TESTED-SBC ADJUSTABLE CAM TIMING 

This channel is pure engine building gold...

I clicked for the Bonus Muff Test 😼

A nice super easy trick to find out the proper length collector extension on "YOUR Engine" meaning anyone's engine in there car or truck by installing a 24" length collector extension on each header , then paint the collector with a engine paint 800degF. not exhaust header paint 2200degF. let it dry, it does not have to be a perfect paint job at all then once it dries. take it for 1 hard run "Think Dyno Pull" then look for the worse burnt paint spot on extensions and cut pipe there. That should be "YOUR ENGINES" optimum collector length for what your engine wants

You're a BEAST !! Richard !! Thank you for educating me !!

Another great test, thanks Richard. I know that many of these tests are older ones but they are just as important today as ever and I for one appreciate you putting them up here. They answer so many questions that we cannot resolve because we don't have the resources and time to do. The combinations you are using are very good and do apply to the vast majority of us and the results for other combinations can usually be figured out from here.

This is the best engines channel ever -- pay-per-view or free RU-vid. Such amazing content. I hope your business model holds up.

Good info as always! Around 1990 I raced (street/strip) a '73 340 Duster with a purple shaft mild hydraulic cam with the '73 smaller heads. The gear was a 3.55 posi and 3,200 stahl. I advanced the cam 4 degrees and picked up a full tenth. As for exhaust, I always ran a "too long" 2 foot 3 1/2" collector off the street headers. The car always had good torque for a small motor plus made it sound like a big block. Can't remember how many times someone would say "you running a 440?" The car ran 12.90 in the quarter as described here plus I could drive it to the strip easily. Always a blast picking up an impromptu race to or from the strip which was always a surprise to the other guy.

Great to actually do the real testing on the Dyno. Great job

As always, Great usable info. I appreciate your testing & the data it produces. Thanks. Stay Real.

Thanks Richard, this is my favourite channel, from NZ.

Great information. You are correct about the muffler being a collector extension. Been there and figured it out.

The removing the muffler test may apply at the drag strip however to fix that behavior, one could add pipe. Also, on street cars, it probably wouldn't apply at all. One test I would love to see is a muffler shoot out. Glass packs, stock exhaust, anything popular.

This was insightful. Thanks Richard. Better late than never. 😎

Always wondered whether the chain wear on my engine had any effect on the power curve, now i'll know. Great info, thanks.

That's what cut outs are for. I did this in the 70's come out of the hole and open the cut outs at 3800rpm. Try it you'll like it. I was supprised to see no gain at all on the top though. We didn't have access to an engine dyno back then so it was kinda hit and miss and hard to get those fine adjustments that normally can show up anyway in road conditions and human error. This was nice to see proven on a dyno.

Becoming my favorite channel!!!

Another great video. I always assumed they built in a few degrees of advance so when people inevitably buy a bigger cam than they need it won’t be too soggy down low

Great videos ! I was only thinking about this yesterday !!

Thanks Richard, very interesting and helpful.

Best channel ever.......

Captain Richard The Dyno King !!!

I love this guy!

Great video

Good info Richard.

An old timers exhaust trick I’ve heard is to spray paint the pipes and run the motor nice and hot, and let some of the paint burn off. The point on the pipes where the paint stops burning is where to cut for best results

A good muffler will act as a collector extension like you stated, and help even exhaust pulse and help low speed overlap scavenging.

Years ago I knew a guy with a 440 torqueflite Challenger. Perennial bracket race champ. Then one year he tried a set of Hooker adjustable headers. It took 15 passes and subsequent primary/ collector length changes just to get it to ET as good as before the change.

Great test.

Awesome video, I have three questions 1st are those 600s vacuum secondaries or manual 2nd what size jetting did you end up with and 3rd what was the overall timing...love the videos, learning gobs and gobs keep it up

I'm building this exact engine except it's a stroker 383 with rpm air gap and 286hr magnum cam. I'm questioning my cam choice though. Should I get an xr282hr or xr288hr instead? Don't care about vacuum and have 4.11 gears. Don't want to rev past 6,200. Love the videos. You have the most specific details I have found on RU-vid.

A lot of sport bikes have a butterfly valve in the exhaust for torque production, just like Richard showed in this dyno graph at about 4,100 RPM.

I don't understand how you only have 84,000 subscribers when you have by far the most informative awesome information I've ever seen on RU-vid and then you have that giraffe in Florida running around doing all kinds of stupid s*** and he has millions of subscribers. But it's okay that's why the ugly car with $2,000 will whoop up on the $40,000 Corvette. because we have your information and know what works.

Do a 180 degree header test!! Vids are great

With bikes, I've seen that the more radical the cam the greater the difference with small changes in its timing

Another guys test could be something with duel overhead cams and adjust them independently. Keep up the good work.

That was so interesting about cam timing. My son who is 18 was just asking me about it yesturday while he is helping rebuild a 1961 SBC. . I'm going to show him this. What about using exhaust cutouts opening up after 4000 RPM that could work.... Keep testing.

Have you ever tested reverse cone megaphones from someone like burns stainless

👍🔔 WOW 5:00 This is the first time that I have heard anyone doing cam degreeing mention CHAIN STRETCH/ wear... 👍👍👍😎😎

Like a slippy pipe in a 2 stroke race kart, a cable operated length adjustment gave it another 1000 rpm up top on a little 100cc Yamaha. Couple inches of travel if I remember correctly

Hmm... U go to a hockey game and end up watching a wrestling match...interesting.. 🤣🤣🤣 came here for the cam knowledge and recieved exhaust flow info..

Buell bikes have a butterfly in the stock muffler that change the pipe length internally and it makes a big difference between 2-3000. We get a bunch come in for a tune where people disable them because the internet said it's a restriction.. Sadly most people mod without asking what actually works.

Oh yeah, I gotta watch this! We always went faster after drilling 1" holes in the mufflers.

I’m guessing an X Or H pipe would negate the muffler effect since that becomes the starting point for the negative pressure wave. Thumbs up for yet another great splainer vid!

Pro stock engines are running really short headers with a collector that looks like a funnel. The difference is a 10,000 rpm engine instead of 6,000. What I found with header length is it's not necessarily HP level to size a header, but mostly rpm range.

R.H. ..........new a stocker guy, H/SA with a Varicam back in the seventies it worked !!!!!!

I saw a variable timing setup on an older style Chevy in the engine masters competition was this a one off or something that just didn't catch on

Now You gotta set up an engine with variable intake and exhaust lengths that adjust with rpm use cut outs and varied length pipes on the exhaust and solenoid actuators on the intake stacks

looks like a 2 bolt main street motor would like advance. thanks mr. holdener

Richard, I have a older 350 and am thinking of going with the Edelbrock package of heads manifold and such, I was looking at the 400 plus hp version, have you had good luck with installing these heads out of the box Thanks

Electronically controlled electric, exhaust cut out, at 4200. Thanks for the tip. Great, great show.

I'm a simple man. I see tunnel ram, I click 👍

love tunnel rams

So you wanna build that collector extension with a pair of actuators and a throttle position sensor?

I'm curious what happens if you add a 90 off the collectors. Does it act like adding serval feet of exhaust?

I would like to see a comparison between putting zoomie headers vs all other kinds. Because it seems like there would be a loss in power going zoomies but thats what they use on nitro funny cars. thanks for all the good content Richard!

Well matching everything, carb, headers, cam, heads, gas, compression. My 383 loved a 750 carb, 1.75 primary tubes, high rise dowel plain with retarded timming. We did the 600,650, 1.625 tubes, single ,dowel intakes, advanced, retarded timming. And found the sweet all around spot, 650 hp, 670 torque. Know custom cnc,heads,intake, custom carb, we do not know what to expect. Great vid seeing what was what is always great instead of what if,cause what if can get expensive.

Have you ever run a dyno test on true roller vs gear drive vs belt? And if any was the power loss'/gain negligible?

Your idea on adjustable/tunable exhaust length. What about a remote exhaust cutout installed in between? Wonder if that’d do the trick?

Could you use an electric exhaust cutout that opens at a certain rpm to ‘shorten’ the exhaust runner length and pickup high end power

Right on

As a young man in the 80s, everyone who installed a cam complained about killing low end torque. We were all shoving cams in low compression engines and it really sucked it you picked a cam from the mild of the page. I always wondered if we could have made up some torque by advancing the the cam.

4-2-1 headers were a beast on 440 magnum

Any thoughts on trying the newer 4.3 the LS based one? Should be a pretty stout piece

hey Richard try that old motorcycle tuner's trick where you put on a length of pipe, spraypaint a line on it, run the engine for 10 mins and then cut the pipe off where the paint stops burning off.. that trick has never failed to work for me on naturally aspirated engines

Very cool test. It would also be fun to see a collector length study. Same engine, same headers, but with 0", 6", 12", 18", and 24" extensions.

Richard is this curve pretty much the same regardless of LSA or is the curve more tilted depending the LSA ?I see that with this cam not much was lost at lower rpm, the noticiable gains and loses are at the last upper rpm of the curve.

Backing off - the cam timing is the way to go IMO The more compression you have the more you can rewind the cam without hurting the low end that much. My combo, lq4 with LS3 flat tops, stock 706 heads and a 220/224 115 -4 119 ICL custom comp cam

Personally I blame squirrels

Ok, so what about running a couple pneumatic actuated cut out valves before the muffler? Set them to trigger at 4 grand?

I forget which race car it was on, but Porsche used sliding intake stacks once to optimize their power @ RPM. Cool stuff.

I really want to see some side by side comparisons of VVT LS cams vs. cams with the same specs that are fixed. Texas speed offers several VVT grinds. The web is full of mixed opinions on VVT. Would love to see some actual testing!

I would like to see a comparison of a degreed cam vs a non degreed cam🤔

Couldn’t you use a electronic exhaust cutout before the muffler and then have a holley ecu open the cut out at the crossover rpm point in the curve where the shorter exhaust starts to make more power

RPM activated exhaust cutouts.

What about those switches that switch from Muffler to open you could maybe leave the muffler connected for the first 3000 RPM and then open it up at 4000 and see what the difference would be

I seen a video of a sliding exhaust setup on a small 2 stroke race boat. Was a 2 cylinder and they picked up 10MPH if I remember right.

I saw you last night on “Fastest car”.

Be cool to see a test of some electric cutouts on a rpm switch

Use the standard equation to calculate header length. 45" primaries really pick up low end. Zooomies are the right length for a high rpm drag engine. Adjustable collectors are available. AS Vizard says you will not lose hp with the right muffler. Try no header at all . Straight from the head. Amazing what that does.

how cool would it be to use your idea of sliding exhaust with vvt timed in sync to take advantage of it.

Race outbourd motors and some race karts have adjustable headers.

i'm not only running mufflers and a full exhaust but it would be interesting to see what difference a larger wastegate would make. i'm running dual 60mm gates.

The muffler did exactly what I tought it would

Was it a Flowmaster, i found they killed my car, was almost .1 faster with a bullet type and little shorter pipes, but i did always run extensions

I was surprised that removing the muffler effected the low rpm torque that much. Have you ever tested an exhaust system with headers, a crossover on the header pipes (no mufflers) and a side exit similar to what NASCAR uses?

what difference do you think there would be with mufflers on a twin turbo setup using 3inch magnaflows per side but with the length on a twin setup??

It's just not easy to screw up a SBC.

While removing a header attached muffler has the effect (shown in the video), on a street car where the muffler is further back in the exhaust stream, is that effect as dramatic?

Richard, do you think a single 3" exhaust with a Y pipe would be a substantial restriction on a typical cammed street LS making 500-550 crank? Or would it be more about the type of muffler being used?

I wonder if one can program a butterfly valve to open the exhaust around it's sweet spot to further fine tune an engine

Run a nitrous controller to pair of electric dumps?

Any interest in doing a terminator x test? How close is the base map and maybe some pointers on getting a boosted motor in the ballpark using the initial start up

hey Richard do you have any data on the 454ho cam testing from the super chevy article? They used the extreme energy grinds from 268-284 and with the 274 the 454 made 507 horsepower which is the cam i have in my 454 along with oval port speedmaster heads and i just saw on hot rod garage they built a 454 with a similar cam only a roller marine xm284hr-12 with rectangular 320cc speedmaster heads and it only made 472 HP. I was just wondering if you would be able to explain why the power difference is so great? I would have thought a roller cam with the same lift and duration numbers would make more HP not less? Are marines cams just that different? or were the 320 heads a little too big for a 454? maybe just tuning? and in the hot rod garage episode they even used a single plane and in super chevy they used a dual plane.Was just really curious about the power differences another thing i was shocked about was the low torque numbers too it only made 470 thanks!!!

I have and love your honda books. Which do you like better vtec or ivtec? My 2013 Si has a K24Z7 ivtec. Both cams have vtc from the factory so duration is changed but lift is fixed I assume. It's amazing what you can do with optimizing the whole powerband. Which version do you think could make more power regular hi/lo cam vtec or performance tuned ivtec?

Richard, I am extremely interested in your opinion on an issue I'm presently faced with. I'm assembling a 383 sbc for my daily driven 4x4 truck. 5.7" rods, 24cc dish D-cup pistons, AFR 190 Vortec heads. Truck will retain the factory Vortec intake with upgraded 36lb injectors, and a ported throttle body(76mm). I'm having a custom ground hydraulic roller made for this engine. I've pretty much settled on these lobes... 266°/266° 210°/214° .505"/.495" I'm still torn between 110 or 112 lsa because IVC point is my main concern. Simulations show that my best torque curve is produced with a 56-58° IVC event. The catch is that I want this truck to run happily on 87 octane fuel. My static compression will be right at 9.0:1. When I advance the intake events to attain the best low to midrange torque and throttle response, I end up with a dynamic compression ratio in the 7.6-7.8 range. I'm concerned that I will have to pull so much timing to avoid detonation that it won't be worth the effort to run the advanced cam timing. Ultimately, my question is which has greater effect on torque production and throttle response in the 2000-3500rpm range......valve event timing or ignition advance?

Always wanted to know how much it changes the curve, thanks.

Richard which intake performed better for LS motor, Brain Tolley or Fast LSXR

Where is the video comparing the tunnel ram to single and dual plane intakes?

You could buy an RPM switch and hook it up to electronic cut outs maybe?

Advancing the timing is prop what Im going to do after checking Piston to valve clearances. What happens to compression ratio when you advance the camshaft 4 degrees?