Does anyone have an idea on a 455 olds and what is the top RPM? It is pretty much stock.
What is the max and what should be a good cruzin RPM?
i keep mine at a safe 35-4000 rpm's when cruising..depending on how much weight youre lugging around. My boat is big though, what size is yours? as for full throttle, mine never sees more than 4600 rpm..just make sure you let off when she comes out of the water or it's bottom end time!
The olds does not like the high rpm, nor does it need to run that high! hope this helps.
Mine is a 19', with a 455. I dont have a place diverter yet, thinking about puttin one on though, did you notice a big improvement in performance when you added yours?
I have an Olds 455 in mine. It has roller rockers, restrictors, oil cooler, forged crank, and a bitchen MSD on it that has the rev limiter. I can run 4000rpm's all day, with peaks at around 5200rpms and still maintain great oil pressure. Keep in mind that not much of the engine is stock anymore though!
As to the place diverter, it makes a huge difference in how my boat rides.
it makes a HUGE difference out of the hole. My boat is pretty heavy and before it would be horrible to get up on plane..now it's pretty easy..and cuts down on porpousing on the rough stuff. As far as improving top end speed, maybe a little bit but it looks great with the rooster tail up. it's more of a low speed mod for me, so i wouldn't have to hammer the motor so bad to get up on plane.
I installed the buttons on the steering wheel, makes it very convenient.
Tim Place at place diverters is a great guy, great customer service there!!
All this talk about the olds not likin the revs makes me wonder if I should look at a A2 impeller to replace my A.
Speaking of, how much power can an aluminum berk A2 take? The Berk chart says not more than about 330HP for aluminum impellers, but I get the feeling people subject them to way more.
Bleh, less thinking, more getting the boat in the water...'scuse me while I go glue down my floor.
I have to agree with the previous posts. My last 18' Weiman had a 455 Olds. It was stock and ran great at around 3500-3800 rpm's. I blew the gaskets (Heads), when I was trying to keep up with my brother's outboard trying to beat the darkness. Taching at about 4300 for a stock 455 in my opinion is not good.
That boat didn't have a diverter. The 19' Rogers I have now also has a 455 Olds. It also runs great at 3500-3800 RPM's. This boat has a diverter. I notice increase performance with nose level at take offs, but the boat without the diverter kicked ass once it got on plane which seemed to be fairly quickly. The only thing I notice at speed is you get the cool roostertail!!
Keep in mind that a stock 455 Olds does not like high Rpm's!! You can build a fast one if you have the money which requires special oil cross drilling etc. My brother use to spin bearings all the time due to the olds oiling problems.
JUST TAKE CARE OF IT AND DON'T TACH IT OUT FOR LONG PERIODS, LIKE OVER 5 SECONDS AND YOU SHOULD BE FINE. JAY
Wouldnt recommend a stock Olds setup for a jetboat. When mine was stock, was able to spin to 4900rpm and it scooted but if I stayed on it for more than 20-30 sec, would empty a 10qt oil pan and run it up in the lifter valley and valve covers and out the breather.
MotorMachine put mine together with oil restrictors and high volume oil pump. Will now run 5000+, good to 5600. Sustained revs of 5000 or more will eventually experience drainback problems even with restrictors. Monster torque tho...
Stock 455's shouldn't run above 4800, Keepem under that and they'll run for 20 years, with a little overhead work.
Mines a bone stock Berkley package and has been run for long periods at 44-4500 rpms. I check and maintain oil levels enough that I don't usually worry about it with mine being at those rpms. Like these guys say, anything higher and you need to consider oil return path upgrades and the such. It has the berkley oil cooler and I run 10-40wt. Haven't had any problems yet. I am on the watch with the throttle though when doing that.
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