This may be a dumb question but is there an affordable combination to build a high-RPM (7k+) 302 Ford? I have a pretty well built C4 and an 8-inch rearend. My 302 in my Shoebox Ford decided it was hungry and ate the cam. May as well build what I want, right?
I’ve built a 302 that will sing up about 8k but it was timid on torque. But basically forget any stock parts. 5/16 rod bolts although impressive, can’t hang at 8k. High compression is a must. I had a K1 crank? If I remember right. With knife edged throws. I forget the cam, solid roller though. And I think I had a 195 tfs head, single plane intake 950 carb. FTI converter. All that said this was a race engine and an 8” couldn’t deal with it very long, turned the internals into driveway gravel. But in all honesty, if your trying to have a hot street motor, forget RPM and build something with some torque and peak hp at 6kish. My 351w (408ci) made 615hp at 6800 runs 9.7x at 125. Pulls wheelstands and can deal with running around on the street to an extent, with 5400 stall converter c4 and a 9”. And I have not done any substantial engine work in 7 years. My opinion, RPM kills engines and best left to all out race deals. But to each their own.
Sorry I read 8k but your post says 7k but really it’s about the same deal, just don’t need such a stupid camshaft still need a solid roller though. In my opinion though best bang for buck is cubic inches and torque. But, there again the 8” as impressive as it is, won’t hold up if you get serious about using all that horsepower.
No replacement for displacement.... but the 8" won't live through it. A high RPM screamer will make power but won't produce the drivetrain-killing torque, but the downside is you'll need low gearing and a high-stall convertor to make it work. It will be considerably less pleasant to drive.
The Boss 302's in the Mustang and Cougar were screamers. However, they did suffer from a lack of low end torque. When I worked for the Lincoln/Mercury dealer we had a Eliminator 1 Cougar in stock. It had the Boss 302 engine with a 4 speed. It would really scoot, but you had to keep it wound up. Around town it was a bit doggy unles you geared down and wound it up. Great for racing, but not so great as a street machine.
I guess the first hurdle is what's your definition of affordable? And perhaps the second, what would be your expectation for durability? New parts are expensive. But with some carefully selected parts your goal can be met.
Well… I’d agree but it depends, on how you treat it, if you got a motor that’ll actually make power at 7k a 3:55 gear and are leaving at a high stall speed and got a decent tire, it’ll still turn a 8” into gravel. But if you got a tiny tire and don’t leave hard then any combo won’t break the 8” but then, what’s the point of spending all that money on a motor. Truth be told do whatever you want but know without a doubt that 8” is your weak link, and with the power your talking about a stick 9” is also a weak link as the opinion bearing support will crack but it won’t be quite as drastic as the 8” when it lets go. I did run an 8” pretty hard for a while, but that was with a stock bottom end 302 with an aluminum head and a 3800 converter and turned the 8” into mush.
Also know this… there is a difference between the engine just turning 7k plus and making power at 7k plus. Lots of guys think they have a 7k motor but it’s not a 7k motor if it’s not actually making hp at 7k. IMO. I’m sorry to litter the post, but this is the stuff I love. Also affordable, is in the eye of the beholder. Fast cheap reliable…. Pick 2 lol
Agree with ALL the above, build a good little motor that will pull 6500 max AND build some torque while doing it. Save a lot of wear and tear on internals and the cylinders of the block. Turning high rpms is cool and the sound they make is unforgettable, had a buddy with an old early 60's vette that came off the line at 10,000 rpm, rear bumper on the ground, nose almost straight up, shifted at 9,500 rpm. But it took a 1-ton Chevy full floating rear axle to handle it back in the day. Somewhere there's pics of it with even the back tires off the ground it launched so hard. Point is, everyone around here knew the car BUT it was a race car. Wouldn't have lived long on the street. Building a really "good" street motor isn't that hard anymore with all the kits out there today, ones that build usable street torque and hp. Best sounding small block to me was the ford Shelby GT mustangs with solid lifter 289's, man those things were sweet ! Lucky enough I got to drive 2 separate one's on numerous occasions. Ahhh.. the good Ole days and memories... ! ...
Trying not to be a smartass here, but have you ever lived with a heavy car that is also equipped with a high RPM engine? It’s been my experience that the novelty of the experience fades quickly in the reality of the frustrating day to day life. There is much to be said for the satisfaction of simply adding a bit of throttle to a low end grunt monster to pass someone vs. downshifting 3 gears to accomplish the same move.
"Affordable" and "high rpm" in the same sentence usually doesn't match. Years ago, when I was into high-speed cigarette style boats Reggie Fountain told me "Speed costs-how fast do you want to go?" While turning a SBF 7K consistently can be done, it is not cheap.
I had a 302 built with stock and budget parts that would spin to 10500 and did drag strip monthly and daily driver (expressway 15miles)and towed the ski boat. Motor survived 4 years until it blew one day when a cylinder broke into the water jacket at around 5000rpm. The piston got ripped off the rod and parts went in all directions. The secret to that motor was everything was balanced and the cam was custom made by Stan Sainty. Rocker ratio was changed stock heads with lots of work. L34 valves roller rockers holley intake with 1100cfm holley and electric fuel pump. Stock cast iron exhaust manifolds with dual 2” exhaust. Built c4 and a stock 8” with 2.75 gears. It was a bit slow off the line. It could not spin the tires (burnout) but it would haul the fairlane down the 1/4 mile in the low 12’s on pump gas (super). It was a pig to drive in traffic and it sucked gas at an average of 6mpg. Not saying it was pushed to 10500 all the time but it did it when asked when needed.
How are you really going to use the vehicle? If you want more power, step up to a 351 Windsor. Want more power with a higher rpm range? Build a Cleveland or a Clevor and get those bigger valves and better breathing heads but you'll gain that power at the sacrifice of lower rpm torque so while you're changing out the rear to a 9-inch, you're also swapping to 4:11 or some higher ratio. Even Goldilocks had to make choices.
Your build, your decision, but when someone asks us to quote on a project such as yours, we send them down the road, "We wouldn't be able to even talk about it this year." (and wouldn't be able to talk about it next year either.) Bottom line - high RPM is just the most expensive and least durable horsepower there is. It has no place on the street and we don't need the grief. jack vines
Right. Keep in mind that the '67-'69 Chevrolet 302 was made for one reason and one reason only; so Chevy could compete in Trans Am racing that had a 5 liter displacement limit.
this is what I mean by turning 10k vs making power at 10k. Not to be a sour puss but I’d guarantee it didn’t make power at 10k
I’ve built high rpm engines in my past but my personal preference now is around 6500 rpm. Trying to build a high winding small block Ford that lasts more than a Friday night is going to cost twice as much as a 500 hp 347 and it might not make the same power.
Under 2800 it struggled and power dropped off a lot after 8000. It would get to a point where the motor went silent just past 7400 and all the noise was air passing the car and the tires on the road. I did a 15 mile expressway run against a guy with a 327 to see who had the top speed. He won but the creepiest part was the long run of silent. Now I am getting into tires coming off rims from centrifugal force which happened to another guy who tried his luck at the 15 mile run. Both his front tires came off the rims and wrapped around his front suspension at around 140. The deep v of the grass median saved him but not his car.
I have built 2 high rev motors both Windsors one was a 427 Yates block and the other was a 347. Both lived on the street and wasn’t that bad to drive every day except for the 427 that was alcohol fed. If you want to do it be prepared to spend money, a must have is a Mexican block with a solid roller and girdles for the block because it will split in half.
The short stroke 289 crank is going to be more amenable to high rpm than the longer stroke 302. Bothe the hipo 289 and Boss 302 used 3/8” rod bolts rather than the 5/19” bolts of their pedestrian brothers, but I imagine finding a set is rather unlikely fifty years after production ended. The Boss had the advantage of a forged crank and four bolts on the center caps. It uses the 289 hipo rod but with spot facing instead of broaching. Both are the same length, unlike a standard 302 vs 289 rod . I’m running a Boss crank with standard 5/16” rod bolts and a 1972 ish two bolt crank up to 6500 and haven’t broken anything, but yrmv.
I have late model roller 302 , x cam and springs port matched dual plane intake , 1 .7 roller rockers , GT 40 heads , exhaust port bump gone , roller fuel pump eccentric , arp rod bolts , Keith black pistons , annular discharge Holley . No problem to do 7k it would probably do more , but I’ll never do it . Only wound it tight a few times . Got to thinkin it’s gets out of hand , and bustin up 32 tin , not tops on my priority list as fun
Was just viewing a SS/K 1965 Mustang on the RevanEvan video. 289 a-code that spins to 9000 rpm through the traps with a Jerico dr-4 and 6.29 gear. Impressive with the little 1.78 valve and 480 cfm Autolite carb they have to run. Not an engine for a budget by any means.
My HS Buddy built a W motor , used 318 Mopar rods and special pistons , I really don’t think a chain saw would rev any higher or faster . It lived many miles and years of hard abuse , believe this or not we worked at a Ford dealership in parts dept . . He went out of town to inventory a dealership in NC , and found 427 SOHC sitting in the shipping crate , at the dealer . He bought it for cost , returned it home , out went the W in went the cammer . He started down the wrong road with divorce and drinkin , he went to the county farm for a few months on his return he was an addict and sold everything to support his habit , until checkout time . The car was sitting at his Moms house for years , the undertaker took it for payment to bury him . Sad ending
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