Heres my story, im in an auto mechanics class
my teacher gave me a project ... to tare down a 307 olds to nothing ... and rebuild it
no big deal right? Well, word spread around to another class ... that was building up a 305 chevy...
so anyway long story.... at the end of the year where having a dyno pull... my 5.0 Vs there 5.0
LOL... witch should be cool...

So now my teacher, wants me to build a ratty motor on my own... and with a little help from his check book and what evers laying around the shop...
im going to try my best to beat that other class's 305...

.........................................................

The Olds motor is a 5.0liters (307.12 cubic inches) H.O... "heres what it has from the factory" full floting horseshoe pistons, roller cam and lifters ... 7A heads... 800cfm carb... HEI distributor, olds also ran timing (20 degrees advanced)... aluminum manifold...

mods......things i have done, or are doing................

took off all the emissions ****....

took off the 7A heads and replaced them with 5A heads... heres the number info

"7A Heads"
Combustion Chamber Volume 64 cc
Intake Port Height 1.30"
Intake Port Width 1.30"

"5A heads"
Combustion Chamber Volume 67cc
Intake Port Height 2.03"
Intake Port Width 1.30"

Also knock out the A.I.R tubes in the heads, witch should make more head flow ... AIR tubes are for emissions...

Took out the valve springs, replaced them with duel coil HI- proforments valve springs for a 350

polished the valves

also filed down the 2nd dariy latch on the carb instead of opening at 60% they now open at 100%

MSD HEI distributor ... and plugs...


Brand new metal timing chain... "GM used the plastic ones"

putting in a bigger roller cam... the cam now is "440" Intake and Exhaust Lift
looking in to getting something bigger then "572"

also have headers...

K&N filter, like it really matters that its a K&N

14" or 15" open element air cleaner

the engines going to be balanced, and honed,

not sure what im going to set the timeing to?

......................
Can any one give me some numbers?

 

a polished and non-polished valve i did

 

any tips or tricks?
by the way forgot to tell ya... the 307 came stock with 180hp

 

With that combination of mods I think you might be sitting around the 300 hp mark. I think the 305 will win, although I'd like to see what the 307 is capable of.


Those valves are looking pretty good.

 

If all your doing a is a fun pull on the dyno for max hp, get the biggest highest compression domes that'll fit and a big cam. Port the heads to the max and let'er rip. I'm sure there are some Olds web sites out there that can get you going for little tips and tricks.
Doesnt seem odd the guys running mopars, fords, olds, pontiacs are just a "little" different than the "norm"

 

hate to tell you, but yours is actually a 5.1

 

What yr the 307? in 86 & 87 they switched to a roller cam which didn't really help any. The 87 regal I had w/the 307 & 500 yrds of Vacuum hose was still a dog.
Edelcrotch makes "some" stuff for teh prior yrs 307, although I rank it up there w/the Poncho 301

 

Project: 85 2.8 bird
what the hell is that in your icon in the back window?

 

It's a 5' tall stuffed muppet "Animal" I won a few yrs back at Kings Island. Same thing as Kings Dominion, just different name.

http://www.daytonfbody.com/bb/viewtopic.php?t=560

slightly bigger pic of it.

 

heh heh,

 

my friend had a 300 HP 307 in a second gen. the car was stolen and stripped though the thing ran high 13s
it wasn't an olds 307 though, it was a chevy (stroked 283 is basically what a 307 is)

 

that sucks about your friends car,

iv heard of some trans am around here with a 307 and runs mid 12's im not sure if its olds or chevy...

 

307 was a 283 block and 327 crank.

 

So basically it was the ****ty parts lefts behind after chevy built the 302s?

 

still better than a 305!

 

i doubt there is even enough difference to mention.

i suppose the 307 might be better than a 305 because it has a slighty larger bore, that could allow for larger valves.

as said above, the 307 was simply the leftover parts from the 302. the 327 crank, and the 283 block.

 

From my experience the olds engine should make more torque. Make sure you hog out the the intake ports on the heads and manifold.

Depending on how bad you want to beat the other team. You can find lighter rocker arms and titanium spring retainers. That would help reduce the mass of the valvetrain.

After inital break in I would also run a 5/30 or 5/20 synthetic oil for the dyno pull. What happens to the engine after the contest?

 

bigger bore and smaller stroke. if it can run 2.02/1.62 valves it's much better than a 305 cause it can run any 350 head, and I am pretty sure they can. as I said my buddy had a 307 putting out close to 270 RWHP (around 300 CHP) and it was nowhere near wild
yeah it was sort of a throw together, but a stroked 283 (307) is better than a de-bored 350 (305)

 

port work and compression!!! If you cant afford pistons, mill the heads down as far as they will go before you run into piston to valve and piston to head problems.

 

if its just peak HP you're after, hog everything out, stick a big cam in there, run a large carb... (or dual carbs!) get/make some headers, ect... :lala:

 

haha that little dancing ninny is true to that statement lol. if it's just peak HP you want, get a supra and race dyno runs rofl!

 

olds 307 = 3.800" bore with 3.385" stroke. Chevys 307 = 3.875" bore and a 3.25" stroke. The olds has a little better bore to stroke ratio than a 305 and chevy 307 having the best of the three.

 

take a 307 over .030 and you've essentially got a destroked LS1, that means big valves! I'd say it's second only to a 302 as far as it's displacement is concerned

 

Well Today,
i took off all the EGR stuff in/on the intake,
also got a set of roller rockers off a v6 that came in... they fit perfact now just need 2 more...
im all roller now

 

well i just tested the rollers on another 307 that runs, they bolt on and line up perfact, but they dont seem to work that well... i need a braket to keep them in place... they walk around the valve spring... and im not fab'ing up brakets
o'well back to stock

 

im getting the 307 after im done with it, im thinking of droping it in my camaro if i makes more then 300hp... what do you guys think?

 

The 305 chevy is going to toast you in low end torque and maybe horsepower. I am making 250 HP @ 4,500 at the rear wheels with my little 305. It still has the cast iorn manifolds on it too. The bore stroke ratio of the 307 is about ideal for max horsepower. Make sure you get the right intake for the heads. An Edlebrock intake should fit the early model 307 heads. Gasket match and pocket port the stock heads, leave the 1.75 & 1.50 valves, 8.0:1 compression, 795 cfm q-jet, 1 3/4 x 3 in headers, an isky non roller cam P#691262 ( 208* @ .050" intake and exhaust, .445" lift). Desktop dyno estimates.

RPM HP TQ
2000 118 310
2500 149 314
3000 182 318
3500 215 322
4000 247 324
4500 272 317
5000 285 299
5500 284 271
6000 269 235

Sounds like a healthy small displacement motor to drop into your camaro. You will need an olds trans either 2004r or TH 350. You can adapt mounts. The engine is about the same size as a smallblock chevy and weighs about the same. Shouldn't be that hard of a swap as chevy made many cars where they used these engines interchangably such as the monte carlo and the cutlass, cadillacs, caprices, etc. You are going to have to retain the olds computer or else you won't have timing advance.

I want to know who told you a 307 chevy was better than a 305. The 305 will run circles around a 307 in the same vehicle.

 

you should pm Gumby he's some kind of either a olds or buick freak maybe he can help you out

 

Your shop teacher is possibly either:

1. Having a big laugh at your expense;
2. Planning to manipulate the dyno results like a Florida election;
3. Has a reverse bet with the other instructors that it won't cut it (ala Pete Rose);
4. Doesn't have a clue;
5. Intends for you to learn by example of what NOT to do.

Polishing the faces of the valves is good practice, but will net you a whole zero horsepower and torque. You really need to pay attention to the other side of the valves, the stems and perimeter, and probably should do all that on larger diameter valves.

Lowering the static compression isn't going to produce more of anything but inefficiency. You'll have to do something to the chamber to get the compression back up to at least 9.5:1. Big free areas arent' going to help cylinder scavenging, charging, or mean effective pressure.

Removing the EGR will gain you nothing but perhaps a little more space to work.

The "5A" heads may have taller ports, but also need deeper valve bowls and larger valves to take advantage of the port volume. If you have iron heads, enlarging the valves should be easy. Make your flow through valve diameter instead of lift as much as you can.

I don't agree with the bore/stroke ratio advantage being in favor of the Olds engine to the point of any significance. For peak HP (which is usually measured as torque at RPM) the shorter stroke Chevy 307 used in the comparison has the advantage. For peak torque, the Olds may have an edge, everything else being equal. That is for a dyno pull, not a street engine - which is supposedly what you are shooting at. However, since you are competing against a 305 Chevy, the advantage for RPM goes to the slightly shorter stroke Olds. The heavy crank in the Olds may be a penalty, however. When you balance the assembly, be aggressive.

What length rods are you installing? What dome/dish volume pistons?

 

It's a little difficult reading but I know someone who has put some time into his 307:

http://jimscutlass.tripod.com/id17.htm


You definitely did good on changing the heads. The problem you'll have with the 305 is that stock, they had bigger valves, higher compression ratio, better flowing heads, bigger cam... lots of which doesn't matter since you're changing your parts out, but all stuff to consider and shoot for so you can beat him.

Excellent move on going w/ roller block & 5A heads.


You can build a killer 307, but it'll take some work for sure.


175 actually in 86-87 with the 7A heads. Those heads are built for velocity, not flow as you saw. Kinda like the TBI SBC truck heads of the late 80's / early 90's





Agreed; a negligible difference in bore / stroke ratio isn't worth discussing when there is head work and cam to be done.

 

Oh, did i mention im in a auto class? And every thing im doing is free? and im learning things i didn't know? Sure the olds 307 isn't the greatest build up.. hell i would shall out my own cash on a 350 and make it a 383 if we had one... but we don't... so before you bash me... just think its not like im spending any money on something stupid ... hell im taking it home for free
maybe all weld up a go-cart frame and put it on there? and race you? LOL... then will see who makes more power? or will your 4.6 HP lawnmower take me?

By the way your Location? A galaxy far, far away... i bet its your moms basement, with a post count like that... im not trying to bash you, i just want you to think what you said was wrong.... it isn't pointless to build up a olds for learning purposes and have some dyno fun.. at no ones cost...

 

the engine is gone, there is no more engine...
it got tossed out like an ugly 2 doller *****...
long story - to much money for a new crank they wouldnt let use run it with out a new one...
o'well nothing i can do...


can i use the olds 350 duel coil HI- proforments valve springs
for some chevy heads?