4.3L L99 CAM (& ROCKER) TEST-(THE OTHER LT1)
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- Опубліковано 5 лют 2025
- 4.3L CAM & ROCKER UPGRADE-WHAT'S IT WORTH? FULL DYNO RESULTS!
WE TESTED THE L99 CARBURETED (NOT EFI). FULL CAM SPECS (CAM 2 WAS 410/433, 207/214 AND 117 LSA). WE COMPARED THE STOCK L99 CAM TO A PAIR OF MILD CAMS FROM TPIS WITH SIZABLY DIFFERENT LSAs. HOW DID THE DIFFERENT CAMS COMPARE TO THE STOCK CAM ON THE CARBURETED 4.3L V8? ALSO TESTED A SET OF 1.6-RATIO ROLLER ROCKERS-HOW DID THE LITTLE MOTOR LIKE THE EXTRA VALVE LIFT? ITS ALL HERE.
Thank you for posting this right now, I'm trying to avoid news at all cost this evening!
I HEAR YA!
I can just imagine Richard alone at 3am at Westech jamming to this music cranked up to 11 lol
all the way up to 11!!!!
@@richardholdener1727 do you randomly yell DISCO DISCO at the top of your lungs!?!?
Why 11 why not just 10
@@Kelemen1 Because it's 1 louder.
Loving the spinal tap eggs
That is how every cam should come packaged.
@DropDstar yup i have a few
Howard's has been using these exact same yellow boxes for 10 yrs +.
@@Torquemonster440 never had a single howards cam come in a plastic tube. always a box
The amount of effort Richard puts into this is fairly astonishing!!
The dude is a machine. Feed him junk food and cheap beer, and he just goes.
Hi
Very pleased with all the efforts that you've been putting into the L99 4.3 L 263 cubic inch small block Chevy it's nice to see somebody going for the little guy I've been into these engines since the late seventies and I have several of them I had a 262 Lv1 from the 75 to 77 Monza Nova and Ventura and I presently have several L-39s witch is the 267 out of the G-Body I don't know if you were aware but the cubic inch displacement of the L99 is 263
4.3 L the bore on a engine is a
3.736 which is identical to the 305 and the stroke of course being 3.00 with a one-piece rear main seal it shares the same bore with the 305 I just wanted to clarify that for you for your information okay thank you and have a nice day and appreciate all your time PS
It was Chevys tribute to the
1955to57 265 bore 3.740
Stroke 3.00
It's amazing how such a small engine can still sound so monstrous!
Open headers FTW! 😎👍
That wide LSA killed the torque!
Imagine a 262 v6 lu3 doing it or a 3.8L buick series 2. Or a 305 or scca 302. Or a 250/292 I6 or 4.2L I6.
4.3 such a small engkne. Meanwhile here in the UK my 3.0 straight six is seen as a massive engine.
@@ravennexusmh Amazing, isn't it? It's all perspective.
@@ravennexusmh geez ANY v8 would be a monster then lol what do you guys do when you come up with a Jag v12,etc etc well any euro 12
Like the plastic tubes for the cams? Howards camshafts out of Oshkosh, WI ships their cams like that. Good people.
Need a real cam custom ground for your app... call howards in Oshkosh they are FABULOUS!!!
nope, never had one of their cams come in one.
My aluminum 1.6 roller rockers fit under my stock stamped steel centerbolt sbc valvecovers. You must need to get narrow body, self-aligning rocker arms. It's a little snug, but I can get them on and off twisting them around the front accessory drive and brake booster and A/C lines in the truck. They do not hit the valvecovers with .550"/.546" lift. They are the blue pro comp cheapies from summit. They were $200 when I got them. I have another set of those 1.5 roller rockers in my 3rd gen Camaro that I bought 10-12 years ago.
THAT 109 LSA is right at the edge of fuel; injection coputer readiness.....and sounds awesome too with flowmaster super 44s..great job...
Love that Latvian disco tech 🎶. I appreciate the knowledge Richard
I just love these 4,3 l series! Richard, awesome job! Keep up!
Richard doesn't work out, he just changes a lot of valve springs. :)
LT4 hot cam 218I 228E 525 lift with 1.6 rockers, I ran one in a 383 with Vortec heads real nice low to mid range power .
what is the LSA?
@@richardholdener1727 112 degrees
Great series. I'm really enjoying watching, so many thanks. A custom ground can is a must!
Rich this is awesome. Seriously, I have never owned anything with a SBC in it, let alone a LT1 OR a 4.3L V8. 4.3 V6 yeah, but no 4.3 V8 OTHER than my 76 Buick Skylark with an Olds 260. I'm still not giving up on begging you to test and mess around with an Olds 260...never will give up. Anyway, I am seriously pumped about seeing this seriously small block with boost. I think that it's going to surprise alot of people. It already has in my eyes with something as simple as a cam swap. I am definitely not going to miss a single video!
thnx-and keep pluiggin' the Olds 260
Hi Tim Tom my name is John Paul Schafer and I'm into 4.3 & 4.4 L small block Chevys
the to 263 L99 which riches building and also the 267 L39
An acquaintance of mine who had a 260 in an Oldsmobile and I understand that you cannot use a 4 barrel intake manifold on 260 heads I'm not sure of all the details but you may want to inquire if you can figure out some way to put a Quadrajet 4 Barrel on your 260 you'll be amazed with the results I've done I've done a lot of experimenting with the 262 LV1 which is out of the 75 76 77 Monza Nova Ventura and I've also done experimenting with the 267 L39 out of the 79 to 82 Malibu and been very pleased with the results it may be that you can fabricate a four barrel intake off of an Olds 350 I know Chevy made some of theirs out of aluminum and maybe that you can find an aluminum Edelbrock manifold that like a performer or something that you can fabricate to your 260 just a word of note these engines really respond well to dual-port 360 manifold from Offenhauser they no longer manufacturer that intake manifold but if you can find an old one floating around somewhere used I highly recommend using the dual-port 360 manifold since it produces a lot of strong vacuum signal with high air velocity at low R P M which is what Small displacement works well with
Cam selection 106 to 108
.int.435/435ext to works well made 200to250hp with L39
267 with stock heads
look forward to your response I'll share with you all my findings in tips that I have discovered by running the 260s cubic inch family small block Chevys have a nice day and God bless you
I’m wondering how bad the factory LT1 intake is going hurt torque with the short runners. That TPI intake should make a strong showing on this 4.3!
LT1 intake test coming tomorrow
In theory it should be 300 to 350 in TQ.
I would expect around 310-320 tq with the TPI intake. The dual plane and carb is already going to be a good 20-30 ft/lbs higher than the short runner LT1 intake.
Thankyou for doing a video on these oddball engines. There is a small audience that can appreciate them so I'm happy to see you waste so much time showing what they can do. A cc503 would be a go to for lt1 fans so maybe see if you can put that together.
The GM 12677151 the roller cam used in the SPO 357 hp 350 Vortec. It is 215/223 @ .050, .473 lift, (.503 with a 1.6 rocker) with a 108 LSA and 109 ICL. Runs very well in both the 305 and 350 Vortec I have tried it in. I think it would work very well in the little L99 given the heads likely flow very well.
I think you should have tried the COMP Cams Thumpr Hydraulic Roller Camshafts 08-601-8 Dur: 235 int./249 exh. Lift: 0.522 int./0.509 exh. lsa 107 it probably would have made 300 hp + and similarly torque. Always love your videos and the way you think out side of the box and teach us very valuable info that no one else seems to think we need. Thank you for everything you do Monte
not sure that would fit stock p-v
@@richardholdener1727 what is stock p-v
Richard I’d like to see you explain how to select the right fuel injector size and system! I think your approach is very well done 👍
Looks like it wants more cam. (probably more head flow too) That's encouraging.
This is an epic channel. Thank you so much.
I generally like your videos because you do things which make me think. With this test I would not personally use the small cams particularly with such a wide lsa. It’s a matter of economics for me. Most bang for the buck. I understand that this is supposed to be a teaching moment by you and you combined that with parts supplied by a vendor. We did learn how to spend money and get mediocre results. Been there, done that and kicked myself while my wife berated me for wasting her money on something that didn’t get the desired results. Listened some more when she found out for the same amount of money I could have had what ultimately did work. She still loved me. Just hated “My wasting her money”. Lol. I tried very hard to not have to have my wife’s repeat performance. Lol. So far I have succeeded. Great video. Not hating on you as I always learn something from you. Thanks for sharing. Btw I do like the small motors. It’s always fun to snooker someone who thinks the small motors won’t run well.
Best part of the video is when the Opti-Spark came off. 😆 JK
This block needs a stroker kit. I don't know if 334 stroker kits are still around but you could run 400 rods if you can't find the pistons. Put a tpi with the runners siamesed at the plenum end on that or an accel super ram with lt1 aluminum heads and a centrifugal supercharger to extend the top end and it could be quite the engine and able to rival many modern engines. Although I want to see an lv3 modified with a carb manifold for an ls3 with 2 runners sawed off for comparison. At supposedly 360lbs the lv3 could be a hot little 4.3l v6.
I always miss the live stuff! I'll catch one one of these days 👍
Glad to see you doing more trials on my second favorite engine. I have three L99s stored away for future projects and I have L99 internals stuffed in a 305 block residing in my 88 Formula Firebird T56 TPI. I would love to see dyno results of a cam close to the Duntov 30-30 specs except in a hydraulic roller. Better yet, go buck wild and see how it compares to its big bore cousin the Chevy 302.
I still keep coming back to the l99 video's after 2 years😂😂😂 and my 385 will be ready to drop in within the next couple of months. It's down to the external nickel and dime stuff outside of assembly. Headers, engine mounts ect. Would you be interested in dynoing a goofy little l99 if I slap one together in a couple of years?😂😂😂 I have some theories for a budget goofball engine. Bone stock outside of cam, pistons and what I violate with the dremel. NA 87oct streetable of course. Even though I have no use for them. If I was to take a stroll around the block, I don't guess I'd say much if you stuck one of your hairdryers to it. Might need a little heads up before I gap the rings though 😂😂
That was very interesting for sure how the lobe separation angle affected the engine performance.
I had issues with the bolt tubes in the center bolt valve covers, but I was running trick flow twisted wedge heads, the valves were at different angles, the ran awesome! But the 1.6:1 rockers got in the way of the tubes,
does trick flow make LT1 heads?
@@richardholdener1727 yes they do! Look up part TFS-30410010
@@richardholdener1727 these was tpi heads, pre LT-1, but I haven't seen the SBC twisted wedge heads, last time I looked , all I saw was standard 23° heads, they were awesome heads, they could use better springs, I broke a couple springs, but I was a bit hard on it, they made awesome power!
@@richardholdener1727 YES, they make LT1 heads and they even list one for the L99, this link shows the lookup for a 1996 4.3L LT1 style head;
www.trickflow.com/search/department/cylinder-heads/section/cylinder-heads/make/chevrolet/year/1996/engine-size/4-3l-265?N=4294961402%2B4294965891%2B4294966157%2B4294966016%2B4294966142
Love the channel Richard this is Engine Masters for UA-cam 👍🏻
When I built my Lt1 way back in the day I used the comp 501 cam, it's very similar to the GM hot cam. I would like to see either one of those
Good job that was interesting I think a bigger cam and tighter loop separation would make a little more power good job
I’d like to see numbers for the hypothetical cam that you described at the end, Richard.
we will run more cams
I would like to see
212/220
.525/.525
106LSA
102CL
I think with this small cubic inch engine it doesn’t like the wide LSA because it reduces running compression and cranking compression. It need compression!!!!
Thanks for your effort. Even though I have LS swapped everything I can, I had a 1994 caprice with this motor. Cool to see what it could’ve been
I'd like to see you test an old school GMPP LT4 hot cam in that wee beasty...
Second the motion! LT4 Hot Cam, Yes! Thanks!
Badass vid, loved every second of it, this motor seems like a perfect fit for a smart car
I tried to drill and tap some old pushrods I had to make a tool to find the right length for this new build but apparently my cheap taps aren't gonna cut it. I'll see how I get on tomorrow.
Holdener for PREZ. A ('other guys'!) small block in every garage! I'd vote for that.
and boost for ALL!
@@richardholdener1727 Would a comp 268XFI HR be too big, or just big enough, cam wise, ya think?? 113 LSA might not be overly wide, but I couldnt say for sure. Lots of lift though! Maybe better for a 5.7...
Thanks for all youre doing!
Lt4 hot cam with factory efi intake or tpi intake also lt1 heads
Whenever you're working with a small cubic inch small-block Chevy it is always wise to go to a close lobe separation angle I had a267 L39 with a 3.48 stroke with a 3.500 bore and I used a 435/435 108 degree load Center on my original to 267 from isky race cams it was a flat tappet cam workd excellent another thing that works really well on this small engine combination is an Offenhauser dual-port 360 manifold I'm using one of those on my to 267 presently with a 5sd stick and it works great as got gobs a bottom-end torque with the factory Roller cam
u just removed was pn#600 or 779
111 lobe ctr. 418int/430ext
Is it possible 4 u 2 try offenhouser duel port 360 mannafold w/a Q J carb ?
The advantage of a Offenhauser dual-port 360 intake manifold with a Quadrajet is a Quadrajet in the primaries has dual boosters which gives you a strong vacuum signal coupling that to an Offenhauser dual-port 360 manifold in effect works on the same Principle as having four valves per cylinder with the high velocity of the fuel-air ratio mixture coming in from the primaries you end up with a strong vacuum signal at low RPM
Packing the cylinders thus vastly improving bottom in torque
Keep the lsa tight and get up to max lift with those springs and use the duration you like, 224 232, and see if the cam is "too big." I'm loving the 4.3! I run a hot rodded 265 in my 55 Bel Air.
Hm interesting, dont like that bigger cam, more duration narrow lsa i think will be the winner. Thanks for all your info
Wide lobe separation not good...why? The answer is it kills the overlap which is the key to mid-range torque production. Widening the LSA means the intake valve opening moves away from the exhaust valve closing, that’s less overlap, or maybe more negative overlap. It also makes intake valve closing later, which promotes high rpm power (torque, which corrected for rpm is horsepower) but kills lower rpm torque. So the results Richard reports are completely predictable. Just look at an LS with an LS9 cam vs an aftermarket cam. The LS9 cam makes good top end with a complete lack of mid-range. The SS2, for instance, makes the same top end with lots more mid-range. That’s important on the street, or, with any small displacement engine that is torque limited. That TPI manifold is probably going to be very good with a cam that has decent, relatively short, duration, 0.500 or a bit more lift, and 110-ish LSA. This 4.3 could be a great engine for a light weight street machine like a Fox body or kit car. We’ll have to see what cam and intake are going to work best for that application. Of course boost is going to raise the power to levels for a wider range of vehicles.
Capable of building a one piece crank(3.0),with 5.7 roller block to achieve a modern 302 inch ripper.
I would like to see an LT4 Hot Cam if possible.
Is it possible to video the torque procedures for the rockers and the head bolts on these motors and also the LS engines? You do alot of cams and head swaps i figure you prolly can do it in your sleep. I would love to know some tricks to get faster. Yeah yeah I'm new to this.
I think that really short stroke plays a big factor in how it responds with these cams. Seeing the loss of power way down low with the wider LSA surprised me. Made me wonder why it reacted so well to a tight LSA. Usually tighter LSAs world result in lower bottom end power.
Maybe in wrong? I'm just thinking that short 3" stroke is the reason.
Alright since you asked ill take a swing... id like to see a 220/224 cam 108 LSA but I think you could widen the LSA to 110 when you put the heads on it with the 1.94 intake valves soooo I guess you have choices!
Needed this just pulled my l99 out my caprice, can I use this set up on a b-body? Is there a part number for the rollers and rockers, or what do recommend for a little extra hp, with killing my daily ride, thanks your video gives me hope 😂
I thought this was about the 4.3l. V6. I want to see performance upgrades for for my boat assuming the Mercury version is compatible.
Very happy to see the attention you gave this forgotten engine. I'd like to see you de stroke it, shave the deck and then spin it to 10000rpm.
this l99 already as a short stroke
@richardholdener1727 thankyou for the correction. I was just thinking about piston speed. Long rod short stroke
It'd be awesome to see that little thing turn some rpm. I don't know how strong the rotating assembly is but it's small and should be relatively light for stock at least compared to a 350 or something. With only 3 inches of stroke piston speed should be relatively slow too. Plus I have a thing for high revving small v8s lol
Very interesting.
Do we know what the compression ratio is on this motor?
I also wonder how much overlap there was on these cams, respectively.
Very interesting indeed. You keep going, I'll keep watching. And learning.
negative overlap and i think compression 9.4:1
@ ~ 2:00 - Dampers are there to prevent spring surge; do they make beehives that'll fit? Better solution...
You can just use ls springs but you need retainers
Would really really like to see the 230/236 duration @ .050, .510/.520 Lift and 110/112 LSA, also if the OPTI SPARK is removed any sbc cam can be used as well as other sbc timing chains sets with the exception of a double roller because of clearance issues of the timing cover, this info should really open up the number of cam testing!!!!!!!!!
.480 lift and 230 duration at .050 with 106 to 108 LSA. Perfect camshaft for this engine
Cam packaging reminds me of a welding rod storage box. Dunno about the cam, dyno doesn't lie. 250hp will make the nova into a more than adequate daily driver, IMO.
4:45 - 4:47 Here by called the "head assembly" at all good raves. Cutting extream shapes.
LT4 Hot Cam along with LT1 intake should make for a nice high-revving combo in the baby 4.3
Sticks to the OEM style setup with OEM parts.
Or 212/218 but on a nice tight LSA (and compare LT1 with TPI intake).
How tight would you go Richard? 106 Straight? +4?
How bout the Lunati 20080721? 270/278; Dur @ .050: 219/227; Lift: .515/.530; LSA/ICL: 112/106
I have two questions...
1) If you were too install guide plates can you use regular non-guided roller rockers?
2) can you run that engine if the opti-spark dizzy is removed?
yes-you could machine the head for guide plates and screw-in studs-yes the opti can be removed with a different front cover
@@richardholdener1727 awesome and thank you for answering my question personally. I love your content especially the odd engine build ups! Cheers~
Richard, I'm sure that small-valve head is limiting the RPM of the wider LSA cam. Try it again with the LT1 head if you find out the valves fit in the bore. I would expect the old GMPP 12730846 to work well here too. This engine needs to see 7000 RPM, unless you're afraid to turn this series into a big bang video?
with the right cam and springs-it will see that rpm
Right on
Where can I buy the roller rockers for my engine specifically?
212-218 max out lift maybe 450 450 on a 112 lsa would work we’ll either carb or fuel injected I’m thinking the second cam is a no tune drop in emissions friendly camshaft
Richard, have you done a cylinder head shoot out on the 6.0L with PRC cylinder heads from Texas speed, afr, brodix, trick flow, etc?
Also Howard's rattler cam?
the ls head test videos are up
I need to chill cool music like that when I’m working on my engine!!
Great testing, I bet a comp X4260HR 4x4 cam would be pretty nice in it. 210/214 .474/474 lift 111 lsa. Pretty close to cam 2 but with a little more lift and tighter lsa.
Or xr264hr 212/218 .488/.495 112lsa might be a little hotter. What's our rpm limit on this little critter?
we will go MUCH higher later
@@richardholdener1727 a little late since you already broke it lol but the reason for me to build one of these would be to keep the mild cam V8 sound but with better fuel mileage. I'd love to play around with one of these or Destroke a 267 to a 231 with about a 3k lock up stall and 411's in a g body. A fun fuel saver to beat on that would probably out live me lol especially with modern rollers and thin ring technology.
@@richardholdener1727just a little funny math. Considering the shorter stroke and the average vehicle is driven 12,000 miles per year. If you figure 2,000rpm average excluding idle time and stop lights it adds up to each piston in a 305/350 traveling an additional 184 miles per year up and down the cylinder walls😂😂
Over the course of 20 years in a daily driver (yes I've been driving the same 03 sierra 20 years) it would add up to about 3,680 miles difference.
What a dream job
I think a custom grind l79 roller cam would have been perfect!!
222/222/ 447/447 110-112 lsa
Would be perfect
needs more lift
@@richardholdener1727 maybe a hotcam ?? Its around 215 duration , 525 lift.
220in/228ex dur .500in/.520ex lift
108 lsa.
Maybe the header primaries are too large for the wide overlap, could also be showing the limits of unported stock heads...
I wonder about that miulling the manifold thing. Isn't this a tyriggering issue? to trigger the ignition events, a trigger wheel distributor 'stub' might be used or aftermarket (edit: Crank Trigger) setup?
git'it'onthere! get'it'done! lol,
That triangle always comes in on the weirdest beat...
I would try a 218 duration, .500 lift, 105-107 lsa and, then ported heads,
i love this test thanks man yep 510 lift max n fat n tight be good cam love to see it in new video
Oh man, you're killing me, making those baby steps with the small cams. Get up into the 219 or 224 effective duration territory. Then put the LT1 heads on it. 267 HP doesn't get me excited.
Are there any size/weight differences between the 4.3 and the 5.7? Personally on the hunt for a small V8 for a Baja Bug swap and I don't realistically need 300+ hp to make mine fun, but I want the good noises!
the LT1 had alum heads so it would be lighter
I have a question, do you ever measure on your dyno , the time to max torque or the time to a specific rpm?
I thought that this might be of value in differentiating engine designs.
the rpm rate is fixed and controlled by the dyno (we tested at 300 rpm/second)
Did you ever seen on any L99 (LS3) oil leak from head gasket? I have small leak coming somewhere from top, couldn't determine, is it valve cover or head gasket leaking :(
valve cover usually
@@richardholdener1727 many thanks
This is going to be a great baby lt1 boost motor and surprise some people!
Do something like 285/285, Lift .470/.470 on a 108 lsa, let her sing.
They way you talk about Self Aligning rockers is like you guys never heard of them out West lol. I've got a set of self aligning 1.52 roller rockers on my boosted and forged 355 LT1.
I am speaking to the people who have not heard of them
So basically both those cams are already gm grinds.. ramjet cam and 88/89 L98 cam
Hey Richard, if u have some time i would love to get ur advice on a build im workin on.
ask away
@@richardholdener1727 im tryin to build a 04 tahoe for a good performance daily, im doin a btr stage 2 truck cam with beehive spring, 7.400 pushrods, ls7 lifters, longtube headers, tbss intake, 80lb injectors and a procharger. Is there any recomendations u would have that would give me the longest life outta my lm7 with this setup?
Crane 227, LPE 219, GM HoT Cam, GM 845 all good cams for a mild setup imo
I would do a 200@.050 with .480" lift in/ex on 108 lsa and switch to 1.5" primaries and a 450cfm carb
I wish he would show the specks each time
Howard's cams come in the same yellow tube
Any idea how much this engine weighs?
Try a Comp 08-422-8:
218/224 110 LSA
.495 / .502 @1.5 | .528 / .535 @1.6
Please go flow those heads so we can nail down the lift limits lol.
Good call! I'm right there with you.
that should work well
What about a LT4 hot cam?
That grind, with 196°@ .050" will will work best on 112 LSA, get it ground on 107 LSA if you want max bottom end torque.
What ever makes the most usable HP
whats that things between the timing cover and waterpump?
Opti Spark distributor
That second cam sounds a lot like a factory L98 cam
Have you got any videos for the alloy 5.7? Send us Aussies some love!
I will be
@@richardholdener1727 awesome! Big fan of the channel
I'd really like to see a vortec sbc with the stock intake that would be cool