Camshaft / Exhaust Combo

Camshaft / Exhaust Combo - 09/11/12 12:53 AM

Currently finishing up my 440 build. I want to reuse my factory hi-po manifolds from my roadrunner.

The two cams I'm looking at are the Lunati 60303 and 60304.

I've read on other posts here that guys ran the 60303 in low compression 440's but had headers. I want to run the 60304 since my 440 short block is running six pack pistons and higher compression.

Can I run the larger cam with hipo-manifolds and a 3 inch exhaust or is it not a good idea?

Posted By: BSB67

Re: Camshaft / Exhaust Combo - 09/11/12 01:58 AM

What heads, and actual compression ratio?

Of the two, the 303 would be a better choice, if you don't have too much CR. If you have iron heads it might not run on pump gas. If you want a larger cam try Mr Six Pac or Dwyane Porter.

Posted By: Pacnorthcuda

Re: Camshaft / Exhaust Combo - 09/11/12 02:03 AM

The issue won't really be the Cam, as much as manifolds and a 3 inch system. You're just begging for DRONE. I bought my 'built' 440 Cuda with HP mannys and a 3 inch TTI system. Dynomax mufflers.

Excruciating drone.

Went to headers/2.5"/magnaflows (Dynomax would have been fine) NO drone.

I also run the 60303 Lunati.

Posted By: CurYellowBird

Re: Camshaft / Exhaust Combo - 09/11/12 02:09 AM

The heads are 452's from Aero Head that have 2.14/1.81 valves. The heads were surfaced so probably close to stock cc. The short block is close to zero deck after going with L2355 flat tops.

Please define drone for me because I don't really know the term.

Posted By: Pacnorthcuda

Re: Camshaft / Exhaust Combo - 09/11/12 02:12 AM

Quote:

The heads are 452's from Aero Head that have 2.14/1.81 valves. The heads were surfaced so probably close to stock cc. The short block is close to zero deck after going with L2355 flat tops.

Please define drone for me because I don't really know the term.

Its a resonance (think BUZZING) in the exhaust while your cruising at light-mid throttle. Often in the 40-60mph range.
Noise to the point of NO conversation in the car. VERY annoying.

3" pipes often contribute to it, and in my opinion 3" pipes connected to manifolds ASK for it.

My experience was brutal. Previous owner installed a 500W stereo to drown it out!!!

Posted By: Pacnorthcuda

Re: Camshaft / Exhaust Combo - 09/11/12 02:16 AM

Your engine will be fine with either cam. BUT! Do you have an automatic tranny? Whats the converter? Do you have power brakes??? The 60304 could very well be a concern with power brakes.

Posted By: BSB67

Re: Camshaft / Exhaust Combo - 09/11/12 02:19 AM

Exactly how far down are the pistons, and what head gasket thickness? Were the heads cut?

You are probably around 9.5:1. If so, the 303 will be close with with 91 octane IMO.

Posted By: CurYellowBird

Re: Camshaft / Exhaust Combo - 09/11/12 02:30 AM

This is a 4 speed car with manual brakes.

With the piston at TDC, the ridge is barely enough for me to catch with a fingernail. I am not at my dad's so I can't give exact measurement. I'm using Felpro replacement head gaskets to try and keep the compression somewhat down rather than using steel shim gaskets.

Now I know what drone is. I've heard it before just never knew there was a name to it.

Posted By: CompSyn

Re: Camshaft / Exhaust Combo - 09/11/12 04:11 AM

Quote:

If you want a larger cam try Mr Six Pac or Dwyane Porter.

I believe the distinction has been drawn that a Big Block Mopar with exhaust manifolds benefits from a cam center line somewhere around 112-to-114 and exhaust duration not much more than 284.

Andy Finkbeiner's dyno testing seems to confirm this as well as the track tuned Mr. 6Pack cam from Bob Karkashian.

So there again, the Mr. 6pack grind I decided to go with is optimized to run with bone stock 906 heads and HP manifolds. It's center line is 114 and has exhaust duration somewhere in the ballpark of the stock Magnum/Road Runner cam ~ 284.

Posted By: DaytonaTurbo

Re: Camshaft / Exhaust Combo - 09/11/12 04:19 AM

I have run the 60303 as well. First question, what is your rear gear ratio?

I ran the 60303 in a smogger 440 with headers, 440 source heads and 3.55 gears with a stock converter. It really needed more converter and would have liked more gear because of the lack of compression.