Holley Tuning Question

A bit of a different animal than what you're building but I'm running the identical Cam Research stick in my 10:1,SCJ headed,545 street motor. Lots of chop at idle and light spring requirements which I'm hoping will be good for longevity. It runs awesome other than a weak idle vacuum signal so tuning 2X750's has been a challenge. Bounces off a 6200 chip easily and seems like it wants to spin higher,6500 maybe.

the tree man wrote:A bit of a different animal than what you're building but I'm running the identical Cam Research stick in my 10:1,SCJ headed,545 street motor. Lots of chop at idle and light spring requirements which I'm hoping will be good for longevity. It runs awesome other than a weak idle vacuum signal so tuning 2X750's has been a challenge. Bounces off a 6200 chip easily and seems like it wants to spin higher,6500 maybe.

So How Much Vacuum are You Pulling at Idle and What Size Power Valves if any are You Running?

^I Would ASS/UME You are at 2.5Hg-3.5Hg on The Valves

My 294B8 With 1.8 (Would Be About .609/.640 With The 1.8's) Rockers would Not Be Much Smaller Lift Wise Then What You and Dave Have, and The Duration is Almost the Same, Like 255/265. All Three are 108LSA.

^ The 1.8's Would Up The Duration a Small Amount Also, I Believe.

Interesting Thread on The Larger Rocker Arms Below V.

https://www.460ford.com/threads/1-73-1-8-rockers.158495/

Bounces between 7.5 to 8.5 inches at 1050rpm in park. Drops to about 5.5 to 6.5 in gear at 850rpm but it really doesn't like that so I bump into neutral when in traffic. My Coan converter is a bit tight,3500rpm,I'm sure a looser converter would help the idle in drive rpm. Idles/runs best at 31 degrees locked out and that's where it generates most vacuum also. My experience with dual quads is at least a couple more inches at idle,10 inches+,makes tuning the idle,tip in and light cruise AFR's easier. Oops,forgot about power valves. I don't recall what's in there now but I've tried 6.5 up to 10.5 working to eliminate a light tip in flat spot but non of them seemed to make an appreciable improvement so I'm still farting around with it.

the tree man wrote:Bounces between 7.5 to 8.5 inches at 1050rpm in park. Drops to about 5.5 to 6.5 in gear at 850rpm but it really doesn't like that so I bump into neutral when in traffic. My Coan converter is a bit tight,3500rpm,I'm sure a looser converter would help the idle in drive rpm. Idles/runs best at 31 degrees locked out and that's where it generates most vacuum also. My experience with dual quads is at least a couple more inches at idle,10 inches+,makes tuning the idle,tip in and light cruise AFR's easier. Oops,forgot about power valves. I don't recall what's in there now but I've tried 6.5 up to 10.5 working to eliminate a light tip in flat spot but non of them seemed to make an appreciable improvement so I'm still farting around with it.

Sounds Like Bigger Shooters and More Agresive Pump Cams May be in Order.

Are You Running Them Progressive or 1/1?

1 to 1. Never had any luck with progressive linkages. Bigger shooters is my next move but ran out of summer up here. I already have 37's with the quick blue cams which I thought should be plenty but with the reduced velocity of the low vacuum I may have to overcompensate. It's only lean as I ease into it,steady idle and light cruise AFR's are around 13.5 so I don't want to fatten it up much more to crutch over the lean spot. Maybe bigger shooters with a slower cam will work better. The blue is stroked out at about 1/4 throttle. I initially had 600's on it for a season and they drove a bit nicer but the 750's give a seat of the pants boost from about 4500 to 6000+ and I hate to leave those ponies on the table. Hopefully I can get the bigger carbs driving as good as the 600's,have my cake and eat it too.

the tree man wrote:1 to 1. Never had any luck with progressive linkages. Bigger shooters is my next move but ran out of summer up here. I already have 37's with the quick blue cams which I thought should be plenty but with the reduced velocity of the low vacuum I may have to overcompensate. It's only lean as I ease into it,steady idle and light cruise AFR's are around 13.5 so I don't want to fatten it up much more to crutch over the lean spot. Maybe bigger shooters with a slower cam will work better. The blue is stroked out at about 1/4 throttle. I initially had 600's on it for a season and they drove a bit nicer but the 750's give a seat of the pants boost from about 4500 to 6000+ and I hate to leave those ponies on the table. Hopefully I can get the bigger carbs driving as good as the 600's,have my cake and eat it too.

If You are Going To Run 37 or Larger Shooters, Grab a Pack of The High Flow Screws.

4 Pack  V

https://www.ebay.com/itm/154655834344?chn=ps&_trkparms=ispr%3D1&amdata=enc%3A1ciMbbab3QmCusEQpSng7Rg95&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&mkscid=101&itemid=154655834344&targetid=1644837434763&device=c&mktype=pla&googleloc=1026515&poi=&campaignid=20125739985&mkgroupid=149128855676&rlsatarget=aud-1317154473495:pla-1644837434763&abcId=9312975&merchantid=114593520&gclid=CjwKCAiA9ourBhAVEiwA3L5RFkYD627vgYY-76JeV85Jatk6Q88JxaN_BPdsyC-1gy1Hy_4pZINscRoCVf4QAvD_BwE

2 Pack (If You Need a Few Extra's For Something Else, The 4 Pack is a Good Bargin)  V

https://www.ebay.com/itm/165132913315?_trkparms=amclksrc%3DITM%26aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D20201210111314%26meid%3D05b41a134b564a879bca624c62072d5c%26pid%3D101195%26rk%3D2%26rkt%3D12%26sd%3D154655834344%26itm%3D165132913315%26pmt%3D1%26noa%3D0%26pg%3D4429486%26algv%3DSimplAMLv11WebTrimmedV3MskuWithLambda85KnnRecallV1V2V4ItemNrtInQueryAndCassiniVisualRankerAndBertRecallWithVMEV3CPCAuto%26brand%3DHolley&_trksid=p4429486.c101195.m1851&amdata=cksum%3A16513291331505b41a134b564a879bca624c62072d5c%7Cenc%3AAQAIAAABUObhgc4Nk8%252BdtAwOww4FKLaj%252FQ5qqgDlQCuqZA43WcPFUWDERCUugbbOk7XQv0JXlBfqCg2xKF3WcPghxGMFw2oSlXvfExEaMYr7I7LmrHcP6czY1wIMt0ORyKiCWt95xldincyyBx3g%252BNDW%252B%252FhWUgTaBhK6xAm%252BJIbCOMehu%252BdwgLt5izZNHlsnMShGKs6leDHD6WHyASNQNbLhKRkmbjGRLd0maeUOUB0vmKQOiI7g2%252BGDZFyb2r0QcqmXIdkuG5VpJaoqadYooWkaRe4mIBU4MHKaC3kw2SCsHR8xasVlNKTxgyOMDXTZmP8IScJCm27N6WP9k56KDnVKwsju7uauJJCpsZq%252BNIZomdRqPuKrC4%252FSjhhhTsTP%252BTZ7bJ%252FInzZdwNIDV0EU6va1CFK%252B0EeAn7xpd7xVObfQddnqgLlTZ62QalTJVKgs8T4Flu2KLg%253D%253D%7Campid%3APL_CLK%7Cclp%3A4429486&epid=227109608



Try Turning Pink Cams Upside Down.

Next Step 50cc Pumps.

I Would Not Go Back to 600's with your Combo.

Get Some 780 Downleg Booster Main Bodies. The Down Leg Boosters are Supposed to Flow Sooner and The Bar Being Removed, Through the Center of The Booster Adds Like 30 Cfm, Bringing 750's to 780's, According to the Old Holley Books.

I TellYa Your Car is Just Too Cool For School.  Very Nice Ride


PS1: Think About This For a Second. A 1050 Holley Dominator Comes With Two(2) 50cc Pumps

PS2: Are You Running The 3310-2 and Up #21 Metering Plates?

It's very close so I'm committed to resolve the issue and use the 750's. I have a lot of Holley supplies so everything I need is on the shelf including hollow screws. A local guy has hundreds of Holleys and thousands of parts he reworks for peanuts. All dipped and cleaned including new beautiful rainbow dichromate/yellow zinc perfect for my old school taste. I paid $500 for the two 750's with all the parts I speced out for my use! Killer deal. 3310 with single feed to fit on the Blue Thunder intake. I don't recall the metering plate # but I did drill them to 4 jet sizes bigger to get 12.5ish AFR's at wide open. It sure feels like it needs more pump shot so that's the first project this winter and we'll see how it pans out next spring.

the tree man wrote:It's very close so I'm committed to resolve the issue and use the 750's. I have a lot of Holley supplies so everything I need is on the shelf including hollow screws. A local guy has hundreds of Holleys and thousands of parts he reworks for peanuts. All dipped and cleaned including new beautiful rainbow dichromate/yellow zinc perfect for my old school taste. I paid $500 for the two 750's with all the parts I speced out for my use! Killer deal. 3310 with single feed to fit on the Blue Thunder intake. I don't recall the metering plate # but I did drill them to 4 jet sizes bigger to get 12.5ish AFR's at wide open. It sure feels like it needs more pump shot so that's the first project this winter and we'll see how it pans out next spring.

I Bet I Talked to Your Buddy on FleeBay up There.

He was Selling his Replated Main Bodies. They are Extremly Nice Looking. He Said he Had a Commerical deal for a while and did a bunch of Them.

Thow some High Flow Screws and Some 50cc Pumps on Them and Play with The Shooter Size and Cams Until You Get it Like You Want it.

When It's Cold They Will Want Quite a Bit More Pump Shot. Just Something to Keep in Mind, Especially if You are Running No Choke/Chokes.

Also a Couple of These with a Balance Tube will Open More Tuning Windows.

https://www.ebay.com/itm/380404514465?hash=item5891e03ea1:g:s9gAAOSw5rBlVMwr&amdata=enc%3AAQAIAAAA8CHJ5QpjlN2fmmqWe26CpnAN9P8Ed2Eb281VQqsz41H%2FzFZvRJCqAjmXb%2Fgjx46NBACF9ElQnx1il5KJ3nZIecNH2cPWbUZxjjEwS7YCxSuDV7%2FHCk48IntOwHDs8tatP%2FfmyeaNDAxtu2VG9OTIJtwGUqBq7VCWvsMSeLHpSY6LFjVgBEAwtjF6t9m2PJewSl7RvxCXs%2BG8o1LUu1zPkNOyb0vBffxSKImGWG4otggXk85JmywLxbEZKUtnbKf%2BALb%2BpfbTOktMedCmslln4%2FxrcqlZwAfNb6Z1gFYTY0XmLY7u%2F%2B%2FC%2BlV792Zu412UbQ%3D%3D%7Ctkp%3ABk9SR8766L2CYw

Or If You Like Semi Old School, These

https://allcarbs.com/product/holley-vacuum-secondary-with-balance-tubes/

Gotta be my pal. He has Holley stuff stacked like cord wood. He had a jobber connection and made the most of it to everybody's benefit. Kudos to him for sharing the wealth. He's got some cool Fords too. I have the quick change pots with a balance tube on there now and once I'm done musical chairs with the secondary springs I'll put on the sweet dichromate originals I got from him also. I've seen the adjustable pots but I think I have that area sorted. I'm going to try .040 squirters/hollow screws and see if it solves the problem,if it's better but still there I'll give the 50cc's a whirl. I bought a couple pairs of carbs and a bunch of parts from Allstate over the years. I had some issues but they made it right. Considering where they are and where I am it was very inconvenient but did get resolved.

They are Nice if it is the same Fellow.

He had a few crosspic's slip in the 3310 listing when I spoke to him. Very Nice Guy and Quality Parts, For Sure.

https://www.ebay.com/itm/364462853182?mkevt=1&mkpid=0&emsid=e11051.m43.l1123&mkcid=26&ch=osgood&euid=5f6a5d5050e04a9e8a13e38383bcfc24&bu=44118527576&osub=-1%7E1&crd=20231001085331&segname=11051

Chekout the Extra Hole above the Transition Slot on My Marine 460 780 Holley's.

Not Sure if it will help with extra fuel in that area but, they are different then the 3310 Down Leg Booster Main Bodies.

The Rear Boosters Also are Cut Out at The Bottom Front/Sides, I ASS/UME to Help The SCJ Intakes They Came On in the Boats.







IFR Hole Size on The Primary Metering Blocks as Well as the Secondary Metering Plates, Plus Transfer Slot Lenght and Width all Affect the Intermediate Circuit Transition.

The Shooters and Pump Cams as Well as Secondary Spring Rates are easy tuning Semi Bandaide Routes.

If You Could Lower The Primary Throttle Blades (IF) and Raise The Secondary Blades, (Especially if Their Transtion Slots are Fully or Almost Fully Covered) May Also Help a Tad Getting Them To Turn The Transition Fuel on Quicker.

Keep Working With Them, You'll Get it Lined Out.

PS: I was Looking at You Bud's Other Auctions. I Think I might Get One or Two of These Bad Puppies for Christmas. Never Seen Nothing Like Them Before, Cool as Hell

https://www.ebay.com/itm/363777753696?hash=item54b2d80260:g:LfYAAOSwsWxiOLy8

Bump for Tree Man !!

the tree man wrote:Gotta be my pal. He has Holley stuff stacked like cord wood. He had a jobber connection and made the most of it to everybody's benefit. Kudos to him for sharing the wealth. He's got some cool Fords too. I have the quick change pots with a balance tube on there now and once I'm done musical chairs with the secondary springs I'll put on the sweet dichromate originals I got from him also. I've seen the adjustable pots but I think I have that area sorted. I'm going to try .040 squirters/hollow screws and see if it solves the problem,if it's better but still there I'll give the 50cc's a whirl. I bought a couple pairs of carbs and a bunch of parts from Allstate over the years. I had some issues but they made it right. Considering where they are and where I am it was very inconvenient but did get resolved.

Tell Your Bud Thanks, and Happy New Year's.

An engine with a camshaft around 260@.050" on 108 separation will never have much more vacuum than 8" to 10" at a low idle, no matter what you do to any carburetor that is used.

I'll chime in again. Has been a bit quiet around here. Thanks.

I'll pass your holiday regards to Adrien next time I see him. I'm sure he was thrilled to get your high test American dollars for those rings. I'll probably get my bigger squirters and some other bits from him this winter,if he hasn't buggered off to somewhere warm for 6 months.

My cam is actually a 110 so that can't hurt. The performance improvement was noticeable with the 750's and they're staying on. I port matched the intake to the SCJ heads and in hindsight I wonder if leaving the smaller passage (the intake was cast to fit standard port heads) would have improved velocity through the runners vs the loss in power leaving the smaller port? It looks to me like my heads were ported pretty heavily. I got them from a buddy and they were on a 598" race motor. Probably overkill for what I'm doing and may be contributing to my issues but they were too nice for low bucks to pass up.

^ Check and see How High The Primary Blades Are in The Transition Slots?

Also Ask Your Bud, When You Get Your Parts, If He Has a Couple of #21 Metering Plates. If The Secondary's are Tipping Early They Might be The Culprit. You Could Lock Them Closed, and Test, To Be Sure. You Could Try More IFR Fuel on Them, If Needed. Or Not, You Would Have Them, Just in Case.

I Don't Think You Can Get Those Rings Anymore, Especially at That Price, but, That's A Whole Nother Story.

As To The Intake and 545 Cubes, Big Cam, Decent Compression, I Don't See a Problem. It's Hard To Make Intakes Big Enough for These Monsters is The Problem.

A 4,500 Stall Would Likely Do Wonders

It was way fat at idle so I restricted the IFR's about 20% which solved that and it's 13.5-14 AFR,screws 1 1/2- 1 3/4 turns out depending on weather. I have the secondaries closed tight so I can open the primaries a bit more but the blades are still almost covering the transfer slots. I'm running a PCV and want to keep it but I'll try plugging it to see if eliminating that extra incoming air would allow opening the primaries a bit more to expose more of the transfer slot. PCV is from a low vacuum application,Boss302 or DZ302 if I recall. I thought about cutting the transfer slots a wee bit deeper or or shaving off the lower edge off the throttle plate at the slot to get more air movement but that's an ugly change to rectify if it doesn't work out. To be honest,the whole car,not just the powertrain,has been a far longer road to get serviceable than it was supposed to be and I eventually tired of wrenching on it. Once it was driving at a level acceptable to me,I just wanted to mile it up and have some fun. I'm more motivated this winter to get back on it and make it better so I've got a list of stuff to repair/improve/experiment with....again. When I checked the lash last winter,I tightened it up a bit out of curiosity (I think about .005) and did see a loss of approx an inch of vacuum so this winter I'm going back to the .015 speced for it.

Not much I can do now about the porting of the intake anyway so that's that but I wish I would have gone looser on the converter. It's a Coan and they built it for my combo but to keep it close to coupled up when I'm cruising on the highway they shot for 3500ish and it's almost bang on when I punch it. I think a higher stall would help my idle in gear but may make traction an issue when it comes on the pipe. Coan will re-jig it to about 4000 for me if I send it back but there's not enough room in the tunnel to drop the tranny,I have to pull the engine to get the converter off and that nightmare isn't happening unless absolutely necessary.

Happy new year everybody and thanks for the input on my project over the last few years.

^ Have You Thought of Trying .020" Lash?

If you pickup some 50cc Pumps be Sure and Get the Brown Cams for Them.

If you are not getting a stumble from a dead stop off idle I would not worry about uncovering those transfer slots. From a roll punch they'll be uncovered, and the lower point you start from, the more transition fuel available.

I'd see what you can do with pumps cams and shooters, as well, like you said, Valve Lash.

Happy New Year