This is the second set of crate 454's previously I have spun rod bearings and glad they had warranty. I really would like some expert advise on breakin for these GEN IV motors, also what about specific brand breakin oils?

Tro,

The first thing I want to say is that you will get a lot of replies and opinions on this but .... the only one that really matters is the one from the builder of your engine(s) You really should be doing exactly what the builder tells you to do !!!

I really think that the most important thing is how you run the boat for the first couple of hours. I always tell my customers that the longer you can be gentle with it, the longer it will last. I like to see them put a real easy hour of running on an engine, then change the oil and cut the filter open to look for any problems. Then take it easy for a while longer before you really start hammering on it.

As far as oil goes, personally if it is a hydraulic roller cam, I would put 15W40 Mobil 1 in it from the start. If the engine was properly machined the rings will be sealed up on the engine stand, or at least as soon as you start it. If it is a flat tappet cam, then I would use a good performance oil in a 10W40 or so weight along with a dose of ZDDP additive.

Chevrolet engines are really pretty bulletproof as far as bottom ends go if they are assembled properly. I cant imagine two in a row spinning rod bearings unless something else is causing it. If you have oil coolers, they need to be replaced and all of the plumbing totally flushed out. You need to use a good quality filter, not your run of the mill parts store automotive stuff. I have been using Wix racing lately but have also had good luck with Fram racing filters.

Just my opinions, talk to your engine builder !

Bill Koustenis
Advanced Automotive Machine
Waldorf Md

Thanks for the help I have replaced both oil coolers and cleaned all oil line and I also had some new lines installed I think it just was unfortunate but the builder has not provided breakin procedures and my local performace builder had mentioned some addative during break in. previously I had changed oil after intial start up and cam wear about 20 min and then after about 5 hrs of run time (packed gas cans and all to put the oil in) then I lost the rev rotation and new one in placed with same cam process and splashed down with about fifteen minutes run time and lost the standard rotation So here I am with two new and no real breakin time that was the reason for the post

Just went through the same things and was told exactly what BillK said. The only difference was I told to change out oil at 10hrs, and not to keep the engine running a specific RPM for more than 7-10 minutes.

Interesting My revers rotation is about 45 minutes run time (including my last dunk in the water and the standard will only have cam breakin I never kept either motor at idle or at high rpm it was feathered up and down and I thought the reverse was just a fluke that it spun but when the standard did it I thought maybe I done some thing wrong or missed a step

I break in mine with rotella....cahneg after8-10 hrs to synthetic....Rob

There seems to be some debate going on about "crate engines". Some claim they run great for MARINE USE right out of the crate. Personaly, I would never take that chance....especially from a factory mass produced engine. They should be disassembled and have all piston-to-wall, ring end gap and bearing clearances adjusted for Marine use by a competent engine builder who is familiar with what it takes to make a marine hi-perf engine survive. Just my .02

Whoa! Blue writing! Threw me there for a second.

It's okay, I'm awake now.