I was told today by someone that the Chevy 307 is actually a stroked 283 with a 327 crankshaft in it.
Is that true?
Is that true?
307 Engine question
ddx77
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I don't know if it is true or not, but I remember reading somewhere that the 307 came about because from 1967-69 to make the Z/28 302 they used a 327 block with a 283 crank, so Chevy ended up with a lot of 283 blocks and 327 cranks. They put these 2 together after the 1969 model year started and that is how the 307 came about.
I do believe there were more than 602 307's made.
The 307 uses a large journal cast iron crank. So the 307 block and crank are made for each other, not left over 283/327 parts.
Cars and trucks were getting heavier and had more accessories, so a larger hi-torque engine was made, the 307 was the entry level, the 350 in at the top and in 70 the 400 came about as the top spot.
BBC's were considered performance engines even though they made a 396 2 bbl in 68-69
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:noway: nice story though l
^^^ What he said :thumbsup:
GM didn't usually use the "let's clean out the basement" approach to engineering a power plant for a production vehicle
'IF' the internal parts used in one offering could be used in another (or many others!), then the resulting economy of scale would dictate that that is the approach to take ...
There are many examples of the above in SBC's - bearings, rods, cams, cam drive, oil system, 'tins' and etc.
This just brings the per-unit cost down and makes multiple offerings for flexability and customer demands a very economical process.
It's one of the reasons GM/Chevy could offer such a wide array of engines in most of it's models :thumbsup:
Besides the point that no production 307's were assembled by GM from a 283 casting - they were a 307 specific casting number
3914635/3914636 are common early 307 castings, and none of those were 283 castings ...
The 307-327 cranks are pretty close to each other, but the counter wieghts are different and they can quickly be identified by the odd 'key-hole' flange used on the 307's :yes:
I imagine you could interchange them if you compensated for weight with the balance - but 'why'
... with 327 cranks a dime-a-dozen ...
Alan, check your calculator battery....
3.875" DIA/2 = 1.9375" radius
(1.9375)² = 3.7539 in/sq.
3.7539 in/sq X 3.1416 (pi) = 11.793²/in.
11.793²/in. X 3.250" = 38.328³/in.
38.328³/in. X 8 = 306.6³/in.
:beers:
3.875" DIA/2 = 1.9375" radius
(1.9375)² = 3.7539 in/sq.
3.7539 in/sq X 3.1416 (pi) = 11.793²/in.
11.793²/in. X 3.250" = 38.328³/in.
38.328³/in. X 8 = 306.6³/in.
:beers:
It's not my battery, it's my brain. I multiplied Pi by the bore instead of squaring the radius. Ugh...but I am petitioning my college to review my physics tests as when I took the courses, matter couldn't exceed the speed of light but last week, that was proved false. I might just pick up a few points and raise my GPA.alan
Good luck!
I tell people here as in everybody sending electronic mail,
"Electrons move at the Speed Of Light, but, not in this building."
I tell people here as in everybody sending electronic mail,
"Electrons move at the Speed Of Light, but, not in this building."
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'Fess-up' Alan ... you just fiqured you'd be boring it .060" over anyway and then it would have 316 C.I.
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Hey Guys while we are on 307s I read somewhere that the 307 block had a low nickel content and is not a good block to rebuild or use due to this. Better off starting with a 350 block. Is this true?
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You're better off starting with a 350 block due to the .125" larger bore.
AFAIC, the Chevy 307 is the bastard red headed step child of the Chevy V8 engine family...
AFAIC, the Chevy 307 is the bastard red headed step child of the Chevy V8 engine family...
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And the 305 is it's conjoined twin.....but with a crank rods you can at least use....As in conjoined twins, sometimes they have to share stuff while the other one gets the short end of the stick.
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:noway: I'm pretty sure that 'award' has to go to the mighty 267 :yes:
Even I've never found a use for one - other than doing a fantastic job of keeping a boat in place ...
I've got a set of heads from one right now - someone dropped them off saying 'I think these are 350 heads off a Monte Carlo' - I didn't have the heart to tell him ... just said "thank you"
Hopefully next week he'll bring me a 267 crank - I need a better door stop ...
Do a search on here for 307 information - I think you'll find folks image of them is slightly missplaced ...
They are not and never will be a 350 - but for a torquey little street engine they are very 'do-able' :thumbsup:
And you can install any SBC emblem you want on the fender
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The 307 was created in answer to the increasing pressure for control of emissions; the smaller bore resulted in a lower (more favorable) bore/stroke ratio, which slightly reduced NOX emissions. As previously noted, it was created from scratch (new block, new crank).
:beers:
:beers:
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