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.

Wow! 600 hours is pretty good for stock Merc 'black' engine!

1000hp Sterlings, I change the oil at 20 hours. Mike says" DON"T
TOUCH ANYTHING and get them back to me at 50 hrs ". By the way 50 hrs is further than you think when you can cruise at 80-
85 mph.

I have ran joey griffen 800's they last about 100hrs. Currently I run Eickert 675's I change the oil every twenty and they say to freshen them up every 200hrs. Joey's 800's were ok but Keith's 675's run cleaner, faster and have alot more torque.
The trick is drives if you have bravos talk to the guys at machine max they seem have the fix. Also the Imco SC's have been holding up well for some of my friends.

boost is everthing. the moore boost the less time you can get out of a engine. i bet 200hrs is 5lbs or less. i am running 10lbs. and plan on rebuild after 70hrs. to be safe. iam by no means an engine expert. 528cu. 420 megabolwer, superchiller, oil cooler, nickerson carbs, 18qt. oil pan and best internal parts i could by. bravo1 drive race gears platinum shafts 25 hrs so far and praying. pushing 850 to 900 HP.good luck!!:cool:

Re: How reliable are those big hp motors?
 

Merc 900 were in need of valve train work at about the 50 hour mark. And the new 1050 comes with a free rebuild at 50 hours so your guess is as good as mine. One thing I do know is they always run the fastest and the best right before they launch their guts. Been bit by the bug too many times.

From what I understand, driver/throttleman abuse has a lot to do with how long big blower motors will last. So, a conservative person will probably get twice as much life out of a pair as Stinson ever will, since he forgets that the throttles have 2 directions....right Sean???? :D

Change the oil every 20 Hrs., listen for valve taps, don't over rev, (put a rev limiter on it), I have an Offshore Performance 588 Tall Deck N/A roller, 10:1 engine that keeps on ticking, just like Timex.

Cheif Engines!
 

ASK TONTO...... HE KNOWS!:D

TONTO Tow in Savannah, GA...?

YEP!
Not one single hiccup, cough, or sneeze....ALL WEEKEND!

I complimented TONTO.
Mentioned the fact I was quite surprised
with the "strain" of pulling several boats and playing..w/ the big motors.
He has been out on several runs since and she's still going strong!
So , proof is in the pud'dn.

Cheif Engines!

... eeehh...I forgot excatly what TONTO is running .... but...
I want to say twin 900's...
help me out here sweetie am I right?....;) :D

Famous last words......
 

"....man this thing is really runnin great, dialed in and hooked u....

............what was that ??????" :eek:

Re: Famous last words......
 

LOL - isn't that the truth! :)

Pfaff 598 NA 800 hp
 

120 hours no problems, change oil every 25 hours, Pfaff says its just getting broke in.

MAINTENANCE!!! Worth it though! Works on everything!

Seems to me I didn't hear any complaints when I blasted you across the Pacific in the NorTech, bro. In fact I think the question was raised on how do you keep the RPM's within a couple hundred of the sustained RPM while running in the rough at over 5000? It seems to jog my memory but I must say I do have that A.D. whatever you call it sh@*.:cool: :cool: :cool:

Hey bro long time how you doing?

Sean

Blower engines have come a long way---they're not hard to get them to run these days. They make a ton of power, sound cool and look awesome under the hatches. Blowers are also much harder and stressful on the engines internal parts, transmissions and drives too. Anytime you add a blower you've just made things that much more complicated and the potential for failure has at least doubled. They require a much higher maintenance schedule and can cut an engine's life in half as compare to a N/A engine. And when they let go the damage can be a little more catastrophic. I run N/A engines and try to keep things a little simpler. If I want more power I will probably go to larger cubic inches vs. a blower-----either way you pay, but I must admit that I do have a healthy amount of repsect for the guys that run their engines with blowers. I guess it comes down to how much SMACK you're willing to lay down and what chances you're willing to take. Just my preference and .02

Sean, I will never complain about going fast! I was just pointing out that when you push a pair of motors every time out, well they won't last as long as they would for someone who runs them well below WOT on most occassions. Since, you (which is what I like about you) don't know how to drive at anything other than WOT, your motors tend to give out a bit earlier than some! :D

How's life? Are you going to be in Cleveland this weekend?

It is a very easy subject...keep the oil changed and 90% of keeping a big engine running and out of the shop is up to the
driver/throttleman. The harder you run the boat...the more rebuilds you will be achieving!!!

Good luck!!!

DMan

I was just bustin your balls bro. I was going to Cleveland but I am now packing and getting ready to move to the right coast. Starting over there at a new shop in a couple of weeks.

Sean

I know you were busting my balls bro. That's why I was just giving it back to you! :D

Where are you going on the right coast? What shop are you joining? It wouldn't have anything to do with Apache, would it???;)

"someone said they got 600 hours ! "

That may have been me. It is actually 707 after the weekend but these are just stock baby '89 420's. I run them WOT 40% of the time at 5200 - 5300. Now just this weekend I have a MAJOR oil leak that will be looked into this weekend. I'll power wash the bilge and on our trip this weekend look for the squirt. I'm going through about a quart every 4 hours right now and when I pulled the plug last night .... guess where it is going. In the bilge.

WH

stinson where are you moving too????

I agree, you can't beat cubic inches. You don't need chillers & blowers, just build a 701 CI merlin super tall deck, with a tunnel ram with two 1050's @9.5-10.5 to 1 and you will have more reliable power than you ever dreamed of. This will be the combo in my next CAT...

Mountain motors
 

What is the magic ratio for dependablility???:confused:

Mine: 225 hrs. with no knock on wood hrs :p

540 ci : 620 lift, heavy worked heads, 10:1 comp, 93 fuel

683 hp @ 5700 on dyno
Don't like turnin one that hard so
675 hp @ 5500 on dyno so at the prop would be???
This is guess work.
-30 hp for drive
-20 hp from dyno headers to CMI's elbow top
-10 hp accesories
-------------------------------------------------------------------
675 - 30 - 20 - 10 = 615 hp @ prop.

615 hp / 540 ci = a ratio of 1.139
701 ci x 1.139 = 798 hp at the prop

What do you think? Is 800 hp on a 701 ci tooooo conservative?

So what is the cost of this motor if I buy parts at retail and assy. myself. Be easy my wallet is thin, Mike

This thread just got real interesting!!!!!

900's, honest 900's probably 60 hrs with no hic-ups. I'm planning on 250-300 hrs between rebuilds. My normal cruise is 3000-3500 rpms so I'm not out there running the snot out of them every time I go out. But,HELL you let Stinson pull up beside and I'll blow my **** to smitherinzes to out run him :D

Robert

I'm getting the feeling that Stinson is detrimental to engine heath whether he's in the boat or not! :D

You just bring those grenades to Key West and we'll see who does it better in the rough stud.