likenew94stang

So what makes the 347's not "reliable" and not street friendly?

Everyone seems to be really into talking about how they aren't reliable, but I want to know why. The newer pistons get rid of oil usage by piston ring groves and ring package so that the piston pin bore does not intersect the bottom oil ring grove like the SRP 347 pistons or something similiar. What else makes them "unreliable?"

Just as much as the reliability issue, I hear people say that for a daily driver I probably shouldn't use the 347. I'd like to know why they aren't "good" for a daily driver but why a 331 is ok???

ikeybmg

ive not seen the proof. i hear they are not as reliable, but its not as big of an issue as people carry on. say a 306 driven exactly the same way as a 347 last 150000 miles before rebuild time, the 347 would last 130000. thats about the reliability ussue. you cant substitute cubes when it comes to boosting. psi means pounds per square inch. thats around 45 more cubic inches recieving boost which means alot more power. my next build will be a 347, just like the one a have now.

Tims 88GT

ikey yes and no, do to the stroke being so long the piston rocks in the bottom of the cylinder well and it causes wear on the motor, over time you get problems. also they burn a good bit of oil due to the piston coming down so far. and a good build is a 351 more power than a 347 and the reliability of a 302.

ikeybmg

yea i would agree on the 351, falling into the more cubes the better category, more the merrier with cubic inches. and yea the 347 may wear a little quicker but i dont think its as huge of a difference in reliability as some let on. id say its worth the extra cubes though if youre boosting it.

Tims 88GT

^^ i would not count on that. every 347 i have been behind smoked like a ****

ikeybmg

mine neva smokes. but id love to have the 418 stroker the guy at the performance shop near me has, it runs consistant 8's and a best of 7.50. hes hits it with like 350hp shots of nitrous though. its a 95 cobra.

likenew94stang

is that because they are harder on rings?

the NEW 347 kits only have a 5.315" rod, and the oil piston ring groves and ring package so that the piston pin bore does not intersect the bottom oil ring.

won't that stop the smokin and leakin problems?

Tims 88GT

yes it helps. but in all honesty get a 351 if you want power.

ikeybmg

yea they build them alot better now, some people dont realize it though. they realized some problems and did good in correcting them.

likenew94stang

is is true they wear out rings faster because of the angle?