Have a 557 being put together. Looking to turn it up to 7-7,500rpms. Anyways beings it's almost 100 cubes bigger then what they rate cams at (460 cubes I imagine in this case) for rpm range, etc what kind of equation/factors should I be figuring in to come into a power band of around 3-6500/7000 rpms. Would like to turn it at around 6,500/7,000 rpms down the track (truck pulling motor), but yet have it somewhat streetable and maybe do some mud draggin with it. It'll be set up to run E85, should have around 14:1 compression with John Kasse Alum SCJ heads.

 

I'd get on the phone with whoever you are going to buy your cam from. They will have a list of questions for you to answer and then together you can make the best choice. Good luck.

 

Well I was just looking at getting something off the shelf from Summit or Jeg's and wondering if anyone had done a 557, what lift, duration, LC they used and what kinda results they got out of it so I'd kinda have a baseline. In a few weeks I'll go talk to the engine builder again and I'm sure we'll come up with something, but it'll prolly end up being a custom grind for some more $$$.$$. I was just more intrigued in general of the subject of picking a cam for a stroker motor weather it's a 347 or 557. Obvoiusly it takes more air/fuel per combustion cycle due to the larger volume. Which makes me wonder what kinda difference you get when you get cams for a 429 to a 460 or a 352 all the way up to 428? Kinda vague when you have a huge family of engines such as the FE's.

 

Since your engine combo is unique to what most people would build you really need to go custom cam. The use of E85 as a fuel, the big cubes, and the rpm you want to run all say CUSTOM!

 

I actually have a 557 Myself. It is in my driver. I have tried Three came so far and just installed another new one today. The pattern I see is that i lose about 500rpm from what it says for a 460. This last time I just called Lunati and talked to a tech to get advise. He confirmed my wanting to bump up to bigger.

 

Redneck
You are going to have to look at your whole picture. The camshaft is probably the most critical decision to be made in the whole engine build.
The key factors to picking out the right camshaft will depend on your compression ratio. What cylinder heads you are using? If you are using headers or not. What intake manifold and what the actual use is going to be for the engine. (pulling, street strip, weekend warrior, mud races etc)
You will need to make a decision on what type of cam you are going to run i.e. hydraulic flat tappet/ mechanical flat tappet/ Hyd. roller or solid roller. In quickly looking up a few camshafts for the rpm range you have stated it will be hard finding a camshaft designed to turn 7000 in any of the hyd. cams. If you are running a automatic what is the stall of the converter you have?
If you would like to give me a call I can go over several camshaft choices with you. we carry pretty much every camshaft line out there from Lunati, Crane, Competition, Crower and more.
Daymon
1-877-354-3812
RPM Machine


We are distributors for pretty much every cam maker there is and can help you pick out a camshaft

 

Any "off the shelf" cam choice will be dis-appointing in a 557. I'm running a custom REED cam in my 512 and it has always ran flaw-lessly for 10+ years. Solid roller would probably be the way to go, they just don't like a lot of idle time.

 

what size carb and type? lookin at about 1250 cfm just a guessin. big engine and big carbs jsut go together. just a basic rule guideline is cubic inch x 2= 1114 cfm. 557x 7000 x .9= 3509100 divide by 2820 or 3456. high end carbs use 2820 and old school is 3456. modern carb ball park 1244cfm cfm and old school = 1015cfm. next question is type of fuel will vary the cfm of carb. good reads are pro system carbs, AED carbs. BLP carbs, quick fuel carbs! their are more good companys but these are the ones I'm familiar with especially quick fuel! all good companys and have their own little twist on their carbs and should do well once they are given proper info to give you their best answer. get educated on booster types within carbs. this really changes the carbs and type of carb. down leg or annular or straights booster are several types. you will probably have more questions than answers if you really look into this subjet. BLP has lots of parts for holley types and purpose and fuel types. BLP has been around for atleast 20 yrs that I know of. good luck and will be checkin in on your selections.

 

I do the "old school" (3456) and then add 20%

 

I run 512ci with a 1500cfm C&S aerosol billet. Best choice I ever made!