How many hours on bigger power stuff?
10-21-2015 | 06:04 PM
#51
Registered
Joined: Feb 2012
Posts: 643
Likes: 7
From: Chesapeake Bay
What about the way big power (700HP and up) is run?
Example I only ran my boat on avg. 5-6 times a year. And if I ran it at idle for 30 mins to get to lake and then cruised (3800RPM) to my beach spot and sat all day and then came home. Would that extend my longevity?
I know big lift cams, blowers,and turbos are hard one engines BUT if your not running them super hard all the time can that buy 200 hrs on a motor?
Brad Malcuit a circle track builder told me once 1000 laps after that your on( borrowed time) BUT we ran the snot out of it!!!!
Example I only ran my boat on avg. 5-6 times a year. And if I ran it at idle for 30 mins to get to lake and then cruised (3800RPM) to my beach spot and sat all day and then came home. Would that extend my longevity?
I know big lift cams, blowers,and turbos are hard one engines BUT if your not running them super hard all the time can that buy 200 hrs on a motor?
Brad Malcuit a circle track builder told me once 1000 laps after that your on( borrowed time) BUT we ran the snot out of it!!!!
10-21-2015 | 06:38 PM
#52
Registered
Joined: Feb 2007
Posts: 1,124
Likes: 13
From: Hamilton, Ohio
I have Back4mores old Fountain, hour meters are right around 300hrs 557 Dart BIg M blocks Canfield aluminum heads & 8-71 blowers 850hp @ 6.5lbs. He did the lifters around 200hrs & I believe that's all that has ever been done. Had to rebuild one this summer from burning up a few pistons from an ignition issue. Just did a full refresh since it all had to be apart. Leaked down the other & gonna give it another season then rebuild it. Cant remember #'s from leak down, it showed a lil tired but nothing major.
Last edited by jmoore1225; 10-21-2015 at 06:48 PM.
10-21-2015 | 07:08 PM
#53
Registered
Joined: Nov 2005
Posts: 1,028
Likes: 2
From: Grand Rapids MI
I do agree. And probably why, a guy who has a big twin engine vee bottom, who spends alot of time at high rpm or wot, will wear stuff out faster than the small boat, who cant stay in it very long due to being hull limited, like chine walking , etc, or simply a smaller lake where you are real estate limited. I know some guys who rarely hold their engines wot, and some who do for ridiculous amounts of time. The guy who runs his big power stuff wide open for 20,30 miles at a crack, surely better have his chit together, or as we see very often, the end result of what happens when its not.
Some things that are rarely spoken about, is valve seat material, and valve seat widths. If your building a big power offshore endurance engine, that is an area that should not be overlooked imo. I paid extra money for all new tucker seats in my heads when they were being redone, per the machine shops recommendation . I believe teague uses them as well as mercury racing on some of their newer big power stuff. Fancy high flow race car valve jobs, might not be what you want in an offshore endurance engine either.
Some things that are rarely spoken about, is valve seat material, and valve seat widths. If your building a big power offshore endurance engine, that is an area that should not be overlooked imo. I paid extra money for all new tucker seats in my heads when they were being redone, per the machine shops recommendation . I believe teague uses them as well as mercury racing on some of their newer big power stuff. Fancy high flow race car valve jobs, might not be what you want in an offshore endurance engine either.
10-21-2015 | 07:10 PM
#54
Registered
Joined: Nov 2005
Posts: 1,028
Likes: 2
From: Grand Rapids MI
Being easier on your equipment will absolutely make it live longer, but if I had a big power engine that was only used 5-6 times a season (assuming you have a realitively short season) you should most definitely back off your rockers in the offseason to not leave undue stress on your valve train and be sure to make sure it's fogged properly. For what it's worth most big hp stuff (1000-1200hp) I am personally familiar with look to be refreshed in the 120 hour range. Refresh it before it breaks and it's a lot cheaper and a lot less downtime.
10-23-2015 | 11:20 PM
#55
Registered
Joined: Aug 2010
Posts: 2,227
Likes: 547
From: Cape Coral FL
The rocker deal is a bunch of bull. heat and cycles are what kill valve springs. You can keep a quality valve spring compressed at near coil bind for years and it will not change. The only reason to back one off would be to seal up the cylinder to keep moisture or critters out.
10-26-2015 | 01:04 PM
#57
Frank's Marine Service
Joined: Sep 2002
Posts: 11,959
Likes: 142
From: Elkton, MD
For the past 11 years I've run 572/580" blower engines. They've been 830/875/965hp respectively and my refresh intervals were at 250 hours.
The last go around (965hp) I bought new blocks because the bowtie blocks were showing their age. Most of those 11 years I was running solid rollers and had one lifter failure because I tried to get an "extra season" out of them knowing I'd be doing a full overhaul last winter. This last build I switched from a solid roller setup to a hydraulic setup and "picked up" nearly 80hp/ft.lbs.
The last go around (965hp) I bought new blocks because the bowtie blocks were showing their age. Most of those 11 years I was running solid rollers and had one lifter failure because I tried to get an "extra season" out of them knowing I'd be doing a full overhaul last winter. This last build I switched from a solid roller setup to a hydraulic setup and "picked up" nearly 80hp/ft.lbs.
10-26-2015 | 01:36 PM
#58
Registered
Joined: Nov 2005
Posts: 1,028
Likes: 2
From: Grand Rapids MI
