731-741 or 502/502 cam?
 

Hi guys, i need some help, i have a 435 hp 502 gen vI and im about to update the engine. I just bought crane gold roller rockers with new springs also and i want to change the cam as well, i have read some of the post and this 3 cams are the most talked about for the 502, im running an 850 carb and have stainless marine long risers. Any help choosing any of this cams would be appreciated.

Re: 731-741 or 502/502 cam?
 

If you are running stock heads either will work. How much RPM you want to turn will determine which cam. Likely the 731 will be the better of the two.

Re: 731-741 or 502/502 cam?
 

Thanks for the reply, i am running the stock rectangular heads, i just a cam that wil give me more hp in comparison with what i had, i thought this was a good idea since im changing springs and roller rockers, as for rmps, i want to get more if i could but i dont want to sacrifice the engine.
Thanks

Re: 731-741 or 502/502 cam?
 

I think there was a stock 470HP version of the 503 in the gen VI EFI motors. Maybe you could rebuild it to those specs and still get good reliablity? I thought Gen VI already had hydraulic roller cam istalled?

Re: 731-741 or 502/502 cam?
 

I would stick with the 731. It will make good power, and should keep you out of reversion problems.

Re: 731-741 or 502/502 cam?
 

the 731 pulls good up to 5400 rpm's,if you want or need more go with the 741.ben there done that,i'm running the 741,it works better for me.

Re: 731-741 or 502/502 cam?
 

741 is the best of the two haverun it many times

Re: 731-741 or 502/502 cam?
 

Thanks for the advise, what is the difference in hp between these cams versus the stock cam in the 502? and what realistic hp should i get by putting the roller rockers?

Re: 731-741 or 502/502 cam?
 

How would either of these cams work in a blower application. Lower boost 5 - 7 PSI?

Where are the spec cards for these cams?

I am in the search for a new cam for my motor also.

Not trying to steal your thread Migara422!!

Re: 731-741 or 502/502 cam?
 

How many rpm do you want to turn Pantera?

Re: 731-741 or 502/502 cam?
 

I decided to keep my Merc ignition with the Rev limit "set" at 5350rpm decided to use the 731 instead of the 741 for the above reasons. I am very happy with it and my overaul performance.

I have turn key engines that have a great idle and no loading or reversion.

Re: 731-741 or 502/502 cam?
 

I'd like to see 5400+ for short bursts. My cam now is a real dog. i can't get much over 5000 RPM.

Whats the profile of the 731 vs 741?

Re: 731-741 or 502/502 cam?
 

go to www.cranecams.com

specs:
731 is 226/234 .587/.610" lift
741 is 234/242 .610/.632" lift

I'd suggest shooting for 5800 and running the 741 cam. Don't be afraid to turn some rpm! :p

For reference, a stock 500EFI cam is 230/236 .598/.610".

Re: 731-741 or 502/502 cam?
 

yes i just did a 510 with the a fare set of heads and it made 903 hp at 8 lbs yes the 741 loves a blower

Re: 731-741 or 502/502 cam?
 

Are the 741 and 731 cams ground on the same LSA for blown and NA motors? For some reason I thought I saw they are available on 112 for NA and 114 for blower apps. Just curious and thought it may be good for these guys to know when shopping.

Craig

Re: 731-741 or 502/502 cam?
 

If i dont plan on turning more than 5500 rpms, would the 741 be too much cam compared to the 731?

Re: 731-741 or 502/502 cam?
 

I have all the take out valve train out of my 500efi. The 500 efi cam is real close to the 731 cam.I even have the valves and Crane rockers :D

I put the 741 in my blower motor.It worked good with the blower.

If you are going to buy new ? Call [Bob] RMbuilder and have him design one for your aplication it will be real close to the same price . He just did one for a member on this board and it picked up 9 MPH!!!

Re: 731-741 or 502/502 cam?
 

I have the Federal Mogul Lifters. I'll have to look them up as far as limits for lift.

Re: 731-741 or 502/502 cam?
 

I agree. the 741 for the blower is better. 731 for n/a. And to get all the torque, oval ports.

With the blower, rectangle ports and the 741. I have one in perfect condition if interested.
DAVE

Re: 731-741 or 502/502 cam?
 

Anyone know how to get in touch with RMbuilder?
Maybe he can help me with a cam
Thanks

Re: 731-741 or 502/502 cam?
 

You will glad ya used him!!


[email protected]


http://www.offshoreonly.com/forums/m...poster&t=99919


Rob :drink:

Re: 731-741 or 502/502 cam?
 

How do those cams compare to the 641?
Looks like the 741 is the replacement for the 641. I have been running the 641 for 5 years, no reversion problems.

Re: 731-741 or 502/502 cam?
 

Mr Velocity,
Correct the 139641 part # is the same grind as the 139741 that replaced it.
Bob