OLDs 400 engine

[Downeaster]

I am using a 1967 Olds 442 400 ci engine in my 1972 Glencoe with a Jacuzzi WJ . The engine is a low mile and recently freshened engine. I replaced the 442 cam with a Mondello jetboat cam and a Edelbrock Performer manifold. Can not seem to get engine to perform above 4450 RPM. Boat previously had a Olds 455 low compression engine which would turn about 4800. GPS shows 52 MPH. Anyone have any knowledge about these 400 engines? Also since I am new to the boat not sure if maybe I might have a pump issue. Would like to see 60 MPH.Thanks.

[BIGA]

most likely the dropping of the 50 cubic inches you have lost 50 hp and 50 foot lbs of torque hence the drop of rpm which is consistant on the berkeley impellor chart of about the same hp. you will need to boost your horsepower or cut down the size of the impellor to restore your rpm. i doubt that you have a serious pump issue as i have found that if there is something wrong with the pump that it will die quickly and not just slow down to a constant lower rpm. however one should ckeck the drive for any problems.

[Downeaster]

Thanks for the input. I suspect I can get in touch with Jet Performance to find out what impeller I should use.

[Bies]

If you need I have a set of aluminum Olds exhaust manifolds, make you a deal on them

[Propster]

The 400 motor is actually a better motor. It has a steel crank. Not sure if it is a reduced torque issue or if it is just not running right.

[2slow4u]

the highest rated factory horsepower in a CAR for olds was the 69 455 in a toranado. if memory serves me right it was 425 or around there with a factory steel crank. lil tid bit.

[boatermike]

http://www.442.com/oldsfaq/ofeng.htm


clears things up


i acquired this by simply typping a question at www.ask.com

[Downeaster]

The Jacuzzi 12WJ pump I have has a B impeller. The 455 that was in it would turn 4800 RPM and gave 60-62 MPH. I do think I need to better by adjusting timing and such on my 400 motor but it may need some help with the impeller size. The 400 engine now has a strong 300 HP and 400 ft. lbs..

[Downeaster]

Found performance problem with boat. It was the engine. Weak coil. Replaced coil and now engine spins back to 4800-4900 and speed back to 58-61 MPH. Perhaps some more fine tuning and run it for awhile. Hope to next winter put 455 back in it and check out pump more closely.