I want to eventially go to blower motors but was wandering how many hours go between valve jobs?
I would like to also know specifics such as what head setup you have,how much boost,RPM range you run your motors,etc,etc.

Thanks..........

We ran the AFR 335 Aluminum heads on 540's last year put 85 hrs on them last summer. Hyd roller springs and manley severe duty intake's with inconel exhaust. Didnt pull the heads this winter but the boat ran as strong the last time as it did in the spring when the motors where brand new. Whipples at 7 lbs, 5600-5800 rpms.

Inconel Exhaust valves and a wide seat width are keys to longevity on blower heads.

That, and the fact that the valve guides are always under pressure from below makes guide oiling a bit of an issue. Running bronze guides with the clearance on the sloppy side and an oil groove knirled into the bottom of the guide helps immensely there.

Come on I thought this was TECHNICAL FORUM.
Only two respond to this thread?
Maybe I should have started a thread like:
"What color is your Kitty Cat?"

When I bought my Cigarette it had 120 hours on the engines and I went through the heads because I didn't like the leakdown results I got. After doing the heads I ran the boat another 85 hours without any problems, removed the engines for freshening, and again, wasn't overjoyed with the leakdown numbers I was seeing. With that being said, These engines still developed 644 horsepower on dyno runs just before being torn down. Blue Lightning Marine advertised these engines as 650 hp so I guess they were running alright.

We're getting about 65 hours. Using Teague/Merlin heads, Inconel valves: exhaust, severe duty Manley: intakes, bronze guides, etc. Custom Crane hydraulic roller, which has an aggressive lift and rate causes stems on the valves to wear; we replace the springs and hydraulic rollers for "insurance": otherwise no problems.

Due

So you're changing springs and lifters only and cleaning up the valve stems?
Do you think I would get more time running a Crane 741 roller cam?

Unfortunately, I don't have the answer for that question.
Due

Hey...What are you up too...?

.........6'...........

Mark,
Going to Sportmaster shorties with P-5 Hydro's
for this season.
Over at Sean Stinson's shop today talking blower motors for '05 season.
Thinking about 871's
Correct me if I'm wrong but you're running 871's.
Is that right???