A little correction on your math there Egoman. The FE deck height is 10.17". So, when ordering your custom pistons, you want 1.932" to achieve zero deck, since you can specify whatever compression height you want. Here's how I calculated it:

10.17-1.75-6.488= 1.932" <-- That's the compression height you want.

 

So your saying I want "zero" deck? The calculator suggested 1.932 as well I just wasnt sure if I should go to zero or not. In that case they will have to be custom....If those stupid rods were proven to be strong enough i would have this problem.
10.17-10.14 = .030 thats where i was getting the 1.902 from. gives me .030 from top of deck.

 

Right, you want zero deck. That, of course, means to have the top of the pistons flush with the block deck. This is a very desireable thing to have. You gain compression, as well as having perfect quench distance between the piston and the head.

 

Thats what i thought but I knoew that they didnt offer a piston that height so I went with the other. I guess i need to have some custom made, I hope Keith Black can make some because ross only makes forged and Those will be more expensive than the Hyper pistons. Problem is They dont return emails......I'm just going to have to break down and call.

 

I've been looking at this piston ordering form here and i can't figure some of this stuff out. Like ring groove, and ring radial widths.....Valve pocket info......skirt info....I couldnt tell ya some of this stuff like the cylinder bore length. I would hope that the machine shop would have that info, kinda like this is what i want you tell me what i need type of thing. check it out..http://www.diamondracing.net/Custom%...0rev%205-2.pdf

 

Yep tell 'em you want a standard FE flat top with valve reliefs, but with the higher compression height. They'll be able to help you.

 

That sounds good to me...theres nothin special to them accept comp height. thanks rusty.

 

I bought some ROSS pistons once.... When I got them, they had a warning sheet stating not use them on applications over 250HP....so I shipped them back. And, they were forged too? Go figure... JMHO

 

Did you get the custom ones? Those give you a selection of whether you're going to use nitrous, etc. They also give a place to put your compression. What motor was it for?

 

To get what you want, you'll need to go with either custom pistons or longer custom rods. If I was you, I'd stroke it to a 390 and be done with it. Using taller pistons will get you basically what the 351M was -------- a dog. That was it's problem, the very tall pistons to reach the deck with a 1/2 shorter stroke than the 400's 4.00" stroke. You may get lots of torque, but not your 400 hp goal.

 

They were flat top pistons for a 360. I spoke with the Sales Tech and nothing about any HP limitation was ever said. I just assumed forged pistons would be the end all for strength and that they would be good to at least 500HP. I am not suggesting not to buy them...just make sure you get what you want. Hey...They looked great...just that 250HP seamed light duty for forged pistons and that for the same price, I could get something with a higher HP rating. So, that is what I did, I got a set of custom forged pistons from Shelby Systems.

 

Ok, is there a good setup with the 427 crank, like the 410 or some other stroker combo that works with a .30 over bore on the 4.05 engines that makes good HP and is still pretty good with low end torque? I'm sure this one has been ask a 100 times already...but it sounds like you guys know the trick setups.

 

Who said 390's had no bottom end torque ? The 390 and 427 used the same cranks. Ditto for the 410/428. If building a 390 just make sure to use a flat top piston that has a comp height that'll get as close to zero deck as you can find. Silvolite lists the #1131 as having a 1.76 comp height, that's what you want . You can mill the block another .010-.020 to get the rest and to clean up the decks. If anybody tells you the 390's had no torque, then they're full of s*&% and haven't a clue as to what they're talking about.

 

I used the silvolite hypereutectic pistons in my 390. They are HEAVY! Add another $30 onto the price of the pistons for the cost of mallory in your crank and I would not turn these suckers over 5500 rpm or so in a 390, a little higher for a 360. The machine shop I use said they've had great luck with these holding up very well in tow motors and the like. Which is exactly what I was shooting for. You do not want "zero deck" or .030" below. .006"- .010" below deck is where to shoot for a non full race engine that's going to see any mileage on it with a standard .041" felpro gasket. carbon will build up and cause piston to hit the head. Good luck milling hypereutectic. That stuff will eat carbide. Manufacturers use diamond tooling for hyper alum. There's a guy at the local muffler shop with a highboy with about 9 grand in a 360. Sure the motor's alright. It sounds great, but people give him strange looks when he tells them he's got a built to max 360. If you want all your questions answered on safe piston speed, ring locations, sizes, whatever get "4 stroke performance tuning" by A. Graham Bell. Some good advice I got was "don't build oddball motors". I didn't listen and my first engine build was a 302 gmc six. Turned into a big mess because the parts simply weren't available to obtain the power level I was after. I ended up with a miss-matched motor full of problems that nobody had a clue what it was or how cool it was back in the day when jimmy's killed flathead fords. It just didn't perform the way I hoped. I next built a sbc and was blown away by the results and for 1/3 the money! By no means am I saying build a small block chev, just saying that if you want good results in the end, build what other people build. The parts are out there, the performance will be better, people won't give you funny looks and your wallet will be heavier. Good luck with whatever you decide to do .

 

Well i figured with the edelbrock intake and heads and a good cam like a 941.....I would get as close to 400 hp as possible as long as i could get the taller piston. Its just a street truck, I dont plan on doing any more than run what ya brung at the strip. I just dont see how the taller piston will make the motor a dog. Could you elaborate on that? the 351m is a junk motor off the shelf but it can be built to be quite the powerful one...I have seen it done. I could just build a 390 but then there would be nothing special about the motor, it will just be another mild 390 that has been built a thousand times before. Is there any reason that It wont work? What are the cons to building it this way? aside from the price of custom pistons Its a very cheap build even with the heads and intake. I mean even if i got 350 hp or 370...it would still be worth it I think.