Omc 115 Turbojet stripped down and starting the rebuild

[Faztbullet]

Re: Omc 115 Turbojet stripped down and starting the rebuild

(1) get rid of the strainer if still equipped (2) Make sure you take thew wiseco's thru a minium of 4 heat cycles to temperer them up, even through they are a forged piston they are soft till tempered.

 

[Abomb27]

Re: Omc 115 Turbojet stripped down and starting the rebuild

I always thought the strainer was to small. Not a 100% positive but is a heat cycle from start to operating tempurature. And do that four times before operating the boat? My first rebuild.

 

[Faztbullet]

Re: Omc 115 Turbojet stripped down and starting the rebuild

A heat cycle is from start to operating temp to complete cool down, basically you can get 2 cycles done in 4 hours if you have no problems, also dont run the the engine over 3500 for the first hour.
www.mar-fab.com/BREAK-IN-PROCEDURE.pdf‎

 

[Abomb27]

Re: Omc 115 Turbojet stripped down and starting the rebuild

Can the heat cycles be done on the hose? Or do they have to be done with the boat in the water?

 

[Faztbullet]

Re: Omc 115 Turbojet stripped down and starting the rebuild

The have to be done with a load...you can just back trailer down in water and run.

 

[Abomb27]

Re: Omc 115 Turbojet stripped down and starting the rebuild

Ok. I know I can get the WOT timing close without running it in the water. Do I do the heat cycles first before I set the wot timing?

 

[Faztbullet]

Re: Omc 115 Turbojet stripped down and starting the rebuild

Set all your timings/sync and link then take to water and final adjust under load as you can get it close on land but it needs backpressure to set accurately...

 

[Abomb27]

Re: Omc 115 Turbojet stripped down and starting the rebuild

Ok thanks faztbullet

 

[Abomb27]

Re: Omc 115 Turbojet stripped down and starting the rebuild

I just got my block back from the machine shop. Cylinders look good, and I have my brand new wiseco pistons. Do I have to bevel the exhaust ports?

 

[racerone]

Re: Omc 115 Turbojet stripped down and starting the rebuild

Do the cylinders have a nice cross hatch pattern from the honing ?-------Yes the sharp edges on all ports should be chamferred.

 

[Abomb27]

Re: Omc 115 Turbojet stripped down and starting the rebuild

Yes they do. But the guy said the block needs to be cleaned well to remove all the fine particles.

 

[boobie]

Re: Omc 115 Turbojet stripped down and starting the rebuild

We used to chamfer the ports with a medium grit ball hone after the boring was done. The machine shop should have done this for you. Check with them.

 

[Abomb27]

Re: Omc 115 Turbojet stripped down and starting the rebuild

I asked him before I left. He said it was preference if I wanted to or not. He said that the factory had a decent chamfer, and that he didnt take off that much. But I could hit it with some sandpaper to break the edge if I want to. I though this was a must do, not an option. Do people all do it or not? By the way I paid $520 altogether. $400 for the pistons, and $120 to bore all 4 cylinders. Is that a good price?

 

[boobie]

Re: Omc 115 Turbojet stripped down and starting the rebuild

Yes it is. They told us in a factory service school years ago to use the ball hone. That was OMC by the way.:joyous:

 

[V153]

Re: Omc 115 Turbojet stripped down and starting the rebuild

use the ball hone

Indeed. And in both directions ...

Sounds like a fair price for the pistons'n machine work.

Now. Follow the recommended break-in procedure(s), religiously. This can't be stressed enough. Hate to see ya mess up one'a them purty pistons.

 

[Abomb27]

Re: Omc 115 Turbojet stripped down and starting the rebuild

I will take a ball hone to the ports. I will definitely take my time and follow the break in procedure exactly, when I get it all done.

 

[Abomb27]

Re: Omc 115 Turbojet stripped down and starting the rebuild

Just wanted to let everyone know im still working on it. I injured my knee and im having surgery on it this friday. So where im at with the rebuild. I am waiting for my gasket kit to arrive. I eased the edges of the ports with a round file to remove the sharpness. I am cleaning off all the old residue from the gaskets. Then I will wash, air dry, and lightly oil the parts.

 

[boobie]

Re: Omc 115 Turbojet stripped down and starting the rebuild

Keep us posted..........

 

[Abomb27]

Re: Omc 115 Turbojet stripped down and starting the rebuild

Latest update. I sprayed down the parts with gasket remover.... helped a little bit. I scrubed the block and heads with soap and water, then dried them, then lightly coated them with oil. I removed the rods from the old pistons, and attached the new pistons to the rods. I had no idea that the wrist pin bearings would be such a pain in the butt, and the wrist pin clips.. I got them attached....will post again soon.

 

[racerone]

Re: Omc 115 Turbojet stripped down and starting the rebuild

Not sure why you say that wrist pin bearings are " pain in the butt "-----Never have a problem doing them at all.