I have a 400 that I had rebuilt earlier this summer. I had a .485 intake lift .520 exhaust lift cam put in it. How can I get the timing set to give it a lopey idle? I have played with the distributor and can't get it to idle the way I want it. Pretty soon I am gonna change it to a 4 barrel and new intake.

 

What's your duration? lift will not give you a lopey idle. My cam is a xtreme energy series from comp cams. duration is 230/236 @.050 and the lift is 554/557 @ .050. BTW it is a roller cam and it's got a really nice lope to it . John

 

You can't make a cam idle rough, those characteristics are built into a cam.

 

While your cam specs are very respectable(lift wise), it is the combination of duration (both intake and exhaust) and lobe seperation angle(LSA) that will define your idle profile. Changes to your ignition timing is changing the timing of the spark versus the piston location. You will find that most modified clevelands(pun intended) like 12-16 degrees BTDC initial and 30-36 by 3000RPM. Your cam I would run at 12 BTDC and maybe try 14 on a cool day. Timing lights are worth it.

If you have had your valvetrain converted to an adjustable set-up, then your easiest solution would be purchase a set of 1.8 ratio rockers. Several companies make them that will work for you: CompCams, Harland-Sharp, Scorpion. That will definitely make your current cam idle a little lumpier. Otherwise we're talking about a different cam than what you have now, and a larger investment.

For what you want, I recommend a cam with intake duration @0.050 of 225 degrees or more, with a LSA of in the 106-110 degree range. Remember that the larger you get, cam-wise, the more critical it is that the whole system work together in harmony (intake ignition exhaust), and then there's the rest of the vehicle (stall RPM/cam duration working together, gearing/tire height working together with RPM range of the motor).

Hope this helps you figure out what you want to do.

 

well the cam is a 282 292 duration. and yes, thanks it helps.

 

it is a hydraulic flat tappet or something like that. hydraulic something another. no rollers.

 

and as far as stall converters, I have the biggest cam available to work right with my stock converter. And I am gonna get a 4 barrel soon. any recommendations? edelbrock? holley? and what about intake manifold?

 

sounds like your running the edelbrock perfomer plus cam 2172, which is a going to be a reliable running camshaft with a smooth idle and good mid range torque. looking at the specs of that cam which you state has 282/292 duration, that is referred to as the advertised duration. the duration @0.050 inch the edelbrock cam is 204/214 - which is more than stock, and then consider what lobe seperation angle that cam is ground on which in the eddy perf+ cam has listed at 112, for better piston to valve clearance and increased vacuum for brake operation with a 'larger' cam. these spec tell me that your cam will idle tame and operate just fine and pull like a freight train - just not a lumpy cam that will spin past 5600 rpm.

if you run an edelbrock intake, you'll want to invest in atleast 1 inch spacer, and run a 2 inch if you have clearance. as far as carburetors go AFB styles are more forgiving of dirt in the fuel, and simpler as far as maintenance, however once you get acquainted with temperance of a holley and if you have confidence dropping fuel on a hot intake to change the jet and the occasional power valve then you can go with any 600-700cfm.

you can run a 750 if you desire, if so i would recommend inspecting a spark plug about once every couple of months.

 

holley and the new HP series are nice. also the quick fuels and barry grants. having good luck with quick fuels and really like! Several different options. But the real question is what type of holley or quick? is it down leg or straight booster or annular or stepped annular or some other variations. Currently building a 400 ford and will have atleast a 850cfm on it annular style booster. Speaking with another company and they say even bigger in the hp950 annular. I personally think a little to big for my application but interesting. So if you go 750 what type booster style? what application, converter? So when you say 750 this leaves a big question because of the different carb designs. any question drop a message. All carbs are not created equal. If not familiar with different carbs drop a message. catch you later.

 

How are the Weiand made manifolds? what about the Edelbrock spider intake? I am wanting a mechanical secondary. Manual choke. I have (IMO) a great idea for my motor. It is in a '77 f150, I am planning on cutting a hole in the hood, running a summit air scoop with the butterflies, four barrel with the spider intake.