305 stroker

[flrshftnss]

I was thinking of rubuilding, and stroking my 305. I would like to know what a good bore size would be? I hear guys have done them up to 345. I know it would be cheaper to drop a 350, but like the matching vin idea. which would be the better choice what are the pros and cons of each motor

 

[Phoenyx]

Pros of building a 305: none

Enough said.

 

[dogsht]

You can make power with a 305. That said its not cost effective when compared to spending the same money to do a 350/383/400 which will drop right in place of the 305 useing all your existing mounts accessories etc. The bigger motor will make more torque and move that Elky with authority compared to the 305. Plus you already have the stronger 8.5 rear to hold the torque of a larger engine. Last its not like a 442 with a special vin identification. I don't even think the MCSS's had special vins. I recently saw an article that said certain 350 blocks can be poked & stroked to 415ci and are still structurally stronger than a 400 block.

 

[NAILS]

x2 it would go faster if you pulled it behind a boat.

you can build a descent 350ci/300-350hp for 1000-1200 bucks. the machine shop bill alone on the 305 to boil, flux, cut for the crank, and bore /hone cylinder walls etc would be close to that same price range if not more.

 

[88ss408]

305's are good motors but take the money spent on it on a bigger displacement motor will get you better power.
but that is just common sence right ? a 305 with a .030 over bore and the 3.750 stroke will give ya 334C.I. and with a .060 over will get ya a 340 C.I. (i would not go over .030 it dont give you that much more )
the only bad thing with building a small bore motor is head choices you are limited you can go with the 416 H.O. castings to keep the stock 4 corner bolt look. or you can go with aluminum corvette heads (basicly the same castings as the 416) only they have the center bolt down . or you can go with vortec heads but you will need a special intake to work with it .
but other then that i have seen good numbers come from 305 motor's buid the right combo and it will treat you good

 

[monte olrac]

what kills the 305 is head selection. once you stroke it you will limited by your heads, now there is an article where the built 350 and 400 hp 305,
http://www.hioutput.com/tech/343hp/343hp.html
http://www.hioutput.com/tech/400hp/400hp.html

or you can stoke it out and add a supercharger

 

[jrm81bu]

Another thing of interest is the dyno chart on that 400hp build. They had to spin it to 7200rpm to make 402hp. Then it only made 344lb-ft of torque at 5500rpm. This is not gonna be a fun street motor. A 350 or 400 would make that 400hp a lot farther down in the rpm range with a torque jump to 400-425+ range also at a lower rpm, making for a great street motor.

 

[madmaxstyle]

I did up a 305, didn't stroke or bore it, just had it balanced and blue printed, massaged nicely with some better pistons and stronger rods. replaced the heavy intake with an aluminum dual plane after a while mainly because It still had the 2bbl it came with. Winds out nicely now and puts out enough to get a person around I'm not a dyno but I would say I its somewhere in the 179.21hp range with 220.68ft/lbs of torque. Thats an honest guess using stock output numbers, and biasing it higher than stock figures for that year closer to the 305h.o.


I don't regret doing that motor but I did eventually put it in a 3/4 ton and dropped a 350 into the Caballero.(gas mileage wise it makes sense)It still kicks *ss in the 3/4 ton at sub 70mph speeds and will squawk the tires around corners.

IMO your stock motor would be fine to build and would undoubtedly be great to drive BUT :idea: :idea: for more power/torque it is cheaper to go the 350 way. Also there's definitely more for head selection.

 

[85 Cutlass Brougham]

Matching numbers is the Holy Grail of good musclecars. The Monte SS in stock form is NOT a good musclecar. In fact, ditching the 305 for a 350 will increase the car's value if you do it respectfully. If you are a hack, it will make it worth less, but the same goes for modifying the stock engine too. The biggest problem is the small bore you get with a 305. It shrouds the valves and makes it difficult to make decent power in a naturally aspirated form. Remember that in a wedge head 2 valve V8 engine, the diameter of the bore is the limit to the total of the diameters of the two valves (the actual graph would be asymptotic...). So, with a 3.75 in bore, the total of both valve heads is 1/4 inch smaller than in a 4 inch bore engine like a 350 (I forget the exact bore of a 305, but you get the point.). Expressed using limits in Calculus, you get.... well, nevermind. Calc even confuses me! You get the point though. A bigger bore is needed to let the engine breathe, and a 305 has the smallest bore of any Small Block Chevy save maybe the 262. The 350 is cheap and plentiful to find, which is why so many people build them. Is it the best engine for all seasons? No. It has it's flaws like any other engine that can trace it's roots back 55 years (or 43 for the 350 alone). However, the vast availability of cheap parts makes it one of the easiest v8 engines to tailor to your needs. So my advice is to build a low buck 350 Chevy. In the long run, your money will be better spent than it would be on a 305.

 

[bigbrute]

i have done a 305 stroker they hold there own don get me worng building a 350 is a much more powerful engine but on the street i gave 5.0 and 350 hell . You can run stock piston pin wit sbc 400 rods did that till i dropped a valve. Went back with 11.0 piston and vortec heads off a 305 truck cleaned had the cleaned 3angle pocket ported and the bowls blended. Performer rpm and 650 holley comp camp xe268 and 1.6 roller rocker's . It wouldn't stop pullin for sh*t and took it past 7grand many of times . Th350 3000stall and shift kit in a elco . My point is on the street light to light if you can drive and know your car not much of a difference. Stretch it out or at the track give me the 350.