hours on new engine
 

How many hours should you have on a newly built 600+hp big block before you would feel a "broke in" or a more power feeling with it?or a comfortable not going to blow up feeling?

Its not going to gain any power when broke in. All you are trying to do in break in is to get all the parts to mesh with each other. My opinion is about 5 hours with varying rpms.

Engines don't really break in anymore. Years ago, engines were assembled with fairly rough bores and plain iron rings. Nowadays, bores are honed to a fine finish and rings are pre-honed and coated with wear-resistant coatings. An engine will "break in" a very tiny bit, but not much. Other than the bores, everything in the engine is at operating spec when assembled. If things like bearing clearances are expanding, you have serious trouble.

The best gauge of what's going on inside the engine is a leakdown test. You should do one on a new engine and a couple hours in, then regularly- maybe at 50-hour intervals. Then you can track issues and long-term wear.

You have two kinda' mysterious threads about these motors- what's up?

I would say 5 hours once the rings seat I am with Griff

Read above. Rings don't seat. After 20 minutes, they're where they're at- the cross hatch in the bore is broken. If you look at it under a microscope, the fresh honed bore has sharp points on the tops of each little peak. In a few minutes, they'r e runded over. The top one is moly coated and the oil ring is hard chrome. You may get a tiny amount on the 2nd.

This engine has become a nightmare to me because i bought it off of the oso classified from a well known guy in the fall and he screwed me by just putting some good named used parts in a 502 block and selling the engines,i spent all winter spending money getting this in the boat and doing it right and my first time out at the lake,the port side headgasket blew,so i tore it apart and found the engine was all tired looking and worn out and had water sucked in it several times and was basically junk,so i had a very good engine shop in my town rebuild it all,i replaced everything that needed to be replaced,and used what i could,this motor was so bad some of the springs had 1/4 inch worth of shims under them because they were wrong for the cam and they were worn out,so i ran this motor and broke it in properly,and have had it ouon the lake,i put 4.5 hrs on it,went to adjust the valve just for good measure,but i have to remove manifolds first,when i removed the port manifold it had water beads in the exhaust ports,which i think is bleeding through some pourous aluminum in my emi manifolds,had the bad one pressure tested but came up with nothing,i am thinking it needs to be hot?Anyways new manifolds should be here tommorrow and i give it another shot at the lake,i have looked in the cylinders and the pistons have black oily residue and clean spots,also the plugs look tan on the white ceramic part,but for some reason i think it is getting water in it from reversion maybe,there is no water in the oil and it starts right up,i just dont have any faith in it right now,and wish i would had left it stock,not because of the money spent either,ant suggestions?

We can certainly try to guide you the right way.

How about the specs on what you have now? You say a local guy went thru it afer tyou found out what was in it- what did he do? The more specifics, the better. Do you know what cam is in it? The heads/valve train?

Without cam specs, we're just guessing on reversion.

Did the local shop understand this was a marine motor? If so, did you provide them with valve stem and piston clearances and if not, do you know what they used? It's better to know before you seize a piston or stick an exhaust valve and ruin everything.

The block is a gen 5 502 bored 30 over,diamond pistons,eagle rods and a gm performance crank that has been turned downed 20 thou,block was honed out and decked,rotating assembly was balanced(which was way out to lunch)and installed using new main and rod bearing and new rings were filed fitted,320cc aluminum pro topline heads were pressure tested and redone using new comp spring(944-16),new comp roller lifters,new comp retainers,my original ferea severe duty valves and inconel exhaust valves,with new comp pushrods and valve guides and seals etc.
I use a dart high rise single plane intake,hvh 2"spacer and a pro systems built 4150 carb,running sunoco ultra 94 fuel always.Exhaust is emi thunder which i bought used and got screwed,but new manifolds coming,i run ngk plugs(v power 8 r5671a)and thet appear to be tan color on the porcolin part of the plug.
This motor was on the dyno before i rebuilt it and it put down 612hp and 617 torque at 5500 rpm.This builder is very good and anal and is known for his head work,he also knew this was for a boat and has 100 faith in the engine and says i am too worried about nothing,the engine temp is 170 and oil temp is 160,i am going to change the 140 stat to a 160 so maybe i can raise the oil temp,there is no water in the oil or no milky residue anywhere.I almost forgot the cam specs-comp custom grind 606 and 617 lift,234 and 244 duration on a 110 centerline,comp and the builder thinks that his cam will not have a reversion problem but i have been told it is borderline.It sounds bad ass and you can tell it is not stock in any way,what do you think???

Everything sounded right on until the cam. That's alot of stick for EMI's, especially if it's a Bravo boat with short risers. Not saying it IS a problem, but maybe. You can always have them weld the water dumps and weld in bungs- go 100% dry- if you don't run mufflers.

You should get a marine oil stat and get those temps up. That's the only way to cook off condensation.

hours on new engine
 

I am not too sure what you mean by oil stat?i am using my stock oil cooler and i do have a 160 marine water stat in it,the marine stuff is new to me but i am learning,i am a diesel mechanic by trade so i am capable of doing most of this,i have done all the work except building the engine,i did talk to eddie marine about moving the water from the riser and they said it would get way too hot at the riser?i would like to have a dry system,more piece of mind of no reversion and they are the short bravo style you talk about.how do you determine reversion for sure????????the part number for my exhaust system is emi 512,do you have any input on how to make exhaust dry?from the riser i use my factory s pipes but i raised my tips out of the water so the pipes now are turned to 9 oclock instead of 6 oclock.