Cam Specs for Mercruiser 260

[par1969]

Does anyone know the approximate cam specs for the cam Mercruiser used in its 260hp Chevy 350CID. I built a new engine using Comp Cams 260h marine cam. Specs are duration of 212 @ .050 and .440 lift. stating operating range from 1800-4900rpm. I was just wondering how that compares with Mercury's Cam. Thanks in advance, PAR1969

 

[ShamuToo]

Comp Cams and Merc grind are the same. 260 HP designation is for pre-Vortec carb'd motors.

Replace your old style heads with Vortecs and an Edelbrock Vortec Performer or a Performance Parts Plus Vortec intake and push your total HP to about 310. The Vortec head and the intakes mentioned have taller intake runners, so be careful you have an extra 3/4" of top clearance above the flame arrestor. Biggest advantage is midrange power increase and cruise efficiency.

I built two last year for my old SRV 300 and it runs like a striped ape.

 

[sr330daguy]

Your signature doesn't indicate what boat or drive,early Alphas wont take more than about 300 HP.

 

[par1969]

it is a 1978 SRV 195 with a rebuilt alpha 1 and a new motor I rebuilt last year. I was just trying to figure out my best operating range based on how much bigger the cam was to the standard Mercury 260hp cam. The Vortec idea sounds like a great option just don't know if the Alpha would hold up. Thanks for the responses. PAR1969

 

[270win]

I don't know if this is an older Alpha or not, but my buddy had an 86' 23' Wellcraft Nova with a 330 hp 454 and it had an Alpha drive...I wonder if it being a lighter boat had anything to do with the factory using an Alpha...I'd rather have a Bravo personally.

 

[ShamuToo]

Alpha drive were mated to big blocks up to 330hp. When Merc came out with the Bravo drive they also mated the old 370 TRS motor with the new drive and made the 365hp 454 Mag. I think all the 330 BBs also started coming with the new drive, which tells me the 330s were on the ragged edge of what the Alpha could handle. That being said, a 454 produces a lot more torque than a 5.7 in any hp rating. The Vortec upgrade is the way to go and you won't have problems with an Alpha drive. On the plus side, there a boatload of rebuilders out there for the Alpha.

 

[sr330daguy]

Alpha drive were mated to big blocks up to 330hp. When Merc came out with the Bravo drive they also mated the old 370 TRS motor with the new drive and made the 365hp 454 Mag. I think all the 330 BBs also started coming with the new drive, which tells me the 330s were on the ragged edge of what the Alpha could handle. That being said, a 454 produces a lot more torque than a 5.7 in any hp rating. The Vortec upgrade is the way to go and you won't have problems with an Alpha drive. On the plus side, there a boatload of rebuilders out there for the Alpha.

Agreed how ever they changed the ratio from 1.5 to 1 to 2 to 1.