Great News Eric !!!! I was fairly confident there was a dyno issue but validation and relief is a good feeling !! Keep up the good work man, your honesty is a good thing.👍

Youve said it before, and it does ring true; the engine wants what the engine wants. Dynos, flow benches are just an indicator of its potential, track time as this shows was ultimately the deciding factor. Keep the good working coming.

THE TRACK DONT LIE

I was one that suggested your troubles were closer to the cam than anything else you were thinking, in your video. I said that the smallest changes can make the largest difference, when you are already at the best possible range for the particular engine. Several others suggested a different Dyno, but i was trusting that you use the same dyno every time. The best verifications come from repeatability. When the equipment you trust for that has trouble, it can throw everything into a whirlwind. I'm glad the owner took it as it was, and ran it. That is where it counts the most. It proved that you knew it could be better than it showed. Good job, and thanks for sharing.

I run a 251/251 @.050, .60/.60 lift, 105 LSA low-lash solid roller in my 406 in the street/roadcourse car. Max HP is at about 6200. That new cam is NOT too big. BTW, Vizard spec'd the cam for me years ago based on all of the details of the engine and the car/use.

Your findings actually make sense. There is a myth online about larger heads and cams that garnered a following. Keep up the good work.👍

Dyno tuning is a tool Much like boost,it’s just a number You rock man

dude you are one of the most informative guy,s i have followed Eric much respect to you budd ,,, i watch and listen to all you say and do ,,, glad i have found you long ago and enjoy all of your stuff that you talk about ,,, keep up the great work ,,, i am big time fan !!! tony

That Driveline is killing him 😳 you're right about the Dyno and it's great to see your face for once Eric 🤣👍

Hi Eric, I built engines and run the Dyno for Russell Baker in the mid 80’s. I am sure you at least know the name. Given the numbers the dyno produced I would be inclined to believe that for one reason or another you were not getting full throttle. That is the only plausible explanation that can be concluded. By the way I am one of several I am certain that suggested putting the engine in the truck before condemning it. I’m glad to see that the build ultimately worked out. Best regards, David

Eric , if the Water Brake Absorber's "rotation limiter" is bottomed-out , then it will show you Low Torque , but correct HP "after" its not bottomed-out as RPMs increase and Torque decreases . Water Brake Absorbers have this "rotation limiter" feature incase the Strain Gauge bolt breakes during a Dyno test , to prevent the Absorber from instantly rotating with the Engine RPM

The cam making power at 7800 points to something being off in the dyno calibration and software. I've seen guys with similar cubic inches running 260° plus on the intake to make 750 to 800hp

. . It just sucks when your point of reference gets a speed bump of the unknown, although very exciting it is still a ton of fun watching you figure it out, until it happens to one of us maybe! Best intentions, bless you and your wheels and work you make the world turn.

I never had a SBC any where close to this power level, and may never get one. But I met a guy known in the Hi-Po world who told me something I never forgot. An engine doesn't know what size it is, what brand it is, what kind of parts it has, if it has a power adder installed, what kind of air or fuel was intended or actually used, what planet it's on, or what the builder promised power wise, ect..ect...ect With that said, this engine liked what you did...the track numbers...in that kind of vehicle...proved it...hands down. Good job, I want one...how much. The guy mentioned...Jim Kinsler, Kinsler Fuel Injection...1984.

You just made an excellent argument for having a port size that only flows up to max cam lift and gains little flow above that lift. Glad to see you were right, that the dyno was off and not the engine.

Nearly watched all your videos now, love your content and glad you got to the bottom of it 👍 Track doesn’t lie

In high school in the early 90s I had a 406 CID SBC in my second gen 70 Camaro, Victor Jr and holly 750 DP, along with a TH-400 with a 3400 stall and factory 12 bolt, with 3.73 and later on 4.11s with aftermarket Lakewood traction bars. Your findings are pretty close to my experiences, with one exception, RPM! I had bought the motor from a stock car racer as a short block , it was their spare motor! Zero decked, cast crank with forged rods and pistons, It had a rumbling solid Isky cam! With 53 cc heads the compression was 14:1! That was too much so I used some 462/64 cc camel hump heads that were gently messaged...big 2.02 valves and such! The motor was a beast specially with a 150 shot of nitro's! I never revved it past 5500 RPM and it stayed in one piece! If I had to guess I'd say 550 HP with close to 350/400 HP at the wheels! It ran what I assumed were low 12 seconds on gooey tires with street treads cut into them! Never overheated or left me stranded, although one time the accelerator cable stuck at full RPM, that was interesting! Yeah this thing left a lot of tire lines when launching! Never really had good traction! I never took it to the track since they never liked my roll cage! So I don't know but it was a fun ride! … 406's are awesome combos!

I ran my 365” Chevy on my buddy’s Super Flow as a new build. The numbers were extremely high to me, I kept saying so. He said everything is correct I promise. In the end he called me a week later and told me after calibration again and again it kept changing. It turned out the load cell was bad, I went back after he swapped that out and the numbers were exactly what I thought. Sometimes shit happens 🤷🏻‍♂️

Thanks for sharing your knowledge and experience

You dive into information and data that no one, I mean no one else shares! Thank you!

Eric, I've been doing my work 21 years now. About 11 years ago I stopped questioning myself and stuck to my guns. When you know your shit you know your shit, and you can't let anyone bother you when they say different. You did good man that's all....you did good.

I am very happy for you Mr Eric. Excellent outcome. Your hunch the dyno read incorect is very likely. But until that engine as is goes to another dyno for varification and another smaller intake is tried back to back. We won't really know for sure. The most important thing is the customer has a very fast truck.

This is great news, glad the dyno was misleading and your hardwork paid off in the end. Do more videos of the restricted circle track stuff! How to make the most of the small amount of airflow.

That makes such sense! The dyno must need calibrated or is just off. Thanks for the great info!

Awesome job.. Can't wait to dyno my engine with those 10x heads 💪🇺🇸

Glad to hear you have this sorted out! I was in the camp of the cam was to small.....that tells you how far off I was

Love this video man for two reasons. One is so many people get caught up in numbers they may not realize that they already have a neck snapping drag car. Secondly to all the people that say dynos don’t lie well.....top off water to to the dyno brake also I would seriously consider checking the return line for obstructions.

Man that’s great news! It has to be a relief

We race vehicles not dynos. Glad it worked out

Hell ya , i had a feeling thats what would happen … glad u made this video ! Have watched alot of your videos over the last year , but after that dyno video , i had to subscribe … i had to know what the problem was or what the outcome was at the track . The only thing that seemed overly radical about that motor , based off of what else ive learned from you and other engine builders , along with some personal experience was how high that thing wanted to rev and still be climbing in power like it was . That duration is very similar to whats in my blower motor and its only 385”. You can feel power start to fall off around 7800 . Usually when you add cubic inches to a given duration , it will make peak power a little earlier in the rpm range . Before that video , i would have expected power to be all in by 7400-7500 area based off of other solid rollers i have had im my 380” sbc that has grown to 385” over the years . One thing i wasnt sure about though , was how much the bigger bore of the 406 would help carry the useable rpm range since the valves arent as shrouded , if that even makes a difference at all . Those were some impressive results for a 1st track outing w/ the revised combo , nice job !!! Imagine how good that motor would run if it was in a 3000lb car with a better chassis instead a mostly stock chassis that just has a cage !!!

I didn’t comment on it before but when I heard it running on the dyno it did sound like it was running a little less RPM than what the dyno was showing, but I’m glad the truck picked up! My 4500 pound truck traps 110 when I lock the converter, it’s just a 383 with a lunati solid roller and afr 210s, only running mid 12s with a bad 60ft, all on the street

Glad you got some closure Eric 👍🏻 The peak rpm shifting from 6800 to 7800+ is incredible for seemingly small changes. I wonder if that's way off too

So glad for you that it ran great numbers at the track. Certainly points to a dyno issue on the day. It's a damn shame that despite your efforts to get it on another dyno on that day, it didn't happen. I suspect that a lot of us viewers will be joining you and wondering what the real numbers actually were. I'm certainly one that that overlooked a couple of points that you made, including the cam doctor tests, and commented on the camshaft exhaust timing. My apologies to you for doing so.. Thanks very much for the video and updating us all on how it went. Regards Greg

I used to do some machining for a local guy. He sold a lot of intake manifolds out around indianapolis. These manifolds were for some kind of class where you had to run a stock manifold. He had me bore out the 4 holes where the carburetor fits on but I would bore them off center so it didnt make them thinner on the edges. Then he would put acid in them and eat out the ports a little but they still looked stock.

I just commented on the first vid and missed that this was back in time a little. Ideally :) knowing what you know with data gathered, it would be nice to dyno again on 2 dynos. I know, PITA and I am more talking about the puzzle instead of the result. Thanks for great vids and especially this kind of info...

Holy crap it picked up A LOT! Great work.

Racetrack is the final word ! Rest is just reference numbers .

It's painfully obvious that the truck didn't lose torque AT THE WHEELS where it matters because he made such a large gear change! The ring and pinion is a torque MULTIPLER. You have to know this, Eric. Put the other ring and pinion back in it and watch it run mid 11's again! Because he dropped the gear, the torque loss was insignificant and the truck was able to accelerate into the power band much quicker. Not only that, but he raised the shift points.

The customer should be very pleased with that much gain in the 1/4. That is no joke.

Eric, I am so happy! Blair Patrick’s EMC win with factory 352 Heads beat all vintage engines including the 427 Chevy, and I believe the same thing! Rev it until you can’t get anymore! I have been a believer for many years ! Ford and Chevy played to their strengths, and they laid the platter and you turned it into the truth . The SBC and FE were done before smog! Any irony there?

Thanks Eric! Enjoyed the video!

I'm glad it worked out... You are right if it had lost 100ftlbs.. it wouldn't have ran anywhere close to the number it did... Good job.. I know you will sleep better now..

Go Eric,I had the same thoughts when I seen the results. When one power is higher the other follows.

Hey eric been kinda watching for a bit and in enid janes machine is where i go for anything engine related and ive worked with the guy and he is just amazing to work with and knows his crap

Don't be too hard on yourself. You have a great channel. I was stumped because 100fp is huge. All I could think of was the dyno was off. Keep up the good work.

I watched the whole thing the setup was right on brother

Hey good video. I am certainly glad you didn’t change the combo before testing again. I thot you had a sound combination with the chages you had made and it was goin against everything I had ever learned that it would make less torque and power in the midrange like it did.

Nice video. Hope we can see some more results from the truck as he plays with it over the summer .And what changes RPM , shift points , ect

I am so glade to hear sweet redemption

That's why we don't race dynos...

People say dynos don’t lie. That is completely incorrect. The track doesn’t lie. Weird things happen on the dyno. It’s an educated guess made by software. This is an excellent learning experience for all of us. I’m glad you didn’t change anything before it was ran down the strip. Dyno sheets don’t win drag races, and chrome don’t get you home.

Thats the heck of a gain in ET. I run 11.30s with a factory grind Max Wedge cam . I hope I gain even half as much with my new cam this year.

All along, listening to to you defend your point, i was thinking to myself, can you get VE data? From the dyno? Then you revealed your somewhat secret porting of the short side, added that up with the smaller port compared to that LS head, and wham!, i bet the VE was well over 100% in the mid rpm range towards the top end!

You do not gain half a second with a dud engine. Well done. Good build

Congrats Eric , i calculate 103.85 HP gain from your ET Slip Data

Dragstrip is the real dyno. Great job

With the cam, is it duration that would make a cam too large or area under the curve (combo of lift and duration)? From what I've read in looking at cams for my new 434, you can get away with less duration if you increase the lift of a cam and still achieve peak power at the same rpm. -Mike Proctor

that's the answer to every engine problem out there, the carb is to big or the cam is to big. i run a 396 in my 67 El Camino i run a .590 lift soild and a 850 Holley i tried a 750 and the car slowed down 2 tenths. i worked for service center back in the day, we were told by crane and Holley to under size everything because of come backs. if you look at Holley carb selector they tell you to use a 600 on a mildly built 350 that should be running a 750. so everyone thinks smaller is better. not true by any stretch of the imagination. thanks for the update snd your videos, Eric.

Big fan, glad you waited for the track numbers. Could be a dyno glitch, but I find it hard to believe the old 406 could only make 110 mph with 660 hp @ 3900 lbs with a 4.10 gear. 10.9 @ 119 mph with 700 hp is believable.

Great to hear.👍🏼 I get dyno uses and flow benches. They are great tools, nothing but tools. Race track is reality. Not to sound like I knew but I suspected the readings were wrong. As much as you checked things and your experience I figured your part was OK. 100 ft lbs is HUGE. It would have had to had a dead hole and never made that HP number imho to be that far off. That is Error Will Robinson size. 😁

I was taught to make the port on the head larger than the port on the intake manafold just by the scribe lines.

Them dynos will make every good builder question what they know is right. 10.9 in a full size c10 is fast! Good job on that engine!

That truck is now fast!

So the dyno numbers were paid for and wrong but the free ideas based off of the bad information get taken to the woodshed. Glad that engine was a positive at the track. Disappointing to listen to people’s free ideas and comments take a beating. When it comes to teaching and learning the appropriate approaches for the various mindsets are likely too subjective to make everyone comfortable. This one just stepped out there in a fashion that simply took more than it gave. Then I see a piece of clay molded to a port that was engineered to have fuel and air carried through it compared to a dry port? I don’t expect perfection out of anyone. No doubt I have benefitted from the information E.W. has given us for free. I’m just not willing to remain silent on the fact that everyone else’s comments are in fact free inputs. May have not taken near the effort as a video, but the chances to learn from other’s comments is still there none the less. Maybe we don’t do that.

The throttle wasn't opening up all the way on that bad dyno run. The same thing happened on one pull with my 406 that just came off of the dyno. The throttle rod that connected to the carb was slipping and the bracket attaching it to the carb wasn't right. Really good numbers.

Well seems like I need a bigger cam. My cam is similar to the old cam. Nice video lots of info. Valve cover gaskets those look like really thick cork is that a better choice than rubber

Been there... that's why I brought up the load cell on the Dyno..... I never hear back on comments...but I digress....

I got to thinking about this. My theory is, you changed the resonant properties of the port and runner. Just like a subwoofer when you put your hand near the end of the port. A speaker has a simple straight port. Well, the engine has some other stuff going on. When you rev the engine, does the tonal character change at a certain RPM?

Glad it went faster on track.

What was the exhaust set up in the truck compared to the dyno headers?

MPH is all i care about and if he picked up 9mph thats huge considering a truck is a sheet of plywood aerodynamically. That dyno was having issues.

Love your intensity to find an answer to, "why"! Only one way to test if the dyno theory is correct. Or there is a different answer for 100ft/lb loss. Put it on the dyno again. I know if I was you, I would want to know if there is a possibility of a higher learning to be gained from the spec of that engine.

thats dreat news, cheers from Calgary.

You are going to have to keep us informed as he creeps up on the rpms...lol. Your heads are doing great .

I knew that engine sounded like a beast on the 1st video. Great power gain to add 9 MPH. As far as people thinking the cam was too big there's no way. The duration at .050 is not that high for drag racing. Running 10's in a full size truck that's pretty damn heavy with a n/a small block is stout.

Did he attempt any runs at the old shift points to compare the E.T. & MPH directly to the prior setup?

I would.say that from what you said, not changing the port size. But doing the changes you made should increase hp and torque. From what I have seen. New dynos also work different than the Olds hood brake dynos.

Can dyno's be calibrated? If so do these speed shops follow a some kind of maintnance and calibration schedule?

That's crazy that Dyno wasn't working correctly and the engine was actually faster now I am curious if you go Dyno to Dyno just a thought would the hp and torque ratings being different just a thought

Can you tell us what the loss is between engine dyno to wheel I have seen engines lose 100 hp so if it dynoed 600 it put down 491 wheel with accessories

a good cam solid roller by erson was 296/308 108 lobe seperation 680 lift 4500 to 7500 would leave at 3500 good and shifted at 7000

I knew the dyno had an issue. My 86 Corvette has an all 4340 forged 420ci 11.3:1 AFR 210 cc rr, solid roller 249 249 .650 .650 and only dynoed 350hp 350tq at the tires through an unlocked 700r4... it race an untuned minirammed setup and went 11.25 @ 122.04... I think the dyno was messed up that day too.

On the 2 barrel engine find out where the carburetor location is the best, Foward to Back location ? Thank You Sir 👍🏁👍

That's funny. My time slip is exactly the same 60ft and 1/8 mile(1/8 track). 3650/3700 race weight 98 T/A 418 lsx 4.1 stroke. Shifting at 7200 rpm. 4.11's stock gmpp ls3 ported heads. Smaller cam Hyd LT 235/250 620/600 113+5. 3600 Yank. Didn't try shifting at 7400 but wish i had, It loved to rev more than it should have.

I was thinking that there was a compression loss. Redoing the valve seats sinks the valves a bit. Larger cam. All contribute to lower compression. Combine this with the intake manifold change. All contributed to lower torque.

I mentioned in the last vid, i could hear the rpm was reading high. That was not a sbc at 7800, just didn’t have the ring to it

Even Richard Holdener said the duration is what you have to be wary of.

The 50TQ could've been lost going to the larger camshaft, which may have required a higher static compression than the previous camshaft. The track ET's are due to the increased HP number. I'd still check that 406 on another dyno to make sure it was the previous dyno and we didn't lose 50 TQ and "only" making 500tq on a 406ci motor.

truck liked the torque loss sometimes traction means slower 60 but better et hp keeps her moving obviously.

This is why 99% of us are shadetree armchairs and you get paid for it.

I had a ergeument with a friend of mine about cutting the top of the port do the floor of the port gravity pulls the mixture to the bottom of the port can't beat gravity.

He's got an exhaust system on this thing? Richard Holdener lost 50 ft-lb by not having collector extensions after the header on a similar size/power motor.

excellent !

I think the Dyno was set to step 700 RPM/second (about 5 seconds from 4500-7800 RPM) as seen on the original post around 20:18. I think if the step rate was 300 RPM/second (about 11 second pull), the absorber would have loaded the engine more resulting in higher torque (and HP) numbers?

248 @ 0 050 is big in a 406? I've ran 270 @ 0.050 on a 461 that never turned over 6000 rpm and it was all I could do to keep it off the bumper before wheelie bars.

2006 Silverado 1500 X Cab with me in it is 5280Lbs.

I think that you proved what Bill Jenkins did, this revolution of stroker cranks vs RPMs. The more rpm’s of a given engine will make more work done. It’s physics, regardless of the ratio of bore and stroke or the torque to hp, you have to rev the engine to the point that it has to rev. Focused torque is for towing, rpm’s is for racing. I have built 390FE engines based on 427s and went to 7500 rpm s it was a monster compared to a stroker that could not get up to 7500 rpm and I walked them. Why would 50 cubes less walk a car the same weight, my car screams, theirs blubbers. The engine has to turn and make the same power to run the same. Torque is a factor, but I don’t think it is the most efficient way to go down the track.

Less torque can result to lower E.T while more top end power gives faster trap speed. If your engine makes more torque off the line that your trans and torque converter can handle, you cook your driveline before you get to the 60 ft mark. this doesn't necessarily kill the run completely, you just put less power to the track. Now, when your torque level stays inside the parameters of the driveline, you will have more power put to the track throughout the run. Simply because you didn't cook your TC and tranny @ the launch. The engine sounded just like the graph showed, so I don't believe that the dyno was at fault.

MPH doesn't lie

im here like i feel like a teacher is yelling at me .. then i remember.. jokes just having a dig... cant wait for c10 better get all the cameras going going to be mint