The Dodge Challenger Message Board

What is duration and lift and whole specification of standard cam for 4bb 440 engine (727 transmission?
I have installed in my engine "hot" cam but I don't know what type it is. And I don't like it. Engine runs very rough and shakes when idle (I have new wires and plugs)
I want to put standard cam because my axle ratio is 2.93 and car behaviour is little strange.
Or what cam is the best for this configuration?
Any suggestion?

In addition, if your lift is way to much, to radical, it will not hook up well with your auto, unless you change to a high speed stall convertor. That is what I am running. I don't know what my cam is tho. I understand that the max cam you should use with a reasonable stall convertor is about 260.

As a cam gets 'hotter' the power moves up the rpm range so the lower rpms suffer and the idle quality gets rougher. A lot of people (like me) like the rough idle that the drag cars have and so do not mind this.

I will have to look up the spec of the standard cam but I think it is about 225-230@0.050" lift.

How is your air/fuel mixture? When fitting a hotter cam you almost always have to adjust the idle mixture at least. If the carb is not right it could make your idle even rougher.

The rear axle ratio should not make any difference. But your car may want to pull away at idle very strongly if the stall speed is not high enough in the torque convertor.

I just looked up the spec of the stock hi-perf 440 cam.

268 deg. duration on the intake with 0.45" lift
284 deg. duration on the exhaust with 0.458" lift
Centerline of 115deg
Valve overlap of 46 degrees.

Now this is 'advertised duration' as opposed to the industry standard of duration @ 0.05" lift. I think if you take 80% of advertised duration you will get close to the duration @ 0.05" lift.

So that equates to 215 deg @ 0.05" lift on the intake and 228 deg on the exhaust.

Any cam with more than 230 degree @ 50 thou duration will start to sound lumpy at idle.

Recomendations.

I like the cams sold by Hughes Engines.

In your case I would go for either;

HE1923BL
Intake = 219 deg @ 0.05" with 0.489" valve lift
Exhaust = 223 deg @ 0.05" with 0.504 valve lift

This equates to 266/270 'advertised' duration and will give you strong pulling power from 1400-5000 rpm.

OR
If you want to rev it up to 5700rpm go for the slightly hotter HE2330BL;
Intake = 223@0.05" and 0.504" lift
Exhaust = 230@0.05" and 0.515" lift.

This one equates to a 272/276 advertised duration and is as hot as you can go without getting too lumpy at idle.

Both of these cams will give you a lot more power than the standard engine.

Hey, the plot thickens!
Just found out that I have 9:1 Pistons! Geof says I need 12-15:1 for the Herbert roller I am using, Herbert says 11:1 is ok! So is this the problem?
I spoke to Lee, the guy who put the cam in, he says "he was talked into it, but never really kew if it would work"!. His cousin, Dave Billadou tald him not to do it!

Hmmm, here we go then! Previous camshaft was a Crower Hyd. Hauler 294, using V/dur. Hyd. lifters and Manley Hyd. w/adj rock pushrods. I don't know what valve springs were used.

I am very tempted to go back to this config. Any suggestion at all? As I am in the States in 10 days time, I would like to collect parts while there.

That is what I would do but your compression is still a tad low for that cam as well. How do you know the actual compression? How much was taken off the block or heads when it was built or at some time in the past? What thickness head gasket do you use?

I suppose at the end of the day you know the old combo worked so you would be better going back to that.

Well Dave, I really have no Idea! the only one of your questions I can answer, is that I use felpro gaskets!
The Crower Cam, lifters, springs and retainers come to £260.00 inc. It's a real minefield this camshaft selection innit?

Use shims!!! Mopar gaskets are shim type and will bump the comp a tad

I have a pair of heads that came off my brothers 1970 4-door satelite. I thought all 4-doors were ugly, but after seeing that car I not sure about that. Anyway, to the point of my question, the stock comp for my original heads was 8.6:1. The heads of my brothers '70 Satelite came stock with a compression of 8.8:1 and then I had the guy at the local machine shop plane it as much as he could. I am curious, just how much can you take off a stock 318 head and how much of an increase in comp would there be?

Jeffs, Shims are good,huh? Mopar brand gaskets are shim type and will raise comp, am I right Jeffs?

Joel. This thread is about choosing a cam for a 440. If you want to talk about your 318 heads you start a new thread!

Anyway.
The best way to up the compression is to install the correct pistons. Cutting the head or deck should only be done to get them straight and even then you take off as little as possible. Your inlet manifold will have to be cut as well if you take too much off plus pushrods have to be shorter etc.

Jeff.

If your engine was built with 0.035" composite gaskets then the compression will increase a tad with a steel 0.020" gasket like the ones I use.

You can use my maths excel spreadsheet to work this out.

For example: If you have the typical 86cc '906' heads on an engine with a standard bore and you use flat top pistons that are 0.076" below the deck at TDC.
With a 35thou gasket you will have 9:1 compression. With a 20thou gasket you will have 9.26:1 compression.

If you now increase the bore by 30thou it goes up to 9.35:1.

Now machine the deck (bad practice) or use taller pistons so as to bring them up to just .040" below the deck and you will have 10:1 compression.

If my sums are right that is.
Hope this helps.

I never heard of being able to order taller pistons than standard height. Is that a special order item, Dave?

Joel. This is how you set the compression ratio. You can get aftermarket pistons in all sizes and compression ratios and even custom pistons.
You can even get piston 'blanks' that you can cut to the shape and size you want.

Another factor is the piston pin height. This can shift the piston up or down in the bore in relation to the end of the rod. You would need to change this if, for example, you fitted a longer stroke crank. Otherwise the piston would knock the head off would it not?

I know you can get different diameter pistons. But when it came to a crank that has a larger stroke than the stock crank, I thought that you would just order piston rods that were shorter. But when I image it in my mind, scary thought, it would be cheaper and easier to get a pin that is smaller than stock,and then insert blanks into the sides of the pistons then fit the smaller pin through the blanks. Your right Dave, that would be a much, much cheaper way to shift the piston up or down.

Where could you get small block Mopar higher compression ratios? Jeg's and Summit don't carry the higher compression ratio pistons for small block Mopars. You MUST know of a place that does carry the kind of pistons that I have been looking for, for some time now.

Would it be any trouble for you to tell me where I could find such rare findings?

You are looking at a supplier. You need to look up the piston manufacturers like Keith Black, TWR etc.

And no you don't fit smaller pins and blanks to move the piston up and down. Get this idea about a piston being made for one engine only out of your mind. Think of pistons being made in all sizes with differences in the distance between the pin and the top of the piston. Also the distance between the top ring and the top of the piston. Plus a hundred different variables.

Mind you they don't make the combinations there is no market for so although there is a lot to choose from they do not cater to every possibility.

Keith Black and TWR, huh?

No actually that is my dyslexia creeping in. I meant TRW.

Arias, JE, Ross and Manley are other good makes that spring to mind now that I think of it.

I checked out Arias, they only have pistons for 340's and bigger engines. I got really excited when I saw they specialized in forged pistons, to bad, I would love to have a set from them. Oh well, I will try the three others on your list.

What about this one for a Street Strip rig
HE3844BL INT .536"
EXH .540" INT .572"
EXH .576" 238°
244° 283°
291° 108° 14° BTC
53° BBC 44° ABC
11° ATC

How about a roller cam?

(Can't find one)

I think HE3844BL is the one I use is it not? I would have to check but I think it is. Spec looks about right.

Yes that grind is the one I use.

You can get roller cams but they are very expensive.

Well, where do I look. I cannot believe the increase in performance that comes with this type of cam.

You want a roller cam? Well I know Herbert do rollers for 440s as do Comp Cams. Maybe plenty others.

The only advantage to using one is if you want huge valve lifts with a streetable duration.

BUT! You never get something for nothing! The roller lifters have huge side loads on them as they climb the cam lobe. This wears the lifter bores very fast, resulting in huge loss of oil pressure at some point a few thousand miles down the road. It is very expensive to have this repaired.

How fast they wear depends on how radical the cam is and how you drive/how much you drive.

Worth taking this into consideration.

Did not know that. And you are right about something for nothing. The greatest increase in performance is of course, the heads. But, I am not sure I really want 500hp. I want fun, fast, and sounds. I think the cam you are running is the right way to go. And I don't have a clue what my heads are, until I get the valve trane off and see.

Thanks.

The cam has to suit the heads. Don't try to use a cam like mine unless you have the head flow to match.