But maybe not to the same spending level as a big block. The amount spent would go up with the torque output. Ditto with the front suspension. With mine, I did nothing with the front, only about a grand with the 9" rear and traction bars. With a monster bigblock some are alluding too, you're into installing a whole new front and rear suspension to effectively apply the power. You're not going to put a 1000 hp motor into a stock suspension car and expect it to run rings around a small block.
No one was talking about money spent you can spend a gazillion dollars on a big block or 250 grand on a small block twin turbo Pontiac like ''Big Chief'' on street outlaws but when it comes down to it more cubic inches equals more torque more horsepower on the street and the strip you cram more nitrous in it super charge it twin turbo it whatever you do with it if it is bigger it will go faster if that wasn't true then you all wouldn't be building 331 or 347 inch motors you would stick with a stock bore 302 what are you doing? stroking and boring it more cubes more horsepower more torque there is no substitute for cubic inches build a 331 or a 347 it will run better than a stock 302 and that is all I have to say about that
Watch some of the videos of the Pro Stick class,the fast foxes have the whole package,they do not do wheel stands off the line.With the G-Force 5 speeds they run,They drop the clutch & the cars lay flat off the line putting all the power to the ground moving forward,no wasted motion.One of these yrs when I finish my car I would be thrilled if it handled like theirs do.
I guess we all got off the question..."Any of y'all have any tips on a 331 stroker?" him coming from a flat tappet "307"... a 331 roller would be a vast improvement...
I guess you've never been "whopped" by a small block then. Back in the 80's when I had my 67 427 Stang, I got "whopped" by a 340 Duster. When we nailed the pedals off the line he left me sitting cause the stroked 427 under my hood completely overwhelmed the plain jane open rear 9 inch out back. He took off, my car just sat there spinning one tire. I did me no good to have 500+ ft/lbs of torque under the hood with no way to apply that torque to the ground. Sure, out on the highway once you got it rolling it was fast, but not off the line. I used to hear story after story back in highschool in the 70's of small block Stangs eating big block cars for lunch in the 1/4 mile. Those stories were not fiction.
But he also implies that he is not dead set on the 331 with the threads title... "1969 302 swap but thinking abt 331 stroker My thoughts about engine building is this. An extra 24 cubic inches of cylinder displacement from a 1/4" gain in stroke length would not be what I call a "vast improvement". Much more like mild-moderate. Only brings the power on more quickly and you'll be damned lucky to see an extra 30 ft/lbs of torque at peak power(especially if you don't know how to parts match for best results). All other parts being equal from the "little 302" to the "big 331".. the bigger motor just brings the power in earlier, is all. On the other hand.. get better parts on the 331" to move the power peak up to or beyond that smaller 302 and things really start to cook with gas. Always best to build the motor for the expected power level.. AND.. power range you can afford. RPM'ing a little 302 is easy and the rest of the parts don't need to be very big or expensive(induction/exhaust) to get the job done @7,000 rpm+. 331 is still not so bad in that regard but price starts to rise(induction/exhaust) and durability starts to fall(however seemingly insignificant that loss may be). 347's start shoving the cylinder bore on the thrust side a fair bit harder with their shorter rod ratio(higher rod angularity) and the piston gets much shorter leading to increased piston rock and faster onset of blow-by(however seemingly insignificant that loss of cylinder pressure may be). Maybe of even greater concern with larger stroke jumps is that the induction requirements start to get more expensive. Much higher likelihood that little of your current combo will be as happy on the bigger motor and you'll end up with much more than just a bottom end upgrade(more $$$$ spent per horsepower gained). Plus, if you want to start rpm'ing a 347 to 7,000 rpm+?.. you better get ready to spend more cash on the lower end and start praying that the block can take it as you approach 500 horsepower and beyond. It's not just the power level that breaks the stock blocks.. it's the combination of power AND rpm that eats up parts. Then add a bad tune into the equation and parts can start to fry and fly. I said it early on in this thread and I'll say it again. What is the expected power level?.. and more specifically, where in the rev range do you want that power increase to show up? Answer those 2 simple questions and you can better decide on what motor to build.
Something to keep in mind,. There are regulars on this board who are routinely running 12 second ET's with stock stroke 302's in street trim. That is, through the mufflers on DOT rated tires. They will also turn 6,500 RPM all day long with a very modest bottom end and live to tell about it. I would focus on the heads, cam (roller), intake and gear first. Get some experience with the combination and then decide what characteristics you want out of your next engine.
Thanks much for summing up my points above. It's been said many times by pro builders. "Power comes from above the head gaskets and durability comes from below". Another old saying goes something like this.. "an engine builder must build from 3 main objectives. He must balance the ratios between power, durability, and cost.. but can only choose 2 at any particular time during the buildup". Good to get a long term plan figured out early on because waffling back and forth between those 3 things too much over an entire buildup(especially longer term "stage builds") only wastes power, time, and money. So, aside from pushing way too hard on stock parts(they're much tougher than some think) and causing catastrophic parts failure and/or potential for injury, you will almost always be much happier with a powerful engine that wears out a bottom end every once in a while.. than a bottom end that lasts nearly forever simply because it has a top-end that only makes 1/2 the power. Which brings us right back to the .. how fast ya wanna go?.. and how much ya wanna spend to do it? Main point is that it's pretty much a guaranteed result that if you spend 3 grand on the engine's upper end?(AFR, Trick Flow, or similarly equivalent heads, good induction system and properly sized exhaust).. you get far more torque and horsepower for your money. And not only would I be looking at induction/exhaust quality. I'd also be looking to swap over to a roller cam to take better advantage of heavier breathing parts. Aside from maybe an engine that's way undersized for it's current induction system(and how often do we actually see that happen?).. implementing well designed and properly "combo matched" roller cams alone are worth more power than a small stroker kit will ever free up. Wakes up the stock stuff quite a bit and really makes the good quality induction systems sing.
You're over complicating this again. I've had both a high winding 302 and my current 331. The difference is night and day. 30 ft lbs ? Not even close. One more thing to consider in a 302 with a stock bottomend (rods) is the weak rod bolts. That's going to be the Achilles heal in a 302. My 331 has the same heads (very same) as that high winding 302, the 302 had a Vic Jr intake (topped by a DP 650 Holley) the 302 "turned on" at 3500 rpms and pulled to 7500. The 331 "turns on" at 1500 and is done around 6500 . ( DP 3x2 high rise intake with 750 cfm worth of carbs) The 302 had a B303 with 1.7's, the 331 runs a Z303 also with the same 1.7's. That 302 lasted a few months before cracking a cylinder wall. The 331 is going into it's 12th year now with nothing but new head gaskets last year. Both were built around late 80's roller blocks, the 302 was bored 40, the 331 is 30 over. The powerband in that 302 was fun, but hardly appropriate for the street.
I'm not doing anything other than sharing my own knowledge and experience. And surely anyone who builds lots of engines knows that it actually IS complicated. We've literally invested trillions of dollars to get where we are today. Buying parts and bolting them on is the easy part but someone did the math just to be able to design the part so it would work within a particular application. It's matching those parts up with the other parts.. or maybe even massaging them far past what comes out of a box that becomes the far tougher part for the average enthusiast. As for the comparison above.. it tells me nothing other than you figured out the main differences between a 360° single plane manifold and a 180° dual plane manifold on similarly equipped engines with a 23 cid difference. Won't even get into the potential power increases to be had from the bigger engines higher compression ratio or what inherent deficiencies it may have fixed or shored up in the process. Changing one thing always results in necessary changes to another. Par for the course. And I mispoke above. It should've been lb/ft.. not ft/lbs. The math is very simple. Torque x rpm ÷ 5252. Let's take your examples above and have some fun with them. 308 cid.. with an estimated torque peak of.. let's be realistic and say it's a healthy little motor making around 350 lb/ft@4,700 rpm. 350 x 4700 = 1,645,000 ÷ 5252 = 313.21 horsepower. Not bad at all for a little 302 only turning 4,700 rpm. Now lets' suppose that cid's increase by 23 because you changed the crank, rods, and pistons. Same exact motor, same cam, same intake, same everything. What happens? Same power at the same rpm? Nope. Power goes up for sure but not as much as you'd think because the torque peak now comes in at a slightly lower rpm due to the increase in stroke. Very well documented side effect of longer strokes is that they have the ability to make an induction system(including cylinder heads) and the camshaft become comparatively smaller than they would be on a smaller cid parts combo. The new 331" combo now torque peaks at 4,400 rpm but comes in a bit higher.. by 30 lb/ft.. for 380 lb/ft. Any pro engine builder will tell you straight out that gaining 1.5 lb/ft per cid is downright awesome. 23 cid x 1.5 lb/ft = 34.5 lb/ft. Most guys never even get close to that number so we'll round it down to about 23 cid x 1.3 lb/ft for about 30 lb/ft of potential gain from the stroke increase. Now back to the bigger motors higher numbers. 380 x 4400 = 1,672,000 ÷ 5252 = 318.35 horsepower. Wait, so you only get a 5 horsepower gain from an extra 23 cubic inches? Cant' be right, right? Yep, you're right.. it's not. Comparing power differences between engine sizes has to be done at similar rpms to get the full and complete story. Realistically the smaller 308" motor probably only made about 340 lb/ft down at the 331" motors slightly lower 4,400 rpm torque peak. 340 x 4400 = 1,496,000 ÷ 5252 = 284.84 horsepower. So the big bad stroker gains 33.51 horsepower over the puny little 308" at 4,400 rpm.. or about 1.46 horsepower per cubic inch of increase in cylinder displacement. More torque earlier, means bigger horsepower sooner but there is certainly no guarantee that a bigger motor will out-power a smaller one. The smaller one just needs to rev a bit higher to equal the bigger one, is all. The bigger problem that I was eluding to above is that minimizing torque fall-off after the peak is critical for making big power numbers. And that falls down to the induction and camshaft choice. Unfortunately, it becomes harder and considerably more expensive to carry the peak longer as displacement keeps going up. Heads and valve-train cost on a 7,000 rpm 347" motor are always higher than those required for a 6,000 rpm 347" motor.
Oh geez................................................. it's not that complicated. You can mix and match parts all day long and the only thing you'll do is move the power back and forth in the rpm range. Which is what I was illustrating. The thing about optimizing parts ? It's B.S. for the most part. What you're doing is trying to optimize for a set specific narrow rpm range. That 302 I built was not optimal for the street. The 331 is, having a much wider powerband that starts a lot lower in the scale. This is something the OP would more likely want. Of course, he's free to find this out for himself.
Hello. There are some great ideas expressed here but I just wanted to add one thing to clear up the units for torque. The proper units for torque is ft lbs which is length measured in feet multiplied by a force in lbs much like how a torque wrench, which has a length from the socket to the grip and a force supplied at a right angle to the handle. We sometimes express ft lbs as ft/lbs or lbs/ft but actually this is incorrect. Don't bother showing me something from main stream publications because most of them get it wrong, There is no division involved. Foot is multiplied by lbs. Sorry to be an egghead but we don't want to confuse anyone out there. Now onward with the discussion! MD
I completely understand what you're saying and have talked about it many times through the years with guys of all skill levels. So, maybe it's partially a semantics kinda things then. Not trying to be argumentative.. probably more bored and car-talk deprived than anything these days. lol In the end I think we're saying the same thing. Pretty much any way you add more volume, in this case more displacement, to an engine it will always gain torque. Where yuo want that gain to take place is up to you as YOU spec the parts needed to do it(ie; bigger stroke or bigger bore or both). What parts and the size comparisons of those parts to one another is extremely important for maximum effect but most every part can be made to run with other unmatched parts. Engines can be pretty resilient but physics shortcomings will always weigh them down. And most don't use custom cams to help circumvent some percentage of those shortcomings and end up with typical cams that make some of them worse. An engine is just a constantly fluctuating, ebbing and pulsating pressure differential machine with hand grenade like explosions going on multiple times per second. Not a simple scenario to tame and bend to your will. And you're completely right, the broader power ranges have more area under the curve for a street car. The heavier the car and taller the rear gear.. the more you need. Tons of parts out there that will get the job done to satisfy most gearheads. Many are even stock parts and have been heavily massaged to closely match aftermarket parts performance. But there are also some gearheads out there that go far beyond bolton parts. 3 weeks ago at my machine shop I saw a guy bring in this homemade aluminum sheetmetal manifold and was amazed at his craftsmanship. Been wanting to do one for years(still tooling up for it) so I asked if he makes any to sell and he said yes it will cost me $800 to build my similar version. Not a terrible deal for that guys craftsmanship but too rich for me right now so back to a car fund depleted plan B, I guess. The one thing I'm absolutely positive about is that... this shitz gets expensive. Fun and rewarding.. but can get damned expensive as you get more and more carried away. Especially when you want to start going really quick AND very fast. The guys above said it early on. Stroke a 351 based block and spin it to 6,200 rpm for 500 horse 10 second ET's all summer long. No 5,000 rpm stall or real short gears required. As for the factory rod bolts being the weak link. You sure as hell ain't even close to being wrong there. Still seen tons of these short stroke stock blocked motors with typical boltons(cam/intake/carb/headers) buzzing around the streets at 7,000 rpm. The hot ticket everyone used "back in the day" was to only go to an 11/32" ARP bolt upgrade. Polish em' to a near perfect balance(- 1/2 gram), shot peen the hell out of em, machine blueprint em, add the 11/32 bolts and away you went to 400+ horse @7,000+ rpm all day long on a hot day(assuming the induction could feed it well enough). The ones running more power/rpm using the 3/8" ARP bolts broke easier because they were eating too far into the rods already thin bolt hole OD-to-housing bore ID. They didn't break the rod beam shoulder area either.. they cracked and eventually popped the caps off so you could listen to fast spinning parts churning into a great big mess for a few seconds till it seized up tight. Fun times, I bet we all seen some cool things through the years. A "nostalgia thread" about old car stories would be a cool thread to see around here. My last 302 had stock rods with the mod's above and I beat the snot out of it. Plus, that motor saw more than a few missed shifts at up to 8,000 rpm. Just a plain and simple/affordable healthy little 289 headed stocker making around 350 horse. Combo was mostly done by about 6,800 but shifted at 7,100 rpm to help the ET. Floated the hell out of the valves too and even those cheap z-28 valve springs never let the .512 lift solid cam touch a piston. I just pulled those rods out a few months back and was amazed at how nice the bearings still are. They were coated bearings and still so nice that I'm almost thinking on using them again in my AL block. PS. hey just wanted to say thanks again for those header pic's you posted a few months back. You saved my ass from being outside in the cold weather while hand installing a bare block to mock up my heads and exhaust parts right now. Think I have cylinder 1's prototype exhaust port design pretty much figured out and finished now, just need to keep welding away on the other 7 and match em all up. I used to wonder why more head porters didn't design their own ports with aluminum filler. I sure as hell don't wonder why any more because this stuff takes nearly forever to finish and welding ain't exactly cheap when you start doing it for a much longer period of time. Oh well.. will just keep on keepin on till they're done. The Kasse heads will be next in line if no porting jobs fall into my lap and I figure these RHS heads are good economical practice for me so that more expensive set goes quicker and easier my second time around. Doing these kind of more extreme mod's nowadays makes me feel like I wasted a lot of time through the years and wish I'd have bought a nice TIG machine when I was a very young man. Easy to see the past, hindsight is 20/20 and all the rest.
