351W long arm kit?
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66P51GT
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The long arm kit doesn't give you any extra displacement. It will keep the pistons at or near TDC and BDC longer which allows for better air flow (in theory). If you are going to buy pistons and rods already, fork over a bit more for a crank and get the added displacement.
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imshaggy2000
Founding Member
fastcoupe68 said:
In the long run you will be broker with a stroker. More gas, but that never stoped me from anything crazy.
the long arm kit doesn't really offer more airflow as much as it promotes better combustion since the piston stays "parked" at TDC longer allowing the flame front to burn longer before being extinguished by the incoming charge. better combustion means better mileage and more power and overall better effeciency using the same cubic inch displacement, another advantage of using the long arm kit is decreased engine wear, since the rod ratio is much better you get less side load on the pistons, less friction and increased bearing life as well. when i build my next motor it will be a "long arm" motor based on a 94-97 351w roller block, with a high swirl head like a gt-40p head or something similar and lot's of internal coatings, i have a few other tricks up my sleeve as well. should be good for about 375-400hp and idle like a stocker and get excellent mileage as well
well since you pretty much have the bottom end worked out, the next logical step would be heads. you have lots of options, since money isn't a big issue i would look at some AFR 185's as a starting point or a set of TFS twisted wedge heads. for cam i would definitely recommend a hyd roller, but i would consult with the cam company for specs that best suit your overall combo. use a good intake like a weiand stealth, i'd stay with a dual plane if it is primarily a street car, if it is just an occassional street car go with an edelbrock victor jr or super victor and a hotter cam. for carb i recommend demon for whatever you go with. if you have an auto trans go with a vac secondary in the 650 range, 750 mech secondary with standard trans. a good set of headers is a must, again i would choose these based on whether or not is primarily street driven or not, primarily= 1-5/8" primary tube long tube or shorty track or weekend warrior=1-3/4" long tubes. ignition is strictly personal choice but you can't go wrong with MSD. it's really not that hard to get a 400hp combo out of a 351w if you have good heads, intake and exhaust, it's all pretty much in the cam from there.
brianj5600
Active Member
I would not waste money on a long arm kit. Theory is good, but how much hp do you think you will get? There is alot of people that hate the 3 inch journal, and say turn it down and run spacers. lighter crank less friction. There is no end to good theories. Since you are not heads up racing I would not sweat it.
brianj5600
Active Member
brianj5600
Active Member
About all aftermarket block have cleveland mains, 2.75 inch. They sell spacers, but most people say they are not a good idea. I was just trying to say that there are alot of expensive things you can do that only add up to a small gain. Unless you are a serious heads up racer, they are not practical. Rod ratio on a 351 is pretty good to begin with. The almighty chevy has a shorter rod in there small block.
I beleive all aftermarket blocks except the 351w sportsman block have cleveland type mains. Until the other day anyway World products just had a news release and are in fact making new windsor blocks with the 3.00 mains. Unless you are spinning the holy hell out of a stock main bearing setup. Bearing speed is not an issue. I have seen this setup go 7500rpms for 3 years in a racing drag application. Every season we would tear it down and replace the bearings even though they were pretty clean. Just to be on the safe side, and the motor is still running fine today. Lucky, maybe but the quality of your bearings finishing on your crankshaft and a good oiling system play a huge role in reliability
