what type of intake

[460 jus getn it]

im building a 460 to be put in a 18ft kachina. what is the best type of intake to run with this motor......

[Craig]

I ran the Weiand Stealth on my 460. Ran great!
Craig

[460 jus getn it]

craig. thanks for the info greatly appreciated
460....

[Dennis Moore]

Why don't you run an Offenhauser high rise two four barrel setup (tunnel ram). The Ford 460 has evenly spaced intake ports that would work great with two four barrels. You would have a carburetor barrel sitting directly over each intake port. Two 390 cfm four barrels would flow the same as one 780 cfm carburetor so you wouldn't be overcarbureted. This system would be better than running any single plane intake manifold because the cylinder to cylinder air/fuel mixture distribution would be superb.
The best setup would be with two 450 cfm Holley marine carbs. I installed this setup on a jet boat years ago when I worked for Valley Marine in Burbank. Unfortunately I never got to test the boat on the water but the customer must have been happy with it because we never heard from him again. The system sure did idle smooth, all of the other mechanics gathered around when I fired it up and adjusted the idle mixture screws. We were all impressed about how adjustable the idle mixture was! The camshaft wasn't very big (probably stock) and the engine was very responsive when we would wing the throttle.
I installed the carbs inline and the throttle hook up was easy. I wouldn't even bother rejetting the carbs.
I bet you would be happy with it!
Sincerely
Dennis Moore

[460 jus getn it]

dennis, what other suggestions do you have for this motor to put out between 4800-5200rpm's

[hack job]

you could run a victor jr. that would be as good plus its only one carb . i like tunnel rams in fact i have one but i know what gose with them ( los of gas) ! good luck! wink :D

[Hotcrusader76]

Dennis Moore:
Two 390 cfm four barrels would flow the same as one 780 cfm carburetor so you wouldn't be overcarbureted.Sincerely
Dennis MooreActually that is incorrect. Advertised flow cfm is not what you are looking for on a motor. Its all about the vacuum signal and how it pulls the fuel from the boosters, and yes that it determined by the venturie diameter and booster, which is rated at (390, 500, 600cfm, etc). Yeah two 390's add up to more than one 780cfm, but its a completely different animal when it comes to theory of operation for "tandem" carbs... your also pulling idle mixtures from two sources vice one which inherently richens the mixture being pulled from the motors vacuum. I try not to confuse people on this topic but many think that "advertised" cfm potential sells! Well...it does....but that's all incorrect.
Why people spend thousands of dollars on engines and slave all winter to build them, just to call up Jegs and slap on a simple Holley 750DP "universally calibrated" amazes me! Its kind of like buying a Filet Minon and putting ketchup on it...LOL....."Smell what I am cooking here?"
NASCAR runs the 390 and they perform great up to 700HP+ so dual 390's would work, but not with a stock 460 motor, too much fuel metering with less air. If properly set-up and tuned, a set of 500's would work better, but I wouldn't go any less. But taking any two "unversialy" calibrated carbs and throwing them on a motor will 9 times out of 10 run "rich", they need to be leaned out, IE 750DP's.
The best setup would be with two 450 cfm Holley marine carbs. I installed this setup on a jet boat years ago when I worked for Valley Marine in Burbank. Unfortunately I never got to test the boat on the water but the customer must have been happy with it because we never heard from him again.Reqardless of the engine specs....the 660 Center Squirter is by far, hands down the best dual carb Hi-rise set-up. I have always had positive feedback on my Dual 660 set-ups. I ran 660's on my 76'Tahiti for 2 years and then again on my 81'Crusader, flawless and quick! I could even smoke some of the dual 750 guys who claimed they were a quicker set-up.
Well...while I was taking the winnings from the bet, they were getting more gas for their boat...LOL...
There is just too much info out there to explain the workings of a "Holley Carb". There is alot more to tuning these then just jets and fuel floats. If carbs were so simple then there wouldn't be Carburetor specialists.
But that's what I am here for, to explain to the rest of my fellow boaters what it is that makes this thing "tick".
Again....too much Calculus tonight has smoked my brain. :D
-Ty

[Dennis Moore]

I would start with an induction style ignition improvement. The best would be the Pertronix Ignitor II ignition kit. This is an excellent kit that will install inside your distributor. It has a variable dwell feature that will increase dwell at high speeds for a hotter spark. It is reasonably priced and works better than any CD ignition. Buy the complete system with coil and wires.
For spark plugs I would us AC Delco Rapid Fires gapped at .045 inches. I believe that the #1 Rapid Fires fit a 460.
Install a timing tape on the balancer and set total timing at 34 degrees (unless your engine runs rough don't worry about the timing at idle).
For a camshaft I would select the Comp Cams Xtreme Marine # XM 262H-12. This will give you plenty of power with that tunnel ram and it will still idle smooth (with a little lope that sounds cool!). I think you would really like the combination of this cam and the tunnel ram.
If you decide to add Edelbrock aluminum cylinder heads E-Mail me and I will help you install them and do a magazine article on the installation.
Sincerely
Dennis Moore
MoorePerf@Adelphia.Net

[Dennis Moore]

Ty,
I would be interested in knowing what you feel is the difference between a traditional single plane intake manifold and a tunnel ram intake manifold as far as engine operation.
Why does a tunnel ram require such a different carburetor?
It looks to me like a tunnel ram has 8 runners and a common plenum just like a traditional single plane manifold but it is not a compromise on carburetor height (to fit under a hatch or hood).
Isn't a tunnel ram just a single plane stood on end with dual carbs?
Doesn't the tunnel ram have all eight runners the exact same length unlike the single plane?
Isn't the entry angle of the runners to the intake ports on a tunnel ram better than the entry angle of the runners on a single plane?
Doesn't the flow of the air/fuel mixture simply flow straight down from the carbs on a tunnel ram instead of having to make the turn like on a traditional single plane?
They both have a common plenum. Do you think that the plenum or runners on a tunnel ram causes some extra turbulence or something than the plenum and runners on a traditional single plane? If so why?
I hope you don't try and skirt the issue by telling us that we just don't understand all of the complexitys of intake manifold/carburetor design. No bullshit now! Lets hear what you know about intake manifold design!
Sincerely
Dennis Moore

[058]

In a couple of words....Plenum voluume....that and the fact that BBFs can utilitise more CFM than a pair of 390 or even 450 cfm carbs can provide. Try a pair of 750 cfm carbs that are made to run as a pair, not two singles made to run as a pair, the calibration is different.

[spectras only]

460 Jus, the 19 spectra in the picture is very close in dimensions to your kachina. The 460 BBF has 10:1 comp pistons, A443 ford motorsport cam ,CJ cyl heads topped off with the cast iron SCJ intake [missmatch wink ].I've decided on the single carb setup for simplicity.It's the 850 marine holley with 88 primary jets ,94 secondary.Have powervalves in both bowls! The engine turns 5600 RPM with an "A" berk impeller .Boat was checked with GPS, at 72 MPH at sea level. I like the look of dual carb setups,but like simplicity better :D . Ps; if you have trouble finding the SCJ intakes [I see a couple in the local rags all the time for $200 CDN ]ford motorsport has the aluminum intake I think made by Weiand. http://www3.telus.net/spectrasonly/19spectra5.jpg
[ September 17, 2002, 11:56 PM: Message edited by: spectras only ]

[Hotcrusader76]

Now I answered these questions with respect to the stock motor that was mentioned aboveÂ….
Why does a tunnel ram require such a different carburetor? A tunnel ram requires a different carburetor set-up (assuming it’s a dual top style) because you are essentially feeding a motor two mixtures of fuel “vice” one, as I indicated before. By leaning out the idle mixture you can utilize this dual carb system without blackening the spark plugs and you are able to keep that off-idle transition smooth when the hammer is dropped. Running the 390HP carb, which was created not only to help NASCAR/Winston cup officials in tech inspection, but also to offer great results when bolted onto the 700HP NASCAR motors, isn’t the carb I would recommend for the job.
Isn't a tunnel ram just a single plane stood on end with dual carbs? Visually yes! Operationally no! With a tunnel ram, as “you” already know, position the carbs over 4 runners each, which evenly distributes the fuel over each set, vice one carb trying to give fuel to 8 long runners, from dead center. The advantages of the hi-rise are best seen at higher RPM’s where as the “common” open plenums would be the better choice for the more stock motors since the runner isn’t as long and the fuel atomizes much quicker with less air velocity.
Doesn't the tunnel ram have all eight runners the exact same length unlike the single plane? Theoretically yes.
Isn't the entry angle of the runners to the intake ports on a tunnel ram better than the entry angle of the runners on a single plane? Depends on what is the “best” manifold for the motor it’s destined for, a stock 460BBF no, a high compression (9.5 and greater) with an appropriate cam then yes. A tunnel ram would be great just the same as a single plan, open plenum type. To keep this issue simple, if I were running at 6,000RPM or higher on a normal basis, as do most Marine set-ups, I would install the Dual carb hi-rise set-up, and leave the “common” victor 4150 styles manifold for the more moderate revving engines up to 4500RPM or so.
Doesn't the flow of the air/fuel mixture simply flow straight down from the carbs on a tunnel ram instead of having to make the turn like on a traditional single plane? Saying that it “simply” flows down the runners is incorrect, to a certain degree. This is because there are fuel atomization issues and with a rough surface to flow over to achieve that, a volume of air heading straight down the hi-rise’s runner is also needed at much higher velocity, IE High compression motors. Otherwise everyone would be running tunnel rams, flawlessly.
390HPÂ’s are great carbs BTW, but the HP fuel metering is over-kill! Yes I could detune the 390HP (fuel metering wise) and get them to perform correctly, just as I could a set of 450 Vacuum SecÂ’s, but have you seen the price for a 390HP carb? YeahÂ…its not cheap, and the cost to have a 390HP detuned would also add up. Now you are setback $650+($1300 for two) on a universally calibrated 390HP when you could have saved up for a better cam, intake, and set of 660Â’s or even 750DPÂ’s.
I believe sticking a tunnel ram on a stock motor with a stock Marine camshaft is over-kill alone. An open plenum type would disturb the airflow enough to make that motor more responsive at the lower end making it the best choice over the hi-rise, with respect to the cam specs.
By no means do I claim to be an intake design expert, but I know what I have installed and run in the past on boats and street muscle cars, therefore I understand what works and what doesnÂ’t. I have received feedback from many happy customers that are more than excited with the results they saw with my carb/s and manifold recommendation, but when a customer doesnÂ’t return to compliment my set-up, that means 9 times out of 10 that he wasnÂ’t 100% pleased, and complete satisfaction is what set out to achieve. So a good follow-up would be in your best interest.
. Do you think that the plenum or runners on a tunnel ram causes some extra turbulence or something than the plenum and runners on a traditional single plane? If so why? HhaahaaÂ…this is turning out to be a test on dynamics, déjÃ* vu!J
Actually the intricate design of the turns and placement of the open plenum’s runners would cause more turbulence than the hi-rise which is needed to better atomize the fuel with respect to the engines vacuum signal. Compared to the hi-rise manifold, on a stock motor, the open plenum would be the better choice between the two. In order to atomize (disturb) the fuel in a hi-rise the motor needs to really rev itself out, hence the reason they are rated from 2000RPM-6000RPM, and not any less. The open plenums have been proven intakes for that RPM band as well, but for the average boater, a “common” open plenum Edelbrock would substitute.
. hope you don't try and skirt the issue by telling us that we just don't understand all of the complexitys of intake manifold/carburetor design. No bullshit now! Lets hear what you know about intake manifold design! I never said that “you all” would never understand the complexities of this topic. Hell it isn’t “rocket science” here gentlemen. Its just that I have many years of experience, as you do the same Dennis, and for me to explain this in its entirety would constitute a novel, or me publishing a book…hmmm…that has sort of a ring to it. But I am concentrating on one thing at a time. So please do not think I was just getting by to please the eye on this “post”.
Complexities? Well, from what I understand, my previous reply to this “post” was geared towards carburetor knowledge, not “intake design”. But since you threw out the opportunity to test my knowledge, I am up for the challenge.J
Your book was great BTW and your experience is very awe-inspiring. So please donÂ’t think I was discrediting your knowledge or advice. With that being said, welcome to the ***boat.net boards Dennis. http://www.plauder-smilies.de/happy/xyxthumbs.gif
Sincerely,
Ty Lofstrom

[CoastGuardSteve]

Ty,
What year are you in? Are you at SDSU or that other school in SD?
Just wondering,
Steve

[Hotcrusader76]

CoastGuardSteve:
Ty,
What year are you in? Are you at SDSU or that other school in SD?
Just wondering,
SteveTransfer student to SDSU. I have to finish two more semesters of Engineering classes before I can officially enter the department at SDSU. Remember I am the night school type. I attend school Mon-Thurs till 9PM or so. I have over 70 semester hours so far, but 50% of them are Electronics classes, so none of them credit me for Mech.Engineering.
I thought about UCSD, but there is too much Bio-Engineering based thinking going on over there. Plus SDSU has some state of the art equipment to assist me with my passions, so I think SDSU will do for now.
:D
[ September 18, 2002, 01:05 PM: Message edited by: Hotcrusader76 ]

[CoastGuardSteve]

I'm a product of the Cal State system myself! I went to a small JC and then transferred to Fresno State and had the same major. I used my GI Bill, after four years of the USCG, and then worked in housing for the school. Even lived in the Dorms at age 25 and had a great time. College girls seemed to like English speaking engineering students.
I have a cousin at UCSD and she's studying Medicine. My brother is at Harvey Mudd...scored a 1560 on his SAT! I guess the Cal State system isn't so bad though...a lot of nice scenery in the Spring!
Steve
GO DOGS!!
[ September 18, 2002, 04:25 PM: Message edited by: CoastGuardSteve ]

[HOSS]

I`m looking to purchase a tunnel ram for my 460. Lunati cam stock flat slugs, dive, dove, unilite, electric advane with high fire 4c box. I am going to run 2 750 1450. Do they have to be mounted side ways? How much for linkage? I am also going to run a 2" spacer underneath. 1st inch 4 hole and second inch milled to dual plane. What all do I need to do to the carbs? No choke butterfly and heat risers are blocked off.
Please only serious ideas. I tossed this around sometime ago and am now buying parts.

[Hotcrusader76]

HOSS:
I`m looking to purchase a tunnel ram for my 460. Lunati cam stock flat slugs, dive, dove, unilite, electric advane with high fire 4c box. I am going to run 2 750 1450. Do they have to be mounted side ways? How much for linkage? I am also going to run a 2" spacer underneath. 1st inch 4 hole and second inch milled to dual plane. What all do I need to do to the carbs? No choke butterfly and heat risers are blocked off.
Please only serious ideas. I tossed this around sometime ago and am now buying parts.HOSS,
More than likely you will need to run those 4150 Carbs sideways. Otherwise the bowls will not fit being run inline.
Look into adding the 2X4 Floats for your application. What are the list numbers of the two carbs? Are they identical in regards to metering? What are the numbers on the metering blocks themselves?
Also consider only running primary pwr valves if not none. Also see if your accelerator pumps are 30 or 50cc. You should only be running 30cc on all four unless you have some exotic motor that can't breathe with 120cc's total of fuel.
HOSS, if you need assistance give me a call.
(877) TPC-CARB
-Ty
[ September 19, 2002, 07:16 AM: Message edited by: Hotcrusader76 ]

[HOSS]

:p