[57Nomad]

Quick fuel BR-67253 & HR580VS are both vacuum secondary carburetors and according to the website chart both are 4 corner idle and all same features. Even the calibrations listed are identical. There is over 100 dollars difference in cost. I see the Brawler is so marked all over it while the HR580VS is identified with Quick Fuel logos. Any float or seat differences or billet vs cast that is not mentioned in spec’s that justifies the added cost of the HR580VS? True 570 and 580 CFM’s are close but spec’s don’t show any physical size differences.

I can’t imagine only the name graphics is different.

 

[Timtbss308]

Why not, I could. Wouldnt be the first time that a product received a name change and that only, just to make more money.

Sent from my SM-G965U using Tapatalk

 

[57Nomad]

Tim, you could be correct. Even the Holley/Quick Fuel web site spec page is not specific as to what you get. But I have a feeling you get less but not mentioned directly. Photo shows 4 corner idle on BR67253 but specs say nothing about it. Holley’s Brawler ad is a bit ambiguous as to what you get also they are showing and saying different pictures. Such as showing 4 corner idle on vacuum secondary model and saying it comes with all mechanical secondary models. Then 2/4 corner idle not mentioned in Brawler “spec’s” at all. That would determine two totally different carburetors.
Where as the HR-580-VS does say specifics on the meter blocks and base construction. In this case the photo and description seem to agree.

 

[Timtbss308]

Great, hence the stupid little foot note that always says item in photo may or may not reflect the actual product.

Sent from my SM-G965U using Tapatalk

 

[johnsongrass1]

Call Dayton Umholtz, Kinetic Performance Carbs in NY - 607-277-6462
You get way better than the QFT will send out the door.

 

[eric32]

Let me give you a little history on how holley who also owns quick fuel carburetors repackages there different carbs and charges more and even says more cfm for one model over the other but are the exact same thing just with a different stamp and a different set of fuel bowls at times or minus a secondary metering block on the vacuum secondary models.

The holley 1850 which is a 4160 carburetor 600 cfm with side hung fuel bowls and a sercondary metering plate and with the traditional non adjustable or quick change pod on it. The base plate has 1 9/16 throttle bore size and is set up for a 2 corner idle. Then you take the older 2 corner zinc model holley street avenger 670 rated cfm that has a set of center hung fuel bowls and a secondary metering block with a quick change vacuum spring pod topper.

Those two carbs use the same exact main body with all the same size venturi bores and the same exact base plate with the 1 9/16 throttle base plate. The secondary metering block is the same exact metering block that comes with the holley secondary metering block conversion kit for the 1850/80457 carburetors. Both the street avenger 670 and the 600 have the same primary metering blocks with all the same specs on them as well. Base plate all the same.

Air bleeds the same and idle restrictor and emulsion bleed size the same. The power valve channel restrictors are the same size.The street avenger of the older came with the 65 primary jetting and 68 jetting. The secondary 68 jetting is about the same as the metering plate equivalent of the 1850 600 cfm model.

So if you take the side hung fuel bowls off the 600 holley and put the center hung bowls on and the secondary metering block conversion kit they offer for it and put on a quick change pod then you have the same identical carburetor from front to back and top to bottom and jet and calibration and all just with a different number stamped on the tower but the same carburetor.

I have both on hand and have worked on both of those so I can verify all of that. Now the 670cfm rating I believe is once stated that holley over stated that particular one so people would not over carb there vehicle like so many do so they stated a higher rating for it for marketing purposes.

Now if you go to the newer holley ultra street avenger 670 with the billet base plate which comes in bigger with 1 11/16 throttle size base plate which is on all the 650 to 800 cfm rated carbs then I would believe it would flow around 650 legit cfm but they slightly rate it more as 670 to go in line with the 570 and 770 which from what I found the 770 is more likely the 750 vacuum secondary model 3310 which has about all the same specs as the 3310 with all there conversion parts for the secondary side as well.

Also on the quick fuel slayer carbs which comes as a 2 corner idle with a secondary metering plate that accepts jets and they are listed as a 2 corner idle which they come that way but the base plate and the towers are already made as a four corner idle and be converted very easily just by putting in a secondary metering block with the mixture screws and then change the idle feed restrictors to the same as the front and change the idle air bleeds to match the primary and you have the same carburetor as the hot rod series and identical minus a slight change in jetting and maybe the high main air bleeds but only by a few sizes but in all else the same specs across the board except the 600 throttle body has the 1 9/16 throttle bore size vs the hot rod series the only difference regardless billet or cast is it has the 1 11/16 throttle bore size which makes it the 650 aka 680 rated cfm rating but the main body is the same mind body and all things are the same except the part number stamped on the tower.

I have had owned both of them and measured and checked things front to back. Even a lot of the quick fuel hot rod series 580 cfm rated models have the same exact specs almost as the 600 cfm rated slayer carbs but with the a few differences in jetting and air bleeds but the same base plate size and I can't remember on the bore size. Also the quick fuel carbs have a slightly bigger primary bore venturi size of the main body vs the holley 600 bore size on the main bodies. I think the holley is like 1.28 or so give or take a hair and the quick fuel is like 1.31 give or take a hair and just a touch bigger for slighly more cfm.

They do that with there biggest selling size carbs and most popular. The holley 600 4776 double pumper has the same body size as the 650 double pumper but the only difference in the most part is the 600 has the 1 9/16 base plate while the 650 has the bigger 1 11/16 size.

I have taken my holley 600 main bodies and did a little massaging on the throttle bores and fit up the bigger 1 11/16 base plate to make it a legit 650 cfm rated vacuum secondary and it has worked just fine with no problems. Holley markets there carburetors like that in different configurations without the average folks not realizing that they are buying the same carburetor but for a lot more money just becaus how they repackage things.

I have had the same blocks and parts on the cheaper ones and have learned to buy some of the other parts for the fraction of the cost and the parts separate from allcarbs.com and made the same exact carb for way less money.

 

[hirschdalechevy]

Thats great info eric. I have been playing with several different holley and quick fuel carbs on my sp/350 , 600 slayer, holley 1850, holley 670 street avenger , even a 625 street demond and a fst 650,(returned back to summit, JUNK). None of them have ran great but the worked over 1850 is the best and on it now. I would like to run the quick fuel 600 because of the off road features etc... but my sp/350 doesn't run well with it. So my question is can I run the 1850 base plate,(with smaller t-slots) on the quick fuel slayer main body?

 

[57Nomad]

Here is the Quick Fuel spec’s

http://www.quickfueltechnology.com.au/content/Quick%20Fuel%20Carb%20Size%20with%20details-AUST.pdf

It does not even list 2/4 corner idle, but it is what it is.

I’m assuming they are accurate for current offerings. The HR series is listed last at the bottom of the pdf. The one thing I noticed on a few of the smaller CFM models the straight leg is use vs the down leg. I don’t know but I seem to recall many OEM‘s 60’s versions use a straight leg.

 

[eric32]

57nomad what are your engine specs? It sounds like you have a crate motor with the sp/350 being mentioned and I don't know if you can run the 1850 base plate on the quick fuel main body as the quick fuel main bodies are made with a four corner idle setup even though they set up the slayer as a 2 corner idle setup. The only difference between the slayer and a four corner idle setup is the slayer 2 corner idle setup has as you know the secondary metering plate but the difference is the rear will have a richer set aka smaller idle air bleeds vs the primary side to compensate things because you have no screws to adjust things and the idle feed restrictor size in most instances will be bigger as well but not always depending on the carb.

The holley 1850 base plate is made for a 2 corner idle setup and the base plate has a channel that allows fuel to travel from the rear fuel bowl to the front fuel bowl and share so the rear fuel does not get stale as the secondary side is not always used enough to keep fresh fuel in the rear bowl. It also has a very tiny constant fuel discharge port as well. Also on the main bodies the quick fuel body has the two holes that are a 90 degree angle and allow fuel to go through the main body and allow fuel adjustment if you were to put a secondary metering block on it with idle mixture screws.

The holley 1850 main body does not have the rear holes in it for the four corner idle setup feature and also the holley 1850 base plate has to be modified to work with a 4 corner idle main body if you want to run it as a 4 corner idle carb. The base plate channel has to be blocked in the middle to keep the rear fuel from coming into the front and the rear idle discharge port holes which are super tiny have to be closed off and also bigger discharge ports have to be drilled in to the rear base plate on the 1850.

Now I know that sounds kind of confusing but let me say this. The cast or billet base plates that are setup for a 4 corner idle works with either a 2 corner or 4 corner idle main body without any modifications being done and can work both ways. They unlike the 1850 holley 2 corner idle base plate does not have a groove channel to share the rear fuel with the front. I have taken a holley 1850 main body and left it as a two corner idle as it is from factory and installed a billet base plate on it with the 4 corner idle style and put on a rear metering block with no idle mixture feature and also put on a rear metering block that can take idle mixture screws but took out the screws and put in brass allen cup screws just like quick fuel does on there billet metering block kits for converting a holley 4160 into a 4150 carb with two metering blocks instead of just one.

Sorry for putting all this information out there but I am putting all this down in case others might read this and also to give you a better understanding the difference between these carburetors. The quick fuel billet metering block kits they sell for the double pumpers and vacuum secondary kits are all the same blocks except the only difference between the ones for two corner idle vs the four corner idle is on the secondary metering block they just put brass allen screws with loctite in place of the idle mixture screws. I got that information from quick fuel themselves and also found out after working with my own customizing stuff.

The holley 1850 I ran with the billet base plate and the billet metering blocks with the secondary block I ran it as a two corner idle setup and it worked just fine but taking the holley 1850 base plate and putting it on a main body made for a 4 corner idle with the rear holes made into the main body etc I don't know what effect it would have and if it would work or not as I have never tried it but only the other way I mentioned above.

I don't think its so much as a problem with the transfer slot being slightly bigger as for me it has not made any difference on my different builds over the years from the holley or the quick fuel slayer carb but the only thing that made the difference was the idle circuit calibration and that is achieved in the idle feed restrictor sizes in the metering blocks or as in the case of the holley 1850 and quick fuel slayer the rear metering plates which I don't use and swap those out for metering blocks instead and that is where you need to get in the right size idle feed restrictors to give your engine what it wants as that is not only the idle in park calibration but also is what you run on around town and below 40 mph and also under 2000 rpm cruising wise and low speeds.

The quick fuel slayer is way richer out of the box vs the holley 1850 which is calibrated way leaner and is more for stock small blocks and rv cam size and anything over about [email protected] it is to lean and the quick fuel slayer will be pig rich on a really mild small block build. Heck if it tells you anything the quick fuel 600 slayer out of the box the idle circuit would be to rich for even my 377 dart shp build which has a 268/272 220/[email protected] 510/510 lift 114 lsa and dart 200 cc pro 1 platinum heads and around 9:8 compression ratio.

I have a holley 600 1850 carburetor with a secondary metering block installed on it that is the conversion kit one that holley sells that you get with the longer transfer tube and it is also the same secondary metering block on the holley 670 street avenger 2 corner idle carb. It was to lean for my engine so I had to drill out the primary idle feed restrictor size on my metering block to .033 and the secondary to .033 as well so my idle was just rich enough for my engine to run right as a 2 corner idle setup. When I once used a 650 double pumper holley 2 corner idle carb it had the same restrictor size in the two blocks like the quick fuel carb and it was to pig rich and the air bleed size was about the same as the holley 1850 and all I had to do was go smaller in the secondary metering block from .039 down to .033 to lean my idle out so it was not to rich and having a pig rich idle and crappy fuel mileage around town and at lower speeds.

The slayer out of box has 68/74 jetting. 70 primary idle air bleeds/39 secondary idle air bleeds.
Primary .033 idle feed restrictor and .039 idle feed restrictor.

That idle circuit is pretty rich for a small block with a small cam size under [email protected] with at least a 110 lsa. or larger like 112 to 114 lsa. If the cam had a tighter lsa of 106 and a lot more overlap then it might not be overly rich as camshaft specs effect a lot of things on what a carb tune needs to be and the right amount of timing etc. The more overlap the camshaft has the richer the mixture needed to get a decent enough idle along with proper transfer slot exposure, adjustment etc.

Now onto the holley 1850. It has around out of the box 65 primary jets and secondary metering plate equals about a 64 jet size but its way lean on that secondary side part. 78 primary idle air bleeds/49 secondary idle air bleeds.
.028 primary idle feed restrictor and .031 idle feed restrictor on the secondary metering plate.

Now on air bleed sizes you have to make a change of .04 up or down to make a very slight change on the idle circuit to have any difference but the air bleeds are not as sensitive to change vs the idle feed restrictors in the metering blocks. On the idle feed restrictors just changing the ifr size .001 bigger or smaller make a double percentage difference of change in the fuel flow but I don't know the math formula for all that as its in my books. Going from a .028 size to a .031 is quite a difference in change in just one block and doing it to two blocks will really effect of the carb tune.

I don't know what all issues your having but that is why your getting different results between using the different carbs and for me wise the quick fuel base plates with the slightly longer and bigger transfer slots has never caused me any issues like some people have had to the point that folks actually put transfer slot restrictors in the main body to help lean out the transfer slot because of certain cruising conditions they could not get it to lean out enough or it was just always to rich when they used an o2 air fuel ratio gauge to monitor things.

For me with my milder and even radical builds before I have never had to do any radical thing such as having to put restrictors in my main body to get better control of the transfer slot in relation working with the idle air bleeds and the idle feed restrictors in the metering blocks. All I have had to do was get the right idle feed restrictor size front and rear regardless of what carb brand I used to get it running right. The holley 1850 I had to drill out the pressed in ifr's and tap the blocks for 6/32 x 3/16 brass allen cup screws and drill them to size of what I needed to get what my engine I needed.

Post all the specs of your engine and your vehicle and transmission and rear gears and what problems your having etc and hopefully I can help steer you in the right direction.

 

[57Nomad]

Eric32, thank you for info. You guys helped a lot on setting up my last project.

I was initially inferring that the Quick fuel BR-67253 & HR580VS offerings were not specific as to differences in Holley spec’s.

Possible application would be for 327, L79 with Comp 270 hydraulic cam and HEI only modifications as a replacement for Holley 3810. I understand both QF’s are set up far more rich than 60’s vintage. So full adjustability with be of consideration.

 

[hirschdalechevy]

Thanks eric , I will post a new thread

 

[eric32]

I can tell you that most likely the quick fuel carburetors will be richer setup wise out of the box vs a similar size compared to holley and not just in the jets but also on the air bleeds and the idle feed restrictor size on the metering blocks and or secondary metering plates.

Also the brawler carbs were very nice when they first came out as they not only had changeable air bleeds but also the metering blocks had changeable idle feed restrictors and also power valve channel restrictors could be changed.

I had gotten a quick fuel brawler double pumper earlier this year that came with the billet metering blocks and I was expecting changeable idle feed restrictors along with the power valve channel restrictors and holley completely got rid of that feature and went cheap on those carburetors and now use pressed in restrictors like the other carburetors they have on the cheaper list of things and there listings on there site are not as specific like they used to list, but give some basic information such as air bleed size and jetting size on most of there quick fuel brand carburetors.

The brawler metering blocks I had with my double pumper I could have made the idle feed restrictors changeable by drilling the pressed in ones out and use brass allen screw cups in there place drilled to size but the power valve channel restrictor hole was a massive .070 which was way to big for a 650cfm carburetor as they range normally within .040 to .050 at the most and a 750 will range around the high .040's to high .050's. From when I posted it way earlier this year an 850 cfm carburetor takes about a .070 size power valve channel restrictor.

It's sad how holley took the quick fuel carbs and cheap out on them yet raise the prices quite a bit. The brawler carbs were nice when they first came out and now there almost a hundred dollars more in cost while being made with less tuning features. The billet block on the power valve channel restrictor size was to close to the power valve threads which would not allow me to drill a proper size hole to thread a small restrictor in place by using a brass allen cup screw as it would have damaged the threads and made the power valve unable to screw in.

The holley brand ones I have not checked to see but I have messed with them enough to pretty much know real close what they would be calibrated at to a point starting off wise. The quick fuel slayer 600 still used the pirmary metering block to where you can change out the idle feed restrictors and power valve channel restrictors at least the last one I had gotten for a spare was about a year and a half ago and they might have changed that too but I don't know. I just leave it as a two corner idle carb setup and buy a secondary metering block conversion it from all carbs for $42 bucks plus shipping and take out the pressed in restrictor and tap it for the brass allen screw cups and make them changeable for the future if need to do so.

If you want the best bang for the buck with out having to rob your bank account of around $500 bucks to have a carburetor and if your not going to race your vehicle and just cruise with it, holley in there store on ebay has refurbished carburetors of the 600 0-80457 street warrior for $229 with shipping before taxes or if your lucky they have the quick fuel 600 slayer for the same price as well and I just checked and it would work excellent on your 327 build as I use them all the time.

The only downside on the holley street warrior it would be kind of lean and you would have to get a secondary block if you really want the carburetor to be more tunable as the secondary metering plate is about worthless and is only like a 64 jet size and is not enough for the secondary side of things. The quick fuel slayer is more better as you can change things on them without having to drill and tap stuff at least the last one I had came with those features minus the rear metering plate having no options replacing the idle feed restrictors but they are a better metering plate in the sense they take jets and is more better for the same cost plus they come with center hung bowls vs the street warrior comes with side hung fuel bowls but for just cruising and no racing there really is not advantage one over the other if just doing normal driving.

What I do is buy the refurbished ones as they are just as good as new its just where people got them and did not know what hey were doing and most likely could not setup them up right. Holley goes through them and replaces anything that needs replaced and uses all new gaskets etc and are as good as new. I just looked up the quick fuel brawler 570 and it uses the same main body as the 600 street slayer and the same base plate and has the same size bores and boosters so them listing it as a 570 cfm carburetor is just a marketing thing and its got a 4 corner idle system and changeable air bleeds but on the metering blocks I don't know if they have the changeable restrictors or not and I doubt they do since the higher priced billet series don't.

They just have it jetted down some and smack a label on it as a 570 but it would honestly most likely flow more then that at 600 plus cfm as it actually has bigger primary bores in the front vs the holley 600 street warrior which I have on hand as well ( got plenty of spares and parts laying around) and the quick fuel main bodies used for there 600 and 650 series carbs are 1.30 on the primary side vs the older style holley main body which has only 1.28 so there is a slight difference there but not enough to make it a night and day difference. Also the picture is misleading as the brawler carb of the 570 and the quick fuel 600 slayer since they use the same main body have straight leg boosters and used to come with down leg boosters.

The HR 580 would be the same as the brawler except it has down leg boosters and more cost and is also a 4 corner idle and should have the changeable air bleeds still and also should have the changeable idle feed restrictor option and also the power valve channel restrictor changeable option as well, but they could have changed that but they are the same size main body just with different boosters and also the same 1 9/16 base plate and the $580 is in reality a 600 cfm carb just stamped with a different part number and labeled as a lesser cfm rating for marketing purposes to sell.

Just some differences in the jetting and air bleed sizes for them and the booster type being used and the metering blocks may or may not have the changeable restrictor options. The main body on those HR 580 with a 1 11/16 base plate would make it a 650 cfm carb and that is what quick fuel uses on there HR 680 and the only difference is the base plate bore size and different size jetting and slight difference in air bleed size but nothing more then that.

The brawler would be nicer for the price wise but I don't know if the blocks are a newer design like the crap billet ones mine came with or not or if there still using the better old quick fuel cast design blocks which even if they had pressed in idle feed restrictors and just a drilled hole for the power valve channel restrictor they can be tapped for brass allen cup screws if you want to make them changeable.

The HR series carbs I would hope still come with the changeable restrictor options. So the brawler carb would be good for the price since it already has a secondary metering block and would save you cost there and its a four corner idle setup and with that comp cam 270 H it would be really close out of the box and you might need to change out the jetting on the rear up a few more sizes to about a 74 from the factory 70 which would be kind of to lean in my book.

My 600 holley carbs and also 600 or 650 quick fuel carbs I have used for my 350 builds over the years and similar to your 327 minus the cubic inches difference I have had mine jetted most with 65 to 68 primary and around 73 to 74 secondary on the jetting wise and its been really good with that setup and also it depends on the power valve channel restrictor size as well and the main air bleed size that will also make you need to go up or down a hair on the secondary jetting.

Normally the rule of thumb is about 6 to 10 size difference on the jetting from front to rear. Many factors can determine that such as engine build and the cubic inch size and also the intake manifold being used along with the size of the cylinder heads and how much flow your engine can take in etc and camshaft size.

Mine was setup with a .046 power valve channel restrictor size with my jetting and it gave me great results and that was with a cam with around that same size except mine was a hydraulic roller. I currently run a 268/272 220/[email protected] 510/510 lift 114 lsa hydraulic roller in my dart shp 377 small block and I run my carb setup like I mentiond above and it runs like a charm and I get 19 mpg with my 96 s10 and a turbo 350 and 3.42 rear gears.

 

[57Nomad]

Eric, thank you big time. I feel good I was looking at good choices. The Holley rebuilds will be my first choice. I did not know they were selling rebuilt units at such a big price break. I was under the impression (I don’t know why) that Holley just rebuilt customer owned carbs. My old 3810 zinc alloy carb has seen better days. I’ve straightened and surfaced flat and rebushed the throttle shafts and it will be still a “leaker” again. I runs great, but who needs the leaks. I just don’t want more disappointment redoing it again and have the same results a month or so later. My thought is the zinc is not stable any more. The “modern“ aluminum Holley’s I’ve used lately don’t disappoint me with leaks.

 

[eric32]

Yeah 57nomad the aluminum carburetors seem to be better and I bought some brand new zinc bodies from Holley and believe it or not they were not flat enough on the surface of the primary side and leaked and I had to sand and grind them down just to get a flat enough surface for the primary metering block to seal around the power valve area. When I get any new carburetor I always check for warpage and machining surface flatness with a feeler gauge to save my self a headache etc before even bolting it on. The aluminum main body of the holley or quick fuel carbs have been .002 or less as to a lot of the zinc castings have at least a .006 or more towards the center area.

The base plate on the newer holley street warrior has the better primary throttle shaft with the nut on the side of the throttle shaft bracket so you don't ever have to worry about it getting loose like the original pressed on holley throttle ones pressed on bracket that is on the side. The street warrior carbs even though they come with side hung bowls are not the best for any track time and don't hold as much fuel as the center hung bowls but for anything just for everyday cruising and driving they are fine as long as you don't plan on doing a lot of cornering and extra long wide open throttle bursts etc.

On my 377 build I currently have one of the old 600cfm holley 80457 with just a rear metering block and the side hung fuel bowls and nothing fancy on it except an adjustable vacuum pod top like all the quick fuel vacuum secondary carbs have and it runs fine on my build for cruising around. I use it as a winter carb since I have my truck sit during the winter time and its just an old one I got off ebay for less then a hundred bucks and don't worry about it going bad over time from sitting.

My custom good one I have with all the fancy features and stuff I keep it for the spring through late summer months and then pull it off come storage time and put my old 600 holley on for the winter time and it sits for the most part but I have it on just in case I would have to get it out for an emergency purpose. I just know todays fuels are harsh on carburetors especially when they sit and yeah I can drain it but there is still fuel that sits inside certain areas still.

My custom good one when I take it off I drain the fuel and spray silicone on the gaskets and needle and seats to keep them from getting dry and it has worked for several years that way without me having to do but bolt it back on and it runs like a charm. I just know the modern fuels eats at them and in my area unfortunately all the gas is E10 and I use the E10 fuel stabalizer during the winter months and spray some in my carb as well to keep the fuel fresh and help against moisture forming in the gas and it going bad.

 

[eric32]

Me swapping out carburetors is most likely overkill for each season time but I want to keep my main carb in good shape as long as I can while the other one for the winter months is a sacrificial one.

 

[eric32]

Below is a good buy and only one left when I last checked it. For $229 shipped before taxes you can't beat the price.

Quick Fuel FRSL-600-VS Slayer Series Carburetor 600CFM VS-Factory Refurbished | eBay

Factory Refurbished carbs are NOT old worn-out carbs that have been rebuilt. Generally, they were simply adjusted out of working range by the installer. Rather than scrapping them, we are making them directly available to the public.

www.ebay.com

 

[hirschdalechevy]

Thanks again eric, great reading, great info. Right now I have the street warrior on my gm sp/350 and it runs the best but not perfect. Started with the quick fuel off road 600cfm , paid 580.00 dollars for it. Took it apart to change ifr's and main jets etc... and its stamped slayer inside on the main body. On the holley web site the quick fuel off road carbs are no longer made, I got one of the last ones. So I paid big bucks for a slayer with different vent tubes. But I will say the side hung fuel bowls on it are way bigger than the regular side hung bowls. Great looking carb but everything I have done with it I still cant get it to run as well as the street warrior. I am still learning the carb. thing , but having fun with it.

 

[eric32]

Forgive me for not having all your user name but hchevy what is your exact engine you have and what vehicle is it in and also on your street warrior is it still in stock trim out of the box? What issues are you having and what transmission and all your other info and maybe I can help you iron out your issues and get in you in a good direction. I have the equivalent of the street warrior on my dart 377 shp small chevy build and its a pretty stout build with high flowing heads and a decent size cam but nothing overly radical and a high stall convertor and all I had to do was recalibrate my idle circuit and make it rich enough to work with my build and I added a secondary metering block with being able to put jets on it and hardly had to do anything but just a minor idle circuit calibration change and it runs like a charm with no issues in any giving driving situations and that is with the side hung fuel bowls and nothing else fancy on it.

 

[hirschdalechevy]

User name is rich, I have a 77 chevy blazer 4x4 , 4600lbs apx. 37 inch tires, 4.56 gears , turbo 400 auto. I had a gm h.d. motorhome convertor in it but just swapped it out for a 2,000 rpm stall convertor because my blazer is a dog on the bottom end.

bought a new gm crate motor sp/350 , 357 hp, 410 tq.

9to1 comp.
vortec heads
gm dual plane intake
gm roller cam 215int./223ex. @ .050 , .473 lift int. @ ex. 108 lobe sep.
1 7/8 headers , dual exhaust , h-pipe , 2 1/2 pipe, borla pro xs mufflers
I live at 5,500 feet elevation

I did check for top dead center and its all good . This motor seems to like a lot of timing 22* initial and pinned the h.e.i. for a total of 33* coming all in at 2,300 rpm, have 6* more with vac can plugged into full vacuum.

The warrior has 64 primary jets and a modified metering block by comp carbs. It runs pretty well now but its super rich on the afr gauge under light throttle (10.5) so I have been lowering the power valve thinking that might be it . I am down to a 4,5 as we speak. Idle is 12.8 to 13 and wide open is 13.5 or so. Under light throttle load I see 10 all the time. Dropping the power valve size seems to be helping. This motor has low vacuum as well , 11 idle, 9 in gear.

I would like to run the quick fuel because of all the features but I can get it to run right. I dropped main jet sizes , ifr sizes , changed pump cams etc. and I cant get the idle great and its rich everywhere with a big lean spot in the middle. The primary metering block has custom emulsion set up by comp carbs as well. I could go back to comp carbs. but its a drive for me and I would like to get it perfect for doing it myself. Thats why I was thinking make one good carb. out of the two. They are both brand new as well.

The street warrior runs well I just want it to be perfect and get the rich spot gone. I was thinking of trying an open 1 inch carb. spacer as well.

 

[eric32]

Well first off you can't always get the magic 14.5 air fuel ratio number especially on performance motors with bigger cams and I can tell you on my build with my cam similar in size to yours but still different and with a little more duration @50 but with a good bit of a wider lobe separation angle I still have to run my idle circuit on the slight richer side compared to a smaller cam size as when you get into the bigger cams and tighter lobe separation angles with yours being at 108 it takes more fuel to run it and with both of your carbs being customized I don't know what size ifr sizes you have in your metering blocks and what the specs are of your metering plates on the rear.

With them having messed with the emulsion holes that can affect the entire fuel curve to be rich lower and leaner higher to leaner lower and richer higher and that goes hand in hand with the main bleeds and jetting but that is only at higher speeds. On all my metering blocks I have always had them left at .028 on all the holes and on the quick fuel blocks there is three spots and they are always left at .028 and that is almost the universal standard for beginners on the 600 to 750 range holley and quick fuel brand carbs out of the box.

The bigger the emulsion holes the leaner the overall fuel curve is from top to bottom to a certain degree and the amount of length it runs it like that. The smaller the emulsion holes the richer the fuel curve will be in relation to the jetting and the air bleeds and will differ from the bottom to the top of the fuel curve. I have never had to mess with that before as its really tricky to mess with that area as that is way super advance tuning and I honestly have never had a need to do that.

Now on some aftermarket metering blocks they have a whopping 5 emulsion holes on each side of the metering block and that is mostly used for all out drag racing motors that see no street time and the five ports are usually the first one is open, second one plugged, third one open, fourth one plugged and the last one open for street use or if you don't do it that way depending on the engine build can lead to a really rich fuel curve that is really hard to get dialed in well so its not super rich and the emulsion tuning area is not done to often for street builds and is over exotic to do so especially with a milder motor like yours.

Even some of my more wilder motors I have never had to mess with those areas of the holley style carb. For me in my opinion I don't know what size you have and what they have done to your blocks or what size ifr sizes you have or what power valve channel restrictor size you have as well. Is your richest running area while cruising when the mains are into effect being used at 2500 plus rpm and going down the highway at 55 mph or so or elsewhere?

Also you can't always try to get the leanest setting at idle as with most of my research the bigger cams in the high teens and going into the 220 and more @ 50 duration cams and with a later closing intake valve and more seat to seat duration and with more overlap as the size increases the idle circuit has to go up richer to a certain degree and you can't always go for a 14.5 idle setting as it will make it often to lean and most on average is around the 13.5 area on the idle but can slightly differ and you can't always shoot for the leanest across the board.

Also what pump cam color are you using and also depending on driving conditions etc your air fuel ratios will won't always be lean all across the board like you might want as the performance builds need what they need and more often or not need more fuel vs something way milder. An o2 air fuel ratio gauge is something to help you fine tune things but is not the be all end all of tuning of things for numbers wise and you still have to give your build what it needs to run right.

I have been there before but not with a gauge though but with old school methods and tried to always calibrate mine as lean as possible but end up always having to keep it slightly richer then what I want but I have to give my engie what it wants to run right.

I would take out your metering block and measure the emulsion holes and see what size they are and as far as wide open throttle goes your way to lean and should be around the 12.0 to 12.5 at the most and the power valve should not have any effect on cruising unless you go below the vacuum rate of the power valve so your getting a ultra rich mixture even though you have your jetting on the small size and most likely the secondary metering plate on the street warrior is like a 64 jet size as i looked it up and that is way to lean for wide open throttle and you would need at least a 74 jet as a starting point on the secondary side of things.

As far as your idle goes you need to make sure your transfer slot is not showing more then .040 thousandths and no less then around .020 give or take a hair as you can't have it completely closed off or it open up o much or it will make for a pig rich idle as it will be pulling to much fuel from the transfer slot and make your idle mixture screws not adjust very well or not at all as it needs to have just enough transfer slot without being to much and you also need to make sure your secondary side is open up at least some to help balance out the primary side. That will effect idle readings on your gauge as well.

Also shooter size and pump cam combo can make a quick lean condition when hitting the throttle during take off and will read high on your gauge then go back down after the transition picks up the momentary lean spot and adjusts to it. Or if you have to big of a shot it can sometimes show a temporary rich spot but its mostly rare for that unless you have the pump shot way to big for your said application and other factors playing into things.