

Good information!

[@alcoatornado2749]

I'll take the thicker deck of the AFR for boost sealing every time...........

[@jasonstormoen]

On stock block stuff going to 1/2" head studs and flame hoops (top fuel hoops) it'll hold all the boost, until the block says I'm out.

[@terryenyart5838]

I was just going to ask about port length. I'd guess the 243 casting has higher velocity, a bit more compresdi9n making it a better head.

[@willrobb9520]

I really wanted to see the port velocity for the 243! I feel like that's part of the dominator mystery on the ls3. I'm real curious what the velocity profile is from top to bottom (roof to floor) between the two heads. And yes, RFG power from a set of 243 heads.

[@dennisrobinson8008]

Excellent.

[@lukesimeon5756]

Very good info ... could you do port molds of both before you port the afr thanks

[@WeingartnerRacing]

Maybe

[@rle1020]

Love the work and effort you’re doing to actually show the differences but I think it’s gonna boil down to the cost factor in the end. Afr enforcers are 1500 and you said there was a 10hp difference vs a ls3 head and those could be had for 500 or less. How much does it cost to get a set of cathedral heads done like you used in the test 2500 or more? Definitely appreciate your effort. Thanks

[@robertbailey3057]

Where can I contact you to discuss purchasing a pair of those 243's?

[@miniblackmog]

I've heard engines that have to small a head for the displacement/rpm will respond well to a bigger carburetor. Bigblock mopars love big carburetors and it seems to trend with what I've seen

[@WeingartnerRacing]

This maybe the case.

[@joshwynn1836]

How would the differences in the heads affect power on a turbo setup? I'm doing a 11:1 408 w/a FIS 91/102 T4, for my 99 Camaro. I chose a set of Dart Pro1 225's. I've had 2 motors, a 408 w/a worked set of LS3 5462 castings done by Land Speed, flowing ~365cfm @.650 lift, about 10.7:1. The other motor was a 403, 11.3:1, w/a set of Trick Flow CNC 225's, a bit more cam, but on a 113° LSA vs. 112° in the 408. Seat of the pants feel, it felt like the 403 would pull from down low, all the way to 7500rpm, where we stopped because of LS7 lifters, still holding power. The car made 540whp. The 408, didn't have the Torque, but I feel it'd pull in the upper RPM hard, but made 556whp. On a different dyno, so the #'s are likely irrelevant. I think with the LS3 heads, you need more cam to use the CFM, but not sure on boost. Thanks!

[@ShawnGilbert1967]

I'd have liked to known what peak timing for HP/Rpm was for each head like 243s were 27 and ls3 was 31 degrees? Thanks for all the work and info

[@WeingartnerRacing]

29degrees for both. If you really played with timing curve you could gain 5ft lbs of torque but no peak horsepower

[@ShawnGilbert1967]

@WeingartnerRacing thanks Eric, I went back and caught up on some of your videos and was able to kinda see that, I liked the timing section. I do very similar I pull timing approaching, during and just after peak torque ( and it's shift recovery so it helps on the street) and add it back 6500 and then 1 more degree past 7000 ( 7500rpm shifts ). Really enjoying the content!! I'd like to see stock Eric ported 823 castings vs ported aftermarket ( I wish you had a straight 6.0 or 6.2l yea yea I know send ya one and you would do it ). Really appreciate ALL the time and effort you put into providing info for us, good luck to your son this season...

[@FORCFED]

Great job and information sir , what was the jetting on dominator? Did it change from BBC and SBC? Power valve? Thanks 🙏👍

[@WeingartnerRacing]

No

[@FORCFED]

@@WeingartnerRacing awesome response ty

[@samstewart4807]

hi, 1 point of compression is worth 4%?? hp. Do you think you should factor that in at all? maybe use 3%? because it is not a full 1 point of comptrssion?

[@WeingartnerRacing]

That’s theoretical. An actual engine doesn’t follow that as you will see with the promaxx small bore ls3.

[@abdullaalameri90]

Superb

[@RoyOlsen-mm4fm]

How long are you going to bang your head in the wall with that ls3 victor jr intake? It seems like everybody knows it’s trash but you . I switched to the Holley split and the struggles went away. BIG TIME difference. Also 11:1 against 11.8:1 is 6-7% with right induction

[@WeingartnerRacing]

You work with what you have. I don’t have others to test. That percent is theoretical and engines don’t always follow that as you will see with the small bore promaxx.

[@RoyOlsen-mm4fm]

@@WeingartnerRacing I know for a fact that LS3 follows that theory. Absolutely 100% certainty. I understand that you work with what you got, but then you can’t state that you test the difference between two platforms. In this case you should have used a set of ported 823 heads and equal compression. Also it is a known factor that the rectangular intake is no good, but not so bad on cathedral. That’s your answer to why you always lose with the dominator on ls3 heads. Even the super victor is no good, proven over and over again. LS3 will beat the crap out of any cathedral port any day under the same criteria ( maybe not in a tow truck). Same performance level, same valves, same camshaft and equal compression. And FYI the hydraulic lifter loose 5-10thou also, not sure about the short travel.

[@riggedandjimmiedgarage7268]

​@RoyOlsen-mm4fm I disagree with rec port vs cathedral port. Tony Mamo and Brian Tooley will also disagree as they stated many times on LS1TECH for the past 15 plus yrs. The vic jr is one of the worst cathedral port intakes made. I'd personally use a holley split on the cathedrals.

[@WeingartnerRacing]

@@RoyOlsen-mm4fmI can tell you 100% from actual testing that formula is not right. Because 2 point in compression did not do that on this Ls. Hell go look at the bbc testing. It didn’t do that either.

[@sl3878]

proven that the 4500 SV is far better than the 4150 SV LS3 , the disparity in compression ratio makes it hard to really evaluate 1 head versus the other also .

[@doolallyproductions7234]

Its really hard to beat the stock ls3 intake and ls3 heads theres a reason why they say the LS3 is the best engine GM ever made and ever will be made

[@moparman2692]

I mean, it actually is easy to beat them when nobody takes advantage of them. Just big lazy ports (mostly why Eric saw nothing with the dominator on them). Ls3 heads really need some rpm and to shine bright.

[@codycopenhaver]

Could there be a test for the ported enforcers vs ported and milled enforcers? To see the difference compression makes. I know that’s a lot to ask but just curious.

[@WeingartnerRacing]

Probably not

[@leighhaberl981]

the bloke on the street is going to like the 243.

[@InnocentMiscreant]

Similar to some BBC oval vs rec port comparisons almost like the large rec port stuff is too big for some combinations

[@WeingartnerRacing]

That one went the other way

[@e85performance]

Can you do a 4150 intake manifold with the HVH dominator adapter, verse a 4500 intake manifold with a 4500 HVH spacer?

[@WeingartnerRacing]

I have done that on the sbc

[@Fatt-billy.racing]

If you need a ls3 4500 intake with out having to use a taper spacer let me know ... or if you want to use a bigger cam

[@WeingartnerRacing]

I do on both

[@CJ5EVOLUTION]

I'm by far an expert, if one carburetor is not working correctly in one head, wouldn't that point you out that the air velocity is low? Do carburetor venturi sizes don't have a direct correlation with carburetor size and what air velocity is needed? If that same cylinder head worked better with a smaller carburetor would be a relationship that points out to the air velocity to be more adecuate thru those smaller venturi, is like the principle of sucking thru a 1" hose and a 1/4" hose, which one will result in a higher velocity? Do the carburetors don't work on the base of air velocity and differential pressure above and below the venturi, at higher velocity more fuel is pulled out and atomized better? I don't understand much of your test cell but, I will guess that only paying attention on your O2 sensors seems to not be telling you the complete story, as I understand it, more velocity more fuel thru the carburetor if these are in balance you will have "X" amount of O2 in your exhaust, then you increase or decrease the jet sizes to obtain your desired O2 ratio. Based in that is needed a working flow meter on top of your carburetor and a working flow meter on your fuel line, then you can accurately understand what is going on. Like I mention I'm far from even be a rookie, but it seems you need more data. With a FI system you tell it what O2 you want to achieve, then you can see how busy your injectors are, then I guess one can understand that if they are not flowing much is because not much air is going thru the engine.

[@WeingartnerRacing]

There are other factors that play a part besides velocity

[@johnzeek4731]

The LS3 head can use more camshaft.

[@WeingartnerRacing]

Watch future videos because I tried that.

[@jasonnash2691]

Hi mate, didn't see whole vid, which cam did you use

[@WeingartnerRacing]

Watch the whole video.

[@ironmike742]

​@@WeingartnerRacingexactly. Nice video sir

[@jasonnash2691]

@@WeingartnerRacing nar, I'll keep watching holdenas vids, least he answers with out being a nob jockey

[@HerrPoopschitz]

@@jasonnash2691🤣

[@ezmny1387]

@@jasonnash2691 all good man, if you cant read that it says "texas speed stage 2 cam" on every sheet you have no business doing anything to an engine anyway

[@GaryWhipple-q6w]

The 243probably alot better street able head

[@drcolster]

Good testing... But i don't think i saw the Valve Sizes for the 243 Cathedral heads...??

[@WeingartnerRacing]

2.02/1.55

[@drcolster]

@@WeingartnerRacing Thanks.. i have LS1 cathedral heads.. the C4B ones done by Callaway for the 300kw engines, used in our Aussie HSV cars... Have you Flowed any C4B Callaway heads, they are cnc ported...???

[@jmflournoy386]

Nice but I think .050 and ,100 matter on running motor cheers

[@mcintyretyler89]

🫡

[@faustthehammer8706]

Torque wins in 1/8 or 1/4 mile that little bit of hp won't win of launched same ask buick

[@myrondel]

Eric, I did realize you have a Dynamometer, how come you don't show us the runs? There's nothing like listening to horsepower, it keeps thing real.

[@WeingartnerRacing]

I show dyno runs in the video.