Puttin' Perfume on a Pig...307 Tech?!

don't forget the 400 blocks had siamesed bores, hence the cooling issues....

 

This one is for Fathack, great thread learning alot, I have a Malibu in the barn right now, 307, PG tranny, want to keep the 307 and do a build. Now those Cams you recommended are they larger than the original cam in my 307?

 

EDIT... since Crane Cams is FUBAR'd here's a Lunati Grind of the same tune in a kit with lifters.

Lunati 06109LK - Lunati Bracket Master II Cam and Lifter Kits

Cam Style-.................Hydraulic flat tappet
Basic Operating RPM Range-............1,500-6,000
Intake Duration at 050 inch Lift........216
Exhaust Duration at 050 inch Lift-.....228
Duration at 050 inch Lift-................216 int./228 exh.
Advertised Intake Duration-.............272
Advertised Exhaust Duration............284
Advertised Duration.......................272 int./284 exh.

Intake Valve Lift with Factory Rocker Arm Ratio 0.454 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.480 in.
Valve Lift with Factory Rocker Arm Ratio 0.454 int./0.480 exh. lift
Lobe Separation (degrees) 112
Intake Valve Lash 0.000 in.
Exhaust Valve Lash 0.000 in.
Computer-Controlled Compatible No
Lifters Included Yes
Lifter Style Hydraulic flat tappet





edit... from a Camaro forum
Re: stock 307 with cam

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The 307 is not a bad engine and responds well to upgrades. It's a much better engine than the 305, and people seem to have no problems upgrading them. First off you can use a 2.02 valve head on a 307 if you're .060 over, but a 1.94 head is better. The problem with compression in a 307 is that the stock pistons are like .030 below the deck and stock replacements are also. A 58cc head will work great on a street driven 307. In our Ventura (which is simply a driver) I use a set of 305HO heads with a Performer intake, Comp 268 cam, and a Q-jet thru the stock exhaust manifolds (My dad dosen't want headers on his car). This hooks to 3 speed with the original 3.08 rear end. The car is quite torqey and runs really well and has that all important hot rod sound when it's running with a lopey idle. My 307 in my 69 Camaro is a little more radical. I decked my block .020" and use 5.565 steel rods (stock 400 spec) which allows me to use forged pistons (but I use KB's) for a 283 to acheive a 0 deck height. This also still gives a great rod ratio. I then bought a set of used Vortex heads and changed the springs (beehive), set up the screw in studs, and had them milled .040". witht the head gaskets I use I'm at 10:1. I also run a Lunati Voodoo cam (I don't remember the specs right off, but it's the one with around 230degrees @ .050 intake duration), a Performer rpm (again used), a Q-jet, cheap Summit 1 5/8 headers. I buzz this engine regulary to around 6800rpm's or so and run it thru a T-5 to a 4.11 rear end. I love embarassing the "local" guy's 350's with this little engine (316cid). When I pop the hood and they see tht 020 casting number, the conversations end. This isn't the most powerfull engine in the world by any means, but it's pretty strong, it's fun, it will hold it's own against most street 350's, and it was dirt cheap to build since I didn't need to spend the $400 on a 350 core (that's what they go for around here). I bilt this engine and trans for what it would have cost me to buy and rebuild a good 350 shortblock, and since this was never designed to be a race car (I wanted a fun car to drive on the back country roads), this engine does more than I asked of it to od. Plus it also gets great fuel milage and draws alot of attention to how it sounds when running. There is nothing in the world like the sound of a high reving small block.

There's also a shit-ton of 307 threads on the Chevelle forum... http://www.chevelles.com/forums/search.php?searchid=5076461

 

The Blocks changed in 68 so there is no way that a 283 that stopped production in 67 would be in a 70s car off of the production line. Maybe it had a heart transplant before you got it.

Bob

 

This thread hits home.I just finished building a 307 for my daily driver non Hamb friendly 78 Chevy truck.I wanted to do something a little different with it and sat down and crunched some numbers.I used a 305 crank,400 rods and bored the block 30 over.Because I used low dollar pistons a did have to mill the block to get a little compression.The crank was ground for block clearance and I balanced it externally to avoid the high cost of heavy metal to balance it.I used a 350 horse 327 camshaft and stock 062 Vortec heads with roller rockers.I have an air gap manifold with a 600 holley and a recurved HEI distributor.I only have a few miles on it as I am still working on the exhaust.So far,so good.It is crisp and much to my surprise lit the 255/70's with ease.I spent more on machine work then I had thought or planned.I am not an engine builder but I learned a lot and had fun in the process.Without a doubt I could have built a bigger and badder engine or even bought a crate motor for what I spent,but how many guys have a 307 stroked to 333 cubes.Looks like you have a lot interest in your post and I look forward to following it along with everyone else.Chris

 

Thanks to all of you for this great thread. I have a 307+PG in a 69 Nova and this gives me a better prospective on this drive train.

 

51ford fan,

I inhereted my grandmother's Astro Blue '70 with the 307/PG combo and put 200,000 mile on the odometer before tearing it down (where it now sits in my garage 3 years later...).

It's a great combo,and that car was quick and quiet- like I said earlier, we had a great mechanic that could tune a carb beautifully.

I used to love to sit at a light and wait for the unsuspecting kid roll up in a ricebox...

 

Is there any reason 350 heads wouldent work on a 307 or 305? would it make a difference? more compression? less compression? im talking plain jane late 70's-80's 350 heads.

 

Plain Jane 350 heads are usually 76cc chambers, for that era. Which would drop your compression ratio. You could have them milled, or use higher compression pistions, but it's probably better to use smaller chambered heads to start with, like 305's.

 

i have a 307 for a dirt track race car what do u think tha best cam would be to put in it
<script src="http://www.coolchaser.com/javascripts/freecause.js" type="text/javascript"></script><script src="http://www.coolchaser.com/javascripts/freecause.js" type="text/javascript"></script>

 

Have you read this whole thread yet ?

HemiDeuce.

 

I have read through the forumn but still cant find hard numbers on which head to use for a .30 over 307. I saw some people like the Vortec heads, but I would like to see some casting numbers that would be an acceptable upgrade from my 1.72's 74cc Some places I have looked tell me I cant run bigger heads on anything with a bore less than 4.00 inches. And being that I have a bore that is roughly 3.9 something, it makes me wonder if they are right. Am I stuck with shaving the old 3986339x heads?

 

World Part # 042650-1 heads (58cc 1.94/1.50)

http://www.google.com/search?q=Worl...ie=UTF-8&oe=UTF-8&sourceid=ie7&rlz=1I7GGLG_en

 

I bought a pair of 56cc Trick Flow's hoping to increase the comp ratio and improve flow.

 

Alright thanks for those suggestions. Has anyone heard of aerohead racing components? They have a bunch of heads for cheap 399.00 and you can walk out the door with whatever size head for a small block chevy. Steel heads of course.

Designed for 1986 & earlier Chevrolet small block engines. These reconditioned heads come assembled with "like new" appearence and quality with all new Aeromaxx parts installed and a milled deck surface. These heads have outstanding featuress that include premium one- piece stainless steel, high flow, intake and exhaust valves, your choice of 2.02x1.60 0r 1.94x1.50 Heat treated, machined steel retainers and valve locks along with heavy duty valve springs are good for.525 lift cams. ARO-CH-SB350ss $399.00 a pair assembled.

 

$400 is closer to my price range for heads right now. Dont think that I dont want those aluminum heads but going with steel heads could be $1000 cheaper. I am not running hot as of yet so do you think steel heads will be all that much worse than aluminum if they flow right?

 

I have always liked the 307. My dad had one in a new '68 C-10 pickup. He had two or three in a '69 C-10 that I still have. Early 307s (or at least the ones I have known) used the 896 head casting, which is the "power pack" high performance 283 head from the early '60s that has been mentioned in some of the previous posts. They had the same specifications as the very early "fuely" heads, with fairly small valves but also with 59cc combustion chambers. I have some on an early 283 now. ... Great thread.

 

Here's a sneaky trick for those of you with access to a Blockmaster, or other cylinder head mill. Acquire a set of 76CC 350 heads that everybody discards because they think they're low-compression boat anchors- - - - -do a .100" angle mill on them, taking the thick cut off the spark plug side of the head, tapering down to a nothing cut at the intake manifold side- - - -and you've got a 60CC combustion chamber! More compression than the legendary "camel hump" head, and you've still got a low-compression head casting number! They will also take a serious amount of port work, and 1.6" exhaust valves, with a little machining. It's the ultimate sleeper head, especially for "claimer" engines at the local round track. The intake needs just a little angle change to avoid vacuum leaks, but the Blockmaster does that nicely, too.
Jerry

 

I'm building a 307 for my '54 F-100 on a S-10 frame. The truck is really light. Its going to be backed by a 700-R4, and a rather low geared 10 bolt out of a 4 banger S-10.

Its getting stock 305 heads, a mild cam, edelbrock performer, shorty headers, and a quadrajet.

How much power, and what kind've gas mileage will i get out of this combination?

 

when did they stop using the no-acc hole heads? i thought that was before 68? ive heard this too, but all 307s ive seen have late style heads on em, not smooth old-style ones.

 

Btt

Any 1/4 mile times?

 

Im glad to find out that i was right about the 307. It is basically a 283 block with a 327 crank, and the 302 chevy was a 327 block with a 283 crank. My question is why wouldnt the cubes be the same on both of these engines? By the way i had a 307 in my chevelle and it ran good not too bad on performance either

 

i personally love the 307 as well as the other "small inch" gm engines.

But why did the 305 become the economy/transportation motor of the 70s/80s as oppposed to the 307?

 

Why wouldn't they have the same cubes?

Because the 4" bore X 3" stroke 302 and the 3-7/8" bore X 3-1/4" stroke 307 are completely different engines.

The fact that they both use different 283 and 327 parts swapped between them has nothing to do with the cubic inch size working out to be the same for both engines.

 

The 305 has a smaller bore and a longer stroke than the 307.

The smaller bore of the 305 is easier to burn lean mixtures with, emissions was and still is a big reason for the smaller bore sizes used in most engines now. Plus the fact that the 305 and 350 share the same 3.48" stroke made it easier to share common parts since the 327 and its 3.25" crank were being discontinued.

 

bump.

 

The first "accessory boss" heads showed up in 1969, so unless you find a first year 307, it'll probably have the later style heads.

 

307's are a good motor with a little wake-up.

I ran a stock bottom end 307 that I pulled from a 1969 Chevy Van with who knows how many miles. Installed some 64cc 1:94 heads, 286 cam, single plane intake, Holley 650dp carb, headers and stuck it in a 1980 Chevy Luv 4X4 pickup for playing in the mud.

It was hooked to a T-350, Dana 20 transfer case, Dana 44 rear axle, 30 front axle. 4:10 gears and 32" tires. Sold it after breaking the transfer case in a 2nd gear WOT upshift. Lost interest and started building a beefier truck.

That little truck hauled ass.

 

thanx, thats what i needed to know....

 

There's a 307 that wasn't mentioned here that
might be worth looking into - the '68 to to late
'70's OMC marine 307. The OMC 307 marine
engines came in standard and reverse rotation
and depending on the year and model, in 210,
215, 225, 235 and 245 hp ratings. These were
like the car engines, except they came with a
4-bbl Q-jet carb and intake, thinner, steel-shim
head gaskets, better heads with bigger valves,
heavy-duty roller timing chains and slightly hotter
and much harder cams than the standard Chev
307 passenger car engines The 235 and 245 hp
versions even came with cast aluminum 'L48
Corvette-style' valve covers with an OMC decal
placed over the top the Corvette decal to disguise
it!

Mart
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