Hi! I've been posting in the cl***ifieds for a while but this is my first post in the general forum. So hi! I am building a chopped and dropped '54 Chevy Bel Air, and am looking for some input on my engine build. It's a early, small journal 327 sbc with code and date matching 461 camel hump heads that I am buying from a fellow HAMBer, and I now have a Offy six deuce with six Holley 94's also bought from a HAMBer. I want to use a 283 crank and rods in the 327 block and a set of Speed Pro 302 forged pistons that should give me close to an 11.8:1 compression ratio with the 62cc combustion chambers. I have been recommended to use a Isky 505 cam. This is turning into quite a scary motor and I am trying to soak up as much experience and information on it as I can. I have been told that racers used to bore out thier 283's .125 over to a 4" bore and do the same thing. Oh, and I will be using a T10 or early Muncie 4 speed, and am on the lookout for a '57 - '64 Old or Pontiac rear axle (I have been told to look for one with three ribs on the casing). So far there is nothing on this car later than about '65 and I want to keep it that way (engine internals aside). Any opinions, information or experiences with the motor or driveline combo would be very much appreciated! Rich
Having built a few of these engines over the last 40 years I've only got one question. Do you have gas available to you to run that compression ratio? If so your lucky cause it's a rare comodity here in the states. Oh yea, one more question. Why would you want to loose 25 cubic inches and a bunch of torque just to say you've got a 301/302? If nostalgia is your goal the 327 is dripping with it and makes more power. Frank
So far I haven't made up my mind to build it as a 302, to be honest what interests me is the ability to run the engine at 8 or 9k and take advantage of that extra rpm on the track without a O/D transmission. I have heard stories of one particular racer named Sam Cunningham who raced a bored out 283 "4 incher" in a Corvette in the 60's in Texas. As far as the story goes, he regularly left the line at 9000rpm and held many NHRA ***les at that time with the car. I don't know if that's true, but it definitely got me thinking and I wanted to ask some questions and see what I could find out. Before the idea of building a 302, I was replicating a 327 build up that supposedly dyno tested at 390 HP @ 5500rpm and 380ft lb @ 4900rpm with a six deuce and camel hump heads... identical to my long block. I have no idea how much power and torque are affected with the lost displacement, and what exactly there is to gain by running the motor at those speeds, but I was hoping you guys could tell me. I'm here to learn! Thanks for the input! Rich
The Isky 505 was considered a kick-*** item "back in the day," but if actual performance is the goal, there are dozens of cams that will do better now. If you have one and just want to use it for bragging rights, it will be great. As previously mentioned, swapping out the crank to reduce engine size by 25 doesn't seem like too clever an idea unless you are shooting for a particular racing cl*** that makes the smaller motor advantageous. The 3.25 stroke of the 327 is certainly short enough to push to serious RPM. Good luck with your new motor, and keep us informed as it progresses.
Ask Rocky, he built the 302 in my 53, it's a 283 .125 over, said it should push 9K or better, haven't done it yet, but....someday. Farmall
The 302 revs nicely (and yes, that 8-9k rpm limit is a bit better than the 327 will do) but it doesn't have great low end torque numbers to move a heavier car around (it was pushing it to launch a DZ302 Camaro off the line without winding it out on every launch). The 302 is well suited to a light car that the torque is suitable for, or for use behind a 5 or 6 speed with short rear gears. To make it live on pump gas with that compression (and 11.8:1 asn't bad, I've run almost 13:1 on pump gas in a 302) you have to have a long overlap cam, which kills the low end torque even more (but is part of what allows it to rev so high). The 505t is good, but for that compression ratio and rpm range, the Z50 (or preferrably the Z60) is a better cam choice. Remember to use good valve springs and port the heads for optimum flow to get the rpm numbers you want. None of the cars I've put thee in (or have had friends put them in) are applicable to this board, but all of them have seen daily driver duty as well as racetrack use (drag, slalom and road racing).
From experience,use doubble springs,roller lifters.with a "rev kit"(springs on the lifters,in the valley area). You may see 9k once or twice! The second time for me was the last time on my 283 Sparky
Thanks you guys, this is great! Yep, maybe moving a 4000lb car is going to be a bit much. I still like the idea of the short stroke, if I bore the 327 .060 over it gives a displacement of 310.7, not that it will make too much difference to torque. A five speed would help, but I'm trying to keep the car period correct, and correct me if I'm wrong but I don't think anyone was running five speeds in the early 60's. I was going to run a 4.11 rear end. H.P. is a product of torque and RPM right? If that story about Sam Cunningham is correct, maybe that's why he had to launch at 9k. A Corvette isn't as heavy as a '54 HT though. The car will see way more street use than track use, so it's not every day I'm going to be putting the motor through that kind of torture. Well, I'll keep checking things out, see what else people have to say for a while. Rich
Well, I don't know if anyone was running DZ302 road race clones in '54 Chevy's in teh early '60s, either, so you could simply make the 5-6 speed shifter look like it was a 4 speed unit, or something.
True, I have been told of people boring thier 283's .125 over to 302 but not using a 283 crank in a 327 block, it seems as though it would be a natural progression though. I mean the 327 came out in '62 and why go through the trouble of boring out a 283 when you can have a fresh block that already has a 4" bore? Of course this doesn't mean it was common practise, or that anyone did it at all for that matter. A friend on hotrodders.com is going to run the number for me, so I'll see what the figures look like. Maybe they won't be so bad, in which case a 4 speed may be fine. I'll have to wait and see. Rich
A friend and I run a very similar package back in 1968. We ran a 5.38 gear and took it to town only on Saturday nights. It was a gutless wonder unless your foot was on the floor, then it run like crazy. Six 94's are not a lot of fun on a regular basis. My $.02. Pete
I had a friend of mine run it through the desktop dyno, the screen shots of the results are too big to post but here's the rundown. Block: Chevy 302 (actually a 327 using a 3" stroke but had to put it in as a 302) Bore: 4.060 Stroke: 3.00 Total Displacement: 310.7cid Cylinder Heads: Wedge / Stock Port and Valves Intake: 1.94 Exhaust: 1.50 Compression Ratio: 11.9:1 Induction Flow: 900cfm (6 x 150cfm) Manifold: Single Plane Exhaust: Small Tube Manifold w/Mufflers Camshaft: Roller, .602 / .602 intake and exhaust lift, 282 / 282 dur, 109 lobe centre RPM / HP / TORQUE 2000 / 113 / 298 2500 / 150 / 314 3000 / 188 / 329 3500 / 240 / 359 4000 / 296 / 388 4500 / 349 / 407 5000 / 395 / 415 5500 / 427 / 408 6000 / 441 / 386 6500 / 450 / 364 7000 / 435 / 326 7500 / 417 / 292 8000 / 386 / 253 8500 / 352 / 217 9000 / 316 / 184 9500 / 273 / 151 10000 / 229 / 120 10500 / 181 / 91 11000 / 123 / 59 Nothing on this motor apart from rods, pistons and a cam kit will be newer than about '65... not bad eh? What do you all think... yay or nay? It's not too late for me to go back to just building a 327 with a much more normal power band at much more conservative rpms. I like this a lot though, it's certainly different. Not your cookie cutter sbc! Rich
I had a home grown 302 in my old 57 Chevy ragtop. Very radical engine, BIG compression, real roller cam, rockers, ported angle plug heads. If you are looking for a good street engine in a 54, then you should probably stick with the 327. It's not the HP, or max torque numbers you need to look at, but the overall torque band the engine has. a longer stroke 327 will have more torque, and will feel stronger, and pull more in a heavier car. The 302, unless geared high, won't have much pulling power until you hit some high RPM's. My Chevy had 4.88's and was a screamer, but not very polite, streetwise! In a lighter car, like a T or early roadster, it would be a fun, high revving engine to tear around with. But in a heavier car, it's not as practical.
If you were Joe Sherman I'd say go for it but I think your gonna need 10 sacks of kitty litter and a tow rope...
At 8,000-9,000 rpm, you can't invest heavily enough into valvetrain goodies. Get a solid roller cam and lifter kit, good pushrods, full-roller rockers (look into the new shaft-mounted bolt-on units offered by Crane- they're nice) and invest in the best-quality valvesprings you can afford (I like K-Motion, Crower, Manley, and Comp springs). The rev kit is a good idea. If you dont' go with the shaft rocker idea, at least go with a stud girdle to keep everything aligned. You'll probably be running a tall tire and I bet you'll need 5.13:1 cogs to get through all the gears and clear the finish line at 9,000 rpm. Run synthetic fluids (especially engine oil) and make sure you've got a rev limiter installed. Check valve lash and spring pressure frequently. If you're not totally in love with those out-dated, overrated heads, consider an upgrade to something more modern. I like AFR aluminum heads and Motown iron heads, depending on what you like. There's another 50-100 peak HP waiting for you right there.... Scotch~!
Thanks for the input. I may try to shed some weight by losing interior fluf and maybe the back seat. I may also shed the front inner fenders. I'm sure I can get rid of some weight in some other places with some thought. I am in love with the heads, so unfortunately at the expense of maximum potential HP and torque, the camel humps stay. I hear you about the valve gear though, it's going to have to be built right. I am debating over the transmission though, I want to keep this car as period correct to the early / mid 60's as possible which limits me to a T10 or Muncie, but what this car really wants is a 5 or 6 speed. I may have to make a compromise in that area. You're spot on for the rear end gearing, 5.13:1 is exactly what I was thinking. Do you think I'll get away with only four gears with that rear end ratio and some tall tires? Rich
I'd also recommend putting a 4 or 6 cyl tach in it and avoid racing anyone. That way you can claim to be undefeated and your RPM goals will have been met. If that is unacceptable then start borrowing heavily against you inheritance, become a good poker player, or buy a gun and and a mask. You'll need all of the $$$$$$ you can get your hands on to buy spare short blocks and that kitty litter that was mentioned earlier. Frank
Is it safe to ***ume that you have your sfi bellhousing and clutch/pressure plate already lined up? It must be easier than I thought to get parts down there. Mutt
Do you think I'll get away with only four gears with that rear end ratio and some tall tires? Rich [/QUOTE] Final gear ratio in either of those transmissions is 1:1...so the math will be easy to do. I'm estimating about a 30 or 32 inch tall tire to make it manageable on the street, but I'd bet a 28-inch tall slick would be really close to nirvana as far as getting through all 4 gears shifting at 8,000 or so, and screaming through the lights at redline rpm. It'll take some experimentation (I don't know what RPM you're launching at, or how much rpm you'll lose between gears or anything), but with 5.13s and a near-30-inch tire diameter, you'll be close. Scotch~!
Nope, I'm not that far yet. I'm shipping a big crate out from Portland later this year. So far I just have the Offy 6x2 and Holley 94's, a cal custom finned aluminum oil pan and cal custom valve covers (putting the cart before the horse... but they were a good deal). I've got some leads for a short block and heads, and I still have to get everything else together, belhousing, trans and rear axle included. I can get all my kitty litter here though, no need to ship that out. Rich
Final gear ratio in either of those transmissions is 1:1...so the math will be easy to do. I'm estimating about a 30 or 32 inch tall tire to make it manageable on the street, but I'd bet a 28-inch tall slick would be really close to nirvana as far as getting through all 4 gears shifting at 8,000 or so, and screaming through the lights at redline rpm. It'll take some experimentation (I don't know what RPM you're launching at, or how much rpm you'll lose between gears or anything), but with 5.13s and a near-30-inch tire diameter, you'll be close. Scotch~![/QUOTE] You're reading my mind, that's exactly what I wanted to hear! Rich
I don't profess to be any sort of an expert, but it looks to me that spinning her up to 9000rpm is just playing to the crowds, and wasting time and money. Surely you're best changing up a gear when you get past your peak torque numbers?? Carrying on to 9000rpm achieves nothing but cost/destruction.
I'm no expert either. I'm trying to learn and set my car up right on paper before I spend money on parts. I definitely can't afford to go through engines too quickly. If the factory 302 had a factory redline of 7000rpm, I'd think shifting up to that point shouldn't be too unreasonable. I'm happy to be told otherwise though if I'm wrong. Rich
It's all relevant to the cam you're running. I suggested a solid roller, and I meant it. To make good power at 8,000-plus rpm, you're looking at something like a Comp Cams 12-817-9 (Grind number 307RXD-12), which has crazy .739/.693 lift and 307/320 degree duration numbers. With your setup, this should peak around 8,500 and justify your being up there. Otherwise, you're just hurting parts. You didn't want it to idle below 1,200 anyway, did you? If you want to play up there, get the stuff to make it work up there. Yes, the 301s were terrors back in the day, but they were running crazy solid cams like this without the benefit of rollers. ...and they broke a lot. You can do it better today, but make it work right~! Design it from day 1 with the intention of living comfortably at 8,500 and make power up there. Consider things like windage, coatings, drainback, and oil control. Overbuild the valvetrain. Launch at 5,000 rpm, shift at 8,500, and have a ball. Just don't expect it to be good at anything else. Scotch~!
The 302 was for the under 305 cid cl***es in the old days. Great in a light car like a chevy II or vega or maybe a gutted camaro with front end fibergl*** at most. 4.56 or 5.13 gears were normal. Remember the tracks compounds and the tires weren't as good back then. The idea was to launch side stepping the clutch at about 4500 rpm and let tire slippage take the initial shock load. If the tires didn't slip there was a good chance the clutch would take off your leg when it blew. Also without the tire slip you couldn't keep the revs up till the car got out of the hole as that combo relies completely on RPM and ****S for low end torque. You'll burn up the clutch slipping it at every red light and stop sign to get the car moving on the street. Driving it on the street will feel like driving a Caddy with a pinto engine. It'll be totally gutless at the 2500 rpm around town driving speeds. Guys with those 8000 rpm screamers bought a lot of them. And if you've ever seen what a clutch explosion at 8000 rpm does....
Man, that's sure some food for thought. It's sounding more like I should reconsider just building a hot 327. Rich
I've been looking at gear ratios in the T10's and Muncie 4 speeds, a 2.52:1 first gives a total of 12.92:1 from the engine to the back wheels. Oh, and I've got no illusions that this motor will idle at anything less than 1200. So I have a question. If I'm sitting at a red light, and it turns green. I give it gas to about 2000 and let up the clutch. What happens? It's gutless, sure, but will it move? According to those figures I'll have 113 HP / 219ftlbs at 2000rpm. Surely that's enough to move even a '54 Chevy with that gearing at least as well as the stock 235 did, probably quicker. Oh, the guy that ran the numbers for me on desktop dyno also ran a larger and smaller cam, peak HP and torque fell off either way, so the cam chosen is darn near perfect if those results are anywheres near accurate. Rich
You can probably build that 327 for the same HP with a much broader powerband and a 6500 rpm redline for half the money. Then you can drive it on the street without slipping the clutch and keep both your legs. The 302 was at it's best in road racing where it was operating up in it's powerband most of the time and shifting didn't load the clutch like a drag racing launch does. Remember in the seconds you're drag racing you spend much more time CLIMBING to your high rpm than you do AT your high rpm. That's why guys started worrying more about torque and wider powerbands than high rpm HP back in the late 60's. Also the advent of VHT and real slicks and soft tire compounds instead of the hard retread slicks meant you were no longer slipping the tires as much on the launch and you needed power down in the rpm range. Much cheaper and easier on parts than the old screamers.
The Jalopy Journal
