how to build a 301, Chevy

Build a "stronger bottom end" 301/302: here's how. Start with a 4 bolt 350 block, and get an aftermarket Scat/Eagle/Howards 3" stroke crank (or a # 1178 GM crank); use whatever 327 1.67 CH pistons you want, and a 5.850 long rod; this gives you a 9.020 stack height against a stock 9.025 deck height. OR, same deal, but use whatever 350 pistons you want, and 5.940 rods (factory powdered metal rods as used in the L99/LT1 3engines). Longer rods=less side loading of the cylinder walls. Small journal rods are generally weak after so many years and cycles, so stay away from them unless they are aftermarket. The 262 CID engine crank, with 3.10 stroke, is a cast crank. You can use it with a rebuilder type 350 piston (1.540 CH), and a 5.940 rod for a 9.030 stack; use a THICK head gasket. No matter what "formula" you use, get the rotating assembly balanced! That's the thing with the SBC, and the ability to mix and match factory parts, you can really build just about anything. Butch/56sedandelivery.

 

I'm at work right now, no speakers on this computer. When I get home, I can listen to it on that video on the '55 thread, then I'll take a stab at it.

 

I used to build stuff like this on a regular basis...except the shit I was working on usually had a bunch of .040 holes around the circumference of of the piston top...

 

The Z 28 had a bore of 4.002 with the 3 inch stroke = 301.89 swept volume. 301.59 is 4 inch bore.

 

Ok, not on the video. I'll take a WAG and say 40 lbs.

 

If you were racing before 62 there were no 327 cranks, so we had no choice but to bore a 283-.125. Keep in mind all early 283 small journal cranks were forged, but not all small journal(pre 68) small journal 327 cranks were forged. Its true its eaiser to get horsepower with more cubic inches, but there nothing like sitting on the line at 7500,when the flagman pointed at you, put it on the floor and pop the clutch, and start pulling the handle.

 

I've done that on a Bridgeport with a rotary index.... It helps with the top ring seal on the pistons... Pain in the ass job.... It's much easier on a cnc mill...

 

Ha! I used to do it by hand with a little c-shaped jig dealy that slid into the top ring land. And yes, it IS a pain in the ass.

 

7500 rpm is the bottom of the power band on a 292/301. I have built street-driven, solid lifter 340 Mopars and 350/377 chevies that shifted at 7500. The (relatively) mild streeter solid lifter 327 I am building for my chevy II will have a shift point around 7200. I dont know when it happened that people started to think 7000 rpm is a lot of rpm for a small block. The MP motors my mentor used to build (and I used to wrench on) in the '70s were usually launched on the dark side of 9k. .043 pressure back rings, gas ports, aluminum rods, stud girdles, triple springs, titanium valves and retainers. Just the way it was.

 

I am impressed. What a cool car !

 

I drop the clutch at 7400 with my 383 sbc and start rowin that Liberty 5speed!Whatta rush! Think thats to much rpm for a sbc 383? R~R

 

Wouldn't be my choice. Remember 4th is 1-1, fifth is an od. That little 302 is gonna fall out of the bottom of the power band like a rock when you pull 3rd gear. I would use a 2.95 gearset, and some real steep (Like 5.13) rear gears, let the od do its job for you.

 

still friendly to 287 ci 12,000 rpm small blocks in nhra comp eliminator

 

Good {Posts} Just helped my brother put 2.02 "492" casting heads on another 292" old 70's motor.....TRW 12:1 Pistons, 327 steel rods, steel 283 crank balanced. Dang thing is even a Nova block with the reloacted oil filter, first I have seen up close and personal.

"good quote earlier"....when did 7000 RPM become high.....most likely when everyone started building big blocks, or hydraulic cams, or automatics, or even lame bracket racing..... 4 speeds got kinda rare there for awhile...... I think nostalgia racing is bringing this back into the limelight.

 

Hell, I've run rat motors past 7K. So, I guessed 40 lbs, how heavy is your wheel??

 

50 lb...Hays Flywheel.........with RST McCleod Clutch.

 

These motors are killer but remember they aint crap with out the high comp.12.5 13.5 to one and with todays gas it sucks for a driver

 

I still say you can build a 302 sbc with 9:1 pistons and be happy!
Ford did it in the late '80's with their HO pony motor with the same bore and stroke...
Now I'll never hear the end of it!!....

 

I Bet E85 would run just fine with the High Comp. Talked to some Gasser Buddies....they run E85 with 12.5:1 with 30% overdriven 6-71 blower on 392 cubes with no issues...... If I can jet up my multiple 2BBLs and update accel pump, fuel pump and regulator to tolerate the Alcohol ......I could slap on the blower.............dang.. No need to look for big CC heads.

 

Tech Update: This is for the SBC guys using the SJ cranks and stick shifts.
(Tried to put this in tech area, but did not have access)

Small journal cranks have 2 possible pilot bearing diameters in the crankshafts.

Understanding that there are 2 pilot bearings available, one for the stick shift, and one for power glide or auto cranks, you can avoid a lot of headaches.

Use a good micrometer to identify which crank you have. Then you will not have to argue with the auto parts tech.

1) ID 0.593" Dia ; OD 1.094" Dia (stick shift cranks) < Std Pilot Brg (common)

2) ID 0.593" Dia ; OD 1.065" Dia (auto PG cranks) < Dorman P/N 690034

Dorman Dimension Listed ID 0.593" ; OD 1.060" Dia

Doug

 

FWIW guys, I am already discussing with metalshapes, the possibility of doing a HAMB friendly 301 build step-by-step for everyone to follow along with. This will solely be based on my very possible moving to the Tuscon area this year, nothing is confirmed yet though. It will be a old school build 100% or very close to that of a build from back in the day, with a bunch of tricks and mods thrown in here and there. Chevy crank and rods, stock but highly modified block, that most mods can be done at any relatively equipped home shop or garage. No billet main caps, no aluminum heads, none of that nonsense. We will be looking for help locating the parts we need, and yes at the HAMB discount prices of course. When is all said and done, maybe someone will donate a few hours of dyno time.

I have finally started with my first album if you want to check out some of my work. The 301 engine build might lead into a Paxton supercharger blow set-up thru I'll design. If not we will just go a high compression street/strip deal. Again, no telling what the future will hold. TR

 

Hi. I don't know if anyone is still following this thread but here's an article I found in Hot Rod. It's a standard 302 short block (with low compression pistons) and a modern induction top end (aluminum heads, Super Ram intake, roller cam) that put out 550 hp while still nailing down 23.5 mpg. Yes, I know it doesn't look nostagic, but you can't argue with 23.5 mpg if you drive your car frequently or long distances. Gears are important with a small cube motor. My high school '56 Chevy 210 ran a 283 with double-humps and a 327-350 cam, a BW T-10 and 5:13s. I drove it every day (it's the only car I had) but I never did calculate the mpg (who cared?).

http://www.hotrod.com/techarticles/302_small_block_chevy_engine_build/

Richard
Palominas, AZ

 

Just wanted to say WHY THE HELL would you ruin a 327 by turning it into a 301, The 283 was the one to bore and do the work to, making yourself the 292 or 301 this way you are getting the bigger bore to make the power you are after. In my book the 302 was it own engine and they were a good engine don't get me wrong, but this thread is about 301's and you make them out of a 283 NOT A 327. Turning a 327 into a 301 is just going backwards. Take your 283 and turn them into a 292 or 301 and then you have a very intents engine and just go have some fun with it.

 

a '68 307 is a large journal motor. pretty easy to swap the crank into a 350 block and have a 327 or into a 400 block bored .030 and have a short stroke 350. The307 cranks are cheaper and more plentiful then large journal 327 cranks. They will not spin a bazillion RPM for hours on end but properly balanced and clearance they will turn 7 easy for 1320 feet at a time. or cruise @ 5500 for the two hours it takes to get to the nearest track and race all day and come home again.

 

I'll take a shot at that (why destroked 327 vs overbored 283). ^^^^^ IF I were going to build a 301/302 it would be because that's the cubic inches the rules allowed. If you could run a bigger engine, then more cubic inches = more horsepower. So we're class racing and you need to do everything you can to get more horsepower out of what you have to work with. Better ring sealing = more horsepower. Less cylinder wall distortion = better ring sealing. Thicker cylinder walls (standard bore vs. .100 or .125 over bore) = less cylinder wall distortion. So there it is.

 

Got a new project 64 c10 lwb, came with a standard 283. Old guy I bought it from says it has never been bored.Just was wondering should I bore the engine 030 to try and gain some more power? Factory heads and I haven't pulled anything apart but I am considering a cam swap. I have owned a few 350's in my time but never a 283.Any thoughts...?

 

Bill Jenkens used the 400 block with the small journal 327 crank. Buick rods and venola pistons.

 

All you need to build a 301-302 short block, minus cam and cam bearings!
All just posted in the HAMB classifieds.............................................