How Much Power Can We Squeeze Out of GM’s Tiniest 4.8L LS?

[@curtmeyer4894]

Round of applause for that little 200k mile engine turning 7200rpm and not coughing up a rod... Well done little guy...Well done indeed!! 😅

[@hemmingsmotornews]

Go get'er 4.8!

[@87Aquarian]

I saw 7,500! What a champ!

[@kskip4242]

​@@mewrongwayKOCXFthe Chevy LS is extremely close to the architecture of a 351 Windsor Ford I hate to tell you.

[@kskip4242]

@@mewrongwayKOCXF the Flathead Ford is nothing like the d-series GM V8 lol 😆 the ls was originally designed for Ford and was supposed to be used by Ford but Ford didn't want to use it so they went ahead with their plans to use their modular V8. All the information is there if you do the research. The ls nothing more than a modernized 351 Windsor. Also you're trying to say that GM is the one in the lead when Ford was making dual overhead cam V8s way before GM ever thought to. Hence V8 tank engines.. GM decided to stick with the pushrod V8 so yeah. You're telling me in LS V8 is more technologically advanced than a Coyote 5.0? Look I like all cars it doesn't matter to me but you just sit there and act like ford is just trying to copy GM is just silly dude. If you don't like Fords that's fine but don't sit there and make up stupid shit.

[@mogulme6190]

@@kskip4242technology doesn’t equal better

[@The_R-n-I_Guy]

A 4.8 would be great in an 80s F-Body. Without even doing any big modifications it would be a big improvement over the old 5.0, or even the 5.7 in stock form.

[@FlawleZ31]

Nearly double the horsepower to the ground if you pair it with a manual transmission.

[@swiftxrapid919]

also a 4.8 has a stronger shortblock compared to a sbc

[@teabag402]

Oh it is lovely, my Camaro is so much more fun after the swap

[@tedhamilton2362]

LOVED my 4.8 in my 2003 Silverado. It had good power and got consistent gas mileage. I miss it!

[@robboss1839]

I consistently get shit gas mileage around 10 mpg, but my truck has a booty setup. Other than the mpg complaint the 4.8 is mechanical sound and stupid reliable.

[@Sunspot-19]

@@robboss1839 Around 10 mpg? A classic 427 would do that and produce one hell of a load of stump pulling torque!

[@shadymaint1]

The stock intake manifold you started with is one of the best LS intakes you can get.

[@EvPerk]

No doubt there! It was a runner for sure. Not as good as the LSXR though.

[@itsoundzgood]

I put that intake on my Gen 3 4.8 that has a big cam and 243 heads and it really helped the power band from 3500 and up quite a bit. Definitely noticeable.

[@rustinrodgers5807]

I mean.... that's 100 hp / L out of a pushrod 2V engine. That used to be exclusive domain for DOHC 4V systems, so pretty awesome overall. That RPM range is badass, 7200 RPM!

[@rol1in0n20s]

Since DOHC engines are currently making 125+ HP/L yeah I guess that's to be expected

[@Mastermindyoung14]

​@@adamdodsy84GM is sticking with pushrod V8s. The Corvette might be getting them, but Corvettes had DOHC 30+ years ago as well

[@lucysmith4242]

They didn't rev the engine enough. Power still climbing

[@RealSVTJunkie]

⁠@@Mastermindyoung14yes, you mean that Lotus/MercuryMarine engine put in the mid90’s ZR1 corvette? That engine was a absolute dawg and nothing to write home about

[@Mastermindyoung14]

@@adamdodsy84 so the new pushrod engine they're developing is fake news?

[@Chris-pz4mb]

The whole point of the 4.8 is high RPM & boost. Put a little cam in it and a cheap turbo and let it eat. No issues making 600 whp all day long on them even with high miles.

[@adamscott9725]

200K on the motor, overhaul it with new rings and pistons that bump up the compression ratio. This will add HP and a little bit of torque as well as help with the throttle response.

[@JacksoNR26]

I agree 100% I'd buy a nice set of .030 over keth black or a good name brand piston with a anti frictional skirts chrome moly rings and cylinder hone for it and a set of gen 4 rods that are rod checked for roundness and a set of load/heat resistant bearings any high preformance bearing. Idk my thoughts. And get a set of 10.5 to 1 compression pistons with big valve reliefs like 80 thou or more and run it on 91 octane with that same combo of the heads and manifold and headers and tune I'd bet it pick up a decent more power. Idk I'm a educated enthusiast at joliet junior college automotive who works on cars and I love engines, transmissions and rear ends. Great video guys please keep dynoing engines

[@anthonyseiber]

Why does every other person write the phase ( as well as ? ) Just write well as..... I'm guilty, I'm so guilty as well as others

[@letsdothis9063]

I had a 4.8 in my old work van. That is a tough little motor. I loved it. It was used, abused, and never got regular oil changes. I delivered medical supplies, and (mostly) oxygen tanks. When loaded down in my 2500 express, the suspension and brakes complained a lot more than the motor. Sometimes i would drive more than 2500 miles a week, and she never let me down. I had a dead battery once, but nothing engine related. And, for a big van, that thing had plenty of acceleration. If i was empty, that thing would move.

[@fivespeed3026]

I have a totally stock 4.8 in my Silverado. I love it because it’s still got some grunt and it also gets great gas mileage.

[@robboss1839]

My dad’s 6.2 gets double the mpg of my 4.8

[@fivespeed3026]

@@robboss1839 Surely there are major differences between the two trucks. My 5.3L has a ladder rack with ladders and it gets about 8 mpg.

[@MOE13576]

Cap

[@watajob]

Power increase is impressive but spinning a 200K mile engine to 7500 RPM and it lives?! WOW!

[@hemmingsmotornews]

No kidding! Well-engineered hypereutectic piston, small bore, and short stroke all working in perfect harmony.

[@spartan92296]

474 out of a junkyard suburban engine with 200k on it is very respectable

[@kevindiossi]

The reign of the LS1 has lived on because it’s just such an economical package for both price/performance and package dimensions. Would love to see a tear down and refresh for a boost build.

[@chadkent1241]

Reign of the LS? Which one has gone 5.88 @ 256mph with an almost entirely oe parts engine? None. John Mihovetz has taken the 4.6 4V to that level. Which LS has gone 300.4mph in the standing mile? Zero. A prepped 5.4L Ford GT has. Which LS has won overall Sick Week, Tx2k24, Import vs Domestic with a sleeved oe cast block and heads and oe crank breaking every Drag and drive radial record ever? None. Brett Lasalas Coyote has. The LS has "reigned" on cheap easy builds... but not ultimate performance with oe cast engines. Last note. The one year 4V engined were allowed in the Engine Masters Challenge in 2013, the 4V Fords took a clean sweep on the podium and crying from the GM camp forced a rule change and the 4V aren't allowed now against the pushrod engines. All those extra cubes don't make up for inferior flowing heads. Fact

[@kevindiossi]

@@chadkent1241 that’s great. Brett’s Snot Rocket 1.0 and 2.0 were insane. Still doesn’t change anything that I said from being true. The LS swap reigns supreme because of price/performance and engine package dimensions. At this point, everyone knows the Coyote is a phenomenal engine. But the 4.6 and 5.4 are not ideal swap engines BECAUSE they’re so massive and heavier than an aluminum LS - making them harder to use in some vehicles. Not sure why this provoked a history lesson from you about Ford engines, because it wasn’t a personal attack on Ford engines at all. Just the fact that the LS swap (especially the junkyard truck engines) are still one of the best options to swap into your build.

[@hemmingsmotornews]

The LS in Speed Demon went 400mph. That seems like a pretty impressive number to us. Also, no one hates Ford's here, there's simply no denying the LS's prevalence in the high-performance community.

[@HioSSilver1999]

​@@chadkent1241 shouldnt yours be just as fast if that shit was true

[@ericcook5586]

​@@chadkent1241 can't get a modular motor for a couple hundo..

[@bryanphipps9131]

I see the GOAT Holdner in the background!

[@adamreynolds1851]

Figure probably on hub dyno 300. To the wheels ,would be fun in any around 3k curb

[@jarrodwidiger5472]

A buddy of mine blew up his turbo'd 406 ci LSX, waiting for a new block they threw all the speed parts on a 4.8 sitting around. Made 1048 hp.....for a little while anyway.

[@redlight3932]

theres one common factor at play here

[@jarrodwidiger5472]

@@redlight3932 I know you mentioned that as a dig, but the rebuilt LSX has 15 years at a 1000+ hp tune and daily driven and 4.8 was one of a dozen sitting around he bought for 200 bux. They got several weeks horsing around at 1000 hp on a 4.8 They were fully well aware it wast going to survive and it still lasted longer than anyone guessed.

[@denalidriven1574]

355 stock is impressive for single over head cam push rod that small.

[@kylemilligan752]

Baseline horsepower is about 20hp up on a dozen of Mr Holdener's stock 4.8 dyno baselines

[@bunter6]

Arent all those baselines the same? I'm sure Richard uses the same baseline for all his 4.8's

[@bluecollarhotrods9781]

And Holdener usually tests Gen III engines, This is a Gen IV.

[@hemmingsmotornews]

@@bluecollarhotrods9781 That's correct this is a Gen IV. WAAAAAAAY better manifold than a Gen III so we had a bit of a head start.

[@montanamountainman]

I LOVE my 4.8! I have a 2011 silverado with 247k and still runs strong. They don't have the dreaded afm either. I pull a little 20' camper and does pretty decent. I also have my HD but I prefer driving the 1500 any day. When it finally dies (as long as the block is intact) I'm going to put the e street heads, cam, and possibly intake. Great video. Glad someone else appreciates the 4GREAT. It's a 5.3 with a shorter stroke but with no afm or displacement on demand. Same heads, intake, external components. Crank and rods are the only difference as far as I know

[@hemmingsmotornews]

They are great engines! Glad you liked the video and are enjoying yours.

[@streetfighter398]

Are you still on the orginal transmission?

[@glock22357]

Excellent showing that the PFI/manifold is the best. It always is, but other dyno session videos clearly deliberately skip it completely, or set-up the carb with a ton of other power adders.

[@natricjol]

GM cts-v lifters and a cam with a tighter lsa will go a long way towards making a LS breath at a higher rpm. These intake manifolds like velocity and having some kind of a horn on the throttle helps it breathe better as well.

[@irvingcobian]

This gives the 4.8 in my van some hope. One of these days I'll slap some speed parts on it.

[@hemmingsmotornews]

Sounds like you have a plan!

[@hydrocarbon82]

Go with a Truck Norris, Chopacobra, or Summit 5/4 Nasty cams. They offer great power but huge gains from 2k-4k vs any stage-2 sized cam.

[@sstevocamaro]

The thing is the LS7 is rated 505hp with full accessories, cats, air box, etc. manufacturers test the engines how the engine sits in the car! Many of magazine/youtube engine dyno’s DO NOT give accurate results because they test in gross and not net like the manufacturers do.

[@hemmingsmotornews]

For most racers the traditional 300 RPM per-second-sweep on a water brake dyno is more than sufficient to determine how a component (such as induction or camshaft) affects the power and torque curves. Net or gross doesn't really matter when your goal is to validate if a new part is beneficial for an engine combination. OEM dynos are a whole different animal. They hold the engine at different RPM points for a painfully long duration. The final numbers are actually an average of the engines output during a measured time span across those ranges. Things like catalyst protect, which richness the air/fuel mixture to lower exhaust temperatures at WOT, and other tuning parameters, such as a reduction ignition timing as the engine coolant temperature rises, will actually lower the measured output during an SAE dyno pull, so the final numbers are more like average peak and not true maximum power. That's why we often see stock vehicles make more power than they are rated at on aftermarket dynos. For racing and street performance, we're not looking to produce a product brochure with guaranteed output to go with a new vehicle, but more to find the delta in performance increase between multiple component or tuning variables. Hope that helps explain why we dyno in this fashion.

[@V8RJIM]

Have a 4.8 in a S10 with a small cam, hooker blackheart exhaust manifolds , true dual exhaust with a x pipe, stock intake manifold, and a stock tune. Makes 285 wheel 305 torque. So around 380-390 crank probably. After a tune maybe around 300 wheel.

[@hemmingsmotornews]

That's awesome! I bet that truck is a riot!

[@V8RJIM]

@@hemmingsmotornews it’s pretty sporty when you want it to be

[@kskip4242]

Perfect engine for a G-Body. You can daily Drive the shit out of it and then take it to the racetrack and dial in the chassis and have some G-Body shuffling fun!

[@alphasaiyan5760]

350 hp out of the stock 4.8. That’s pretty damn good considering the stock 5.7 LS1 makes that. Nice video 👍🏼

[@tescoshortage]

100hp/liter out of a 4.8 is pretty incredible!

[@9Apilot]

That would be a pretty rowdy motor. Driveability would be a little rough. The reason why you don’t see more 4.8 builds like this is because of all the other LS motors exist. Those same parts on a 5.3 would have made 500

[@KimiWallrus]

I'd like to see how much the headers add over stock manifolds

[@EvPerk]

Good question! The manifolds are pretty dang good but I’m curious as well.

[@bobhill3941]

I love videos like this❤ taking the smallest V8s and making them make impressive horsepower with basic modifications. I just recently watched a video of the same thing with a 305!😊

[@RANDOMNATION907]

As someone who wants to put a 4.8LS in my Grand Cherokee, I'm more concerned with off idle, and partial throttle torque. Which wasn't covered here. _BUT!_ . . . the bone stock engine had over 300lbs. of torque at only 3000rpm , 1:51 , which is perfect for my intended application. I won't be doing WOT runs, I just need more low end torque than my 4.0L six can make. It costs real money to get over 300lbs of torque out of the 4.0L. The 4.8LS does it right out of the junk yard, stock.

[@troywood7170]

The straight 6 is more a torque monster then you think. Check out Clifford performance.

[@RANDOMNATION907]

@@troywood7170 . . why would I put that kind of money into any engine when I can get the same performance out of a cheap junk yard V8? I've already been thru all of this and done the math. The 4.0L is a DUD of an engine. I get that some people are very defensive of that engine, and I'm fine with the criticism.

[@idahomike3448]

@@RANDOMNATION907 The love comes from the 90's when they added fuel injection to that motor. It made 190hp and 225 pound feet of torque which was really impressive back then. Inside a little CJ or YJ they were more than enough. That and they lasted FOREVER being an I6. However they were a lot less impressive in the Cherokee due to the weight difference especially in the Grand Cherokee, so I can see why you'd want the change. LS swap that thing and don't look back. The 4.8 or the 5.3 are amazing transplant motors and everything you need to to make it easy is right on KZbin. I think if you grab the donor trucks ECU, wire harness, and fuse box that's about all you need. If you want more customization/control Holly makes amazing engine management units for those. In the end you'll make more HP per dollar than dumping money into the 4.0.

[@troywood7170]

@RANDOMNATION907 I can see that in a Cherokee a six may not be enough, i had a 4.2 in a cj and it was a beast. Had

[@troywood7170]

@RANDOMNATION907 had low end like a tractor. In a Cherokee I can see a v8

[@EvanAxer]

now can you do the same thing with the 5.3L ? I would love to see the comparison 4.8 vs 5.3 since those are the 2 most popular available LS engines at the scrap yard.

[@reyperez3424]

The 4.8 loves boost

[@chriscovington11]

I'm pretty sure Richard holdner has a video of that on his page.

[@EvanAxer]

@@chriscovington11 ouu i probably missed that. Just saw his k24 turbo video. Im gunna def check it out. But any LS will make tons of power if you boost them

[@EvanAxer]

@@reyperez3424 all LS loves boost

[@Jihadbearzwithgunz]

4.8 is easier to go for simply cause it never came with the dod and afm garbage I'll take a 4.8 over a 5.3 most days only difference is stroke throw a 5.3 crank in it and watch it

[@vr6prodigy]

I really only have interest in carb stuff for low budget builds. It's cheaper to land a carb than it is a full fuel injection system, but this is proof that carbs work but aren't the best.

[@jtpadventures7189]

Great video. The LS7 was rated at 505 SAE horsepower, that’s all accessories and full exhaust. It would probably put down 560 or 575 on an engine dyno. I’m just sayin’.

[@hemmingsmotornews]

That's fair!

[@brentbaker4463]

not bad for a junkyard stock bottom. Get some compression in it and it would be a little beast !

[@demarques1911]

4.8 is PERFECT for daily driving. Thats the engine you choose for daily driving, fuel economy and comfort .. Put it in your hot rod though? Would be better to opt for 6.0LS or maybe even a hot 383 or BIG BLOCK..

[@alleybuilds5370]

LS1 is the best bang for buck my 2cents or cast iron 6.0. With those two you would have cleared 500HP no problem

[@ericfuller6326]

Dad had a 2000 regular cab sierra with the 4.8 drove it for 17 years. The truck rusted into pieces but that engine ran like a top

[@hendo337]

The best thing to do with a GenIV 4.8, would be cam+springs and a GT45 Sloppy Mechanics Don't B.S. Me build. Otherwise, before I spent for aftermarket heads and a FAST 102, I would probably go to a set of 706/862 heads with the ports touched up, milled from 61.5cc to 58cc instead of 799/243 heads with 64cc and 2" intake valves that arent needed, then thinner headgaskets, like 0.039"-0.027, rather than stock 0.051", really for what aftermarket heads and intakes, expensive cams and shaft rockers cost and if you have accesses to a reasonabibly priced machine shop, either get a 5.3 core engine, or buy a used 5.3 crank, GenIV floating pin 6.098" rods, cheap cast floating pin 3.898" pistons, assemble the engine as an iron 5.7L, then run the original 243/799 heads, TBSS/NBS intake, ebay/amazon SSIII 238/242 or Summit Single plane 240/252 cam + Pac 1218s, 1.75"-3" headers, try ebay 1.8 rockers to raise the lift to .630/.630 or .604/.604 at the valve, get the compression up to 11.4-11.8:1, get the quench dialed to 0.040" or less. There's your 500hp n/a for similar money to the 4.8 with that expensive top end, induction and cam+valvetrain. Then as you work that bottom end you could make 540+hp with higher end cams, head work or heads, induction, very high compression for e85, nitrous or boost. An SBE 4.8 is really best used for boost, a dude ran 7s in the 1/4 with one in a New Edge Mustang that he claimed he never took the heads off. 4.8s will never be n/a heroes without being bored and stroked. They are cheap and perfect for amatures getting into turbo builds because the power capability is there and if it's destroyed because of a mistake or misfortune it's not a huge loss. Most people really can't use or apply the 1,000+hp a turbo 4.8 is capable of so seeing people waste a good aluminum 5.3, 5.7, 6.0, 6.2 or iron 6.0 they didnt need and couldn't use in a turbo mishap is sad and was an engine some guy running n/a could have gotten a lot of use from. I always reccomend iron 4.8/5.3 for turbo use. A 6.0 iron that could have been used n/a or to build a 408 stroker being destroyed in a budget turbo build is a sad thing.

[@EvPerk]

The problem is the factory pistons don’t have valve reliefs so putting a .630 lift cam with 240° @.050in of duration will cause the pistons to hit the valves. We used a 235° cam and it barely cleared with just over .090in piston to valve clearance which is tighter than I like things to be. There is certainly more power on the table with a full engine build, higher compression pistons with valve reliefs, and more camshaft/cylinder head, more displacement. That just isn’t what we were trying to test here with a stock short block.

[@damianlindsey6177]

Hell, I got a set of 243 heads off an impala ss for 180 out the door at the pull a part, am running the texas speed 228r 600 lift cam, trunion upgrade, efi source gold box, and kooks full long tubes and true dual exhaust on my 2002 Camaro and let me tell you, the 4.8 in this thing screams. I usually dont shift untill 7100

[@MichaelKrzykowski]

I have a 4.8 in my 03 silverado with peformance reman 706's and tri metal race head gaskets. It also has a 15 whp edge tune on it and 3.73 gears it does surprisingly good for having a stock cam still.

[@pinchnloaf]

Link

[@Joseph-xx3rz]

If N/A I would also bore the cylinder out quite a bit. Believe LS1 pistons fit. They have extremely thick cylinder walls. I would change the compression with the piston swap to match the cam, too. At least 10:1.

[@thereluctantgearhead4544]

Back in the 70s, Modified Production class cars ran 288ci, 292 cube SBCs making 550-600+hp NA turning 9500-10,000 rpm. 2-bolt 283 blocks.

[@beefsupreme5132]

Perfect for a manual transmission screamer.

[@Green_Leaf]

That 7K rpm would be fun with a 6-speed manual behind it.

[@hemmingsmotornews]

That would be a fun build!

[@yehornaumov5893]

4.8 rev really good 👍

[@dannydionne7620]

💯💯 CHEVY IS KING 💯💯👑👑👑

[@zosickracing]

With a small bump in compression like 11.5:1 would have more than likely put you over 500 hp. 1 full point of compression= 4% gain

[@JS-oy6nn]

This engine would be a great option for a S-10 street buggy of death ☠️

[@Fatal_Inertia]

The 4.8 is the best platform for high rpm because the stroke is shorter than that of the larger LS engines and slightly less bore. Ported heads, high rpm springs and lifters will get you over 8000rpm

[@tonymickens8803]

I Literally Screamed NOOOOOOOO, when you put that Carbur-Tator on that LS HAHAHAHAHA! @Hemmings

[@TobyBielat]

I've never seen a carb lose to efi in any dyno test, and I watch a lot of dyno testing

[@rosskrause3926]

I have an 07" GMC Sierra 1500 extended cab truck with the same stock 4.8 Ltr with the factory 243 heads when I got it 3 years ago..for a small 293 CID engine and heavy truck it runs damn good with just 105.000 miles on it..the factory Haines manual lists it at 295 HP at I believe 4800 rpm..so I like this tests..

[@thehighlife1320]

Think of the 327 of the 3rd gen small blocks. It can spin, and produce better torque along the way.

[@nachoandsancho5218]

My mild carb'd 4.8 with factory LS6 cam would spin to 7800rpm. It wasn't a powerhouse, but sure was fun to use in my C10 with a faceplated TKO II

[@hemmingsmotornews]

Sounds like a fun combination, what kind of power did you make?

[@snowcrest7863]

Keep in mind, you are measuring Gross Horsepower, which is measured at the flywheel (Net Horsepower is also measured at the flywheel, not the tires). Gross H.P. is also measured with and open exhaust, open, unrestricted intake, and no accessories connected to the front of the engine. Then it is corrected to STP (indicated on your dyno computer screen) Standard Temperature and Pressure (Sea Level Pressure 29.92 In Hg and Sea Level Temp 59 degrees F or 15 C) very favorable conditions. Net Horsepower requires stock intake, stock exhaust, and full front accessories connected (power steering, alternator, water pump, etc...) then corrected to SAE NET H.P. (29.23 in Hg, 77 degrees F or 25 C) My 4.8 L is 285 SAE Net H.P. on my 2004 Silverado That said, closing in on 500 Gross H.P. from a 4.8L is impressive!

[@rickebbert6010]

Some don't realize that the factory gross horsepower rating died with the muscle car in 1972. Factory net rating after that.

[@johnc.hammersticks]

New bottom end, deck the block and you will pick up a bunch of HP. Throw boost at it and who knows.

[@joeydelmarsjr.646]

any way for little coin to make lm7 little closer to an l92?

[@marcosj7134]

I like how the Westech guys act like this isnt the 50th+ 4.8 dyno test they've done

[@hemmingsmotornews]

You might be surprised to know they have not done many 4.8s.

[@marcosj7134]

@hemmingsmotornews perhaps you should subscribe to Richard Holdener's channel and see his body of work. He's had many 4.8s on westech dynos over the years. Turbos, NA, fuel injected, carbed, head shootouts, cam shootouts. 4.8 vs 5.3. Too many to list.

[@armcchargues8623]

The thing that blows me away is turning a 200K stock bottom end 7200 rpm and the thing just yawns and does it again and again. Hard to believe stock pieces can take that kind of repeated abuse and not scatter themselves all over the floor.

[@hemmingsmotornews]

It’s amazing what they can handle!

[@NathanaelNaused]

Just saying, long tube headers aren't stock on a Silverado but I guess you could just subtract a few HP

[@hemmingsmotornews]

You got us there lol. A factory truck wouldn't have had headers, which is something Westech does on their dyno. The factory manifolds are pretty dang good though.

[@johnbehneman1546]

WOW!!!! THAT IS PERFECT FOR THE EDSEL.

[@jasonrogers9169]

Well normally I wouldn't comment on this but 🤔 f.i. over carb depends on the carb and application. Dual plane intake was not tested. Single plane is not ideal for testing. F.i. is the better choice with computer induced timing on a distributorless ignition. Carbs is one setting with no fine point of accuracy during advancement. Tuning the f.i. factory can boost several h.p. but it's not efficient. Everything is about balance. The more you give the more it takes. I mean I'm sure you know this but it wasn't stated in the video of fuel psi to the larger cam to find a happy middle with the headers and increased flow from the head swap. Need more detail!

[@hemmingsmotornews]

The air fuel mixture and timing was optimized for every condition we dyno'd in. The VR-S is an excellent carb and the mixture was perfect so we are left to assume the results we saw are a function of intake manifold design more so than FI vs Carb. That gen IV truck intake is really, really hard to beat. The LSX-R was absolutely better but not by a ton.

[@UrR2KBA]

Maybe I missed it, how much were all the parts?

[@jeffthisted]

Looking good Evan buddy!!

[@pinchnloaf]

Well put an ls7 on an engine dyno with headers and no accessories it’ll be at least 550 hp

[@MrPhukyew]

Needed more RPM with that cam. It was still climbing! The stock 4.8 bottom end will safely do 8k. I'm surprised Richard didn't mention that.

[@hemmingsmotornews]

We did several pulls to 7,500 and the power was falling off. If it had made power up there, we'd have sent it!!

[@quartamile]

How many mpg will the 4.8 REALISTICALLY claim over the bigger LS motors? I remember in the 90s, owners of 305 V8s wishing they got the 350 because the mpg was the same. Thanks

[@hemmingsmotornews]

Well whatever mileage benefits it had I think we've ruined by now!

[@ImNotHereToArgueFacts]

That was one sweet factory exhaust

[@frosthoe]

whats really interesting is i know of one drag racer running this same size engine size but built out from Proline. It makes around 3500HP at 60+ Psi manifold and 3 stage 1000HP nos. 6 second car...on a 4.3 ! P.s yes a 4.3 it was special built and then left on the shelf. He needed an engine for 2023 so thats what he got. Theres a two year waiting list otherwise. And this although small, was a full tilt build...I think it was like 70 grand on discount for the orphaned bare long block. It was $85k ordered as is, customer put down 20k and never picked it up!?!

[@evanspage5]

4.8s love boost!

[@hemmingsmotornews]

They sure do!

[@kalybnielsen4183]

The smallest LS that GM built was the 4.3 liter V6 most commonly used in vans.

[@EvPerk]

That is not an LS in name or architecture.

[@Jihadbearzwithgunz]

​@@EvPerkthe 4.3 is based off the ls1 architecture and has the same stroke and bore as the 5.7 as well just minus 2 cylinders.. The ecotec lv3 4.3 also has been show to handle boost and cams real well.. Sdcp makes cams and what they call a stage 2 cam with 14 pounds of boost led to the little lv3 making 700hp to the crank

[@Jihadbearzwithgunz]

Lv3 4.3 and the earlier tbi and the vortec version are all based off the ls1 architecture. Same stroke and bore and even uses alot of the same accessories sdpc make cams and afm/dod delete kits for the lv3 ​@@EvPerk

[@jcanfixall1585]

You can delete this ignorance at any time, we won't hold it against you...

[@Jihadbearzwithgunz]

@@jcanfixall1585 it's based of the 350 5.7 same stroke and bore takes same mods the same the 5.7 is the ls1 architecture though the lv1 and lv3 4.3 are based off the Lt architecture

[@juanc5149]

20 weight oil with e85 you’re begging for a spun bearing.

[@Mitchelldhays]

I LOVE that holdener was there

[@grantellis3046]

This mini motor was in my 2003 Tahoe

[@chevyboyforlife4234]

Wow with the right carb intake you should of found at least 40hp

[@jakobhurlin461]

Awesome job!

[@joesutherland225]

How does that motor compare to the rover 3.5 v8 in dimensions and weight .I have an idea lol

[@EvPerk]

Very similar dimensionally. That rover 3.5L actually draws its roots to the all aluminum Buick 215ci V8 of 1961

[@andreagageby4854]

The 4.8 was the perfect engine to be the mid line 300 hp non afm or dfm BS for a 40-50 k reliable work horse truck for Chevy and GMC till present day but stupidity and greed didn't allow that to happen

[@hemmingsmotornews]

It was a great engine in its day! I dont disagree.

[@jorgemaldonado327]

Its a 5.3 has dished pistons 4.8 i belive have flat top pistons

[@hemmingsmotornews]

Correct. the 4.8 does have flat tops. Which is what these are. They are not dished.

[@DANTHETUBEMAN]

The torque curve was very flat from the start vart good street engine. 🤠

[@kleenhall6885]

Weird how motors rated at 265-280 make 350 on these dynos I call bs. We all know you can alter the numbers but geez almost. 100 more than factory

[@hemmingsmotornews]

No BS, just a different testing protocol with a different intent. OEM dynos are a whole different animal. They hold the engine at different RPM points for a painfully long duration. The final numbers are actually an average of the engines output during a measured time span across those ranges. Things like catalyst protect, which richness the air/fuel mixture to lower exhaust temperatures at WOT, and other tuning parameters, such as a reduction ignition timing as the engine coolant temperature rises, will actually lower the measured output during an SAE dyno pull, so the final numbers are more like average peak and not true maximum power. That's why we often see stock vehicles make more power than they are rated at on aftermarket dynos. For racing and street performance, we're not looking to produce a product brochure with guaranteed output to go with a new vehicle, but more to find the delta in performance increase between multiple component or tuning variables. Hope that helps explain why we dyno in this fashion.

[@kleenhall6885]

@@hemmingsmotornews ain’t no way 4.8’s make that kind of power.

[@scooterbobscout]

I agree, the newer gen 5.3 make 355, that 4.8 had to have been tuned to the max

[@hemmingsmotornews]

@@kleenhall6885 I did it, and they do.

[@DejanUnscripted]

Bruh my truck Norris Cammed Silverado 4.8 did 320 to the wheels on the dyno . I know it’s an engine dyno but damn . 😢

[@hemmingsmotornews]

That's really good!

[@crw3673]

Am the only one shocked 😲 at the cam specs of 235 intake and 251 exhaust? What about revving to 7500 rpm? What springs did you use on the rockers?

[@hemmingsmotornews]

The Edelbrock heads came with higher pressure springs for a hydraulic roller cam that let us rev to 7,500 with no discernible valve train control issues.

[@Maverick09171]

Yeah. That’s honestly a stupid size cam for that engine. I wouldn’t go that big on a 6 liter if it was going to be used as a street car.

[@hemmingsmotornews]

@@Maverick09171 but race car stuff is cool lol. I actually just stuck a similar cam in a 408 I built and it had a beautiful torque curve. 600 hp and over 500 lb-ft on tap as low as 3,500rpm.

[@Maverick09171]

⁠@@hemmingsmotornewsyeah it is! But that’s what I’m saying. That cam in a super light race car, sure. That cam in a street car with a 4.8, no bueno. Not a fan of dyno queens personally. But yeah we can agree a 408 needs a lot more cam than a 292, yeah?!

[@hemmingsmotornews]

@@Maverick09171 This setup is going in a land speed Camaro.

[@NoGoodGamer30]

Love the video concept.

[@saidtheblueknight]

Holy moly, dropping several thousand dollars on mods with a big honkin' cam in an LS to make just a hair more power than a bone stock Coyote from the same time. Good ol' GM engineering.

[@blueduster74]

quiet down, a simple cam and spring swap in a lowly 5.7 hemi can make 550/510. and a 5.3, 6.0 or 6.2 LS would be almost as good. GM and Mopar can power 2500/3500 trucks with the torque they make. Ford had to create a whole new engine for that. A Coyote has to rev to 7000-8000 rpm to make power without boost.

[@DaDeCodeIsTruth]

way to completely miss the point. Also a Coyote NEEDS DOHC to even compete. different paths to the same goal. GM's LS do it with square and over square big displacement OHV engines in a SMALL and efficient package. Ford went the complicated route and is limited by huge exterior dimensions and small internal displacement. Also any GM LS engine is far cheaper to acquire and build than Ford OHC V8s. simple because GM made MILLIONS of them and Ford only has Coyotes in performance apps and as an option in trucks. the Ecoboost V6 far outsells the 5.0 in the trucks.

[@sammyrothrock6981]

Instead of a high Rev dohc long timing chain 🔗 complex garbage. The squared engine Bore Stroke reliability trusty pushrod and longevity trusty true is the way to go for everyday practical ! The Chevy and Dodge have the better MORE RELIABILITY and they can run with the best of them! It also depends on torque range and power curve applications the longer stroke for Truck applications Dodge and Chevy will win every time normally aspirated! They don't need to scream 7k to make grunt power! It all depends on the applications

[@travisbickle9357]

Is that motor physically smaller than other LS's, as well?

[@hemmingsmotornews]

No. Same dimensions externally. Just a smaller bore and shorter stroke.

[@joeyjojojr.shabadoo915]

This is impressive for a 9.0-9.1:1 Engine, but I think the biggest mistake was using the Edelbrock 64cc heads to replace the Gen4 243/799 65cc heads. The heads that SHOULD have been used are the OEM Gen3 706/862 Heads after CNC Porting.Not only would the Compression Ratio jumped up to over 9.5 or 9.6:1, those heads that I have mentioned have been proven by Richard Holdner to kill it on a 4.8L when CNC ported and valvetrain upgraded.....even though 500HP is a tall goal. Your camshaft was a giant in terms of duration, something that Richard hasn't put near a 4.8L, so you had THAT in your favor. Had this little 4.8L been closer to the 10.0:1 mark after a cylinder head upgrade, it would have made the power target. Unfortunately as has been explained by other builders, even though a 4.8 can be made to spit out 500HP @ over 7,000 RPM, who would want to attempt to drive it on the street ?

[@vans1107]

Those edelbrock heads won't cut it, a better set of heads would have probably made the number..those are basically a slightly better 243/799 head. A set of (good) CNC ported 243s, trick flows or AFRs with a smaller combustion chamber to bump compression would put it at or over 500.

[@DullBoyJack]

How come you didn't do springs? Looks like you were getting some valve float at the top end there, I think you could have made even more power if you could get that under control.

[@hemmingsmotornews]

We did not have valve float issues during the pulls. The engine would pull clean to 7,500 but did encounter float higher than that.

[@DullBoyJack]

@@hemmingsmotornews Yeah that's what I was noticing on the pull to 7600... but I guess it all depends if you would want to regularly spin it that high anyway.

[@peterb121]

Well done however the air filter and alternator will sap some power when fitted.

[@AdamOpheim]

Pu the ls7 on that dyno back to back and I bet it makes more than its rated 500.

[@hemmingsmotornews]

I would love to have an LS7!

[@justinvanburen8259]

Great test, thanks!!!

[@tyler87kelley]

4.8 would fit real nice in a xj or tj jeep.

[@TerryPatton-q2n]

can you provide a parts list?

[@hemmingsmotornews]

Here are the parts tested. They are also listed in the video description. Edelbrock E-Street Cathedral Port Cylinder Heads: PN 77617 COMP Magnum Pushrods: PN 7162-16 Edelbrock VR-S Series 850CFM carburetor: PN 1308 Hydraulic Roller Lifters: PN 8957-16 COMP Camshaft: LSR 235/251 PN 54-478-11 COMP BSR Shaft Rockers: PN 1981-16 Edelbrock Victor Jr. Carbureted Intake: PN 2908 FAST LSXR Fuel Injected Intake: PN 146302B

[@felonysounds]

Hotrod Magazine made somewhere around 800-850 hp before their engine gave up. It was originally supposed to be a 5.3 build, when they took the bottom end apart to investigate the damage they realized it was a 4.8

[@hemmingsmotornews]

Familiar with the story. It made 1,200 but it was twin turbo, which is a completely different animal than what we did here.

[@felonysounds]

@@hemmingsmotornews they used a bone stock engine and one turbo and e85. The twin turbo is another completely different build altogether

[@hemmingsmotornews]

@@felonysounds You sure about that hoss? I only recall one time a 4.8 was mistakenly tested instead of a 5.3. www.motortrend.com/how-to/hrdp-1109-stock-gm-ls-engine-big-bang-theory/

[@goodvibrations7274]

You forgot to tune the ECU. Sometimes just throwing parts at it won't yield the best results. Tuning is your friend

[@hemmingsmotornews]

Eric Rhee at Westech tuned the engine every time a parts change was made.

[@krakhedd]

4:20 is a great number - but it's also a time stamp for a dyno where you guys stopped revving at 7200RPM even though you were still building power and it doesn't look like there are obvious signs - at least from my comfy seat in front of a computer - of valve float; I know another one or five hundo rippums isn't a ton, but it might have been cool to see juuuuust how far it goes

[@hemmingsmotornews]

We did run it out to 7,500 in multiple pulls (not shown). It didn't make the edit because the engine did not make power past 7,200. Eric Rhee is an excellent dyno operator.

[@redgoatgarage]

That's interesting - great video!

[@causeimbatmaaan]

Title misleads a bit. Twenty years ago a guy was testing copper head gaskets on a 4.8 and was making 2600+HP.

[@EvPerk]

Must be metric horsepower.

[@causeimbatmaaan]

@@EvPerk So you don’t know what horsepower is.

[@EvPerk]

Sure lol.

[@jamesislas8269]

Do a 4.8l northstar comparison would be great

[@hemmingsmotornews]

Thanks for the suggestion!

[@bradleymadosh911]

I seen racers take a quart of oil out to get more power out of there engine

[@A2J_Tim]

needs a big turbo

[@mostlypeacefulmisterputin]

*292.91 cubic inches if we're being technical*

[@hemmingsmotornews]

We're a glass-half-full kind of place 🤷‍♂