Ultimate Street / Strip Performance Cam Shaft Selection

[ykf7b0]

I would love to read input from you Moparites regarding what would be the ultimate choice for a street/strip camshaft for the most horsepower/torque with factory unmolested iron heads and still retain a very reasonable level of streetablity with a 440. I currently have installed a 284/484 Mopar Performance PurpleShaft and have utilized it to the max as my E.T's of mid 7 second 1/8 mile time slips will confirm. My 440 has a 10.15 compression ratio and will perform and idle just fine with 92 octane gasoline with my current set up and is installed in my 3500 lb fully street legal 10.25 mpg 69 road runner. I am using 915 heads with a Torque Flite with a 9 1/2 inch converter. I know I could gain performance with a roller camshaft and I know some of you have vast knowledge and experience pertaining to this subject. I would appreciate the opportunity to read your experiences and recommendations for a nominal performance gain over the 284/484 PurpleShaft with merely a cam and/or lifter swap with regards to my application! Thanks!

 

[benno440]

stick with lunati or hughes cams.

for lunati i would suggest a lunati 60303 cam, but get some ported heads imo the HP is mainly in the heads man

 

[ykf7b0]

stick with lunati or hughes cams.

for lunati i would suggest a lunati 60303 cam, but get some ported heads imo the HP is mainly in the heads man

I am well informed of gains with megabuck headporting but I am looking for potential gains with what I have WITHOUT head work and only a cam swap. Thanks!

 

[benno440]

check out that lunati cam 60303 i have had it in 2 440's now i really like it

 

[ykf7b0]

check out that lunati cam 60303 i have had it in 2 440's now i really like it

Will do. Thanks Again!!!!

 

[Budnicks]

I know from your responses already, you don't want to hear it, BUT.... Maybe if you can't afford to do the professional head porting, "the single best money spent on performance engine builds" by far, the engine is just a big air pump, air in & air out, the heads are the lungs, if it don't breath, it won't run to it's full potential, ever, no matter what camshaft you use.... I guess you could buy some adjustable rockers & appropriate type/style/length of quality push-rods, so you can zero out the preload on the lifters & get all of what you can out of the camshaft, for about 1/2 of what a "basic" decent professional head porting job will cost, maybe $350 on 1.6:1 ratio rockers & shafts, another $150 on the proper type/style/length hardened push-rods, with the same exact camshaft & lifters, you have now, will net you 10% more gross valve lift & some "minor" more usable flow, it's money well spent either way... But for probably a good 30% improvement, the aforementioned adj. rockers & push-rods & head porting, can be done for, between maybe $500-$2500 or more, depending on how far, you want to go, with a Cast Iron Stock type cylinder head & your budget, the pockets are a big chocke point, hampering flow, it's money better spent than a camshaft change, where the heads are still the biggest choke point, in your engine... You will spend $350-$500 easily for a decent new camshaft, new lifters & the proper size & style valve springs, retainers seal, locks, etc.... You can go to a larger diameter valve & multi angle performance valve job also, in your current cylinder heads, will help some too...... Good luck with the camshaft change....

 

[Meep-Meep]

To me an ultimate street strip engine is one that will last for a long time, able to be driven in all weather conditions, run pump gas, be cost effective to build, provide plenty of driving excitement, get reasonable mileage and not produce excessive emissions. For something like this to work I believe a cam no less than 112 lobe separation is best to keep the idle quality and vacuum high. A strong vacuum signal also means that carburetors work better, not to mention power brakes.

I'm running a 440 with 10.1:1 CR and 915 heads but have the smaller MoPar .455" cam and I love it. I get by with less converter and gear and a stock iron intake. 1/4 mile performance with the single AFB in a 3900 lb as raced car is low 13's @ 109 MPH on street tires, 3.55's, full exhaust and air cleaner installed. Not sure what that is in 1/8 mile numbers.

 

[Bigal75]

To me an ultimate street strip engine is one that will last for a long time, able to be driven in all weather conditions, run pump gas, be cost effective to build, provide plenty of driving excitement, get reasonable mileage and not produce excessive emissions. For something like this to work I believe a cam no less than 112 lobe separation is best to keep the idle quality and vacuum high. A strong vacuum signal also means that carburetors work better, not to mention power brakes.

I'm running a 440 with 10.1:1 CR and 915 heads but have the smaller MoPar .455" cam and I love it. I get by with less converter and gear and a stock iron intake. 1/4 mile performance with the single AFB in a 3900 lb as raced car is low 13's @ 109 MPH on street tires, 3.55's, full exhaust and air cleaner installed. Not sure what that is in 1/8 mile numbers.

Got the same combo but with 3.23's and I agree, it works pretty good.

 

[RustyRatRod]

You will not see a huge improvement over what you have without some port work, IMO. The limitations for stock port iron heads is around .500 lift and you are there. MAYBE one of the newer Lunati or Hughes grinds might get some better performance, but IMO it would not be enough to justify the expense and work it would take for the swap. Throw head porting in the mix, and it's an entirely different ball game.

 

[ykf7b0]

No Gain Until.........

You will not see a huge improvement over what you have without some port work, IMO. The limitations for stock port iron heads is around .500 lift and you are there. MAYBE one of the newer Lunati or Hughes grinds might get some better performance, but IMO it would not be enough to justify the expense and work it would take for the swap. Throw head porting in the mix, and it's an entirely different ball game.

I was considering going with a roller set up but it seems I would not gain much based on what I've been reading and the cost would be great. I love the Mopar 284 / 484 and it is a great match for my set up. I think in the future I will aquire some aluminum heads and have them worked before I spend a bundle on these 915's. Anyway, thanks for your recommendation!

 

[RustyRatRod]

I think that's a smart plan.

I was considering going with a roller set up but it seems I would not gain much based on what I've been reading and the cost would be great. I love the Mopar 284 / 484 and it is a great match for my set up. I think in the future I will aquire some aluminum heads and have them worked before I spend a bundle on these 915's. Anyway, thanks for your recommendation!

 

[67 B-body]

Good choice!
I contribute most of my engines performance to the heads!

 

[Meep-Meep]

You can get plenty out of the factory heads and racers did it for many years with all makes during a time when Edelbrock heads were not available. It is also a fact that careful porting is required to get even more out of those same stock heads and this is what made guys like Joe Mondello famous.

The whole concept of putting in a bigger cam is to get more out of the stock heads, but as explained above, there is a limit and the limit is how fast do you want to go? Followed by the next question of how much money you got. It may also be said that you can get to the same peak HP (up to a point) with factory heads or Edelbrocks, but in theory the head with the more efficient port should require less cam so to speak thus giving better over all performance throughout the RPM range. And on the flip side the less efficient head may require a cam that is very unfriendly to drive on the street - resembling more of a two stroke motorcycle.

My old 72 Porsche 911T is a fine example of efficiency. 2.4 liter flat 6 with about a 3.5" bore. Hemi heads with 1.88" / 1.60" valves (and people complain about the 351C having valves and ports too big). 8.0:1 compression (stock was 7.5:1). Very mild cams with maybe .450" lift and glass smooth idle with 160 PSI of cranking pressure. This thing was as comfortable at 5500 RPM as it was at 2500. Would these heads support very high valve lifts or other more radical cam profiles? Sure, but you don't HAVE to go there. Same engine was available up to 210 HP I believe with just a slight tweak in cams and compression and still wasn't hopeless on the street. It's all about the COMBINATION of parts right down to the car weight and gearing.

 

[Supershafts]

I was considering going with a roller set up but it seems I would not gain much based on what I've been reading and the cost would be great.
I love the Mopar 284 / 484 and it is a great match for my set up. I think in the future I will aquire some aluminum heads and have them worked before I spend a bundle on these 915's. Anyway, thanks for your recommendation!

Actually you'll gain the most you can with a roller, you can't be as aggressive with a flat cam and move the valve as quickly , solid flats will make more power than the hyd you're using even with a unported head simply because the solid won't lose any of thje cams profile, a hyd roller will make better use of the head than a flat cam, and if you wanted to go to a solid roller, you can simply add a solid roller lifter to the hyd roller cam profile and the rocker if you aren't already using a better non flexing rocker and gain more performance down the road simply changing hyd rollers to solid.

I am very surprised at how performance is quickly regulated in the mopar world when it comes to using roller vs flat and how much people are willing to give up based on cost

The sooner and faster you can open the valve and the later and faster you can close a valve are very important to the power increases you can make, and these are power increases you'll never get from using a flat cam.

 

[ykf7b0]

Great Observation!

Actually you'll gain the most you can with a roller, you can't be as aggressive with a flat cam and move the valve as quickly , solid flats will make more power than the hyd you're using even with a unported head simply because the solid won't lose any of thje cams profile, a hyd roller will make better use of the head than a flat cam, and if you wanted to go to a solid roller, you can simply add a solid roller lifter to the hyd roller cam profile and the rocker if you aren't already using a better non flexing rocker and gain more performance down the road simply changing hyd rollers to solid.

I am very surprised at how performance is quickly regulated in the mopar world when it comes to using roller vs flat and how much people are willing to give up based on cost

The sooner and faster you can open the valve and the later and faster you can close a valve are very important to the power increases you can make, and these are power increases you'll never get from using a flat cam.

This was my initial thought when I started this post. Thanks for your input!!!!

 

[Cranky]

As for mega bucks with ported heads.....have you ever looked at the area that's just under the valve? It sucks. This is the valve pocket area and if you clean that up to look like the heads on the Porsche 911 heads that Meep was talking about, then you've done something and doing that and just blending the pockets into the ports will make the heads act nicely and doesn't cost mega dollars to do. I 'fix' the pocket area on all of my builds including bone stock engines. It's been many years since having that done for me since I now port my own heads but last time I had a set done, it was 200 bucks.

 

[ykf7b0]

I have had these 915's cleaned up a little. They currently have 2.14 / 1.81 valves too.

Intake Exhaust
200 135 106
300 186 135
400 217 155
500 228 166
600 225 174

 

[ykf7b0]

Do any of you have a manufacturer recommendation for a quality set of 1.6 ratio roller rockers?

 

[benno440]

hughes do a nice set, i also like comp cams rockers,

 

[Budnicks]

Do any of you have a manufacturer recommendation for a quality set of 1.6 ratio roller rockers?

Crane Super Gold Series, I have used them for 30+ years never any issues ever, I was sponsored by them, so I may be a little biased too.... Harland Sharps are also very nice if you have an extra $300 to spend over the Cranes... PRW, T&D, Hughes, 440Source {were} are also decent choices, depending on your budget... you will also need to change & especially measure for correct/proper length, diameter, material, type & style of your push-rods, depending on camshaft style & valve spring pressures or even proper pre-load/lash requirements, proper oiling of the psh-rod cups requires only 2 or so threads showing out the bottom side of the adjuster screws on the Cranes...