Automotive Cam vs marine cam ?

[Wellcraft260]

Hi everyone, I am repowering my 1994 26 wellcraft with a chev small block 383 stroker built for torque and it dynoes At 403 hp@ 5250 rpm. Torque is 455 @ 3250 so I believe it should work quite nicely mated to my VP SX-S outdrive compared to the stock 5.7 two barrel original VP marine engine. I originally had it built for my suburban to tow this 5000 lb boat but have decided to use it in the boat instead. My question is can I stay with the mild performance cam in this engine or should I change it to a marine specific grind? The existing cam is a Comp cams XE274H advertised duration is in. 274 / exh. 286 total lift is .490" both intake and exhaust with my 1.5 roller rockers and 110 degrees of lobe separation angle. The Comp marine cams have very similar duration and lift numbers but use a 112 degree lobe separation angle. My concern is reversion and my engine builder says he has built dozens of these engines for marine applications and has had no problems. They are a very respected machine shop and engine building facility here in Edmonton so I trust them but would like to hear from some of the very knowledgable folks on this forum regarding this issue. I have noticed that some of the regulars here are very generous with their time and knowledge and it is nice to see people giving up some of their valuable time simply to help others! Thanks in advance guys and keep up the good work.

 

[kingrich]

Re: Automotive Cam vs marine cam ?

I have recently put a new GM 5.7 L truck crate engine in my 1997 2000S Wellcraft. Still not finished but I pulled cam and replaced with the original Mercruiser cam. I had same dilema when deciding what to do about cam and am not sure how much the 2 deg lobe seperation makes. I would suggest going to offshoreonly as the guys there are more geared to racing and familiar with cam specs. Good luck in Alberta.

 

[Bondo]

Re: Automotive Cam vs marine cam ?

Dennis Moore,.. along with Every other reference I've been able to find,......<br />Recommend a LSA of 109* to 112*........<br /><br />You Should be Just Fine........... Go For It........

 

[Olds Eddie]

Re: Automotive Cam vs marine cam ?

My new 400 SBC engine is doing great with a Comp Cams Xtreme Marine 270 roller cam. I have broken her in easy and shes had her first oil change. I am running through the transom exhaust and 6" riser extensions. My last engine took in salt water as the static line was too low.<br />Good luck on your new engine. Don't forget to break it in above 2000 rpm's for 30 min if it's a flat tappet cam.

 

[Ralph 123]

Re: Automotive Cam vs marine cam ?

Cam Specs with part numbers per Moore for SBCs:<br /><br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=24;t=012378#000001

 

[rbezdon]

Re: Automotive Cam vs marine cam ?

Hey Ralph, now we both owe you for the cam specs.

 

[Wellcraft260]

Re: Automotive Cam vs marine cam ?

Thanks everyone ! I will proceed with this cam and post the results for those considering a stroker on their 350 rebuild. Seems like the most inexspensive way to more marine style torque from a standard 350. If I am overcammed I will know right away! Anybody know how much power is too much for the V/P SX-S? I have been told by several marine guys it is tougher than the Alpha and will be just as stout as a Bravo 1. With 400 hp spinning at 5200 I hope they're right! This is my first Volvo and would like to know if anyone out there has a DP lower unit for sale since I believe it will bolt on to my SX. My understanding is that it could add 3 or 4 mph and deliver better fuel economy due to added lift at cruising speeds? Has anyone made the swap from a single to dual prop outdrive for some real world comparison numbers? Thanks Again everyone!!