migara422

I have a marine crate 502 435 hp, motor is apart to replace a piston and i would like to get a little more hp since its apart, i guess the easiest way is to change the cam to maybe get 40 or so hp without having to change anything else in the motor, any suggestions in what kind of cam i would need? and also would it affect reversion if i do this? i have stainless marine exaust
Thanks in advance

TomR

Why are you replacing a piston?? If there was damage I would be very suspicious of the condition of the valves in that cylinder! If I where you, I would go ahead and send the heads out, have the surface milled about .015, and then a good 3 angle valve job. Have the shop install the proper springs to match the cam that you put in the motor.
That being said I would pick something along the lines of 226 intake 234 exhaust.
Go to CPPerformance website. part# 295-012008K, this should be a great cam for your motor.
You will have to have the valve guides machined to allow for the proper seals and springs for this cam. If the machine shop is any good they will know to do this. The kit comes with all of the parts that you will need. Also , you will need to install adjustable rocker arm studs and get a good set of roller rockers (Suggest the CompCam Pro-Magnum roller rocker CP part# 295-1320-16) Just take the springs, seals, retainers to the machine shop and have the heads all set up to be re-installed.
When you install the cam, install it at about109-110 degree intake lobe centerline for best results. This cam is for a GenVI motor but could be adapted to a GenV if yours happens to be a GenV. This cam will give you what you are looking for!!

migara422

I broke a ring and went on top of the piston and got it all messed up, heads are in the shop now, i checked the price on that cam and that is a little too much to pay for a cam, i mean if im gonna spend $1000 for just a cam a rather put anothe 2 and get a blower, I wanna keep this motor simple for now since i cant spend too much on fun until the winter then the project on a big hp motor will start.
Someone told me to put a the cam that is on the 502/502, put the cam and go, i wonder if that was a good suggestion.

migara422

TomR, thanks for the help on the 502 cam, i guess the last thread was deleted when they changed the layout, i cant get that cam till this weekend and i want it asap, do you know of any other cam close to the 502 cam, com cams or crane, or should i just wait and get this cam? I have been boatless for a while now and im getting really ansy but i would wait if that is really the cam i need for now
Another thing is reversion with this cam, am i gonna have any problems with that? i read some posts and people often complain about reversion, kinda concern but im sure you would or someone would know
Thanks again for the help
Carlos

RLW

Send Bob Madara an e-mail.
[email protected]
He is brilliant when it comes to this subject. He has a business called Marine Kinetics that specializes in marine valvetrains.

CONDOR24

hi,ive got a gen 6 502/502 hp roller cam less than 30 hours running time,its coming out of my motor as soon as the new one arrives shortly. $ 150. plus shipping if you are interested. this is out of a marine engine too,thanks ,bob [email protected]

Pat McPherson

The least expensive way to go is to drop in the ZZ502 Cam. They are $165 new and all of the other GM valve-train parts will work...
If you have the long riser stainless marine, you should not have a reversion problem. If you have the short riser for captain's call then this cam or the Merc/Crane 500HP cam are a big NO NO!

migara422

Thanks for the Info guys, Pat what kind are these?

Nordicflame

iTrader: (4)

If your interested, I have a low hour Ultradyne Gen VI cam that would be a very nice choice for your 502. It's a 232/240 114 .600/.600.
I upgraded to the 741 cam with my head upgrade. This cam idles very well with the 114 lobe centers and will pull hard all the way to 5600 rpm on your motor.($75)
Dave
[email protected]

Pat McPherson

Those are the long ones...
There is a fella, Floridianson or something like that, running a 502 with the ZZ502 cam.
He is down in your area. You might try to find him here on OSO. He is a good source for experience with what improvement you would see...