250 chevy-165 merc

[kahtadin]

explain in layman's terms what will happen if the cam is not swapped in my chevy to merc conversion(and how big a job is this 'cause I still have the marine cam ...I think)

 

[Solittle]

Re: 250 chevy-165 merc

The power demands you place on a marine engine are far different that what goes on in a 4 wheeler. That is why they make marine cams in the first place.<br /><br />On the "How to do it" go to your local library. There should be several manuals which describe the procedure.

 

[MGuckin]

Re: 250 chevy-165 merc

Power and torque are created at lower rpms for marine applications than they are for automotives.<br />Primarily low to mid-range.<br />Most stock marine motors are not run much over 3000 rpms thus the need for power created earlier.<br />Running a boat with a car motor might be like driving your car from a standing start in second gear.

 

[coupedeville]

Re: 250 chevy-165 merc

While it's true that marine engines have a different operating range from a car's, bear in mind that the 6 cylinder Chev was never designed to be a hi-revver: Top horsepower in a 250 was produced at 4200 rpm, for automotive use.<br />I'd be willing to bet that the difference in cams from the original car engine and from the Mercruiser unit isn't going to be much. And what condition is your Merc cam [assuming you can find it]? I'd love to know what a new cam from the dealer would be worth - if they still stock them, after all, production of the old Stovebolt 6 stopped in '84. <br />My suggestion: Contact one of the cam manafacturers, they all have tech lines, and tell them what you have and they'll suggest one of their grinds. Just go easy on the duration [240 to 250 degrees] and you'll keep the powerband in a reasonable range.<br /><br /> http://www.crower.com/ <br /> http://www.cranecams.com <br /> http://www.compcams.com <br /><br />Also, for reliability's sake, you may want to replace the fibre cam gear [yes, fibre] with a nice aluminum unit from Cloyes.<br /><br />For fun, check out these people:<br /> http://www.cliffordperformance.com/ <br />The kings of 6 cylinder performance parts.