MIKE 1985

i bought a 3310-6 750 vac sec. i took it apart to clean and it has 84 primary jets. I'm thinking this is wayy too big. From reading your post with muggyshaq i was wondering what primary jet, and cam color and position you would recommend and which secondary spring. The carb has a 31 squirter.

My combo is
355
9.4-1 comp
Dart iron eagles ( 180cc)
224-234 510-520 on 112 LSA
weiand stealth dual plane ( hood clearance in the vette)
700r-4
2600 converter
3.07 gear
26" tall tire.

thanks

Mike

MIKE 1985

i found the stock jetting.

oh and it's a 3310-S, not 6 my fault.

So what cam would you reccomend and what secondary spring to start with ?

hydric

with those gears i'd go just maybe a lil more than stock... you overcam it with low gears your actually killing the bottom-end

but if u like to have your power in the upper rpms, increase your cam size... i went from the stock cam of a vette 350 to one a bit smaller and the tke-off difference is unbelievable...

Chickenman35

Yikes...an #84 Primary is HUGE. Either it was on a really big engine making some big horsepower....or someone might has drilled the Primary air bleeds. Hopefully it is the former and not the latter. can you find out the history of the carb? Any other mods done to it?

Stock jettings a good place to start out with. Should be #72's in the Primary stock. You may be able to drop down to 70's. Might be worthwhile, especially if you street drive it. Does it still have the stock metering plate in the Secondary, or has it been replaced with a metering block? What part#plate\Jets are in the Seconadry?

Blue pump cam in #2 hole should work fine. #31 shooter should be OK....but those 3.07's don't help. You may have to go up to a #35 shooter if the car stumbles off the line with the #31's and Blue cam ( Don't forget...install in #2 hole ).

Vacuum Diaphram spring: I'd start out with a long yellow and work down from there.

Make sure that you have enough intial timing in the thing. That will help overcome those tall gears. Minimum of 12 degree initial. 14 to 16 degrees intial, if the gas quality is good enough. Run a Crane adjustable vacuum diaphram. Set it up to maximum vacuum advance ( 15 degrees ). Set the adjustable spring as light as possible. Connect to manifold vacuum. Make sure that mechanical advance does not start until about 1,000 to 1,200rpm. All mechanical advance in by 3,200 to 3,500 rpm. Total advance ( Vacuum advance disconnected of course ) should be around 35 to 37 degrees.

Her's another thread on the " Tuning" subject. Lots of good info here.

I really need help with my Holley

sqzbox

Shame on you for sending him to that thread! I believe if he reads that from top to bottom, he will start having bad dreams.

Chickenman35

BwaaaHaaaHaaa....

MIKE 1985

thanks chickenman,

the previous user actually had (1) 1/8" hole drilled in each butterfly. He said he SBC was just too rich at idle. I epoxied these closed. PLaced th blue cam in the #2 pos and have a #31 squirter in there. So i'm thinking i'm already to fire the motor for the first time....welll not even close.

This is the problem and the explanation for the butterfly holes. When the fuel pump ( elec) is turned on the carb just dumps gas into the engine from the vac opening that located in the power valve opening inb the main body. THIS CARB WAS BOUGHT BRAND NEW AND HAS HAD THID PROBLEM SINCE DAY ONE. It's a 3310-S.

So i take the carb off the car and try and figure this out, what i've come up with so far is the body of the carb is not flat and had to be filled, then the meter plate has a larbe nub ( from the pump shooter) sticking out that's so big the plate doesn't even come close to sitting flat on the body, so the gasket( new) never seals and it leaks in to that big opening and right into the motor.

I will file the meter plate down and see id this corrects the problem, i also plan to call HOlley and share my discust with them on their product.

Has this ever happened to anyone before ?

Mike

MIKE 1985

holley is sending a metering plate out free of charge.

Has anyone ever had this problem before?

It's a 5-7 LB carter pump. no reg required.


Once again it's leaking from the metering plate into the large opening for the power valve on the main body because the metering plate doesn't seal the main body

Chickenman35

If you're dumping fuel from the power valve opening into the main body then your power valve has a leak. Doesn't take much...just a pinhole. Replace the Power valve.

Caution: I'd leave the filing down of ANY projections alone for now. Unless there was a MASSIVE screwup at the Holley factory I wouldn't touch that accelerator pump nub. Make sure that you have the CORRECT gaskets for that carb. Don't simply replace what was in there from before. The incorrect gaskets could have been installed. There are a couple of differnt types that fit the 4150\4160 series.

The nub on the accelerator pump passage is required...it is necessary to compress the gasket an extra amount, so that you get a good seal around the trasfer ports. The factory gaskets are quite thick and the float bowls have to be tightened down firmly to compress the gaskets. All those ridges on the metering blocks are necessary to provide good sealing. One good idea is to replace the factory float bowl screw gaskets with nylon ones provided by Holley and others. Or you can just do what I did and go down to Home Depot's Nut and Bolt selection. They have nylon gaskets there that work perfect. Cost about .03c each..... The store manger says one of his clients buys them by the thousands. Somebody by the name of Mr. Gazzget....

If the block is actually warped it is likely due to the previous owner over tightening things....although I have heard that some of the new Holley lines have poor quality control. Particularily the ones made in Mexico. The HP series are great... US made. The cheaper lines have issues.

But...I think your main problem is that carb is suffering from " Bozo-Itess ". That is... the previous owner mucked things up. "Let's start drilling holes in things cause gas is pouring into the carb"...Brilliant That and the huge Primary jets lead me to suspect that your carb will need some TLC to put it back in shape.

Replace the Power valve. Put the jets back to stock. Make sure that yout fuel pressure is regulated and that you're not seeing more than 6.5 PSI ( preferrably 6.0 PSI ) at the carb. Adjust the float levels correctly. Make sure that the [b] correct [/c] metering block and float bowl gaskets are in the thing...I'd also pull the throttle base and check out that the correct gasket is installed there as well. With 4150 series there are several different gaskets available. Only ONE is the correct one. Others will fit...but you will of course have massive problems. Since the previous owner drilled the throttle butterflies he obviiously ( I hope ) took off the throttle base. Make sure that he didn't drill out the metering plate as well.

I'd just buy a Holley Re-new kit and go from there. The one you want is #37-754....or maybe, a Trick Kit... Part #37-933. Includes extra parts for tuning. More expensive than Re-new kit though...covers many different models of carbs ....so a lot of parts that you don't need.

Holley used to have different Trick Kit part numbers....but now one number covers everything. May not be such a good idea on second thought...you're paying for a lot of parts ( Mainly different gaskets ) that won't fit your application.

Edit: Spelling

PS: Nice of the guy to sell you a carb that had a problem. I'd be screaming at him....not Holley.

MIKE 1985

thanks chicken man.

i bought and unstalled a holley trick kit from autozone. I'll have to check the # when i get home. I installed the new power valve that came with the kit, all new gaskets, neeedle and seats and set float levels. With the exception of thei problem everything else is perfect. Maybe i just have the wrong gasket in the kit, but it appears to be the correct one.

Holley is working with me to fix this, as they can't understand why either.

The guy gave me the carb as he was frustrated with it. I thought taking it apart, cleaningit, and blowing it all out with air and reassembling with all new gaskets and sealing the butterfly holes would have taken care of it. It's only 3 weeks old.


I'll buy a new power valve again tonight from A/Z and check my kit #.

Thanks for your info. as always the part 3's are very helpful too.

Chickenman35

Well, if you got it for free I guess you can't complain about the price. My apologies to your friend.

If the carbs only three weeks old, then yes, it could be a casting problem. Try the new power valve first though.

Last year at the Knox Mountain hillclimb I had a big backfire that blew a power valve ( plug lead fell off ). My carb has Power valve sfront and rear. Replaced them both with brand new spares....still puking gas through PV vacuum well on Primary side. Took carb apart 3 Times trying to fix problem.

Finally got things working correctly when we ran out and bought two brand new valves. Turns out the first brand new PV that I installed in the Primary side had a leak in it....this was a brand new Holley PV still in the blister sealed box. Drove me freakin' nuts. Just a tiny, tiny pinhole...but that's all it took.

MIKE 1985

thanks. i think you may be onto something there as the car did back fire one time on initial start up. I'm fortunate enough to test this off the car with the elec pump.

My local advanced auto has the 37-754 kit waiting for me too. I'll start all over including the base gasket ( which i did not change last time).

I've been reading all your holley tuning post ALL day and have to say i've learned a ton from your post. I will also be changing to manifold port vaccume tonight.

I will also be ordering a crane adj. vac adv. I have already installed the MR gasket adv springs and weights ( which i think are junk) the plastic bushings don't fit the dist very well. Is the crane kit made of better parts ?



thanks and i'll respond tomorrow with results.

Mike

Chickenman35

Most of the HEI recurve kits are made in the same sweat shops in Taiwan...so the quality is equally poor. Only the packaging changes.

All I use in these kits are the springs....the weights and cams are junk IMHO. If you found my post regarding recurving HEI distributors, you have probably noticed that I favor going to the boneyards and scrounging for the cams and weights off of mid- seventies Caddy's or Trucks. These have the most advance of all HEI distributors that I have found. There may be others....but these will work very well.

MIKE 1985

The carb is fixed.

i installed a new power valve and had already filed the body flatter ( it was way off) and this seemed to fix the problem. I'm thinking it was more the power valve that fixed the problem, even though the one in there passed the sucking test. I went on your suggestion and relaced it with a new one.

I'll break in the cam tonight and then start road tuning.


Thanks chickenman35, i'll post results back soon.

Chickenman35

Glad you got it fixed

I used the suck test for years ( For those who may not be familiar...you suck on the PV, and if it sticks to your tongue it's suppossedly OK ).

Finally went out and bought a proper PV tester from Moroso after the debacle at the Knox Mtn Hillclimb.

Tested all the valves in my inventory. Two that " passed" the suck test, failed on the Moroso tester....tiny, tiny pinholes. One of them was the new SOB that I installed at the Hillclimb. The Moroso tester also uncovered a PV that was sticking. Held vacuum, but the plunger would stick. A good investment for me as I work on carbs regularily.

sqzbox

I was just going to ask you about that but you beat me to it! Where'd you get it?

Chickenman35

Got it from one of our local Speed Shops. Summit carries them.

MIKE 1985

YAHOO !! there's fire down below.

Now for the good and bad.



good always first, the carbs works great, just the slightest blip of the throttle and it goes from 800 to 2700 RPM with out effort. Lets just say it's very crisp.

Now the bad.

i have 16deg. initial and only showing 32 total. ( GM HEI with re-curve kit in it) so i can only seem to get 16 deg of mech adv. I then hooked the vac to manifold port and it reads 40 deg. ( need to order the crane adj canister to only allow 15 deg. But if i can't get the mech part straightened out i'm not going to put any additional money into this dist.

My dist. of choice is the ready to run small MSD. Do you know if i can run the crane adj vac on that dist. ?



And lastly this brand new engine has an oil leak down by the balancer. It's coming down from the bottom of the balancer and i need to look into that. It can only be the front seal or the timing chain cover seal. Which do you think is more likley ?

Chickenman35

If you put a re-curve kit in I hope you did not install the aftermarket weights and cam...they can actually give LESS mechanical advance than the stock pieces.

As I mentioned before...go to the boneyards and start looking for early 70's HEI units. Check out the cam closely. The good cams have a much larger " Ramp" profile on the active side. They will be distinctly " assymetrical ". Grab those cams and weights. Heck...grab the whole distributor. Spare parts are always good. Pick-a-part only wanted $10 for the whole thing.

Chickenman35

You can get a MSD unit with a fully adjsutable vacuum advance as well I believe.

MIKE 1985

yes i did replace the cam and weights. I see now thi is a mistake.

I'll call around and also give MSD a call.

thanks.



The summit tech guy says there is a bushing on a pin that can limit adv. ? I'm not sure where this is located, i'll look into it tonight.

sqzbox

What do you think about turning Pikes Peak around and racing
downhill? What the hell would we call it? It sure would live things up a bit huh?

MIKE 1985

ok, i've played with the dist and with 12 init i can only get 32 total. So i'm getting 20 deg. The car starts good there, i'll slowly increase the initial as i go. With the vac hooked up i 'm at 33 initial, and 48 total at cruising speeds. I'm pretty close on this and will tune more as i start driving the car this weekend.

This is with the 2 medium springs from the summit recurve kit. I tried one medium and one light and it will not return fully from adv. Therefore if i use that spring combo i cannot get full adv.

I have the idle set at 900 in neutral and it drops to 600 in gear, must be a tight 2600 stall from 700r-4.com. I have the idle screws 1-1/4 turn out. I'll hook a vac gauge up to it and tune more when i get the mufflers on it. Man it's loud and at 33 i'm getting old.

Almost forgot to mention, the throttle responce is very,very crisp and impressive. Thanks to chickenman35 and the blue cam with a 31 squirter.


Also the compression is 9.3-1 with iron heads. I went safe and plan to run 93 in it.

MIKE 1985

chickenman 35,

i have a slight problem, when traveling along at any constant speed or RPM and if i try to slightly accelerate( 1-3 MPH) the car starts to acccelerate then falls on it's face then recovers nicely. If i just get more aggresive on the throttle this doesn't happen. Also if i slowly rev the car in neutral this doesn't happen.



i currently have the blue cam in #2 position and a 31 squirter. The rest of the carb is stock , even the secondary spring. I will need to order a spring kit, but only wanted to place one order, so i thought i would run this by you first in case i need more parts.

remember i have a dual plane 700r-4 2500 stall and 3.07 gears.

Does this need more pump shot ?

thanks in advance

Chickenman35

It sounds like it should...but from experience with that combo it should be enough. I'm suspecting some other slight problem.

With mptor off, look down the airhorn and check response of fuel shot from nozzles. A very slight movement of throttle should produce an immediate strong spray of fuel from shooter. An initial dribble or weak spray may indicate incorrect adjsutment of pump lever.

Pump lever adjustment: Absolutely no freeplay at idle. Remove all freeplay. then add a slight amount of preload to pump. 1\2 to 3\4 turn should be enough. Check response. Pump shot should be immediate and strong with ANY movement of throttle.

Check pump to lever travel at WOT. You must have .015" extra travel left in pump ( measured at cam ) to prevent damage to pump diaphram. Usually not a problem with a Blue cam.

Remove the Pump shooter and check in the pump passage for a small weght or steel ball. If this is missing fuel can be drawn out of this well at crusie RPM ( or higher ) abd cause a slight stumble ).

If after checking for correct pump adjustment you still have this slight stumble, then you may have to go to a #35 shooter and\or richen the idle mixture setting slightly. A #35 is a pretty big shot though....

You have a fairly stout cam. The 3.07 gears don't help the situation. Also, how cold is the weather? The combination of these three factors may require a slightly larger shooter.

One other thing I would try is to double check the idle mixture. Most Holley's ( other than the Dominator series ) are a 2 circuit carb. The idle and transition circuitry share the same circuit. If the idle mix is a tad lean, especially in cold weather, this can cause the tip in stumble as you describe. Richen idle mixture by 1\8th to 1\4 turn. If problem goes away then you know the cause.

BTW, idle mixture. Set with vacuum gauge and\or hand held tachometer. Base setting 1 1\2 to 2 turns out. Warm up car thoroughly. Watch vacuum guage. Laen out mixture 1\8 to 1\4 turn. If vacuum and\or RPM drop return to base setting. Richen mixture 1\8 to 1\4 turn at a time untill you just get the best reading on tach and vacuum guage. Then stop. Do not richen any further. This is your " Best idle" note number of turns in a log for reference.

Reconfirm "Best idle" setting by leaning mixture in 1\8 turn. Vacuum guage should show an immediate slight drop. This is " Lean best idle " which may be required for Emissions testing. You can go leaner than this...but usually not necessary or recommended.

Reset mixture to " Best idle". Reconfirm " Best idle " setting by richening mixture 1\8 turn. Note: Vacuum guage or RPM may not change when richening from " Best idle" Engine will tolerate a slightly rich mixture better than a slightly lean mixture. This is now your " Rich idle " setting. Note: Any further richening of mixture past " Rich Best " idle will do nothing but waste fuel.

One last thing....you haven't changed jetting have you?

Hope this helps. Let us know how you make out.

PS. Looking at your cam specs and rear gear ratio, I think that you are falling out of the " Cruise RPM " range of that cam. I gather that a change of gears is planned somewhere in the future?

MIKE 1985

thanks i will work with these tonight.

i have the stock primary jets, 72 . My current idle mixture screws are 1.5 out. It may need more. It's 30-40 degrees here. I don't have any choke on it, but it takes about 4-5 minutes and it runs fine on it's own.

with the 700r-4 it doesn't seem to go into 4th till 53 MPH, so that leaves me right at 1700 +-200 most of the time. 373 are plannes for the future.

i have not yet hooked up a vac gauge, ( mine was faulty) i have another one and i'll go through all this tonight and i also have some 74 and 76 jets too.

MIKE 1985

ok, a quick update. I hooked up the vac gauge and 2.5 turns out gives 15" of vaccume. I was way off as i had them set at 1.5 turns out.

i will tape the vac gauge to the window to see where vac is at durning crusing speed.


is it possible that the 6.5 power valve is too low ?

the stumble is slightly improved and the car holds a idle much better when in gear. I do have to adjust the accelerator pump as there is slight clearance there at idle. I will take it to no play then add 1/2 turn.

updates tomorrow.

sqzbox

15 in of vac.? I would be worried if I had less than 20 at idle! I'd be looking for a vac. leak or checking my In. timing.

Chickenman35

Check his cam specs. Flat tappet with 224\234 @.050", 112LCA.
15" of vacuum with that cam is acceptable IMHO.

Chickenman35

6.5" Power valve is just fine. Once you get the freeplay out of the pump circuit and adjust it properly I think it will be just ducky.

I kinda thought that 1.5 turns on the mixture screws was a bit lean. I don't think that you need to go any richer on the Primary jets. You may even want to drop them to 70's when the weather gets a bit warmer.

I'm gonna ots the Emmissions results on my car when I get my scanner up and running. You will not believe the numbers!!!

MIKE 1985

i adjusted the pump cam( all slack taken out and 1/2 turn preload put in) and the same problem still is present. Just a very slight stumble when slightly accelerating.

i hooked the vac gauge up and was driving around ( quite amazing to say the least) but also the lowest cruise vaccume is 10" as i start to accelerate the gauge drops from there and at 8-9 i get the stumble then the gauge will drop and as soon as it hits 6 ish it recovers and goes just fine. If i accelerate more aggresively the vac goes from 10 to 5 rather quickly and it never stumbles. I was reading on the Holley site that the power valve should be set 2" below the lowest cruise vac. which was 10". Iwas thinking of trying a 8.5 power valve ????

I also ran the car on the primary circit ( no idleing) for 4 miles then shut the car off and pulled over to check plug color on primary jetting, their very, very lightly colored. I have the 72 jets in there now, do you think i should try the 74's to see what will happen ?

I do have a 37 squirter , should i try this to just see if this fixes the problem or do you think the power valve is coming in too late ?


I also installed the long yellow spring in the secondaries yesterday.

Chickenman35

I hate it when I do that.....had a reply just about finished....then looked at the Holley site and erased the whole danged thing!!!

Anyhoo...By all means try the #37 shooter. The tall gears and the 700R4 may require it. Try another 1\4 turn of pre-load. Use tube type shooters. They direct the fuel spray more directly to the center of the venturi. Get a hollow pump screw when running #37 or larger shooters. Did you check for the presence of the pump weight under the shooters?

You're running at a very low cruise RPM ( 1700 +\- 200) and I think the main boosters are just a little slow coming in. You're below the cruise RPM of the cam as well.

As i recall...Holley changed the booster design on later 3310's. They went to the cheaper and less efficient straight leg design. Early models had "Dogleg" boosters, which supply a stronger booster signal. Annular Boosters are best of all...very strong booster signal. Enables you to run a bigger carb on a small engine. Great transition. Very little pump shot required.

I don't think that you need to change the power valve...it normally should not affect tip in. If all elese fails though...give it a go. It may be a Band-Aid fix. See below.

Your biggest problem, IMHO, is the 3.07 gears. They put the vehicle cruise RPM below the cruise RPM range of the cam. Now you have to band-aid fix things to cover this inefficiency.

Try richening the idle mix a tad. See if problem goes away.

Here's something i would definately try..... Cruise in 3rd gear. Bring RPM to 2,000 to 2,200...speed is irrelevant. Now slowly accelerate. If no stumble then you know the cause...Booster signal a bit weak ( Due to the tall gears ) at lower RPM's . Gear change should fix it.

Don't overlook ambient temperature. In the spring or summer this problem may not exist.

Getting things perfect can be a bear. The final little tweaks are always the hardest. Good luck. Keep us informed.

MIKE 1985

i checked for the weight, it's present. As i recall the carb has the straight leg boosters. The car did get better when opening the mixture screws 1 more full turn ( from 1.5-2.5). I do not currently have a hollow shooter screw, i will get one.

I will try the additional 1/4 turn adj with the acc pump, i will aldo try the 2000-2200 RPM test. I will try the .037 squirter and the 8.5 power valve.

I will do all this testing over the weekend and come back with results on Monday. AM.

If i'm understanding you correctly your still leaning toward a lack there of pump shot problem as opposed to a power valve issue ?



thanks for your time and help.

Mike

sqzbox

Wana talk about ported timing advance?

MIKE 1985

your reply speaks for it's self.

sqzbox

I don't get it? You want a race car that drives like a caddy? Right?

MIKE 1985

your right ,you don't get it.

with 9.3-1 comp, dual plane, 750VS carb, full exhaust and
180CC int heads and a 224-234 cam it's not even close to a race car.

i have and still enjoy the A/C, power brakes,steering, tilt, elec windows. The only reason the cam is a little big is the 150 shot that will be added later.


No race cars for me...and i don't care for caddy's either. I'm simply trying to get the car right , it's gotten better with the help of chickenman35 and i'm pleased with the progress.

I hope this clears up my effort for you.

Chickenman35

Yep...Pump shot should do it. Bringing the Power valve in earlier won't help because you're not getting enough flow through the boosters and the PV enrichment goes through the booster circuitl. At least least that is my opinion...I could be wrong.

Make only one change at a time. I would not change the PV untill last.

3.07's, Auto tranny, low ambient...all point to wanting a slightly bigger pump shot.

MIKE 1985

ok, i'll start with the 6.5 power valve and put 1/4 more acc pump preload into it. If that doesn't work i'll put the .037 squirter in and only then will i change the power valve.

i'll document all.

Chickenman35

You'd be surprised what a good " Tune " can do. Yes...you can have a Race car that drives like a Caddy. My car is an ESP champion ship car ( And argueably the Fastest ESP car in Canada ), SP3 Hill record holder at the Knox Mountain hillclimb..... and I can still drive it too work. And it will still pass emissions.

Mind you....thre are some definate tricks done to my carb that are beyond average....but you can have your cake and eat it too. Or have a Race car that drives like a Caddy.....a damned fast Caddy mind you

sqzbox

And no doubt! Chickenman can help anybody's holley!

MIKE 1985

oki, here's the update.

1-i tried the increased 1/4 turn on the acc pump, to no avail. I then tried the 2000RPM test and the problem still exsisted. ( this is with the #31 antipullover squirter)

i have 2 squirters the anti pullover #31 that came with the carb and a #37 straight squirter.


Also for the record the carb does have the straight leg boosters.


2nd test was to just swap out the squirter for the #37, and this was a huge inprovement, and passed the 2000RPM test.

I then tried the 8.5 power valve, DID NOTHING.

I then went fron 72-74 primary jetting, DID NOTHING.




The current set up is a #37 straight squirter, (stock screw) all slack removes from pump cam at idle( no preload yet), 74 primary jets ( will adjust according to plug color) and the purple secondary spring.. this works pretty good.


my next plan of attack, i ordered the hollow squirter screw, i will try this first and continue to check plug color and adjust jetting from there. I may also start putting some pre-load into the acc pump.

Now on the way to work today i shifted the auto/manually and shifted at 2200-2500 each gear( as opposed to the 1600 it shifts at normally) and the car way much better on all aspects. I will continue to tune the WHOLE package, especially getting the car to shift higher ( 2K).

the futeure will be a turbo 350 and 355 gears with a 10" converter. My commute to work is opnly 7.5 miles each way.



Now one more question if you don't mind ??

I currently have the stock secondary set up, do you prefer this or is a plte with jets recommended ? If so which plate and what other parts would i need to convert this to 2 metering plates ?

thanks chickenman35 for your help.

Mike

Chickenman35

I would prefer moving over to a Secondary metering block. Ease of jet tuning for competition being the main reason. If it's a daily driver and weekend warrior, then you want to set up the Primaries for good fuel economy and driveability ( and to keep the plugs from fouling ).

All you need is the metering block kit from Holley. Part #34-13 ( Standard finish ) or #34-13S ( Shiny finish )

Other parts I would recommend:

1) Fuel Bowl Vent whistle kit. # 26-40 . Prevents fuel slosh out of vent tubes.

2) Quick Change Diaphram housing. Part # 20-59. Makes Secondary spring changes so much easier.

Nice to have parts:

3) Fuel Bowl Quick Change Jet Kits:

Primary: Part # 34-25 ( Standard finish ) or # 34-509 ( Chrome finish ) Note: Primary side kit includes a nifty jet removal tool.

Secondary: Part # 34-27 ( Standard finish ) or # 34-511 ( Chrome finish ).

Nice to know you've got it just about dialed in. When you change gears and go to the small convertor, you may be able to go back to a smaller shooter.

Did you get my PM on adjustment of the Crane Vacuum can ?

MIKE 1985

yes i responded to the PM, this is probably not helping the issue, but as i explained the repair is on it's way. I will also switch over to the secondary metering block and whistle vents.


i have a 3" element air cleaner with a 1" drop base and i HAVE to run a flat lid on that due to hood clearance, i have also removed and cut and ground away the choke, do you think a stub stack would benefit this application ?



I plan to start with 70 primary and 78 secondary jetting . Do you agree ?

thanks again. I can't tell you how much help you've given to me and how much i've learned.

My brother has a 68 with a supercharged, nitroused 468 BBC and he runs 2 750 vac secondaries on that. It's always had the same stumble and now we can apply this to that car also. On quick inspection we noticed it has 50CC accel pumps , but still has #31 squirters and stock squirter screws, with stock cams. We will apply the same tuning principal there.

Chickenman35

#70 Primaries and #78 Secondaries should be a good starting point.

Is the air cleaner top truly flat cover, or is it a contoured piece like a Moroso drop base unit? The Moroso unit has a drop of about 1.75" I believe and provides good air flow to carb. With a 3" element, the Moroso air cleaner has a 2.5" overall stack height above the carburator iar cleaner lip.

Stub Stack may not help if you are tight on clearance to top of filter. Might be better to use a Moroso type with contoured top and a bit more clearance rather than trying to fit the stub stack in and not having enough clearance.

You're very welcome. Glad to hear it's coming around.

sqzbox

Congrats! I figure you can make it to work in 3.75 min. baring stop lights and such! And NO STUMBLE or HESITATION! How cool is that? If you plan on visiting the strip this year, post a couple of times and let us know how it runs.

MIKE 1985

sorry for the delay, i've been out of the office.


it's the moroso drop base, the vettes have NO hood clearance.


Funny thing is it takes 30 minutes to drive that 7.5 miles. I'll test more this weekend and update on monday.

i do plan to run the car and will be happy to share results.


the gear change will also incorporate the stronger D-44 at the same time. I will install 3.73 gears.

Chickenman35

3" element with a Moroso drop base air cleaner would not leave enough clearance for a stub stack IMHO.

Now a nice Harwood glass hood with a hood scoop would be a different matter. Or add a hood scoop. Might be a thought.

MIKE 1985

i'm working on a 4" cowl configuration.

Chickenman35

Good plan. You do need some extra cleranace above the carb though...so if your adding a larger drop base that may not help. Problem is that with the current height of lid, air has to make too tight of a turn to enter carb. Costs you a few HP...which I'm sure you realise.

With a nice hood bubble or scoop...you could then run something like a Victor JR or a Performer RPM which should help at the track.