Just bought a jet boat and I am building a 455 to power it. Anybody else out there doing the same, running olds power in a jet boat? What are your thoughts? Also I have a question about timing as I know it will be different from what I’ve heard the vacuum advance It’s not necessary. What degree of timing would be best?

 

Welcome to the site. My buddy has a jet boat and he locks the timing at 33/34.

 

Many factory Jet boats were fitted with 455's nothing new there. Tedd

 

Welcome. Post some pics when you get a chance.

 

I've known this to be true for many years, but never knew WHY the Olds 455 was the choice of so many jet boat builders over the more common BBC.

 

500 lb./ft. of torque at 2000rpm-5000rpm. Jet boats are just floating water pumps, and flat torque curves work the best. Same reason 455's were used in industrial pumps in the 70's. As soon as GM killed the 455 in '76, the BBC was the only choice if you wanted GM power.

 

I read somewhere, somebody building jet boats, was a friend of an Olds executive. Can not recall who.

 

It wasn't just Olds engines. All brand manufacturers of BB engines were used in jet boats, industrial pumps, motor homes, etc... I'm sure there were bid requests with a winner take all approach to products.

 

When building a Olds motor always open up the drain back on the heads. That's why they use bigger pans holding more oil. And yes I owned a jet boat and drag cars with a Olds motor.
Gerald

 

Thanks. And here I thought it might be that the Olds 455 was more durable at sustained WOT applications or something like that.

 

Used to be in the boat business and primarily sold Jet Boats and V Drive Boats..

Sold many Sleek Craft boats with the Olds 455 as well as Ford 460 and Cole Jet Boats with BBC engines..

The Olds powered boats were the best performers for a ski-tubing-all around lake boat..

Back in the day, I ran a pretty fast Cole Runner Bottom V-Drive with an Olds DRCE 510 C.I. Ran pretty good..

Check out this company for any and all Olds Jet Boat parts and accessories: https://www.cpperformance.com/

Good luck and have fun

Thirdcoast