So what does everyone suggest?

Rods steel   2.2 pin    .003
Rods Alum. 2.2 pin     .0035
Mains          2.75.       .0035
N/A bore      4.310     .007  wall clearance
Blown bore  4.310      .009
N/A ring      4.310      .025
Blown ring  4.310      .030

Suggestions would be appreciated. I see a lot of posts regarding clearances but not many suggestions.

Pistons and rings often recommend looser gaps for turbo,nitrous, and blowers. I have yet to see a separate suggestion for boating applications.

I guess I should refine my question:

Engine builders, can you give some examples of the engines that you have built? Please include their application (jet drag,comp jet,pleasure craft,.......) and any other factors that have changed your specs.
The intention is to extract information from the applied specs of operating engines and to extrapolate them into the engines that we build here at SCJB. When we get the parts back from the machine shop it would be nice to have a reference for the machine work.

A good reply would be:
Comp Jet
460 base 513 stroker
Steel rod 2.2 pin .003
Forged piston 4.390 bore arias .009

This would be a great thread for the home builder to tap the resources of the SCJB site.

My current setup:
Chevy 468 gasoline
Eagle steel rod 2.2 pin .003 king alecular
Forged crank 2.75 main .003 king alecular X bearings
TRE 8cc dish .009 wall clearance
Moly plasma top ring .028
Cast second .022
This was setup for either an 8-71 or two GT45 turbos in a jet pleasure/sand bar drag boat.

Feel free to comment on my clearances, but only if you plan to supply a recommended clearance AND a reason why. (I don't drink but the beer seemed appropriate)

Pistons and rings often recommend looser gaps for turbo,nitrous, and blowers. I have yet to see a separate suggestion for boating applications.

JE/SRP does have a statement about additional clearance for marine purposes.

Since marine engine blocks typically run much cooler than an automotive engine, the blocks expand less.  On a typical recreational marine NA engine build I allow .0015" additional piston to wall clearance.   

The rings are a "minimum" recommended gap.  I usually use the spec for circle track gasoline engines since the marine engines are run much harder on average than a street engine.

Your bearing clearances are within the target I would shoot for on BBC, and I can't comment on your piston to wall without the mfr spec.  Rings are close,, I might have gone .0024" on the top ring on an NA 4.310" bore, but don't think you will see a difference.  Many builders are opening up the 2nd ring gap citing that the extra pressure on the top ring makes it seal better, but if someone asks me, I say stick to what is recommended in the package of rings you are using.

It is not in caps, but I figured caps were warranted. I guess I just always stopped reading after I passed turbos and blowers. My bad!

So at least you know I was not lying about it.  Sometimes instructions are a good thing. 

I try to run a little big on the mains....about .0035" and I put the rear main at .004".  Reasoning behind this is that the block will probably move around a bit more i'n a marine environment that it will in a car.  I have my rods at .002 - .0022" and after significant abuse, they look new....so that's my reasoning on the rod bearing clearance. 

Wall clearance and ring end gap, I use the piston/ring manufacturer's recommendation....

I have 2 bore guages (in this range) and use them both for redundency...A mitutoyo and a peacock brand, both are generally within 0.0001" of each other.  I use a micrometer to set the bore gauges, and set the micrometer multiple times for repeatablity.  I've been told to run the rods at .0025-.003, but after 1 and a half season of thrashing (5 mile long WFO runs, stupid oil temps, airing the boat out...etc)..the rod bearings looked so good that I reused them in the new motor. 

My understanding is that the mains need to be opened up a bit to allow for block/crank distortion...the crank is 22" long effectively, and it won't take much to deflect and start beating stuff up.  If the crank stays bolted in the block, the only reason for additional rod clearance would be misalignment, which over the 3/4" length of contact area...can't be much, so I think it's a moot point.   Proper oil wedge is IMO about the only thing we need to take into account when establishing rod bearing clearances....so long as a good rod is used and we don't have to worry about rods changing shape too bad. 

There's probably a better answer with a good reason behind it....and if anyone has it, I'd like to hear it. 

All that I need to hear is "I measured it, assembled it, ran it,tore it down, measured it and was happy!" as long as it is accompanied by the words bore gauge, micrometer and recheck! Kudos to you!

What about thrust clearances?

I just gave the machine shop my tolerances and told them to make it happen! I got tired of the guessing game, and not having the proper tools for the job i left it to the preffesionals!

454 BBC 4 bolt
mains .003
rods .0025-.003
clevite h bearings
standard stroke
70 over kb pistons -12cc solid dome
piston to wall .005
rings were per instructions
pistons came 30 thou out of the hole still, so i never figured my true deck height out just an observation when i installed the top end! and never cc'd the heads cause i dont know how to do this, heads are 990's, but i havent got an exact idea what my compression is!

anything else?

....so you're just gonna trust that they did what you asked?  Good luck.

With the pistons 0.030" outta the hole...whatcha gonna do for a head gasket?  If you didn't measure your deck height...how do you know if you have adequate quench?...and more importantly, why the hell are your pistons .030" outta the hole?  If I brought a setup to a machine shop and they gave me back parts that assembled with the pistons .030" out...They'd get that block back in hurry.  That means they didn't do much of an inspection to make sure the block was servicable after they cleaned it and before they started machining.....if they had, they'd have caught that and a phone call to the customer would be in order before proceeding. 

WAIT! Are you telling us that the top of the dome is .030 over the deck? Or are you telling us that the flat surface of the piston came .030 out of the deck?
 
What is a normal thrust clearance? .006-.008?

Nope the flat part before the dome comes out 30 thou. I dont think its a big deal my head gasket is. 064 thick

thanks homeblown! im guessing the oring portion of the block is pribably zero deck, and the deck itself is just below that obviously...the headgaskets are the same size as the cylinder bore...i should run a 3rd compression check, but with a % difference of 3% on the cylinders the last two times im not worried! im even considering going to a smaller head gasket, and still i will have plenty of room in there!

here's a couple of pictures for you guys....