mjr46

the ole 331 vs 347 myth........tell that to my friend who uses his stang in his courier service and has a 100k on his 347, hey that's cool if you want 16 less cubes to not make hp....lol just get use to my licence plate staring you in the face , that is my rear one of course..lol

jeremy93lx

Most 347 kits require the piston to be so short that the piston pin intersects the oil rings. While a nickel-sized gap behind the ring on each side of the piston may not seem like a huge issue, in fact such a gap will increase the oil consumption of the motor to some level. We spoke to four reputable machine shops to get their opinions on using the 347 in a street application, and their responses were equally divided. It seems as if half of the Ford crowd is convinced the 347 is not an ideal street motor due to rapid wear on the rings (from the relatively low rod ratio) and increased oil burning.. The other half feels the piston pin issue is a non-issue, and refers to the number of satisfied 347 owners using them in daily drivers.

Several companies are offering kits with custom pistons which raise the oil ring grooves above the pin hole. The Coast High Performance 347 kits accomplish this with a 0.085" shorter rod (5.315")). Naturally these 347 kits are more expensive, and critics say area above the piston crown becomes so thin that the piston is prone to breaking at the ring lands upon the slightest detonation. We've actually seen this very thing in a supercharged 347.

jeremy93lx

as usual there is always a tiny dude sitting behind his computer calling names. right on man! you got my respect. tell me what you have in your sweet ride so i can be just like you!

primetime5.0

nice cut and paste.. if you wanna make less power by all means build a 331

primetime5.0

oh and let the battle begin

mjr46

an oil burning 347 that knocks on acceleration........looks like you need to be educated a little on the ole rod rational, lets use your example of wanting a 331.........vs my 347....you do realize that a 347 can be built a few ways right?? infact a 347 with a 5.315 rod uses the same piston as a 331 so how is it then that your theroy /philosophy applies??? exactly it doesn't if you look at the rod ratios of the 331 and the 347 there are far worse rod ratios in 100k gm factory produced engines such as the 400 sbc and BB 454
TO QUOTE AN EXPERT ON THE MATTER Jay Allen:

A 5.315 347 uses the same piston as a 331.



Quote from: mikemustang289 on April 30, 2007, 09:11:33 pm
So, why then would Rod/stroke ratio play so much of a role in engine life on a 347 compared to a 331?
My guess is this is not an issue.


Exactly.

Better yet:

An old 400 SBC. 5.565 rod and a 3.75 stroke FROM THE FACTORY with CAST pistons.

R:S = 1.496

100K miles on SBC p/u, wagons, and vans with 400 sbc with CAST pistons. And guys today with WAY better pistons and 1.59 R:S cannot make it work?

It simply comes back to the skill level and not many people are willing to admit that they know less than they think they know. And speaking of R:S why does it almost always apply to the 331 v 347 debate? A 408 has a R:S of 1.5625 and a 418 is 1.5122....end quote, so you see what was once believed is not so much the case anymore....oh and FYI THE slightest bit of detonation on any motor irregardless of a it being a supercharged 347 is DISASTEROUS to any motor and even more so on a boosted motor, detonation doesn't pick it's target based on a certain build, tell me you are smart enough to see through that false statement you cut and pasted??

mjr46

here 5 pages of truth
http://sbftech.com/index.php/topic,6087.0.html

XPBaller

i literally lol'd.

jthorn9

One thought, are you thinking about supercharging this car at all???

Fox23

Lmao!!

Yeah i would take these guys advice and stop being such a peanut butter and dickcheese sandfag cause they clearly know what thier talking about.. And why post on here if you already know what you want and wont take anyones word.