this is the most important thing to have figured out before you start building I decided not to get anything bigger than a 302 just because of the struggles the bigger engines bring with them. with me Im building my engine for (1000+ hp) crazy speed that is hopefully controllable lol for a mild mannered fun street car pull the motor and get a re ring and gasket kit if you take it to the machine shop and they check everything and say its all good. have the freeze plugs replaced or replace them yourself and have the motor honed out. you will be amazed at the power you didnt know was there. I had an old 360 in an f150 that had who knows how many miles on it I put in a re ring kit and had the block honed out and the truck is still going 10 years later long after I got done beating the snot out of it lol
The later 351 blocks gained deck height to lower compression. If you really want to make better power across the ENTIRE rev range and no matter what this build ends up costing.. use the tallest pin height piston that you cas squeeze in there. The cheapest way to go would be to use a stock bore economy style Hypereutectic with NO dish/shallower valve reliefs. This one could bring your compression up by nearly half a point and there's is extra bonus power to be had with thinner ring packages. I would never even dream of using old fatty rings when there's just so many better options available these days. http://www.summitracing.com/parts/slp-h621p/overview/make/ford Use Summits search engine to compare part numbers respective pin heights. Then start cross referencing the part numbers that are most appealing. Much over 400 horsepower pushes you towards forged slugs to improve upon quickly shrinking durability margins. Just to reiterate part of my previous post. It's VERY EASY to build a 350-375 horsepower 351W that still makes 400 lb/ft of midrange torque with the parts you spec'd. And if you're careful with critial parts selection and tuning?.. (anything that improves the compression and quench design pays big rewards).. it can be made to run on the cheap stuff. I myself always build for premium fuel because I'm just not willing to trade power for tuning margin. Best to be cautious when getting much past 10-1 SCR's if you don't have a decently close fuel and timing tune. Improving quench helps to increase preignition safety margin though.
Go to Coast High performance & click on eng. kits & look at their Probe pistons.Go w/ flat tops & a set of rings,plus they show many different compression heights w/ diff. rod combos(about $600).Then go to speedway mtrs & look for the windsor sportsman rods(about $150).Turn the crank .010 .010,& even w/ a stock crank & those light pistons you could safely go to 500hp,& use a little shot of NO2 if you wanted.On the rods they use a .912 wrist pin,make sure you get pistons to match.
looking for a kit that I can keep the stock bore on it and im not finding one on that site :/ do yall know a good piston thats Hypereutectic and the piston ring combo?
You can get KB Hyper pistons with rings in a standard bore. They also have a forged piston you can also get in a standard bore. You can usually decide on 1/16 or 5/64 ring packages. If possible, I recommend the 1/16 ring package for them. The trick to hyper pistons is ring gap. It looks huge but it's what is needed to keep the piston alive. Don't take them out of the package and slap it together, you need to file fit the rings for your application or the hyper pistons will fail. We've run them (the KB hyper) in some dirt short track motors over the last 4 years with really good success. Ring gap. Read the instruction sheet that comes with the pistons and follow it to a "T" for gaps. Don't let anyone tell you their gap theory, or what they used for their engine, follow what the manufacturer says. A lot of guys break the top ring land out of hyper pistons and pronounce them junk. They ran the wrong ring gap, period. Check Speedway Motors for flat top hyper pistons. Also Jegs and Summit used to sell them and standard bore was never a problem to find for us. http://www.speedwaymotors.com/KB-Ford-351W-Hypereutectic-Pistons-Flat-Top-5956-Rod,31901.html I see they don't list standard anymore. Call them. One thing to consider is you are back to rods then. The KB's are set up to float but actually need the pin clearances set by a shop (don't run them out of the box, usually a little tight). You can use them in a stock rod and get them pressed on or they come ready to float. Run an aftermarket rod that is also set up to float for a better package. JMO, SPark
While not as common as the .030-.040 stuff.. there are plenty of stock bore pistons available out there. Just need to go directly to the actual mfgrs site/catalog to find them, is all. And when you imagine all the brand new blocks being sold.. it makes perfect sense that there would still be a demand for stock bore slugs.
I see no problem w/ the hypers however Spark is right about the ring gap.I researched it & thought about trying a set in my build but if you get much detonation the top ring land cracks & comes apart.W/ the windsor Roush SR hds I have,I just don`t want to chance it on a 7000rpm mtr w/ cast iron hds.W/ the hypers your top ring gap will be a least .030,maybe more.Also I would be afraid to run more than a 10 to 1 comp ratio.
We ran them at 10.25:1 on gas with Windsor SR, Windsor JR were around 11.25 and ported 289 heads at 12:1. We never broke a set of them. We limited our hyper piston motors to 6500RPM. SPark
You're not really giving us enough info to offer you better/clearly defined advice. What's the intended purpose of the engine? Mainly street and part strip? Maybe the other way around? What power level AND at what RPM? Extracting decent power from that motor will be VERY easy up to about 450'ish. No head change would be required.. but they will definately need to be moderately ported to reach best power(average and peak). From there the price of power starts rising at an ever growing and increasingly disproportionate rate. I would never push a hyper piston much past 450 or so. I"ve known/seen many turbo guys who run them on stock setups(some "just to see" and/or brag about how well their handicapped motor runs).. and they ALL eventually break down to buy stronger parts for thier "next build". As for potential power with hyper's.. IIRC, the Chevy runs cast hypereutectic piston metallurgy in it's 505 horse/7,000 rpm LS7 motor. That's a.. "was state of the art" design though and that usually never hurts final durability comparisons either. I myself wouldn't push any of the cookie cutter piston designs being slung around the web(some piston designs are well more than 20 year old tech) much past about 400 horsepower. Mainly because the margin to failure just drops away far too quickly. If you're serious about making higher power that maintains much street tractability?(as in.. you won't need 4.30 rear gear with 4800 stall or dual disc clutchs).. you need to build the biggest mouse trap you can afford to squeeze into that block. Bigger bores are better.. but a 4.030" bore x 4" stroke will still give you 408 cubic inches worth of torque to play with. Huge torque spreads of over 500 ft/lbs are very easy at that engine size whereas the stock 351 cubic inches will need to be revved higher and still never hit the same peak torque number in its notably shorter power band. Another thing to keep in mind is that higher revving motors are harder on parts and considerably higher in final build cost. Maintenance becomes more critical and mechanical failures become much more dramatic too. Even with unlimited funds.. it's always a balancing act.
its gonna be mostly street but im gonna be running though on the highway and strip as well power I want to get out of it is atleast 450 if possible with the setup I want and rev to atleast 6500 rpms I wanna build a 408 so I can have massive torque as well
