Alibaba is China's version of Amazon. They have everything under the sun, except it's pretty much all a bunch of cheap Chinese crap.
Eddie

Wow Kurt, I think you are giving me some competition for epic, multi-page valvetrain geometry threads! :p

I'm glad you appear to be on the right track, but I am still confused why you put yourself through all of this for an engine that is running the stock mag cam with the .483 lift. I would have just ordered a set of the replacement non-adjustable rockers from the local GM store or even NAPA and been done with it. I can see absolutely no gain from running a full roller rocker on a stock engine, unless you plan on redlining it constantly - then you might get a little cooler oil temps from less friction, although most of the heat is coming from the valvesprings. Just my opinion, but the stock GM rockers have been pretty much bulletproof on mild cams like this, and they are happily working away on hundreds of thousands of boats out there. When you swap for a set of needle bearing roller rockers of questionable origin / quality, you are substituting that reliability for another opportunity for something to break or come apart and litter your bottom end with little needle bearings to get sucked into your reciprocating assembly or cam and wreak unimaginable havoc. And on top of that you had to spend a couple hundred on custom push rods and spent a bunch of time checking valve tip patterns. :confused: Am I missing something? Did you have the heads milled a whole bunch where you will need different length pushrods? Not trying to bust your balls, just wondering why the upgrade in this area? And yes, the bling of high performance parts is seductive, and has caught me in its trap many times! :D

Good luck with your build - let us know how it turns out.


BTW - if you end up wanting to just go back to the stock non-roller rockers, I think I have a set with almost no hours on them - they would be yours for the asking.

BUDMAN II.
sorry for the late response - been busy gettin boat ready for the Tickfaw 200 poker run in Baton Rouge, La. She ran beautiful except for that dreaded word r e v e r s i o n, or condensation, or both, when idling.

Anyway, on the rockers, Yeah, a bit of work, I kind of wish i had gone the flat tappet route now!!! too late though, haha. I was just drawn because of the appeal of a mph here, mph there, adds up. Heard that stiff roller rockers flex less and can add a few hp. Besides the idea of lowering oil temps a bit.

I've got water on the spark plug threads when i pull them, from the reversion i presume. I pulled them after seeing water condensed in the curve of the Eddie Marine elbows where the cooling water enters. Trying to figure out how to solve that now. Getting ready to add as many inches as i can of 3" diam exhaust tube to match the Eddie Marine elbows and see if it helps reversion. Not much i can do if it is just simple condensation at that spot in the elbow.

i just read every word your mile long thread from 2014 on reversion as i have the same issue after just rebuilding one motor and heads on the other for just that problem. We live with some salt/brackish water here on the gulf coast. lot of good ideas there to fix it.
i am going to try extending the exhaust tubes on one bank and try it next weekend.
by the way, mine got water in the manifolds on the river as well as in the driveway.



what did you end up doing to fix it????
I saw your last post where you were going to install the inner diverter i think you called it, to direct the water toward the back.

I'm having the same issue. Eddie exhaust dry to the tips. But they are reverting at the elbow. Why? Cause someone forgot to weld the seam in the elbow.

BB what seam are you talking about. Some kind of weld bead in the bottom half to act like a "dam".

Where the inner pieces of pipe are seamed together. In the turn of the riser/ tailpipe. Pm me your number and I'll text u a pic when I get to the shop.

Kurt, my solution was basically what you saw in the thread - welded inner pipe to effectively extend the dry portion of the collector and hopefully keep water from getting sucked back. I was running out of time and already had motor off the test stand and installed in the boat, so I didn't really have a chance to test it first hand like before. I ran it a couple seasons, didn't really put many hours on it. Last fall I did pull the headers because I suspected a header leak, and I saw what appeared to be some little deposits in the exhaust ports that could possibly be water either reverting or condensing, but the jury's still out. Only way to know for sure would be to run it and then immediately pull a header and check for water, but just haven't made the time to do that, and haven't really had the opportunity to even run the boat since then. Wish I had more that I could share.

I really think the best solution for my situation would be to also weld in a bung to the collector and divert some of the excess water out of the exhaust stream. The sheer volume of water being put through there concerns me, and I have the Corsa muffled tips that might contribute a little bit of back pressure. One thing that you may want to note from my experiments on the test stand was that either internal or external exhaust flappers can make a big difference by interrupting the reverse back-pulse that causes the reversion. I got tons of water runnning an open header with no exhaust tip, but it seemed to lessen considerably with a tip that had the Salisbury type flapper on it. You might have similar results.