As far as the carb flow is concerned you are fine but if it does not meter enough fuel then that needs to be corrected. Your engine size will not pump more tha 500 cfm at 6000 rpm so your carb is big enough. If there is a definate line that problems are seen then it's not the carb it'self. If you have an RV type cam, it will sign off very fast above a certain rpm. Those type cams make a lot of torque within there rated RPM band but drop dead right quick above the top limit. That's the way they were meant to work. Weak spring pressure will also cause an engine to hit a ceiling. I have been there in the past with an RV cam. It was fun to drive but you lose in a race with another car that can wind higher. The only way this type cam could hold it's own is with a 5 speed manuel, to keep the engine inside the cam's band. I changed to a wide lobe seperation for EFI use, lost some torque but the rpm goes over 6200 rpm with the same heads.
i am running an XE256H it has .477 int .484 exh.... duration is 212 int 218 exh i can def use a better cam... i was told this cam would get me to 400 HP>. lol... i wish i knew that guy was full of it then.. so i could have got the right cam at the start
Well 400 hp out of a 302 is not impossible but difficult to reach in a street engine without some serious heads, cam, compression and intake equipment. The basic understanding is that air has to be pumped thru the engine to make the power. This means the rpm has to go up to do so. Heads have to flow the air, cam has to have durations and lift to wind hi, more compression and intake /exhaust have to be up to the job beside being built from parts that will have reasonable life at those rpm levels and the cost goes up from that.. You can see that most 'hot' street engines will be in the 325 to 350 range with most never reaching 300 hp with the usual parts combinations that are used here. Now this does not count blowers and NOX use but only N/A application or fuel injection. Again it depends on the build level.
question about fuel pump I was wondering if maybe his mechanical fuel pump could be floating at the 5000 rpm level. I have heard of that before and he said the engine had a few miles on it. You can buy an electric inline fuel pump for a carburator with the pressure already set from auto zone.. I think its for a mid 80's oldsmobile. I have one for my mav. If you are interested I can get the part number off the box..
Yeah...I keep coming back to that fuel pump. It seems like every time I complain about any power loss, the pump comes back up. That AutoZone pump is only $30 or so, isnt it? I might just spend the money and give it a try. Can't hurt. If it doesn't change the problem, then I can use the electric to push from the rear of the car, and the mechanical to push the last 3' to the carb...lf I need to do that. I would like the part number if you don't mind, so I get the right one the first time...thanks
Scooper, I would agree with Ken's evaluation of your cam. As you know I'm running the same grind but with 1.7:1 rockers. My car starts running out of breath at about 5000rpm. When I had 1.6:1 rockers it would stop pulling at around 4600 rpm. It's a great low rpm torque cam but you can't wind it up. Edelbrock's rpm claims for that cam are bull and are based on using their aluminum Performer heads. As for others who are running similar lift and duration figures and can pull higher rpm, there's a lot more to cam specs than lift and duration so they may not be good comparisons.
Sounds like the cam is a bit small. I didn't see where you listed the specs though, so take that with a grain of salt. Stock heads don't really "sign off" so much as just lose effieciency gradually. They will spin up plenty of rpm with the right parts, they just don't make as much power as they could, and that curve is ever increasing the higher the rpm. However, they don't just sign off at any point like cam, carb, lifters, and springs will. When those parts go away, it is like hitting a brick wall. You never feel the heads going away unless you are used to big heads and replace them with stockers. Some things that you can do: Fuel pump Increase fuel line size Check for fuel restriction Check for spark loss at high rpm If your cam has some rpm left in it, you may just need a better fuel pump. That would be my starting point. I ran the plain jane, non-polished, Carter strip pump on my SBF for a long time. It was a good high rpm part. If you don't want the extra drag on the front of the engine, you can go with an electric pump. Check the bushings and action of your distributor. The stability of the shaft and smooth advance are more critical the higher the rpm. Use a large diameter stock Ford distributor cap. It is better suited for high rpm. Make sure your carb has no inlet filter like a Holley. I don't know about your brand. Make sure you have no crimped fuel lines or bottlenecks in the system. Your filter should be larger than the rest of the lines, as opposed to same size or smaller. Again, Holley tech, but check the size of the needle and seat in the carb. Holleys can be adjusted to flow more with a needle change. Check the float level... I doubt your pump can outflow your carb at any rpm or float setting, so this is probably what I would check after a change to a better pump. If money and ease are your concerns, then just use the Carter strip pump. Not only is it priced decent, it looks closer to stock than the chrome or polished ones that cost twice as much. You will probably need to 'clock' the outlet to fit the Mav right... I did on my 75. Good luck Dave
you would get better performance if you use a dual-plane intake with your engine combo your running my ..did not see what dizzy you have but if its stock you might want to do some work on it and get a better coil....you may want to check the valve lash set it alittle loose
I had the performer dual plane and hated it. I ended up putting in an open 2" spacer, and like the boost I got from "single-planing" it. I then went to the highly ported torker 289 and this thing accelerates like no tomorrow...it just slows down acceleration when you hit 5000 or so. I will do the fuel pump. Don't like the mechanical pump anyway...it is located right beside the oil filter and makes it quite difficult to get at it. It is much larger than the stock mechanical pump, and I really am starting to think that I am "floating" it at high rpms. When it was new and not yet installed, I wondered about how slow the pump arm returns, and I bet that is where I am losing "some" of my ooopff!
electric pump part # I got the pump from Auto Zone. It is made by Master. Part # E8016S It comes with fittings, 2 small hoses to connect to your existing line, a firewall mounting bracket, inline filter, wiring diagram. All for about $40. bucks. Just connect it to the inner fender, where your fuel line comes through, plug it in to a switched power source and enjoy.. It runs 2.5 to 4psi
It'll sign off very quickly. If the cam is too small, it'll just quit making power...it'll still accelerate, but won't accelerate nearly as quickly as it should. If the carb is too small, you'll find that it'll act nearly the same as a small-ish camshaft. Well, most everyone on here knows where I stand when it comes to carb sizing. Bigger is usually better....but not always. I don't think you're over or under carb'd. I do think that the cam isn't quite right for your combination, though. The intake ain't all that great either. You said you tried the performer intake....yeah...those are nothing more than an aluminum version of a stock Ford intake. They're "ok" to about 4500 and not much more. The RPM intake is a world of difference better. Better low end, mid range, and better top end....at least up to about 7200 RPM (on a 302). I have had many different intakes over the years...most of them on the old GT mustang I used to have ('84 carb'd 302). The 2 main ones were a Torker and a RPM. It came with the Torker; and it was ported to hades and back. Someone had actually broken through and epoxied all of the runners where it broke through. I pulled that thing off (fearing a vacuum leak) and bolted on a stock Torker I picked up at a swap meet. Didn't run much different. Then I put an RPM on it. It was a thousand times better; ran smoother, accelerated quicker, more low end/mid/top. The torker did OK from 2500 to about 4500, then it was like it just quit making power. Sure, it still revved, but not like it should have. Then I tried a Vic Jr 302. Whoa, what a top end! But....I did lose a little bottom end and driveability, so the RPM went back on. The cam that was in it was just a little Performer Plus cam (was in it when I bought it). I changed it; used my old turbo cam (erson hyd roller, .512" lift 228 duration @ .050" I believe and a 114 LSA). The cam guy I talked to said the iron heads I was using would like the wider LSA...said it'll make a wider torque curve. I was using a set of D5TE 351w heads...cleaned up a bit, but nothing out of the ordinary. Something else that I did was blueprint my distributor (duraspark stock). I recurved it to make the advance be "all in" by 2500 RPM (35 deg). I also phased the rotor. You'd be surprised how far off the rotor was from the cap's terminals. Just doing those 2 things netted a pretty healthy gain in power. I'd guess around 20-25. Fuel economy also improved, as did ease of starting. I'm thinking about doing a tech article on blueprinting a Duraspark Dizzy. In short, I think that the cam is small-ish for your combo. That combined with the torker intake. If it were me, I'd look for around a 112 LSA camshaft with about a 230-235 duration @ .050 (flat tappet)..but you can get away with more duration on a roller or hyd roller. Lastly, I'm surprised noone said anything about the rocker arms. IMO (FWIW) A good set of rollers will help you quite a bit, probably free up around 20 HP or so up top. Just don't get the crane energizers...they tend to let the roller tip pins come out. Good luck.
if your engine is slowing when you are over 5000 rpm, its probably not the torker 289. they pull pretty well up to aound 6500 rpm, especially when opened up a little bit, and/or with an open spacer. actually opened up and with a 2" open spacer, i know a few guys that felt they ran well up to 7000 on heavily ported oem heads with 1.90/1.60 valves in years gone by. in the pre victor jr days. are you looking at the electric pump to help the mech, or replace it? if you replace it, you want one with a minimum of 4-5 psi in the traps: preferably 6-7, especially on a holley. im not familiar with edel carb needs.
Just want to clarify that intake is the OLD Torker 289, not the newer Torker II. Quite a different beast, plus this one has been very heavily ported from top to bottom. As for the fuel pump, I need 6psi, and will first try to use the electricl in-place of the mechanical. Depending on how that works, I might run the electric at the rear to push fuel forward for the mechanical to feed to the carb. Then maybe two electrics. Really, I am just messing around, experimenting with various combos to see what works and what doesn't. I will probably have to put a regulator in if I keep messing with this, since I hear the edelbrock is sensitive to pressures going over 6psi. Has anyone done these pump setups, and had any successful working combinations?
Electric pumps You don't need any specific part number. You just need one that will pump enough fuel. Everyone sells multiple versions, just pick a brand you like with the volume you need. I run them on a couple of cars, just like someone stated, mounted to the fender wall, tie power into a fuse and off I go. A switch would be nice for sitting with the car not running and the radio going (and the pump not running) but I don't bother. Dial regulator hooked up I can set from 3 to 8 lbs in a second. Never needed both mechanical and electric. Easy to get, easy to put in, easy to change, not expensive. Added feature, if you run out of gas you don't run you're battery down trying to pump gas back up to the carb by cranking the engine.
