caribbean20
05-09-2006, 08:14 PM
I did a major tune up to the barge this winter consisting of new roller cam (580 lift, 240@50 duration, replacing the 520 lift stocker), lifters, push rods, roller rockers and Vic Jr. intake manifold to my Gen VI 502. I see several references here to "breaking-in the cam." Greg (GS Marine did the work) didn't say anything about breaking-in the cam on this installation, but since we are dealing with roller bearings here, I can't see anything to break in, per se. With a non roller cam, I could see breaking in the bearing sleaves. The extent of my break-in period was the no-wake zone at Mead (I only ran the motor for about 45 minutes on the maiden voyage, post tune). Am I correct here, no significant break in needed for a roller cam?
PS If anyone is interested, my modifications and pre and post performance #s are as follows:
1988 20.5' Caribbean, closed bow, semi-v, bubble deck. I think it weighs about 1,360 pounds dry.
Before
2003 502 BBC Gen VI (4 bolt mains with the forged crank, pistons and rods) and aluminum heads. 850 Holley Marine, Full MSD, EMI Thunder through-transom exhaust, Berk JG12-AB aluminum (worn out rear bearing sleave and wear ring, a basket case), place diverter.
5,200 RPMs, 62.5 MPH on GPS.
After
The cam and intake plus pump rebuild, mag/bronze A/B cut, ride plate, shoe and droop.
Around 5,200 RPMs (had my 8 and 10 year old first and second mates aboard, no good reading) and 67.4 top speed on the tatle-tale GPS, with full load 50 gallons of gas. The water was rough so I did not get a good chance to air it out so I am hoping for another 1 or 2 MPH top end, and I really, really want to see 70 in optimum conditions. Boat really felt more aired out because of the plate and droop, and felt a little more squirrly on the top. Probably the end of the line for top end on this hull.
All in all, I am pleased. I will be on the river from Laughlin to Zoo weekend of 5/18 to 21, see thread below. Hope to see some of you.
http://www.***boat.com/forums/showthread.php?t=114230
PS If anyone is interested, my modifications and pre and post performance #s are as follows:
1988 20.5' Caribbean, closed bow, semi-v, bubble deck. I think it weighs about 1,360 pounds dry.
Before
2003 502 BBC Gen VI (4 bolt mains with the forged crank, pistons and rods) and aluminum heads. 850 Holley Marine, Full MSD, EMI Thunder through-transom exhaust, Berk JG12-AB aluminum (worn out rear bearing sleave and wear ring, a basket case), place diverter.
5,200 RPMs, 62.5 MPH on GPS.
After
The cam and intake plus pump rebuild, mag/bronze A/B cut, ride plate, shoe and droop.
Around 5,200 RPMs (had my 8 and 10 year old first and second mates aboard, no good reading) and 67.4 top speed on the tatle-tale GPS, with full load 50 gallons of gas. The water was rough so I did not get a good chance to air it out so I am hoping for another 1 or 2 MPH top end, and I really, really want to see 70 in optimum conditions. Boat really felt more aired out because of the plate and droop, and felt a little more squirrly on the top. Probably the end of the line for top end on this hull.
All in all, I am pleased. I will be on the river from Laughlin to Zoo weekend of 5/18 to 21, see thread below. Hope to see some of you.
http://www.***boat.com/forums/showthread.php?t=114230