347 vs 331

[eillob]

I 've been looking into dropping in a new engine. I like the specs I have found on the 347. However I keep finding myself talking to people who warn me about the problem with the rod pin being so high into the piston and the possibility of having early compression problems later on down the road.
Should I go ahead and go with the 331 and forget the 347? Or are these stories over exaggerated? My stang is not an everyday vehicle but I still want to be able to get on it without worry.

[boosted331]

What are your plans for the motor, boost, nitrous, or N/A?

[GTStang]

The main knock I have heard agianst 347 is they get oil blowby on the rings cause of the the location of the rod pin. I never had a problem wit this on my 347 that I put 30,000 miles on. And we sell a lot of 347 at my shop that we build there and I haven't had anybody complain about it. And yes there are guys who have 100,000 miles on some of them.

If your going to FI, Nitrous it I get a 331, If you stay N/A I would def get a 347.

[HiFlow5 0]

If your going with a 347, I would suggest a CHP motor. The "Street Fighter" block uses forged pistons that eliminate the intersection of the oil ring and the wrist pin hole. This will help cure the oil blow by problems that some other 347's have.

[boosted331]

Originally Posted by HiFlow5 0

If your going with a 347, I would suggest a CHP motor. The "Street Fighter" block uses forged pistons that eliminate the intersection of the oil ring and the wrist pin hole. This will help cure the oil blow by problems that some other 347's have.

The main reason the CHP 347's don't use oil like a typical 347 does is they use a shorter rod (think its 5.3" vs. 5.4" for a typical 347) which pulls the piston pin out of the oil ring. I've had a few friends with CHP 347 kits and they're doing fine with them, but I've had typical 3.4" stroke 5.4" rod 347's before that have used quite a bit of oil.

[eillob]

Originally Posted by boosted331

What are your plans for the motor, boost, nitrous, or N/A?

Eventually I would like to add on a 6 or 8psi supercharger. But that will be down the road right now I want naturally aspirated motor that will put me in high twelves at least. (94 mustang conv 5 spd)