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Welcome to FordPinto.com, The home of the PCCA => General Help- Ask the Experts... => Topic started by: bombi on January 13, 2014, 03:03:13 PM

Title: Horsepower curves ???
Post by: bombi on January 13, 2014, 03:03:13 PM

Anyone have any horsepower curves for a 1979 Ford Pinto 2.3liter or similar ?
Title: Re: Horsepower curves ???
Post by: Clydesdale80 on January 13, 2014, 04:16:48 PM
This is what CamQuest comes up with if i put in everthing as close to stock as I can.  It must be in the ballpark because the peaks I found online said horsepower  88 @ 4800 RPM,  torque  118 @ 2100 RPM.  Just drop everything a little for smog equipment. Graph starts at 1000rpm,  each vertical line is another 1000rpm, each horizontal line is 10hp/10ft-lbs

(http://i1161.photobucket.com/albums/q514/clydesdale80/23stockcurve_zpse6e70cf4.png) (http://s1161.photobucket.com/user/clydesdale80/media/23stockcurve_zpse6e70cf4.png.html)

This is at best an estimation, someone else can probably give you a better answer.
Title: Re: Horsepower curves ???
Post by: bombi on January 14, 2014, 08:28:17 AM
thanks for taking the time, every little bit helps.

Title: Re: Horsepower curves ???
Post by: amc49 on January 15, 2014, 05:05:04 PM
That's close when power drag is figured in. Old school gross measurements had around 100 hp at crank and 125 ft.lbs. torque........ ......
Title: Re: Horsepower curves ???
Post by: dick1172762 on January 15, 2014, 06:32:02 PM
And that was when NEW! Buy a ricer if you want hp. Buy a Pinto if you want lasting value and style. When was the last time you saw a 71/80 ricer? Oh! I forgot, that they didn't rust proof them. Oh well, live and learn so they say.
Title: Re: Horsepower curves ???
Post by: slowride on January 16, 2014, 10:45:11 AM
Nothing constructive to add, but almost spit out my coffee when I saw the subject line....... ??? Pinto and horsepower aren't normally synonymous.
Title: Re: Horsepower curves ???
Post by: bombi on January 23, 2014, 01:31:52 PM
LOL.....

just looking to see if replacing the torque converter in will help in this application, and what stall speed to go with...
thanks.
Title: Re: Horsepower curves ???
Post by: slowride on January 23, 2014, 07:57:05 PM
LOL.....

just looking to see if replacing the torque converter in will help in this application, and what stall speed to go with...
thanks.
I've been looking at another TC, but not necessarily for stall. Believe it or not, the tweaks on the 2.3 make it launch hard. I just don't want it coming apart at a stoplight....
Title: Re: Horsepower curves ???
Post by: Clydesdale80 on January 23, 2014, 09:01:12 PM
I've been playing with that program more and what it shows would make me agree with Slowride.  It seems that the 2.3 (atleast how CamQuest models it) responds to some fairly basic mods with a surprising increase in torque.  Exhaust and intake gains are substantial.  I ran it with my planned build and it gave me this...
(http://i1161.photobucket.com/albums/q514/clydesdale80/build2_zps198a6185.png) (http://s1161.photobucket.com/user/clydesdale80/media/build2_zps198a6185.png.html)
This is a more involved n/a 10:1 build with porting/valvework, headers, 4bbl, and stock cam.  I feel that the numbers it gives are probably quite optimistic but I also think it shows that there is potential gains.
Title: Re: Horsepower curves ???
Post by: slowride on January 24, 2014, 10:37:02 AM
If I can get my hands on a turbo intake for a reasonable price, I'll be modifying it to be a dual plane, and run a 38 Weber. While I have made the wagon launch hard, the mid-range torque (even with the Comp Cam I picked) is what makes this car "slow". With the runner layout on the stock intake, I'm just beating my head against the wall (and wasting gas) with a useless secondary on the 5200.
Title: Re: Horsepower curves ???
Post by: Clydesdale80 on January 24, 2014, 12:13:38 PM
to get that long flat torque curve I basically set everything up for low rpm torque and then added big valves which made the torque hold on for another couple thousand rpm.  If I can build an engine thats even close to that graph it should be very drivable and fun, especially with a T-5 behind it.
Title: Re: Horsepower curves ???
Post by: slowride on January 24, 2014, 04:37:19 PM
Bigger valves will give it more RPM potential (if flow is holding it back), but my feelings are the crappy A/F distribution is holding it back far more. These intakes are notorious for running #2 & 3 fat and 1 & 4 lean. On top of that, you open a secondary (right over the #2 & 3 runners) and it compounds the problem.
I run an auto and it's a bit deceiving having the torque multiplication at low RPM and having it go away in the mid-range. Give me just a bit more mid and I'll forget about more RPM.
Title: Re: Horsepower curves ???
Post by: Clydesdale80 on January 24, 2014, 04:53:00 PM
I agree, the stock intake is terrible for fuel distribution.  This simulation had a long, approximately equal length runner intake with a 390cfm four bbl.  I have an offenhauser dualport that I plan to start with on my engine but eventually i'd like to make something from scratch.
Title: Re: Horsepower curves ???
Post by: dick1172762 on January 24, 2014, 05:12:38 PM
The stock intake is bad but the problem is the carb and the intake. Put a 38/38 Weber on the stock intake and the engine will come alive. Why you ask? On the 38/38 both barrels work together at all times, not just when your foot is in it. The GT-Pinto class in SCCA requires a stock intake with a 500 Holley two barrel carb. Those Pintos run as fast as new Vetts on a road race track. I saw one clocked at 145MPH at Summit Point race track. Cheap way to fix that "bad stock intake".
Title: Re: Horsepower curves ???
Post by: ToniJ1960 on January 24, 2014, 05:50:19 PM
The stock intake is bad but the problem is the carb and the intake. Put a 38/38 Weber on the stock intake and the engine will come alive. Why you ask? On the 38/38 both barrels work together at all times, not just when your foot is in it. The GT-Pinto class in SCCA requires a stock intake with a 500 Holley two barrel carb. Those Pintos run as fast as new Vetts on a road race track. I saw one clocked at 145MPH at Summit Point race track. Cheap way to fix that "bad stock intake".


 Now look I lpve my Pinto and my Corvette, but be rel ok. Maybe an 84 like mine, but not a new Corvette :)
Title: Re: Horsepower curves ???
Post by: slowride on January 24, 2014, 07:23:08 PM
The 38/38 is one half of the plan. The other half is the modified EFI intake. The gray areas are where the dividers are milled out to create a dual plane intake (1&4, 2&3). Since the 38/38 is tunable for each barrel (and plane), it should be miles ahead of a stock carb intake. The black circles are the barrels. Mill a small equalizer slot in the divider between the planes and it should help smooth the intake pulses and give a better idle signal.
Theoretically of course ;D
 
Title: Re: Horsepower curves ???
Post by: dick1172762 on January 24, 2014, 10:54:31 PM
I don't know what your picture is of, but I have two EFI intakes in front of me and both have four holes below the carb. Explain  please.
Title: Re: Horsepower curves ???
Post by: slowride on January 25, 2014, 12:47:17 AM
The gray areas are where the 4 holes will be milled to create 2 planes. The black circles are where the venturis of the 38/38 will be. 
I just got a stock turbo intake off a XR4TI for $38 shipped, so now to find a deal no a Weber.....
Title: Re: Horsepower curves ???
Post by: dick1172762 on January 25, 2014, 09:36:08 AM
Do like I did. Get a 1.08 to a 1.21 Motorcraft / Autolite two barrel carb. Dirt cheap even if you buy a new one. Got mine for $25.00. The new ones are 1/2 the price of a 38/38. The 1.21 is a 351 CFM and the 1.08 is 280 CFM. On the mini stock web site (4m.net) the racer like them better than the Holley's. Every part for them is still for sale, and there is several sites on you-tube on how to rebuild the carbs. Look at  Mikes Carburetor-Parts.com to see how to's and parts for sale. The carbs also use Holley power valves. They also are not bothered by 4 cylinder vibration like a Holley
Title: Re: Horsepower curves ???
Post by: 74 PintoWagon on January 25, 2014, 09:55:24 AM
Hey Dick, are these the ones you're talking about??, they're about as simple as they can get..
http://www.carburetion.com/ford2v.htm (http://www.carburetion.com/ford2v.htm)
Title: Re: Horsepower curves ???
Post by: dick1172762 on January 25, 2014, 10:50:56 AM
ART! That's them. The people on the mini-stock web site (4m.net) say you can put one together in the dark. Much stuff on you-tube about the carbs. Mikes carbs is very good. He's been building them for 45 years. Looks like the cheap way to go. They were on Ford pick up till they went to fuel injection. Thanks for the web site.~~~Dick
Title: Re: Horsepower curves ???
Post by: slowride on January 25, 2014, 11:24:29 AM
That carb can work too. All that's needed carb-wise is a 2 barrel synchronous rather than progressive (or secondary). The modification to the manifold won't work with a progressive.
Title: Re: Horsepower curves ???
Post by: 74 PintoWagon on January 25, 2014, 12:14:07 PM
Thanks Dick, thought those were the ones, I've rebuilt a ton of those, heck you can do them in your sleep, LOL, In fact I may still have a couple of them in the junk pile I'll have to look, if they work on the EFI intake that'll be an easy setup.
Title: Re: Horsepower curves ???
Post by: 74 PintoWagon on January 25, 2014, 12:25:47 PM
Wow, there's a ton of it on U-Tube..

http://www.youtube.com/results?search_query=Ford+2150+autolite+carbureter&page=1 (http://www.youtube.com/results?search_query=Ford+2150+autolite+carbureter&page=1)
Title: Re: Horsepower curves ???
Post by: dick1172762 on January 25, 2014, 05:16:41 PM
Thanks Dick, thought those were the ones, I've rebuilt a ton of those, heck you can do them in your sleep, LOL, In fact I may still have a couple of them in the junk pile I'll have to look, if they work on the EFI intake that'll be an easy setup.
  Art! They'll only work on an EFI intake if you make / buy an adapter. Just like a Holley (they have the same bolt pattern) Go for it. Its all bolt on. Even a Vega owner could do it, well maybe.
Title: Re: Horsepower curves ???
Post by: 74 PintoWagon on January 25, 2014, 05:32:31 PM
  Art! They'll only work on an EFI intake if you make / buy an adapter. Just like a Holley (they have the same bolt pattern) Go for it. Its all bolt on. Even a Vega owner could do it, well maybe.
Yep, think I'll go that route be an easy deal, ain't nothing to make an adapter... A Vega owner, now that funny, lol..
Title: Re: Horsepower curves ???
Post by: CRUISEWAGON77 on January 27, 2014, 01:39:35 AM
What year do the four barrel intakes come on turbo coupes?
Title: Re: Horsepower curves ???
Post by: slowride on January 27, 2014, 03:07:10 PM
No 4 barrels on turbos. Though it LOOKS like a 4 barrel pad, an upper intake bolts to this flange. The issue I have with "knifeblading" or adapters (or both) is you are not addressing the biggest issue. The A/F mixture is still in shear trying to go sideways into a runner. What I'm going to try is machining plenums that will DROP the floor and smooth the transition from venturi to the runner. The added benefit is rather than the carb seeing individual vacuum signals creating a "pulse", the plenum should combine the pulses making a smoother vacuum signal, and (hopefully) smoother idle.
Title: Re: Horsepower curves ???
Post by: CRUISEWAGON77 on January 27, 2014, 03:40:59 PM
Are there better intake/carb setups to look at for a lightly modified 2.3 (big valves, light port work, mild cam, .30 over bore)?
Title: Re: Horsepower curves ???
Post by: dick1172762 on January 27, 2014, 05:07:23 PM
WEBERS WILL DO THAT.
Title: Re: Horsepower curves ???
Post by: amc49 on January 27, 2014, 10:01:24 PM
I seriously do not know  if I would open that plenum up like that. The 1-4 runners begin to curve hard sideways right at the 'flat' there and any plenum opening is going to come much closer to making in  effect a 'flat' that F/A mixture must hit before somehow turning sideways there. I would much prefer to retain the turn right at the top of 1-4 and then extend any plenum UPWARDS even though hood clearance is iffy. Common adapters made to mount holley 2 bbl. type base carbs on these are either one inch thick or two, I'm thinking two is better to help make the curve there. Just like on X type manifold on a V-8. You need smooth turning room or just throwing away power there. 2-3 are alright since the vertical run is longer before runner curves sideways. Look at a couple of race manifolds ported out and see that they think same thing, they do not lower the opening much maybe to use the one inch manifold and save the hood clearance. They also open up to share all four cylinders, not in pairs. You have to run bigger carb when you separate in two parts, a plenum running to join all four allows for same power with less carb and then car performs better at low rpm too. Dual plane manifolds are to induce 180 degree intake periods on V-8s, 4 cylinders already do that with a fully open plenum. When you split a 4 cylinder intake then you go to 360 periods and then the air gets less active and response drops off.

If I could, I would be using two inch there to allow acceptable vertical spacing to mix easily in the plenum and no lowering of openings at all, merely radius the tops really good. The radius has added benefit of removing more dead flat that can hold fuel fallout, with radius the fuel will run readily into a cylinder rather than stack up in plenum. The two inch adapter comes closer to having the proper plenum area needed there and the expansion from two openings to four is smoother. The interchange and crossflow should be much better.

The 2100 Motorcraft carb still feeds from one side even if the butterflies open at the same time, until the throttles are wide open the angle of them will always prejudice flow to one side front or rear, why you want to lift the carb up again, to allow for more cross-mixing there. Meaning the flow is still 'in shear' even with plenum opened up. Only at WFO is it not. Note the examples given lower, they remove almost all flat space there, the bigger each opening is the more they tend to run closer to equal since the mouths all tend to zoop up any runoff there. The bigger openings also tend to blur unequal throttle blade angles as well.

If carb is jetted right it does not matter if one barrel is bigger than the other provided again carb is high enough up to allow good cross-mixing.

http://www.bo-port.com/index.php?act=viewCat&catId=10

http://www.racerwalsh.zoovy.com/product/RWA1231C/manifold-efi-intake-the-works.html

Note they open up all FOUR to each other, they may be making room for the one inch adapter there to keep carb lower to clear hood.
Title: Re: Horsepower curves ???
Post by: dick1172762 on January 27, 2014, 10:34:00 PM
So I take it, you like the bo-port porting on their web site. I've got about 10 pictures of 10 different EFI intakes and they all look about the same except about half have knife edges at the entry point of the 4 runners. You don't like that do you? What's your tech on this? A radius there would be easyer than a knife edge to port. I've seen a couple for sale where they split the intake into 2&2. Maybe that's why they were for sale.
Title: Re: Horsepower curves ???
Post by: amc49 on January 27, 2014, 10:44:09 PM
I don't like dead sharp knife-edging, preferring to roll the edge just a little bit. Razor sharp can cause F/A separation. Think airplane wing airfoil leading edge. I don't like the LOWERED plenum opening-up but it may well be necessary to clear the hood. Plenum is plenum either high or low but I'd like to keep that 1-4 turn at the top if I could. They remove some of the passage there. I'd like to keep the round shape at the very top to help make the turn easier.
Title: Re: Horsepower curves ???
Post by: dick1172762 on January 27, 2014, 11:05:50 PM
Guess what? The leading edge of the F104 was so sharp, we had to put covers on the edge as soon as the engine was shut down to keep it sharp and to keep from getting cut by it. But I also know that an airfoil has a radius on 99.9% of all other airplanes. The 104 was a rocket with a man up front, but man they sure were pretty and oh so fast.
Title: Re: Horsepower curves ???
Post by: slowride on January 28, 2014, 12:36:39 PM
To be a bit more specific. I want to create a plenum and "drop the floor" to effectively RAISE (vertically) the flow. There is turbulence created when air/fuel tries to flow horizontally out of the venturis. Low pressure is created on the back side of the inside edge that separates fuel from the mixture. Would I like to have 4 cylinders to smooth the intake pulses at low rpm? Yes, but the adaptors I've seen don't create an effective plenum, just a void that still doesn't smooth the flow horizontally from runner to runner. The commercial modifications I've seen create a "tunnel ram" which is fine for mid to hi rpm, but I'm using this car on the street and am targeting more low to mid torque.
All I'll be doing to the engine side roof of the 2/3 runners is smoothing as much as I can without moving that roof closer to the throttle blades. The divider between 2/3 and 1/4 will be milled down a bit creating a floor and small plenum. I'll be making an carb adapter from  1/2" plate and copying the plenum shape extending the plenum up as well.
I may pick up one of the available adaptors to try out before I really get into the manifold. The Weber 38 should work best in this car because it's an auto and I'd like to keep the kick down. The throttle shafts to the rear should be easier to adapt that the Autolite with the throttle shaft out the side. If nothing else, everyone will know what NOT to do when I get done. Of course there were people that didn't believe the plenum I made for the 32/36 would do anything either.....
Title: Re: Horsepower curves ???
Post by: amc49 on January 28, 2014, 07:55:59 PM
'To be a bit more specific. I want to create a plenum and "drop the floor" to effectively RAISE (vertically) the flow.'

Buy the Racer Walsh 2 inch thick adapter, that does that and you don't screw with messing up the 1-4 entries, which is what you will be doing by cutting into them at the top to remove the turn. It is right at the top and any opening up will do that. Any more work to finish at the center of the X in the middle will only make it even worse as you get closer to flat. You need that ROUND curve to make the turn.  Chop parts of it up and turbulence all over the place right at runner tops, a particularly bad area to do that. The commonly used one inch one is way too low in my opinion and why they cut deeper into the manifold trying to relieve that issue. They lose at the 1-4 when doing that, but commercially they make money. By selling a cheaper to make adapter at almost same price as the thicker one, and the look pretty intake port work at $500 to draw in the suckers. BTDT.

Of course the dance again around the hood clearance issue......... ........

With the carb right at the commercially available adapters' location you will ALWAYS have some sort of turbulence issue, there is no one inch straight below the throttle plates to allow mix to get straight to then turn lower to go its' 4 separate ways. The throttle blade angle is going to mess up everything in there until it is straight vertical. On a Weber mounted in conventional location fully one half of wide open mixture is shielded from the outer lying areas by the wide open throttle plates. Why the two inch spacer, to get vertically up some to resolve some of that. You WANT some void in there to allow for good cross mixing at bastard butterfly angles as well as to allow for some splay out further room to reach areas the carb bores are not directly over. Two inch looks right to my eye without going overboard in excessive 'tunnel ram' fashion. I wouldn't hesitate to put that on an ATX car. Maybe advance the cam a bit if uncomfortable about it.

Tunnel rams can easily be made to work at low rpm, they are in effect on almost every EFI car on the planet now. What's the difference? Fuel distribution, which can be fixed in other ways. I built tunnel ram cars with carbs that would pull stumps out at 2000 rpm. You make the plenum area and runners smaller is all.

To Dick, yeah, I know about F-104 leading edges, and was thinking some SA like you would probably bring something like that up............ LOL..........O r course we all know what the mission of the F-104 turned out to inevitably be once everybody got over all the gloss and glitter right? Certainly no stars shot down there for sure.

Title: Re: Horsepower curves ???
Post by: 74 PintoWagon on January 28, 2014, 10:14:17 PM
Buy the Racer Walsh 2 inch thick adapter, that does that and you don't screw with messing up the 1-4 entries,
So, I take it you use this adapter and leave the intake as it is, right?, what if you used a 1" instead wouldn't it work just as good, I would think the only difference would be a little more bottom end, or am I seeing this wrong????..
(http://www.racerwalsh.zoovy.com/media/img/racerwalsh/W145-H145-Bffffff/1232b_almn.jpg)
Title: Re: Horsepower curves ???
Post by: amc49 on January 28, 2014, 10:50:44 PM
The one inch spacer on an unchanged manifold bottom will restrict free movement of mixture. You're asking a fast moving gas to go somewhat sideways with a partial open butterfly and straight down if they are wide open, to turn sideways and then turn and go down again with no room for curving, a sure power killer if there ever was one. With an inline Motorcraft carb at partial throttle part of the mix comes out at an angle and then must reverse almost 180 degrees to go the other way. The other cylinders on that side of engine may want food too you know.......... .....

When you force a fluid to do that it drags more of itself along at slower speed as well as holding it back, with more working space some can disperse to allow for quicker moving.

Why you could often pick up 20 hp. on a V-8 by sticking a spacer under the carb, the mix then had some room to spread out and turn.

I would not totally leave manifold alone, rather I would radius the port entries there. The sharp corner is a power killer as well.

This all may be a moot point. I do not have a car fitted up like this and hood clearance problems may prevent it. I'm just saying that in a perfect world......... .........and we all know there is no such thing.

FYI, Smokey Yunick once designed a single 4 bbl. crossram for roadracing SBC, it sported an unusual feature. It had a big dead flat right directly under the carb, fuel flowed straight out of the bottom of carb and struck that flat and intended to then smoothly splay out to flow into two trenches on the sides, each one feeding four runners that then ran back across top of engine to the opposite side head. At first glance seemed not too hard until he realized how the flat had to be designed at an exact height that was super critical, even throwing say a carb spacer under the carb could cost 25 hp. quicker than spit. The manifold came with specific instructions to NOT CHANGE THAT DISTANCE or kiss the power goodbye. He said as little as 1/16" difference could lose power and they worried how accurate the casting of it for production would be. Edelbrock Smoke Ram, I believe.
Title: Re: Horsepower curves ???
Post by: amc49 on January 28, 2014, 10:52:53 PM
Here we go............ ..........

http://www.jalopyjournal.com/forum/showthread.php?t=696404

I used to get to play with this one........... ...

http://www.ebay.com/itm/AMC-Edelbrock-STR-11-Cross-Ram-intake-manifold-SS-AMX-Javelin-Scrambler-/271382260039?pt=Vintage_Car_Truck_Parts_Accessories&hash=item3f2fa4a947

or here.......... ....number six post from the bottom of page. We dropped the stacks and the Dominator tops were milled off.

http://amccars.net/cgi/yabb2/YaBB.pl?num=1199816371;start=all
Title: Re: Horsepower curves ???
Post by: 74 PintoWagon on January 29, 2014, 06:53:11 AM
Interesting, the identical adapter in a 1" will cause that much difference?, my curiosity is getting the best of me now, I'm gonna have to make a couple of adapters and do some playing around I guess, lol..

I had one of those crossrams before, just got tired of no bottom end on the street and got rid of it, they are cool looking and drew attention though..... That Weiand is a good tunnelram though, I ran one with 660's on a 468 and it pulled hard, not as hard as my injectors though, lol..
Title: Re: Horsepower curves ???
Post by: slowride on January 29, 2014, 01:33:30 PM
Tunnel rams can easily be made to work at low rpm, they are in effect on almost every EFI car on the planet now. What's the difference? Fuel distribution, which can be fixed in other ways. I built tunnel ram cars with carbs that would pull stumps out at 2000 rpm. You make the plenum area and runners smaller is all.

Tunnel rams kill low end as their purpose is to create velocity. Whole different dynamic between EFI (most likely port injection) and carbureted. You don't have the atomization issue with EFI that you do with a tunnel ram.
Title: Re: Horsepower curves ???
Post by: amc49 on January 29, 2014, 07:04:01 PM
'Tunnel rams kill low end as their purpose is to create velocity.'

Nay, nay, good brother, that statement in and of itself is totally off the mark. Every low end intake made on the planet goes first thing for velocity and why the ports are so small, it speeds it up.

Velocity being good/bad is relative to other conditions. It is good down low but having that means engine will most likely choke at higher revs. High power engines kiss velocity goodbye at lower rpm to get it at higher rpm. Why again modern EFI engines have multi-port intakes that use one small port for low rpm and a second bigger one adds in for higher power. So you see EFI cures some but not all mixture problems.

Ask Ford right now about all the atomization issues they have on their direct injection (GDI?) engines right now, it's driving them nuts. Backflow is taking mixture and cooking it all over the intake valves to completely clog ports. So much for complete atomization. The engine does not care whether carb or EFI, it still pumps lots of fuel backwards once injected. Every time an intake valve closes everything behind it slams against the shut valve and sprays back into intake. Where lots of the carbon buildup inside intakes comes from, not all of it is from PCV or EGR. It's fuel repeatedly heated to form coke.

First thing tunnel rams do is straighten the entire port. ALL engines increase power with straight ports. Why carbs now replace gas tank on a hot pocket rocket bike. Why Esslinger went to raised ports on the 2.3 aluminum head. Then, tunnel ram usually gets bigger cross-section in port which LOWERS velocity BUT INCREASES flow at HIGH rpm. The plenums are huge also to better share multiple carb bores. That's why they generally zoop on stock street engines.

Take a smaller volume runner one for like sub-300 inch SBC and minimize the plenum and carb bores and you can get an excellent ATX manifold for like 350+ inch motors. I built one once with a friend on a 408 inch SBC and it would pull your face off. Car ran in the nines with a 2 speed Powerglide. Same engine in say a street rod and shorter cam and lights the tires at 2000 rpm with throttle only.

Title: Re: Horsepower curves ???
Post by: amc49 on January 29, 2014, 07:15:45 PM
74, no need to even make them. Take a sheet of paper and draw the adapter out as a cutaway drawing using the spread of the four runners and the width of two barrel bores and extrapolate that to a one inch and two inch height and look at the space involved there. Then think about fuel curving under all conditions to hit the target four ports.

I don't even have to, I can see the issues in my head having messed with enough intake stuff in the past. You get to where you can see good or bad pretty easy.

The four port EFI bottom port-to-port is about 3 3/16"-3 1/4" wide and a 500 Holley uses 1 11/16" baseplate bores, 350 Holley around 1 9/16" IIRC. Draw a triangle with the car bore at top and bottom being the four port width. Do one one inch high and the other tow inch and compare. Look at adapter pics to get some idea of the angle used there.

FYI, to those in the know EFI is great but any carb setup not running as good as EFI just means the carbs were not right. In my world carbs run just as well as EFI, there is no difference other than carbs fall off from dirt and passage clogging. Many times in drag racing people actually could run faster with carbs than injection but that was using pill type constant flow mechanical which is garbage. True totally electronic injection is wonderful once someone learns how to properly write software. Carbs can still equal it though in the hands of someone competent. Again, the engine is not smart enough to know what's on top of it, only whether it eats or not.
Title: Re: Horsepower curves ???
Post by: amc49 on January 29, 2014, 07:49:25 PM
FYI Weiand never made a tunnel ram for AMC, it was Edelbrock UR-18 with a Weiand top. We used the original UR-18 top, it came with Dominator mounting, you had to improvise to put regular base Holleys on one and why the Weiand commonly used. We ran Weiand on the Boss 302 though, we modded it to remove some plenum and used 2X700 DP Holleys on it. The 700s came off one of our AMXs, we had just purchased one of the first pairs of Dominators from Bill Heilscher, who had retired to run Green Valley Race City. He had an entire room under the timing tower devoted to all his old super and pro stock cars. The carbs came off one of the 454 pro Camaros.

He was up in the tower one night watching cars run  and saw our AMX and thought it ran really well and came out into the pits to talk to us. Really nice guy. When the hood was pulled and he saw the AMC engine his jaw about hit the ground, he though for sure it was a 454 BBC. They sounded very similar once you put Dominators on a healthy 395 inch AMC. Many others thought the same thing, we were often rumored to have like a 482 inch or other big Chevy motor in there, it was pretty funny.
Title: Re: Horsepower curves ???
Post by: 74 PintoWagon on January 29, 2014, 09:56:20 PM
74, no need to even make them. Take a sheet of paper and draw the adapter out as a cutaway drawing using the spread of the four runners and the width of two barrel bores and extrapolate that to a one inch and two inch height and look at the space involved there. Then think about fuel curving under all conditions to hit the target four ports.

I don't even have to, I can see the issues in my head having messed with enough intake stuff in the past. You get to where you can see good or bad pretty easy.

The four port EFI bottom port-to-port is about 3 3/16"-3 1/4" wide and a 500 Holley uses 1 11/16" baseplate bores, 350 Holley around 1 9/16" IIRC. Draw a triangle with the car bore at top and bottom being the four port width. Do one one inch high and the other tow inch and compare. Look at adapter pics to get some idea of the angle used there.

FYI, to those in the know EFI is great but any carb setup not running as good as EFI just means the carbs were not right. In my world carbs run just as well as EFI, there is no difference other than carbs fall off from dirt and passage clogging. Many times in drag racing people actually could run faster with carbs than injection but that was using pill type constant flow mechanical which is garbage. True totally electronic injection is wonderful once someone learns how to properly write software. Carbs can still equal it though in the hands of someone competent. Again, the engine is not smart enough to know what's on top of it, only whether it eats or not.
Well, I'll have to do that I guess, I just bought an intake just waiting to get here then I'll have a better perspective of whats going on with this..

Haven't messed with EFI yet, but I have to respectfully disagree on your thought on MFI, and that can be proven any time but just like anything else if you don't have an understanding of how things work you're in the dark, heck I know a few guys that couldn't make a carb work if they're life depended on it, lol..
Title: Re: Horsepower curves ???
Post by: slowride on January 30, 2014, 06:45:07 PM
'Tunnel rams kill low end as their purpose is to create velocity.'

Nay, nay, good brother, that statement in and of itself is totally off the mark. Every low end intake made on the planet goes first thing for velocity and why the ports are so small, it speeds it up.

Velocity being good/bad is relative to other conditions. It is good down low but having that means engine will most likely choke at higher revs. High power engines kiss velocity goodbye at lower rpm to get it at higher rpm. Why again modern EFI engines have multi-port intakes that use one small port for low rpm and a second bigger one adds in for higher power. So you see EFI cures some but not all mixture problems.

Ask Ford right now about all the atomization issues they have on their direct injection (GDI?) engines right now, it's driving them nuts. Backflow is taking mixture and cooking it all over the intake valves to completely clog ports. So much for complete atomization. The engine does not care whether carb or EFI, it still pumps lots of fuel backwards once injected. Every time an intake valve closes everything behind it slams against the shut valve and sprays back into intake. Where lots of the carbon buildup inside intakes comes from, not all of it is from PCV or EGR. It's fuel repeatedly heated to form coke.

First thing tunnel rams do is straighten the entire port. ALL engines increase power with straight ports. Why carbs now replace gas tank on a hot pocket rocket bike. Why Esslinger went to raised ports on the 2.3 aluminum head. Then, tunnel ram usually gets bigger cross-section in port which LOWERS velocity BUT INCREASES flow at HIGH rpm. The plenums are huge also to better share multiple carb bores. That's why they generally zoop on stock street engines.

Take a smaller volume runner one for like sub-300 inch SBC and minimize the plenum and carb bores and you can get an excellent ATX manifold for like 350+ inch motors. I built one once with a friend on a 408 inch SBC and it would pull your face off. Car ran in the nines with a 2 speed Powerglide. Same engine in say a street rod and shorter cam and lights the tires at 2000 rpm with throttle only.


Guess we'll have to agree to disagree as we can get REAL technical about this and the "backflow" you're referring to (reversion) is an affect of runner dynamics,  cam profile, and pulse timing. Smokey Yunick was a master of this and we both would be humbled were he able to join in the conversation.
Bottom line is, I don't have a problem trying something new as it won't be the first time a theory didn't pan out. If I didn't explain exactly what I was doing, it'll just have to wait until I'm done and can post pics..... and results (good or bad).
Title: Re: Horsepower curves ???
Post by: amc49 on January 30, 2014, 10:01:00 PM
Good enough, your stuff and do as you will.......... .......not trying to take over anyone's mind.

Nothing wrong at all with trying things new out, but not thinking about how to best make an idea work before doing it fails the majority of them I've found.

Yunick? I would not be humbled, he was a man as are we all. I would ask him questions though. Most of his stuff I agree with but some is hype. In later years he got a little full of himself I feel. I notice that Fiero 'hot turbo engine' he hyped so much did not take over the world......... .........he was pretty smart though.