diging around threw some of the motors layng around and i ran all the casting numbers over at mortec.
one of the motors came up as a 307 2 bolt main,though i cant find any info on the heads.

does anyone know what bore/stroke a 307 has,id mush rather not open the motor up to find out,cause if its junk it just going to the scrap yard.

 

3.875" bore x 3.25" stroke (283 bore, 327 stroke)

As opposed to the 302:

4.000" bore x 3.00" stroke (327 bore, 283 stroke)

 

As opposed to the 305 3.736" bore (unique to the 305) x 3.48" stroke (same as a 350).

307's were base V8's in passenger cars & light trucks. They only had 2 bbl carbs. The heads were small valve, poor flowing, large chamber junk.

It could be argued that the 307 bore/stroke is preferable to a 305. More than likely a few of the other 9 engines are even better.

 

is the crank worth saving ???
say i ever want to turn a 350 into a 327??

thnx for the info guys

 

Why would you want to do that? Going too fast already or something?

 

the 283 was base engine until 68 when the 283 went bye bye and the 307 came out


almost every engine size gm made was a base in something or other
but yes the 307 was base v-8 engine in the trucks 68-73

cars i dunno

they were all 2bbl and 2 bolt mains

ive owned a few and the first one i ever owned was in an all original 68 c-10 longfleet pickup with the SM326(full siynch vs. the base non-synch SM318 trans in which was actually 3" shorter than even the 6" tail th350- for comparison) three speed on the column it ran awesome but had a billion miles on it and so a couple months afteri got it it locked up and blew a rod into the pan, so i put in a fresh 355 with TRW flat tops and then later a th350 trans out of a car(6" tail so it would bolt right in, but the trucks were not 9" tail until '73 anyways)

they run as good as any other small cid v-8 does/can

good economy engine

the 307 crank is medium/large journal it will work in the 69-up 350 blocks and make a 327 yeah


good luck

 

toying with the idea of building a turbocharged small block for the car
just comming up with some possible combinations 327/350/383.
figure the 327 would be happier on a high reving turbo motor

 

Cars I do know.

First 307 I drove was my grandfather's '68 Biscayne. It had the 307, Powerglide, power steering, and AM radio (he didn't really want the radio). No other options.

2nd 307 I drove was in a 1-ton flatbed 4-speed truck.

First one I owned was in a '73 Nova, equipped similarly to granddad's '68 but had the TH350, AC, and PB added to the option list.

 

Using a used, 35-yr-old, Lord-only-knows-how-many-miles low-performance CAST crank?!?!?!?

Better buy your motor a diaper

 

lol well i didnt know if it was cast or not,i would have looked first.
lol belive it or not the motor is spotless,we rent out a huge stoarge area to one of my uncles good friends, hes a dam packrat,he has god knows how many diff engines,transmission/cars at his 2 houses,and god knows how many more here.he was cleaning up though and offer me a few diff engines.
did manage to score 2 virgin 010 blocks from him.

i knwo in the storage area right now he has a mint all original 56 belair,and a 40's something maybe ford also all original,this guy has tons of stuff liek that lol

 

ALL 307 cranks were cast.

Which is one reason why I've thrown so many 307s in the garbage over the years.

Although, even though it was considered so utterly useless back in the day with its unfavorable bore/stroke ratio (the 302 would pound it), it's still not as bad as the 305 (as five7 points out). I guess that means that a pile of them doesn't steam quite as much as a pile of 305s? Iunno. I can tell you FOR SURE though, I don't recall anybody putting 327 cranks into 283 blocks to go faster; we put 327 cranks in 327 blocks, up until the time the 350 came out, at which point we all quit fiddling with that old stuff altogether. The reason was real simple: anybody building any of that old 50s and 60s stuff got beat by the 350s and later the 400s. Period, paragraph, end of story. Let alone the big blocks.

Seriously though, it's trash; good for basically nothing.

 

I wouldn't worry about using a short stroke motor for a high revving turbo. In the realm of possibilities, valve train would limit your RPM potential long before stroke.
I'd use a small bore, long stroke motor, for a turbo car. Less detonation prone due to the smaller cylinder - and the longer stroke gives you back some of your cubes.
383 is a good idea.
335 (sigh...) - would sadly work ok for this, except for the 50 some odd cubes that are being left on the table.

 

sorry to bring back an old thread, but i have recently pondered the thought of using my free 307. ive heard its a good economical engine. is that true?

 

No. Not with what's available on the market now.

 

i agree with that because theres fuel injection, lt and ls based engines, but for any carb'd engine its good for a daily driven engine standpoint, from what i understand

 

id rather have a good running 4.3 then a 307.

350s are dirt cheap.

 

Yes, a 307 is good for a daily driven engine. So is a small block 265, 283, 302, 305, 350, 377, 383, 400, 427 or 434.

 

I had two chevelles with 307's. I seem to remember that the rods were different in the 307's not sure... Both of mine were pretty well worn out when I got them. If you decided to build a 307 you may have some trouble getting pistons.

 

307s use the same rods as everything else. Only 400s had something unique.

 

If you decide to use the 307, make sure you at least put 416 casting heads on it - it upgrades the valves to 1.84 Intake from 1.72, and also gives you hardened seats for unleaded gas.