How reliable are those big hp motors?
 

I've always wondered how reliable those 800, 900, 1000+ hp motors from Sterling, Chief, Pfaff, etc, are... I've heard that Merc recommends 25 hour rebuilds or refreshenings on the 900SC's, is this true?

For you guys with big dog motors, what is your maintenance schedule like? Do you have to adjust valves, etc, every weekend? Just curious what the trade-offs are when you move from the "turn key" packages like the HP500EFI's to more exotic blower motors (not counting broken drives! :) )

Yep, it's a slow day at the office..... ;)

Thought I saw on one of their sites that they boasted you could run an entire season (summer ?) with "only one rebuild".

-Greg

It depends on what you consider reliable !!:D

Mine is just a N/A 540 (675hp) .
My boating season is usually around 50-60 hours.

I change the oil , drive oil and check valve lash every 15-20 hours.

She gets a set of lifters and valvesprings every season. And after this season I plan on freshening it up , it should have around 120 hours on it.
So far this motor has been very reliable, I had one problem with a lifter last year and that problem has been corrected.
I have 4 poker runs on this motor along with my weekend boating.
I do not baby this motor.. It has been held WOT (except for throttling) from MacRay's to Sinbads in a poker run. (probably a total of 9-10 miles for an example)

This weekend I plan on checking valvelash and leaking it down because I lost 3 mph Sunday and this boat is usually very consistent.

Here is testimonial on Pfaff stuff from DMAN (R. Songrath) and Board God #1.

http://www.pfaffengines.com/test.htm

Okay , so I'm a little anal when it comes to the motor.
I run a solid roller cam which is my biggest worry. I'm just not really confident in the lifters... no matter what brand they are.
Hopefully I will see some good results on the Shuebeck stuff , maybe I will switch to those.

I have Keith Eickert 800SC in my 35 Fountain. I change my oil every 10 hours and freshened them at 200 hours. With superchargers I find I have to change my oil often since it gets dirty after a short time.

so what is it
 

:confused: :confused:

800 or 900 SC's

Change the oil and check the valves at 20 hours . Solid roller . I haven't had mine long enough yet but I think change lifters and springs every year is good insurance too ! I think if they are built RIGHT, maintaned well , and respected to a point they can last for a long time . There were plenty of guys on here saying they got 400 hours . someone said they got 600 hours ! :eek:

I hope to grow up to be like that guy !:D

It depends who builds them! I have 20 hrs. on a pair of rebuilt procharged 502s dynoed @ 640 hp and now have 0 oil pressure after coming down from plane after a short cruise and oil blowing threw the exhaust. Called the builder 4 times and has not returned my calls. Oh yeah, there were rebuilt because he blew them in the first place!

I have 750 Hawks in my Top Gun(671`s with Superchiller intercoolers)They were freshened up by Competition Marine in St Lewis when I bought it. I`m around 80 hrs so far this season and they run incredibly well. When I bought it back in April, I sent the carbs to Nickerson Performance to be set up to run cleaner. I have not had to touch it since. I change the oil every 20 hrs.and I could not be happier with the way it idles and performs.

Kurt.