302 vs 351
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From: Ottawa, Ontario
A stock rotating assembly will only tolerate a relatively small amount of boost, but either can be built to handle quite a bit more. If your target is over 500hp then the 351 block is the better option.
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can anyone tell me why i cant see any of my own post in the forums i have to view all my post to find them??
and it wont be a stock build im in the works of a new project my original plan was a turbo 460 but i snapped the frame due to rust so im going with the same turbo plans i had and putting it in a ranger with some other ideas i have
and it wont be a stock build im in the works of a new project my original plan was a turbo 460 but i snapped the frame due to rust so im going with the same turbo plans i had and putting it in a ranger with some other ideas i have
Last edited by littleme13; Jun 26, 2007 at 12:25 AM.
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so if i were to build the bottom end with no corners cut 15 to 20 psi would be feesiable its not a daily driver and my turbo setup isnt the easiest so anything is possiable my whole plans where for a 460 but that got scraped due to issuse with the truck so now its going to a small block i also would like to know what the lowest comp ratio i could run and still keep it idling running on 102 octane gas
Last edited by littleme13; Jun 26, 2007 at 05:54 PM.
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From: Calhoun GA
To give you an idea, I've been pushing 14+psi, with pump 93 octane, on my stock rotating assembly for over 3 years now. I believe the intercooling and tuning has allowed it to last as long as it has.
At those boost pressures, with a built motor, I wouldn't even think about using a 302; you'll split the block before you break any parts. I recommend using an F4TE 5.8 and go with a roller cam instead of a flat tappet. The spring pressure will need to be stout at 7k rpms, and 15-20 psi, to keep the valves from floating. I believe a roller cam would be a better option in this situation.
As far the compression ratio, 8.0-8.5 is ideal...no more than 9:1 and idling/driving wont be a problem.
At those boost pressures, with a built motor, I wouldn't even think about using a 302; you'll split the block before you break any parts. I recommend using an F4TE 5.8 and go with a roller cam instead of a flat tappet. The spring pressure will need to be stout at 7k rpms, and 15-20 psi, to keep the valves from floating. I believe a roller cam would be a better option in this situation.
As far the compression ratio, 8.0-8.5 is ideal...no more than 9:1 and idling/driving wont be a problem.
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thanks for the info i have to wait to start the build to see when im getting sent to the sand box so i might wait to see how the new boss blocks from ford racing do id like to keep the 302 due to space in a ranger with my turbo setup but if a 302 wont hold i will switch to a 351 and change my turbo position sum
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From: south louisiana
He wants the "Sleeper" look to surprise the Enemy............ 
Kinda what my 89 Ranger was before I swapped rearends for the narrowed 8.8 shod with 15 x 10's and 275/60's 
My kid's over in the sand box now........Good luck and come back safe. 
Kinda what my 89 Ranger was before I swapped rearends for the narrowed 8.8 shod with 15 x 10's and 275/60's My kid's over in the sand box now........Good luck and come back safe.
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From: Calhoun GA
I'm all for sleeper mode. 
I did add a Powerstroke bumper to the front of mine to help pass a little more air through the intercooler. It has been painted to match the truck so it looks like a factory piece.
650hp is a little beyond the strength of a production 302 block; a 351w would be better suited for your build. A 351w is going to make awesome torque with a turbo so beefing up the trans and rear end is a must.
I did add a Powerstroke bumper to the front of mine to help pass a little more air through the intercooler. It has been painted to match the truck so it looks like a factory piece. 650hp is a little beyond the strength of a production 302 block; a 351w would be better suited for your build. A 351w is going to make awesome torque with a turbo so beefing up the trans and rear end is a must.
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i know a stock tranny isnt gonna hold. i wanna run a 6 speed tremec or if i can afford it when the time comes a lenco. im not a big fan of autos. as for rearend ill prob go with a slightly narrowed 9 inch. looks like imma start lookin for a 351 block i like then thanks for the info guys
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hey guys been pretty busy latly with a new baby and all. ive been doing some research on my build up and have come up with this so far: ford racing 351 4 bolt mains, chp's 427 stroker kit, and afr's 185cc's non emissons heads. was wondering what u guys think so far? the intake and cam i hanvt decided yet because i wanna run fuel injection and turbos but im not sure if im going to run a carb first to get it running and switch later. any suggestions will glady help.