Mercruiser 260 cam upgrades

[Ron EBKO]

I have a 18 foot v bottom ski boat a EBKO 1990 I think I had it on the water last year fought carberator problems. Finley pulled off the quad jet and put on a Holly. Just got it running ok. And the motor cupping went out. I have motor out pulled it apart it looks really good. It is bored 30 over crank is good. Heads are being checked out I am working on the motor mount stringers I also put exhaust out the back. I want to upgrade the cam. I want it to sound good as I am pulling away from the dock. I nothing too big I don't want to cause other problems. Any segestions on a cam

 

[Bondo]

Ayuh,.... Welcome Aboard,...... When shoppin' a cam, look for the power band to be from idle to 'bout 5 grand,.....

Much more than 214?/ 218? yer gonna get the sound, but have reversion problems,....

 

[Scott Danforth]

Comp cams XM268H is the largest cam you can run without reversion.

I ran this cam in my SBC

 

[Ron EBKO]

Thanks for the info
I bought the Comp cams XM268H. I have the motor rebuilt. I still need to get the water lines fingered out. I changed the Exhaust. I have some OSCO manifolds. I am assuming I can connect the water lines Just like the original mercruser manifolds were. Water line in the front out the back and one on the riser. Or ?? I have seen so many different configurations? My exhaust was going out the prop with the original exhaust manifolds, But I now have the exhaust going out 2 stainless through pipes at the water level. I also have to change my alternator mounting bracket. It was originally mounted on the exhaust manifold. I think I can just get a alternator bracket from a Car. Is that correct or do I need ??

 

[Scott Danforth]

your plumbing must match the thermostat housing you have. so if you didnt change the thermostat housing, you plumb it the same. if you cant plumb the same because your manifolds are dramatically different, you need to match your manifold/plumbing to the correct thermostat housing.

also, with thru-hulls on your boat, especially at or near the water line, you need to run flappers. preferably internal AND the external . if you have a swim platform and thru-hulls, many times simply backing the boat in the water will push water up the exhaust and hydro-lock your motor

 

[harleyman1975]

I have a feeling that this won't end well.

 

[kenny nunez]

In regards to the carburetor if you did not use a Marine version of the Holley that is not good. It is not jetted for marine use and if it does not have the down turn vent tubes then if it should flood over and catch fire it would not be a good day. Have the Quadra Jet rebuilt.

 

[achris]

In regards to the carburetor if you did not use a Marine version of the Holley that is not good. It is not jetted for marine use and if it does not have the down turn vent tubes then if it should flood over and catch fire it would not be a good day. Have the Quadra Jet rebuilt.

Or replace it with an Edlebrock 1409.

 

[Scott Danforth]

nothing wrong with a holley marine carb.