Cummins Top-End work Reccomendation

[Jackman]

Looking for a recommendation for top end work on a Cummins 330B 6BTA. I think I have a valve or two that have decided to hangup after inspecting my sick engine this weekend. Two pushrods were slightly bent. Looking for a good place in Md or De or even Jersey (I live in PA).

I guess the goal is to remove the head in the boat and examine the surface of the pistons to make sure there is no damage that would require pulling the entire engine. If I see damage I'll bolt the head back on and remove the engine. If its just the head I'll rebuild it.

So has anyone had any luck with companies in my area of the country?

Jack

[oscarvan]

You can always try to put new rods in an a few quarts of Lucas Mystery Oil. I have unstuck many a sticky valve with it...... Worth a try.

[Boatsb]

Slightly bent rods? That's like only a little pregnant.

Pull it a do it right. If not you will regret it later.

[Jackman]

I can get the rods and replace them but even when I hand turned the engine after just trying to straighten the rod I could feel a rough spot like the valve was binding...maybe it dropped and the piston was contacting it. Lifter was working as we manually checked that it moved up and down. Engine turns fine without the pushrod in place...So its got to be the valves because when I put the rod back in it gives a little resistance and come of the rocker springs do not return the hole way up immediately as they should (uncompress)and are sluggish after opening the valve on two of the intake valves. I'm wondering if this is the residual effect of having a less than optimum Cummins exhaust elbow prior to switching over to the Tony Athens design. Maybe some water in the turbo? I did see some slight corrosion on the push rods.
I guess I can try the MMO...how exactly did you do it? Just add it or did you apply it to the top end directly?

Jack

[jim rosenthal]

Call T&S Marine Engines in Crisfield, MD. Pull the head and send it to them for a rebuild. And, yes, determining the cause is a good idea, too. They will be abble to help you figure that out. Ask for David.

MMO is great stuff but it isn't going to fix this kind of problem. .

[oscarvan]

I put it in the oil, but now agree with the previous posters that you may have more going on.

[Jackman]

Jim,

Thanks for the reference. I called and spoke to David. Seemed like a really nice and honest guy to. We discussed my situation and he recommended that I pull the head and examine the pistons and cylinder walls. If there is no damage he said replace the head with a new head. He does not rebuild them. I'm guessing sometimes the machining is not all that great and the valves dont seat properly. Best just to spend the extra bucks and buy it new.

I discussed the sticky valve situation that may have caused the bent pushrods and he said its quite possible to have sticky valves from corrosion which may have originated from the original posted issue of having the turbo pull in saltwater vapor and most certainly the poorly designed cummins exhaust elbow I had prior to updating with a custom riser from Tony Athens...When I pulled the pushrods I noticed some corrosion when I wiped them clean of oil...which I doubt is just from low hours over a short amount of time. I know its not from my aftercoolers or anything else because I do them EVERY season.

JAck

[whoover]

Hello, I was getting ready to order new mixing elbows from Tony Athens to redo the risers on my Cummis 903's. You now have me rethinking this decision. What is it that makes you think the mixers are less than efficient.

Thanks
Walt Hoover

[Jackman]

It's not about efficiency. I dont believe I said that but if I did I apologize as thats not what I meant. You might want to read Tony's many posts on these elbows. Its all about rise from the water level and how the water is injected into the elbow on the downhillside of the exhaust elbow. Maybe it works in your installation....but in mine it did not. I went through both turbos very early in the life of these engines because of salt water intrusion up the exhaust. My other issue is probably because of engine room ventilation. Your best thing to do is send Tony pictures that show how your engines are installed that are clear and cover the area of the exhaust and turbo very well.

Maybe you do not need the custom work...but I did. I only have 280 to 300 hours on my engines. Turbos should not be killed in that short amount of time. Mine looked just like his pictures of failed turbos because of poor exhaust system design.

[Boatsb]

Any repower needs to have the exhaust evaluated. Its not the off the shelf components fault. There is a specific height above the waterline and a slope that have to be met. Many repowers get custom risers for that reason.

About 50% of the repowers will not meet the Cummins specifications. Every time I do one it has to be inspected before Cummins signs off for warranty.

If you have to do 2 rods and the head why not pull the engine and make it easier to get to everything, clean and paint as necessary and reinstall a 100% sound engine.