347 stroker
 

Hey guys, im new here and i am looking for some help/opinions. I was giving a 302 block thats been all machined bored .030 over and was thinking about doing a 347. What do u guys think and what should i do for parts. I was thinking about getting a kit off of ebay with forged eagle crank and pistons, AFR 185 heads, trick flow or comp cam, gt-40 intake. How do i know if this stuff will all work together or is there anyone who can lead me in the right direction. Thanks

well the block would have to be clearneced for that stroker crank its not going ot just drop in and spin freely. Summit sells nice stroker kits for good prices. head wise any head will work its the cam you have to worry about so you dont get piston to valve problems.

How can i tell if it has already been clearenced or not? prob a dumb question, but will i just see machining marks where the crank sits?

unless the other person was going ot add a stroker it hasnt been clearenced.

ill have to look, im not sure what they were going to do, but they had it all machined.

Ok first you can set the crank in and CAREFULLY spin it with no caps on to see if will clear, if not start grinding but I recommend letting the shop do that and everything else but...... If you wanna do it be careful doin everything!!!! And as far as buying summit kits for good prices, screw that you get what you pay for. Oh yea not any head will work, and its not just the cam you need to worry bout its mainly valve lift and valve to piston clearance. When building an engine your parts must match and be correctly stepped down for max volocity, as far as flow rate (cfm's). example: mass air meter, to throttle body, to intake, to heads need to match and upper to lower intakes need to be only about .003" different with the upper being the smaller port same, and for lower intake to heads. Then you need to pick a compression ratio and and build on that. For heads it really depends but twisted wedge is probly the way to go, for the valves are angled away from the walls for better and more direct air flow. Do not get an intake to big you may choke the engine, bigger is NOT better! get an intake, cam, and heads with the same power band in your rpm preferance. If you port the heads (shouldn't but if so) do not polish, you want it rough for flow, turbulance, and air push. These are a few things to know, do research before you buy anything. As myself, a nascar nextel cup team employee I know these things, good luck!!!!!!!!!!

i knew it was going to be complicated. Thanks alot. any references you have that i can go to get any more info on what to get and what will work with what let me know. thanks.

well I do all my own work here in the shop but if you go to another shop for help use these factors, make sure its clean organized have a good rep around town, see if they have up to date machines ask if they flow bench, if you have any dout LEAVE!! not knowing where you are there is a few really good shops here in Mooresville N.C. I do know that D.S.S. and anderson ford motorsport are really good in building with up to date equiptment. as I said I do all my building, porting, tuning, and testing so I dont really know where to go for any help, I would read mags and see where other people (with good set ups and fast cars) go for help... sorry I cant help in this area, but anything else you need ill try to help!

thanks again. ill be doing the actual assembly myself. the block has been machined, bored .030 over. prob still needs to be clearanced. I guess now i just got to figure out what parts will work perfect together....

Thanks for handling that mess.
cobra 331 your motor sounds like a very powerfull 331, any numbers or graphs on that?

if I were you'd I'd just build yer (now) 306...

You have a good bottem end... just get the cam, heads, and intake... slap some Longtubes on there...

maybe a S/C would be a better Idea...

302s put out great troque stock... IMO, its not worth it to stroke one...

get some pics of that car... what else have you done to it?

I have numbers from the dyno at our shop and two tracks that wont be said, sorry this car rarely gets ran but we do have an 86 GT with a well built 351 that wasnt dyno'd but ran a 6.13 in a 8th (spinning) at the northern track which us up a very slight hill, and it will be ran here in Mooresville N.C.

Was that for me?

probly! stroking, with the correct set up can add up to 50-60 hp (you wont feel much power gain on the street but your time will tell). worth it or not is personal preferance, to me its well worth it. if the rule book allowed our cup cars would be stroked but we are limited on displacement. the 306 is good but i like the 331 over the 347 makes jus as much, sometimes more power with a shorter stroke to last longer in a street car

yah...

So if i plan on using the car on the street alot i should go with 331 over a 347??

I would build a 331 if its on the road alot. the longer (347) puts the rod at a more angle than the 331, (some people say its not true or it doesnt matter, it does though, i build measure and tune engines to perfection down to the ten thousands of an inch) this now pushes the piston into the walls more, causing more skirt wear, friction, and unnoticable heat that wears the walls. the extra heat in the skirt area distorts the piston and cyl. shape causing even more wear. And with the 347 your block is now weaker, which doesnt really matter unless you plan on having more than 600 hp (but that takes alot)

Ok, cause i plan on driving the car a lot so i def want it to be somewhat dependable. Ive been reading on other forums and you get mixed opinions, lot of people say if your going to do a 331 you mine as well do a 347 cuase "theres no replacement for displacement". But ive heard that 347 sometimes consumes more oil, and tend not to last as long.

insteed of reading forums and listening to alot of people who get info from mags and jus doin they're own work in the back yard (or idiots) call a good shop tell them you want a 331 or a 347 and its a daily driver, and tell them what you wanna do with it, they will tell you 331, D.S.S., Anderson Ford Motorsport, CHP, Downs Ford Motorsport, or any other

Its the net man you get all kinda of highschool kids who dont know shit and guys who just think they do.

i hear ya, thats the problem. thanks alot guys. Cobra, those 3 peoples names u gave are all shops i can call for info???

yup