Build with 360 pistons
 

Ok, I am only waiting on the cam now, so I'll start my build thread.
New piston vs old:
http://i105.photobucket.com/albums/m...s/IMG_0736.jpg
http://i105.photobucket.com/albums/m...IMG_0737-1.jpg
The valve recesses give a little more of a dish than I expected, but still less than half the volume of the stock dish.
The 360 piston has more skirt, but it does clear the crank OK. This one is the first one I tried to press together, they don't normally come with that crack. The others are all installed in the block now, waiting for me to take the time to actually finish the assembly.

Looks nice, but a couple of questions. It's hard to tell from the pics, but is the pin height the same? How does the deck height work out. It looks like it will stick out of the bore. Also, not being familiar with the 360, is it a 4" bore stock? Seems like I read something about alternative pistons from some V8 being a bit oversize requiring a significant overbore. I've already decided to build another 300, pretty radical compared to my current near stock setup, but would like some off-the-shelf forged pistons. Knowing what I can use and what it will take to make it work (from someone who has done the mod themselves) would be very helpful.

The 360 has a 4.050 bore, IIRC. A lot of guys use it or the 390 piston. One I spoke to prefers the 352 piston because he claims the .050 over bore can weaken the block. .02

I guess I am puzzled as to why? Unless the price is much better, or the performance is far greater, why bother? Yes, it will boost compression, but that can be addressed by decking or milling the head. Benifit - risk factor= what?

If you were going forged, and stood to save $300 by buying a set of 350 sbc forged, then I can understand why you go that route, swapping to the old rods and changing pin size, etc. Otherwise, I just don't see the benifit.

I'm not trying to upset anyone, just being frank.

The compression height is within a few thousandths, just a taller skirt.
Stock 360 bore is 4.050, I'm frankly quite sick of hearing how you can only bore these engines once- My last built 300 was bored 60 over, and ran fine. I had a small chamber 240 head fully ported and polished, Offenhauser intake, and EFI dual manifolds on it. For a time, I ran it with a single row radiator since that was what I had, and it did not ever run hot. I later went to a two row, and towed a trailer across the country without any issues. From everything I can find, these engines have thicker walls than the FE "mirror 105" blocks, and those can go out to essentially 80 over to make a 428.
Now, if I run this thing and split a bore, well you can all say I told you so while I swap all the external bits and cam over to my other engine.
Going to a non-dished piston is cheaper than having the head or deck milled, since I needed pistons anyways. Going this route gives me about a 9.8-9.9:1 compression ratio, given the 76cc combustion chamber. The chamber may actually be smaller, since the head has obviously been milled before.
I'm still hoping to be able to run this thing on a dyno once it's all together, but I don't know if there is one close by.

Going to a non-dished piston is cheaper than having the head or deck milled,

Boring cost money too. So, with that c.r. you're off cheap gas. I hope it works good for you. I'm sure you'll have a nice engine. 360 oem bore is 4.052". I couldn't help buy throw my two-thousandths in there.

I'm running a set of Keith black hyperutectic "UPS" pistons. They're not forged, but they're stronger than stock and you can specify the overbore to keep up with whatever it took to straighten the bores up on your core. They also have a higher compression than the stockers. Between running them an a 240 head straight up with no decking I'm in the 9's for compression and am forced to run premium fuel. Engine diesels on less it knocks that bad. Why do you want to run forged anyway? You have to wait longer for them to warm up so they don't rattle in the bore under load, and the I6 isn't really a candidate for Nitrous. If you want a boost motor maybe, but you can go an extra 100-150HP with Hyperutectics, and if memory serves Keith black also makes stock compression hyperutectic piston. Just make sure whatever pistons you get to GAP THEM ACCORDINGLY. Nobody told me to do that and I lost an engine setting hypers to the stock ring gap. Big costly mistake.

I've also heard of 400 pistons working with a .040 overbore. .030 over is pretty common to clean things up, .080 over pistons are made, but .060 over is the most I've heard of being reliable. There should be no problem with running a .050 overbore if you want to go that route. If you're really concerned with it you can have the engine sonic checked to look for core shift. This will tell you the sidewall thickness and therefore the max overbore.

The bore is actually 4.080, it wouldn't clean up at .050 or .060, so I went to the 360 .030 over. The pistons are cast hypereutectic, and I'm going to be running an EGR on this engine to help with detonation. I also relieved the sharp edge of the chambers in the head to help get rid of the most prominent hot spot.
My cam got here yesterday but my wife went camping with our daughter so I have to stay home with our son until mid-day Saturday. I'll install the cam and take a few pics of the assembled lower end then.
I was going to put the head on yesterday, but forgot I destroyed the alignment pins pulling them out so I'll have to wait until Tuesday for them.

On hot rodders.com it is mentioned that with the 300 you can, "bore it .050, and 390 pistons will fit, the pin size and spacing is identical, so they are a drop in fit with no machining."

I checked my installed piston height, and they are .040" down in the bore at TDC. I had calculated the c/r with them at .030 down, so my corrected c/r is 9.6:1.
For comparison, the last 300 I built had a 4.060" bore, 16cc dish pistons, and 66cc chamber 240 head, giving it a compression ratio of 9.98:1. Now this is a bit high, and without having an EGR I did have to run premium. This new engine will be running an EGR and less aggressive timing curve so I should be all set on mid-grade. I am applying lessons learned here, so this isn't completely new ground.

Duration is 252, I'll have to double check the spec sheet but I think lift is in the .425 range. Should be good for a nice fat mid-range without being peaky, advertised power range is 1800-4800.

All good info. I had considered hypereutectics since there are several of those out there. I was mostly wanting forged in an effort to build a bottom-end that is plenty strong as a N-A motor and also could take some boost if I can ever muster the finances to go that route. The hypers would probably be fine for no more boost than I'd put to it anyway. I figure that no matter what you do, this is still a low RPM engine, and even with a turbo, one should "play to it's strengths". Doing so, IMHO would mean a small turbo, or at least a small exhaust impeller to get it spooling up and making boost right off idle, but then limiting the total to a pretty low number. (like 8-10 psi) and all in by 4000 rpm or so. Hypers would indeed be strong enough for that. I just figured that since off-the-shelf forged for common apps (Like a small-block Chevy) can be had for not much more, why not build it to be as strong as possible in case I want to get stupid later on? I'm not really concerned about mileage or fuel grade on this engine as it will be for my second truck. (weekend toy - not daily driver). Even at that, I DO have to do everything on a relatively tight budget, so any route to getting what I want cheaper is a good thing. Since the core I plan to use will need boring anyway, that basic machine work expense is already there. That being said, and stronger rods also in the plan, I am basically looking for the cheapest way to do that. If I can buy an off-the-shelf piston and rod that will work together without either item having to be custom built, this would be an instant savings. I also have recently looked again at Col. Flashman's build. He had some impressive numbers with a mild cam. I noticed in the thread that he used longer rods and custom built pistons. I'd like to replicate what he did there, but with lower compression so that I could run a turbo later on. I'm in the early planning stages here, but like to know exactly what parts I need so I can start saving for them or buying bits and pieces a little at a time until I can pull it all together. All the info in posts like this are helpful towards that goal. It's nice to have a group of people with experience on a specific engine to minimize the research!

Some piston installed pics:
http://i105.photobucket.com/albums/m...s/IMG_0738.jpg
http://i105.photobucket.com/albums/m...s/IMG_0739.jpg

LOOKIN' GOOD MAN! I assume that you are going to paint the motor later, but it looks really good thus far. I have heard of some in the 4.080 having heat problems, hopefully not yours. I also wish that I went a little less on the compression at this point, but this also isn't a daily driver. Would be easy for me to add a thicker head gasket and reduce I guess. As for the turbo build, More power to ya. I've heard of them and seen a few, but you're basically on your own on that.

Yeah, the turbo plans are pretty much dead and gone. Most of the parts got stolen in a real horrible housing situation a few years back, and once I've been burned like that it's hard to get the desire back to try again.
I'm going to just do this one in Ford gray, nothing too fancy.
I did hit a bit of a snag yesterday, though- One of the cam bearings was undersized. I've had cams on 300s go in pretty hard in the past, so I was assisting it a bit and managed to pop the cam bearing out. I got a new one so I'll press that in tomorrow and then the new cam, I put the head on yesterday so I'll be able to install all the valvetrain stuff too. I'll try and get an actual number for the lift then as well.