I want the car to look basically stock to the untrained eye ( I like that look, I dont like polished crap and aftermarket names everywhere ). With using a set of GT40 iron F3ze heads, a 5.0 block, and an explorer intake as 'givens', what kind of power can i get from stock stroke and be smooth enough for a daily driver? how much more can be had from a 331? is it worth it given the stock heads and intake?
Its an 86 GT convertible with tremec 5 speed, mac equal lengths, bTFS stage 1 cam, and 3.90 gears.
Its an 86 GT convertible with tremec 5 speed, mac equal lengths, bTFS stage 1 cam, and 3.90 gears.
don't bother with a 331 if you are trying to do that . . . build a 347.
I have often thought how far you could go with that stuff, but I believe with a 347 that 330-340rwhp and ~370rwtq is possible with gt40s/explorer.
With a 302, 300rwhp/320rwtq is possible
You could also run some aftermarket iron heads and play it off. Windsor Jrs come to mind with a 302 and you could even run the roush 200s especially if it was a 347
I have often thought how far you could go with that stuff, but I believe with a 347 that 330-340rwhp and ~370rwtq is possible with gt40s/explorer.
With a 302, 300rwhp/320rwtq is possible
You could also run some aftermarket iron heads and play it off. Windsor Jrs come to mind with a 302 and you could even run the roush 200s especially if it was a 347
what kind of power levels are attainable with gt40's, explorer intake if you keep the stock crank and rods and start considering choices in swapping around pistons compression ratios, cam sizes, and valve sizes? I dont feel comfortable with the short compression distance of the 347 pistons, but is the 331 worth the extra effort to build?
Do what i did....build a 347, put on iron heads, paint the block/heads all the same color...don't spice it up with flasy parts. In the end nobody will know unless you tell them.
Check out these before and after pics:
Before:
After:
Even the well trained eye of a Mustang fanatic wouldn't know the difference. If i didn't paint it, it would've been even more low key (hell give it 20k miles and you won't know the difference). It just dynoed 362hp/364tq at the wheels....i don't see that happening without stroking the engine, or at least without building a stout short block that can run high RPM and running a healthy cam...but the problem then is that your heads and intake won't keep up with the cam.
Check out these before and after pics:
Before:
After:
Even the well trained eye of a Mustang fanatic wouldn't know the difference. If i didn't paint it, it would've been even more low key (hell give it 20k miles and you won't know the difference). It just dynoed 362hp/364tq at the wheels....i don't see that happening without stroking the engine, or at least without building a stout short block that can run high RPM and running a healthy cam...but the problem then is that your heads and intake won't keep up with the cam.
your combo isnt too far off mine currently. mine is an 86 but it is currently carbed with a weiand stealth intake, 600 vacuum secondary holley, a duraspark distributor running a GM 4 pin module....all this on a basically stock 96 explorer engine. i bought the engine and put new rings bearings and gaskets in it, had a valve job done, pocket blended them and had them cut .030 and new comp springs put on, then slapped on the intake and carb and a TFS stage 1 cam. it runs decent but i want more than its current simply 'peppy' state.
i consider 6000rpm overrevving and want my powerband from 1500-5000. the car has 3.90 gears to make the powerband more usable on the street. im thinking stroking it will get me the torque i want, as I am more after torque than horsepower. Ive never built a stroker and have always been predominatly a mopar man. considering the 340 cars I am used to which had a 4.04 x 3.31 bore to stroke setup, a 331 ford having 4.03 x 3.25 would not be far off and still have the advantages of better heads and roller cams.
but.....im not sure if i could get what i want with just simply more compression, bigger valves, and porting on a standard stroke 302
i see far too many people selling used and broken 347 pistons on ebay to want to consider a piston with such a tight compression distance and close rings. its gonna be 302 or 331
i consider 6000rpm overrevving and want my powerband from 1500-5000. the car has 3.90 gears to make the powerband more usable on the street. im thinking stroking it will get me the torque i want, as I am more after torque than horsepower. Ive never built a stroker and have always been predominatly a mopar man. considering the 340 cars I am used to which had a 4.04 x 3.31 bore to stroke setup, a 331 ford having 4.03 x 3.25 would not be far off and still have the advantages of better heads and roller cams.
but.....im not sure if i could get what i want with just simply more compression, bigger valves, and porting on a standard stroke 302
i see far too many people selling used and broken 347 pistons on ebay to want to consider a piston with such a tight compression distance and close rings. its gonna be 302 or 331
Sorry to break it to you but that 347 garbage is a myth.
Who is breaking pistons?
Who made those pistons?
99.9% of the people on the "internet" breaking these 347s either shouldn't be building motors or shouldn't be tuning motors.
I have seen numerous 347s run low 6s in the 1/8 in fact I even ported a set of Windsor Sr alums for one that went 6.30s @ 106-107 on 200. Stock block, eagle sir I beams, probe SRS pistons, victor jr intake, lunati 51012 cam with 1.7s.
And thats with the "junk" 5.4 rod and the "tiny" compression height piston.
Who is breaking pistons?
Who made those pistons?
99.9% of the people on the "internet" breaking these 347s either shouldn't be building motors or shouldn't be tuning motors.
I have seen numerous 347s run low 6s in the 1/8 in fact I even ported a set of Windsor Sr alums for one that went 6.30s @ 106-107 on 200. Stock block, eagle sir I beams, probe SRS pistons, victor jr intake, lunati 51012 cam with 1.7s.
And thats with the "junk" 5.4 rod and the "tiny" compression height piston.
at any given time there are some probe pistons on ebay with the ring lands broken off a piston or two. given, i dont know what they did to the engine to break it, but i still dont like the idea of those piston specs on a STREET engine. for a drag car, who cares, but not a street car wanting longevity.
Yeah and a lot of people still think 347s burn oil like they used to be known to do, but changes in piston design have cleared that up for the most part. I personally wouldn't think 6k is over revving since the stock rev limiter is 6250. If the engine is in good running order then it won't hurt it. If you plan on making 350 at the wheels at 5k then you have to get a stroker...period. There's no way you'll make that kind of grunt with just a 302 at only 5k. My buddy's 347 is pretty well built...there's nothing low buck about it. You could argue that there are better heads out there but he's still making 385/399 at the wheels. He is making around 360-370hp at 5k, but his engine is 11.3:1 compression with a custom cam that's around .630 lift on the intake and .585 on the exhaust with around 320 duration...the thing is only streetable because it's been tuned within an inch of its life. Considering all that, i'm just skeptical that a 302 can make the same power at such a low RPM. I think the power can be made with only 302 cubes but it has to be at a higher RPM with great flowing heads and intake and a rowdy cam.
If you get your heads ported/polished, bigger valves and springs and rockers, it can happen.
I hit 360 with my old setup with performer RPM heads, X303 cam, 1.72 RR, Victor Jr intake, Holley 650cfm, my secret was the compression though, 10.5 - 1. Thats what is gonna hurt you in the end.
I hit 360 with my old setup with performer RPM heads, X303 cam, 1.72 RR, Victor Jr intake, Holley 650cfm, my secret was the compression though, 10.5 - 1. Thats what is gonna hurt you in the end.
But did you make that power at 5k? That's the detail i'm hinting at...it can be done but he wants to do it by 5k. I'm skeptical but i've seen crazier stuff. I'd love to see the combo that makes it...that'd be one fun street engine.
I thought probe pistons were at the top of the list as far as durability, I've never heard anything bad about them.
Oh no, I didnt make it there. Yeah making it a 5k will be tough. You need to take a trip to the machine shop and talk to someone about that.
Your cam will likely be the key to any top end power. Those long runners will make a torque king, but it will be out of breath by 5,500 rpm if not sooner. If you use the heads off a Lightning (not Cobra as those are milled), you'll be able to run around 9:1 compression. I'd like to do the same thing with my combo as it looks very stock.
based on the parts as listed - you won't get 350 to the wheels. Might get it at the crank though if you're good.
those goals are extremly unrealisitic with the parts you want to use. Get a good intake and some nice aluminum heads, save the hassle
I wouldn't count on that with EFI unless you stroke it with a good lightweight kit blueprinted and put a bunch of compression in it's direction, lots of porting on the heads, extrude hone the intake, all the bolt ons you can grab and then get a nice custom cam developed for your setup and a dead on tune....you can do it then, but at that point you have an 8000 dollar engine with stock heads and intake and it's not going to make 350rwhp at 5k rpms still