Fordfoxbody88

hello i want to build a stroker for my mustang. i drive it daily so i would like to know about the myths behind the durability behind the motor. i also heard you have to grind some things out for the clearances for the crank and was wondering if it was true. i also want to know about the myth about it burning oil and how the rings hold up. also i want to know how they affect stock blocks with maybe better main caps and studs. last i need to know if its worth buyin a forged crank and h beam rods and all that good stuff or if it is uneccessary and a cast crank and i beam rods are good enough. i would like to s/c it or something to create just a lil boost to have fun with. last id lik to know the power difference between a 331 and 347, i was always leaning toward a 347 but im still undesided. if you know of any other things please bring them up i need all the knowledge i can get. also id just like to make between 450 to 550 hp

dawson1112

I don't know about all the machining or clearances but , if your looking to s/c it and make 450/550 hp go with forged internals.

reldla1996

Stroker engines are not going to have the same durability of a factory 302, but properly built and tuned, they will last a long time. Usually 347's require notching, and 331's do not, but it depends on the actual parts used. A properly built stroker engine should not burn oil. Studs, main girdles, forged cranks, better rods, and an aftermarket block all depend on power level, intended rpm range, and how often you plan to run it hard. You'll get opinions all over the map. My opinion, at 450, you can think about leaving it all factory (but studs and girdle would be smart insurance), at 550, you probably need some better parts. The difference between a 347 and 331 is roughly 20hp. You should talk to a company that specializes in Ford stroker motors, and listen to their advice.

tinman

A stock block with a 3.400 stroke crank will require a small amount of grinding on the bottoms of the cylinder bores for clearance. There is a tool made that will show you just where to grind.
Stock blocks are not the strongest things in the world and I think that you should think about a Ford BOSS block or an aftermarket Dart block if you really want to play with S/C at all.
If you stay N/A and you have a stock block, don't bother with a forged crank as the block will fail before the crank ever will.
I'm making about 520-530 crank HP on cast crank 347 type engine now. I use studs all the way thru it.
My car goes 128 in the 1/4 mile and wieghts about 2900#. This is at 3500 air density so if you are at sea level like most people are it would be even faster.....

mjr46

Built right sbf strokers are just as durable as a factory 302, got a few customers with 100k on 347 and don't burn oil, one uses his in a courier service. Cast crank, I beam rods and forged pistons in a factory block, no need for a forged crank and h-beams in such, the cast will outlast the strength of the block, if you plan to s/c it, go aftermarket block then you can think of all forged internals. Power level n/a will depend on your choice of parts and how well you match such.......there is tons of info on this topic, use the search function or google.

Fordfoxbody88

i thought a 347 and 331 both had a 3.400 stroke and the only difference was that the 347 had to be bored 30 over. i just want to create a lil boost and have stroked motor i guess theres no way that i can get away with that with a stock block.does a 331 require machining or does it just use the standard bore. why does the 347 need the grind on the cylinder sleeves and the 331 doesnt if they have the same stroke. last do you think i can do a 331 with a blower? doesnt have to create crazy boost just enought to play with. could i boost a 331 with stock block cast crank forged i beam rods and aluminum heads n studs and a girdle. im just trying to figures out stuff so im breaking stuff

reldla1996

A 331 has a 3.25" stroke, versus 3.4" for the 347. Typically both are bored .030. Again, talk to a reputable company that assemble Ford stroker motors for a living, there are several to choose from.

Fordfoxbody88

okay because i was on summit and i was looking at there specifics for a 331 with the eagle and scat the stroke was the same as a 347 but it just used the standard bore. im guessing summits listing is wrong? and do you think a supercharger with a stock block and cast crank and all the rods forged could hold up as long as it isnt a huge blower?

Duncan_GT

Get in touch w Coast High, they'll set you up with the parts you need

mjr46

don't waste your money doing such