HOW TO TUNE A LOW-BUCK, 1850 HOLLEY 600 VACUUM SECONDARY CARB. NOT-SO TOP SECRET 4160 TUNING TRICKS

DO CHEAP CARBS REALLY WORK? WHAT IS THE LIFE HACK, WORKAROUND FOR THE AFFORDABLE HOLLEY CARB? HOW DO YOU TUNE A HOLLEY CARB? WILL CARB TUNING IMPROVE POWER? CAN I RUN A 4160 HOLLEY CARB ON MY 302 FORD? IS THE CHEAP, UNIVERSAL HOLLEY 600 CFM 1850 A GOOD CARB? HOW TO ADJUST THE VACUUM SECONDARY OPENING. HOW TO REPLACE THE VACUUM SECONDARY SPRING. HOW TO ADD A JET PLATE TO THE SECONDARY METERING CIRCUIT. CHECK OUT THIS VIDEO WHERE I SHOW YOU WHAT HAPPENDED WHILE WE TUNED A 600-CFM, HOLLEY 4160 (1850) CARB THAT OFFERED VACUUM-OPERATED SECONDAIES AND NO ADJUSTABLE SECONDARY JETTING.

[@Paulster2]

"PAW" & "Super Shops" ... wow, that brings back some memories, lol. Like, before there was a working internet ... Old School, lol!

[@joelsavage8254]

Lol.... right?... I remember me and my buddies would always try to get off of work early on payday so we could haul ass to "Super Shop's" in the Atlanta GA area. So we could blow our $$ then spend the weekend turning wrenches and doing burnouts.

[@Doc_Fischer]

We had a PAW in NJ. Frequent stop for stupid parts on the way to Englishtown and a stop after at the Shell for 100 octane. Ahhhh the good ole days

[@daryllect6659]

@@joelsavage8254 "... then spend the weekend turning wrenches ..." If you're "turning" wrenches you're using them wrong.

[@jdrods1519]

SBF content is ALWAYS a good thing! 🇺🇸💪🏼

[@mikef-gi2dg]

Holy crap this test really hits home. I have been running the basic 1850 on my very mild 307, 305, 350 for over 30 years. The carb is cheap, reliable and I only changed jets, and vacuum secondary springs. This is my street cruiser, drive to the track foot brake combo, and it's dead nuts consistent in multiple cars, too. Now I know why when I locked out the secondaries, it would sound and feel better, but ET exactly the same . I have that actual plate kit, and now I cant wait to try it. I don't have an A/F meter, must get one now, must! I didn't think it would matter, now I know better, can't wait to try it now! This test was smack dead the SHAHIZZZZLE!

[@mikef-gi2dg]

I watched this again, and I remembered, I purchased the Holley 34-6, 4160 secondary metering block way back in the day. I dug it out last night, and I cant wait try it out on a my Chevrolet Performance crate 260 hp 350. I never tried a white VAC/SEC spring, only black.brown or plain. Have you ever tried the Holley 4160 secondary metering block in a test? I got one if you want to try it out. Keep testing.

[@mudwhistle74]

How did it go?

[@mikef-gi2dg]

@@mudwhistle74 Well it's been very cold/wet in the BIG Mitten state. I don't plan to hit any track before the end of april (rain) and I am 90% done on my home made engine stand. If the test mule re-ring 305 isn't a smoker, i'll start with that, and I still need to find a A/F gauge setup that is affordable $$ and in stock. Got a couple of 1850's about ready to go and a whole lot of hook up coming, and 2 months to get rolling on a over due upgrade, and a big learning curve ahead. Stay tuned.

[@boingkster]

Hell yeah Rich! These little 4160's go pretty well. Funnily enough I'm looking at running one on a 302 build myself. Cheers for all you do!

[@Friedbrain11]

I put one on a '75 318 Chrysler. Changed the primary jets to 64s and other than that it ran fantastic. The secondaries worked just right. Mine was the old green-colored one.

[@aw9680]

This is fascinating. I understand carbs but tuning is never anything I’ve ever done. Feel free to do more carb tuning adjusting stuff.

[@karlsracing8422]

I did that on a 750 3310 what game changer!

[@karlsracing8422]

Finally content for the other 90%

[@richardholdener1727]

other 90%-how many 90% are there?

[@orangetruckman]

@@richardholdener1727 How much does Woodchuck chuck, if a woodchuck chucked 😉

[@karlloper7217]

Wow! I could go on for hours on 4150 tuning, and you made it bite size for the basics in 15 minutes. 👍🏼 Back in the 90s, we would plug the power valve hole and put that metering block on the back. Holley sold longer balance tubes for this! Today, jetted rear plates, billet metering blocks with tiny bleeds, and air bleeds in the throat take tuning to the next level. Thanks again for a basic Holley tuning video.

[@shanecashman6495]

Yeah, I had the same Holley. For $40 they make a conversion kit. 4160 to a 4150 You get the metering block which replaces the plate. Longer transfer tube because of the new metering block. All different size jets and vacuum secondary springs. I had a few different power valves as well. I made mine mechanical secondaries too.

[@yeahididit9054]

Carb on a SBF 👍🏼 nice change of pace.

[@GaryH-pw9cm]

I never thought the vacuum secondary was working so I set up a micro switch and light to tell if the vacuum secondary was working. I was right it was not working. It took a few spring changes to get it to work right. Then I went to a double pumper. No switch or light needed. 😊

[@harleysgarage327]

When I was in high school, this is the carb I ran on my stock 327, worked perfectly at sea level. Later when I moved to the mountains, it was way rich at 7000 ft.

[@MonzaRacer]

Yep you should have dropped your jets probably at least four numbers and played around with a lower rating power valve

[@harleysgarage327]

@@MonzaRacer I replaced it with a properly jetted Quadrajet instead.

[@erickbernard8208]

That's a sharp carb, holley for the win

[@purebredamericanmutt]

Funny I'm putting AFR eliminator heads and matching intake on my 67 327 in a 84 El Camino and channel muscle car solutions had one of these with two rebuild kits. I got it for a song and now I know what jets and the plate to put on when I rebuild it.

[@tankertoad1]

I have a carbureted 331 with a Comp XE 274 cam, TFS 170 heads and an Edelbrock Air Gap RPM manifold on my 80 Foxbody. I recently replaced a 600 cfm 4160 Holley with a QFT 650 AN carb. I too modified the 4160 to add a full up secondary metering plate which made tuning way easier but I never could get the secondaries to work reliably. The QFT 650 AN is essentially a 4150 Holley double pumper with annular boosters. I have found that I actully had to down jet a couple sizes front and back over the old 4160. I also had to go upa couple power valve sizes to keep it from leaning out at WOT ( I have an AFR meter installed in the car). Have you ever run back to back tests with annular booster vs regular (down or straight leg) booster carbs? This carb seems to work VERY nicely but the tuning was not what I expected.

[@paulshurmon138]

Thanks for the video!!!

[@saltracer1]

nice variety

[@jmanke6057]

I like the yellow spring unless vehicle very heavy that seems best for me on the street.

[@timmiller260]

Thanks your motor and improvements are same and thats my carb i rejet i was thing before it hits streets in spring

[@christopherc3017]

These are good videos to share

[@gothicpagan.666]

Learnt a lot from this. Had no idea you could get an extra metering block for those carbs. Allways assumed (wrongly as it turns out) that you just had to match very closely, the carb size to the application

[@karlloper7217]

Metering plates have jet number equivalents, but they are not as cost effective as this set up. While Holley makes secondary metering blocks, we would block off the power valve and buy the longer balance tube (thus making the 4160 a 4150) and jet that way. I love these new plates because tunnel ram in line carbs on my SBF.

[@shanecashman6495]

No one says this that much, but I’d take a manual choke any day over an electric choke.

[@richardholdener1727]

me too

[@goldysgarage189]

Nice, now do a 650 double pumper!

[@karlloper7217]

At desired AFRs, I will suggest that the 650 dp will perform very closely to the wired open 1850. An engine doesn't care how it is fed, it cares about the AFR while being fed.

[@goldysgarage189]

@@karlloper7217 not disagreeing, it’s the tuning I’m interested in

[@karlloper7217]

I liked vacuum secondary over mechanical on my Mustang because 3.70 gears and a C4. Sometimes the foot position for cruising on the highway cracked open the secondaries. With a vacuum, they stayed shut at that cruise position. Dynos are cool for the big number, but it gets complicated when you are drive tuning the carb (carbs).

[@TomSmith-cv8hk]

600 on a 307, lightest spring in the kit.....linished down, that woke her up. Oh yer, gouged a deeper groove under the check ball.

[@TheProchargedmopar]

👍💪

[@MonzaRacer]

Actually a 4160 has a metering plate versus a metering block like the primaries have

[@davidreed6070]

That is a lot of jet in that little guy.

[@richardholdener1727]

we thought it was stange too

[@ldnwholesale8552]

There is about 20 versions of a 600. I have 3 on the bench currently.The intake or heads must be very inneficient as jets that big are way too big for the carb and the engine. I agree with the lack of secondary tuning being a total pain on them. I have never seen those jet plates before, I will enquire of them to my Holley supplier. As for secondary springs,, I have never seen one that is not too stiff. And 600s are hard to change as you have to loosen and or remove the choke mechanism to get them out.

[@richardholdener1727]

THE PORTED BPE ALUM HEADS ARE ACTUALLY OVERKILL FOR THIS MOTOR

[@michaelspiering7585]

How about a Carter AFB?

[@tomrocs]

Great video! What cam did you use on this motor? I built my motor and followed a similar build you did with gt40 iron heads, but my motor isn’t making the torque it’s suppose to?

[@richardholdener1727]

XE274HR

[@tomrocs]

@@richardholdener1727 yes good cam, my cam is not as aggressive as the 274 but my motor doesn’t have the power on the low end. I’m baffled by this because my cam is 270/276 with 214/220 duration 482/498 lift at a 112 lobe sep. So it should make decent torque?

[@ericwilson2585]

I've never used one but would a wide band 02 sensor measure and display that same A/R ratio, so that you'd be able to tune the carb similarly?

[@robtdougherty]

yes

[@richardholdener1727]

yes-AF meters display AF

[@ericwilson2585]

@@robtdougherty thank you

[@ericwilson2585]

@@richardholdener1727 thank you

[@cgarris8674]

@@richardholdener1727 Savage!! 😂🤣

[@orangetruckman]

Great video. Question: Is there any reason why you wouldn’t want to attach a throttle position sensor to the secondary’s of a vacuum carb while dyno testing? It’s just more data to be used for analyzing, right? I know it’d be more effort to make it work, but then you’d know how much the throttle plates would be opening and where in the curve.

[@richardholdener1727]

would be good data-the carb cam shows us this too

[@mikef-gi2dg]

@@richardholdener1727 I would like to see some carb cam shots with different carb/booster setups. Maybe in comparison to a SNIPER.

[@rystydresx78]

Regarding your ls cam videos... is it possible to start recording dyno graph at or closer to idle? For example to possibly see if there is a performance comparison around 1800-2200 rpm. As if you were highway driving or using cruse control. Just thinking if a majority of ls cams featured are going into daily-ish driven vehicles would idle or partial throttle performance comparison or even comparing fuel consumption in the 2000ish rpm range with partial throttle to investigate possible ways to increase or maximize mpg for 50% or less throttle without compromising full throttle performance. Or vice-versa.

[@richardholdener1727]

no on testing MPG on the engine dyno, and 1800 rpm at WOT is not something anyone ever sees

[@rystydresx78]

@@richardholdener1727 Not at wide open. Just partial. Just enough to maintain that rpm. Just to see.

[@ryandoyle4344]

Green, tuning carbs: Are jet sized, commonly even all around? (P=S, P>S, P

[@richardholdener1727]

not always the same-power valves change jet stagger

[@karlloper7217]

Yes and no. To really balance the jets, you need to calculate the PVRCs with the primary jet size to match the rear jet, more specifically, the area of the jet hole. But, this gets into drive tuning, not dyno pulls. Example, take out a couple of jets for gooder cruise AFR, but add the opposite amount of change to the PVRC to maintain WOT AFR.

[@SteveKuzava-cp4ig]

Hi Richard have you ever tried a tapered combo spacer on a dual plane intake upside down does it work thanks Steve

[@richardholdener1727]

it works...but does it work better

[@cgarris8674]

@@richardholdener1727 Sounds like a test!

[@buddysorge5840]

I actually have the older style 4160 1850 Holley carb (not shiny) how do I know what size jets I should use if I don’t have a dyno or other fancy tools.

[@richardholdener1727]

read plugs is possible-or get an AF gauge

[@anthonyanderson1479]

I still miss the dance music!

[@richardholdener1727]

me too

[@stevenshepherd1905]

What happened to the fuel curve as you added timing?

[@richardholdener1727]

as indicated in video-did not change

[@zolkoz4209]

How much did the additional timing affect the AF ratios?

[@richardholdener1727]

it doesn't

[@mudwhistle74]

How would this compare now to a 650 double pumper?

[@richardholdener1727]

would make less

[@RichieCat4223]

Why the dip at 4000 with the A/F ratio all the time? Is that the power valve opening?

[@richardholdener1727]

power valve opens once past 6.5 inches of vacuum-meaning at open at WOT

[@RichieCat4223]

What is causing the dip?@@richardholdener1727

[@johndishong5083]

Can we get a similar vid with the 600 edelbrock/carter?

[@karlloper7217]

Edelbrock has a tuning map in their instructions. Buy the kit for that model, an AFR guage, and you're ready to get 14 mpg with twin 1404s on a tunnel ram 302. 👍🏼

[@mikef-gi2dg]

Yes a test of the Edelbrock 1406, would be great. I was going to replace my 1850 for a used 1406. Now with this info, I might not need to. But I will do a back to back test between them, top see what's what. Great test!