Cam selection for my 451

[747mopar]

I wanted to get some feedback on cam selection from you guys, I'll be pulling my motor soon to do some paint repairs and thought if I'm going to change anything now's the time. The motor is a 456, 9.8:1 compression, ported 452 heads that flow up to .600 lift, Eddie RPM intake, full length 1 7/8 headers and a Mallory ignition box. I selected the cam with cruising in mind but have often thought about bumping it up as it's very mellow, here's what's in it. I might also add that I'm switching to a standard as well that will put cruising in the 2,000 rpm range.

Comp Cam 21-230-4

1,800-5,800 rpm range
110 LS
106 centerline
Int lift .488
Ex lift .501
Int duration 268
Ex duration 274

Right now the cam is the cork so my questions are.....

#1 How much can one expect to gain by going up to the next size up?
#2 Because of the Cubes (torque) are these motors more forgiving on bottom end when running larger cams?

I'm all ears to anything you have to suggest, Thanks

 

[HYRDGOON]

so many suggestions in HT413's build. How close are you to IQ and his son's first 451 build http://www.dodgecharger.com/forum/index.php/topic,77958.0.html ?

 

[747mopar]

so many suggestions in HT413's build. How close are you to IQ and his son's first 451 build http://www.dodgecharger.com/forum/index.php/topic,77958.0.html ?

Looks like we're really close other than his 452s must have allot more work done to them, mine stops gaining cfm by .600 so anything north of that will require more head work. If I bump it up it won't be no where near that much. I've been watching HT413s thread and Hunts but they've yet to run their motors so we'll see although Hunts dyno results look pretty impressive. The big concern is what will it run like at 2,000rpm going down the freeway with the bigger cam.

 

[Meep-Meep]

The cam you have now doesn't sound all bad for a cruiser. If it's cruising you want then you need to keep that RPM range in mind. A bigger cam usually means more upper end power, which is going in the wrong direction for you. Is your 451 built with 440 rods or the 383/400 rods?

The 451 I'm building for a friend I settled on a Lunati that is ground on a 112 LSA with about .480" lift. This engine is 9.5:1 CR and has mildly ported 906's done by Jim LaRoy (IQ52). This is a cruiser car that is expected to live for many years so I wanted to be conservative on the cam choice mainly to keep the valve spring pressures reasonable.

 

[747mopar]

The cam you have now doesn't sound all bad for a cruiser. If it's cruising you want then you need to keep that RPM range in mind. A bigger cam usually means more upper end power, which is going in the wrong direction for you. Is your 451 built with 440 rods or the 383/400 rods?

The 451 I'm building for a friend I settled on a Lunati that is ground on a 112 LSA with about .480" lift. This engine is 9.5:1 CR and has mildly ported 906's done by Jim LaRoy (IQ52). This is a cruiser car that is expected to live for many years so I wanted to be conservative on the cam choice mainly to keep the valve spring pressures reasonable.

Thanks Meep and I apologize for repeating this question again. I'm running the complete rotating assembly out of a 1970 440 (rods too) with KB Hyp pistons. I guess what makes me question my cam the most is when you read dyno results like Hunts where it's making peak power well bellow the advertised rpm range. I wish the dyno sheets showed the lower rpms as well because it makes me wonder if they are coming in earlier than advertised as well. I'm by know means unhappy with my motor but find myself wanting a little more from time to time so I'm just thinking.

 

[lewtot184]

ok, i found it. the advertised duration numbers are at .015" lobe lift. setting the lash at .016" is .010" at the lobe. so, there's .005" of lobe lift on the opening and closing side that isn't accounted for in the advertised duration. actual duration at the valve is probably around 278 intake, 284 exhaust. sounds like a nice street cam and i've thought about trying one. it's probably a lower 5000rpm range peak power cam with those heads, which isn't bad for a cruiser. if you want more on top retard the cam 4 degrees. those cams have 4 degrees of advance ground into them and probably don't need it.

 

[747mopar]

Considering maybe trying a combination of the bigger cam and the Roads lifters, anybody ever run them? This seems like something that would be great for street motors, lift & duration is reduced approximately .010-.020 and duration is reduced approximately 10-15 degrees at idle with everything restored by 3,500 rpm.

http://www.rhoadslifters.com/

 

[lewtot184]

avoid the rhoads gimmick.

 

[747mopar]

The cam you have now doesn't sound all bad for a cruiser. If it's cruising you want then you need to keep that RPM range in mind. A bigger cam usually means more upper end power, which is going in the wrong direction for you. Is your 451 built with 440 rods or the 383/400 rods?

The 451 I'm building for a friend I settled on a Lunati that is ground on a 112 LSA with about .480" lift. This engine is 9.5:1 CR and has mildly ported 906's done by Jim LaRoy (IQ52). This is a cruiser car that is expected to live for many years so I wanted to be conservative on the cam choice mainly to keep the valve spring pressures reasonable.

Here's the problem Meep, I drive it like I stole it almost every time I get it out, hard acceleration and allot of spirited driving but then I turn around and jump on the freeway and drive an hour or 2 to a show or just go cruising so it's really a multi purpose car haha.

- - - Updated - - -

avoid the rhoads gimmick.

Why? Seems like they've been successful?

 

[lewtot184]

rhoads lifters are for covering the mistake of buying the wrong cam. several years ago i had a phone conversation with mark engle at engle cams. i was having the typical hydraulic lifter issues. the conversation drifted to rhoades lifters. he told me that on all the dyno tests were they switched to rhoades lifters the engines lost power. the idea of the "bleeder" tappets is to cover the mistake of too much cam. so the question i have is; why would you purposely buy too much cam and then go to the rhoades lifters to cover the problem? think about it. i'm outa here.

 

[747mopar]

One would first have to make a mistake which I haven't and don't plan on. I'm outa here??????????? No wonder I'm so hesitant to ask anything anymore!

 

[Meep-Meep]

747, the best thing you can do is dial in your engine to your driving habits. I know you, as well as many, are aware of this but really sit back and see where you spend most of your driving time. For primarily street driven cars that is idle to about 3K. Occasional 5K bursts are part of the package but in reality the engine lives at 3000 RPM. So where I'm going with this is perhaps you need to visit a dyno and get the fuel and timing curves sorted. There might be 50 HP on the table. Gear ratio is also important and should be factored in.

 

[747mopar]

Thanks Meep. The dyno is part of the plan this spring which is another reason I want to make any changes that I might before hand. I wouldn't be surprised to find a little more on the dyno especially with the timing but I have spent most of last summer tweaking things and feel like I've got everything pretty close to optimal. Gear ratio might be the answer too as I'll be installing a Viper tranny with some ridiculous overdrive (.050 6th) so that will allow for more gearing, possibly 3.90s or 4.10s?

 

[Meep-Meep]

With a .50 OD you will be looking at 5.13's or deeper! And at that you will have like a 2.56:1 final. Or build a tractor motor and live with a 2.05 final - lol .50?? Really? Wow.

 

[747mopar]

With a .50 OD you will be looking at 5.13's or deeper! And at that you will have like a 2.56:1 final. Or build a tractor motor and live with a 2.05 final - lol .50?? Really? Wow.

I know, I'm amazed at the fact that the Vipers are running 3.07's. I've done some reading on the Vipers and 6th is ECO only, if shifted to 6th while accelerating at high speeds it slows because of the gearing. An eco gear is what I want and I figure my setup is in the ballpark of the earlier Vipers plus they supposedly weigh about 3,400 lbs to so I'm not all that heavier either. I think I've decided to either leave it or get a cam custom ground for it. Sorry, I went back and read my post and must have 2,000rpm burned in my head from the TKO (.064 OD) I had in it. I'll never hit 2,000 with this one, maybe 1,800rpm but after looking at dyno pulls from Vipers I really don't see any reason it shouldn't work the same for me.

 

[747mopar]

3.90s = 74mph @ 1,800 rpm

4.10s = 70mph @ 1,800 rpm

The car is happy at 1,800 as it sits, it's cruises best between 1,800 and 2,000 rpm.

 

[Meep-Meep]

That's all good but plan the engine around that, meaning cam. Think 500 Cad engine. Should be a really comfy ride when done.

This is sort of where I want to be with that 66 hemi Charger I have. No one is going to buy it for what I have in it so might as well make it the Charger Imperial and drive the wheels of it. I already have the Passon OD 4 spd with 3.54's and it's very nice on the freeway. But will be nicer when I fix all the problems!

 

[747mopar]

That's all good but plan the engine around that, meaning cam. Think 500 Cad engine. Should be a really comfy ride when done.

This is sort of where I want to be with that 66 hemi Charger I have. No one is going to buy it for what I have in it so might as well make it the Charger Imperial and drive the wheels of it. I already have the Passon OD 4 spd with 3.54's and it's very nice on the freeway. But will be nicer when I fix all the problems!

Sounds pretty cool, I for one find the 1st Gen Charger to be pretty cool cars especially the interiors and wouldn't mind adding one to the collection. A Supercharger may be the best answer for me haha?

- - - Updated - - -

Wookie316 put me in touch with Nick at Compu Flow so a big thanks to him. This is the kind of guy I wanted to talk to and no surprise.............he thought the cam I had was a pretty good match for an off the shelf piece. He believes the best route is a custom ground one (I'm sure that's always the case) so we'll see what they come up with but I think this is the direction I need to go in.

 

[Meep-Meep]

Yeah, the interior in that car is second to none! Well, maybe second to the turbine car, which is surprisingly similar.

I believe I had the same opinion about your cam so good to know I'm not in outer space in that regard! But a wider LSA might be the ticket for you. Or a lung!

 

[747mopar]

Yeah, the interior in that car is second to none! Well, maybe second to the turbine car, which is surprisingly similar.

I believe I had the same opinion about your cam so good to know I'm not in outer space in that regard! But a wider LSA might be the ticket for you. Or a lung!

That's why I don't take your advice lightly, your always honest and level headed. He did throw around some ideas like less duration, more lift and a possible change in the LSA but the conversation was ended with "send us all of your info and we'll take a look at it". At any rate I feel like this is the right approach (leave what I know little about to the pro's). This does however leave me with another question to answer, one of the valuable pieces of info for them is which gear will I be running? Here's a link to the Viper T56 gearing where their 1st gear is 2.66 compared to the 727s 2.45 and they're running 3.07s in the rears of those things. 3.91 or 4.10s :dontknow:

http://api.viglink.com/api/click?fo...ww.ask.com/wiki/Borg-Warner_...ission?lang=en