First let's start with what I'm thinking, 454 mag stock rec port heads, dart oval port intake ,830 Holley carb, lighting headers.

1st ultradyne dur at seat INT/EXH 288/296 110/LSA grossvalvelift INT/EXH.550/.558 dur at .50 INT/EXH 231/239.

2nd crane part#134561 degrees dur at .50 INT/EXH 236/246 adv dur INT/EXH 296/306 114 LSA gross lift INT/EXH .553/.571 overlap 13 [email protected]

Both hyd flat tappet all so could the crane make more power with a tighter LSA?

Well there they are let me know if I'm headed in the right direction or if I forgot any thing.

THANKS ALOT

Oh boy, Im sure youll get lots of opinions on this. I would start by having JimV put inserts in those heads and if you are running a totally dry exhaust, use the Ultradyne. The Crane seems to be too much duration for a marine engine unless you are gonna run 6500 rpm. And yea, the lower lsa will make more power but you better have dry exhaust for the 110. I think the stock Merc cams are too mild but I also think that big sticks dont work very well either for marine use. Just my $.02. There are lots of people in your neighborhood that can help more than me.

Troy,

I know a guy that ran the Crower 1206. A flat tappet cam, no juice in the lifters..
234/244 .529"/.530" 108LS on a 454 with Merlin heads and Gil then CMI exhaust and it ran quite well..
The old 465hp motor had 240/250 .559"/.578" 110LS..
So it seems your cams are somewhat close..and should work quite well..

good luck!

Dick

In my 502--- I run the ULTRADYNE solid flat tappet cam. 251/259 dur. at .050 -- .601/.625--110 lobe separation. I have stock rec. port heads with Jim's wedges and 2.3 intake valves. The heads have been heavily worked over. I run the rec port DART intake with the port floors raised 1/2 inch. HOLLEY HP 950--- lightning headers. Lots of other things also. The engine is turn key and runs great and will idle all day without loading up. They have all kinds of bottom end torque.

Choose camshafts with about 8 degrees less duration on the intake and exhaust and you will be a lot happier. (224/230)
A smaller camshaft with a tighter 110 degree Lobe Separation Angle will make the same power as a larger cam with a wider LSA.
The camshafts you've chosen would be marginal (to big) for a 502
with the stock compression ratio.
Those camshafts would make maximum horsepower at about 5900-6100 rpm on a 454 with rectangle port heads, single plane intake and stock compression ratio.
Dennis Moore

Won't that 110 degree lobe seperation cam have a revertion problem? I thought you need 112 - 114 cams for HP marine applications.
why are you putting a oval port intake on a rectangular port head??????

go with crane!

Ultradyne baby!! I've used the same soild stick tinker is talking about in many buildups, ([email protected]) although the lift is .612-.630 If your looking to make HP, the choice is clear-cut, ya better have dry ex. and some compression, dump that oval intake and that bit*h will bark fire!! If idle quality and low rpm manuevers is your game, better stay with the kiddie (hyd) shish-ka-bobs

I have 0 reversion with my 110 cam. I am running Lightning headers almost dry. (burn up hoses once in a while)

Ultradyne's are good cams. They have a very aggresive profile. Which means that they have faster opening/closing ramp speeds and this translates into more power. This also means that they're harder on the valve train. I'm not real sure, but it may not be as critical as far as the flat tappet lifters go, but will still shorten valve spring life. But, on a roller lifter (hydraulic or sollid) the faster ramp speeds can shorten the life of the valve springs as well as the life of the roller lifters.