In the Jan edition of CC, "Whats your problem," there was information about how to improve the performance of a 307 engine.  I unfortunately missed the article.  Can anyone tell me the just of it, or have suggestions?

tHANKS

350s are cheap and easy to find, thus making the outdated 307 useless as it never had anything really good about it. (a bunch of the parts don't even interchange to other smallblocks) If you are totally stuck with a 307, say and cannot remove it, do a carb, intake and headers, and a cam too, if you are willing to use crappy heads with a good cam. You can use good heads on a 307, but it wouldn't be worth the time really. 307 engines came with 2 barrels, and really weak heads with 1.78 valves so there is lots of bolt on improvement, but by the time that is all said and done, it would be easier to find a good running 350 Qjet somewhere else that had, say an 882 head on it from the factory and you would be better off performance and money wise. Easier to swap a used motor than bolt a bunch of 350 parts on an engine without a future.

Will

IMO, if you're limited to using the 307 (because of $$ or other reasons) then do the best with what you have.  You can make a 307 a respectable runner in a light car.  The 307 is merely a stroked 283.  You just need to know that you're going to have some limitations, particularly with cylinder heads because of the small bore.

I agree with HW.  If you can spend some extra $$, in the long run you'll likely be more satisfied with a 350.  The options and resulting performance are much greater with a 350.

Bottom line, if you can, then build bigger. 

Everyone uses 350's. Do something different. My 307 can run just as good if not better than you 350 punks.  Every do dyno's? 307 has same HP and about 30 less torque but saves a lot of gas and has higher RPM range. 350's stop 500 less at making power than a 307. Also less weight to move around. Do something different. Everything on a 350 fits a 307 except pistons, rings and crankshaft. I put 305 heads on mine with 1.85/1.5 valves for a ratio of 10.5:1. Lot's of 305's and perfect for the 307.

My friend, you have NO idea what you're talking about....

"Everyone uses 350's."

Have you ever wondered why?  Hmmm, I'm sure it has nothing to do with availability, a much more efficient bore/stroke combo, plus 14% more cubes. 

"My 307 can run just as good if not better than you 350 punks."

Obviously, you've never encountered a wild-oats 350.   

"Every do dyno's? 307 has same HP and about 30 less torque but saves a lot of gas and has higher RPM range. 350's stop 500 less at making power than a 307."

LOL.  As my daughter would say... whatever. 

"Everything on a 350 fits a 307 except pistons, rings and crankshaft."

You missed a pretty important component.  Try bolting a set of 2.02 or larger heads on your 307.

Nice try Sparky.

Less weight to move around  ?

If anything a 307 probably weighs more than a 350.  Smaller bore means more iron block and less aluminum piston.  The block itself has the same dimensions.

Whats this guy thinking a 307 as good as a 350 man thats the funniest thing ive heard all day. And about the weight 307's make a great boat anchor because you throw in once and they ain't worth pulling out the water. Seriously I would rather build a 4.3 or a 305 than a 307. Yes with the proper money a 307 can be bad but why I mean their's plenty of 350's out their. This guy just needs to leave because hes embarassing himself  

And I would say "whatever" to a 350.  It's all in how it is built. You seem to forget that.  Any engine can be built to do X HP.  And it DOES have less weight to move around. LESS WEIGHT IN THE MOVING MASS. .125" extra per cylinder wall does NOT add much weight. The pistons are smaller, hence less weight to move on the crankshaft, and less stroke, hence less weight of the crankshaft, hence HIGHER RPM. I've done PLEANTY of dyno sim's to prove this.  2.02 Valves? yeah might help, I'm NOT A RACER! don't NEED those.   350's are popular because you can by parts anywhere for cheap. You can stroke a 307 to 328 if "cubes" really means more power. Every dyno I have done does NOT show this. It's the type of cam and CFM's you get into the engine. HPTV proved the software is very close to real life.  I've done my homework. Wish you people would to.

Yeah and oh btw, when your 350 stops making power at 5500 RPM, I'll pass right by you at 6K.  If 350 is SO great, why are there so many articles on how to DE-STROKE a 400 to below a 350? Why is carcraft and hotrod (both the same company btw...) putting stuff out on how to build up a 307? huh?  read. Reading is learning.

Quote from August 2002 HotRod PG 38:

"How to make your 307 Live"

"...To make the pistons work with the extra 0.250-inch stroke (compared to a 283), just use stock chevy 400 rods, which are the shortest OE rods at 5.565 inches. Short rods are usually a bad plan, but with such a short stroke, the rod ratio is still 1.71:1, BETTER than a stock 350's" "...with 64cc chambers in the heads, you'll have about 10.0:1. It could make 350 HP very cheaply if you step on it the right way"

And this is true with every dyno sim I have run. Easily make over 400 with a roller cam but I aint spending that much money.  My engine will have more than 10:1 thanks to the 57cc 305 heads. Oh btw, valve size does not mean XXIT at high altitude like me. 

My final point, everyone has 350's. Every car and truck ever made by GM that has a V8 is either a 350, 305 or 400. Yes bigblocks but those are mostly only found in suburbans and I still see a higher % of 350's than any other engine when I look at the junkyards.  Build up what you have. Everyone has a 350. Hence the parts are there.  And anything works better with a charger :P

I'm happy with my 307, when it had 882 heads 8.4:1 compression. It's about to get better.  I've done my homework when justifying weither I wanted to swap it out for a 350. And with every dyno I ran, I couldn't justify the time or the money.  3 extra HP at the top end and 30 - 50 TQ wasn't enough for me.

You state that your are not a "racer."  Yet, you want to debate with one.  Pal, you're debating (read: fighting) out of your weight class on this subject.

Just a couple of comments, then I'll move on:

1. Go back and read the previous posts contained in this thread.  Only this time comprehend the content of each post.  I never commented on the reciprocating weight difference between a 307 and 350.  Of course, a 307 has less reciprocating weight... tell me something I don't already know.

2. "You can stroke a 307 to 328 if "cubes" really means more power."  You need to bone up on the subject.  Cubes really do mean more power.

3.  "Every dyno I have done does NOT show this."  Really?  Pal, get out from behind the laptop software dyno and get in front of a real dyno.

4.  "...when your 350 stops making power at 5500 RPM, I'll pass right by at 6K."  LOL.  Since you don't know me, I presume this is a general statement.  But, if meant for me... the shift point in my 350 Chevelle is actually 7,600rpm.  Makes plenty of power above 5,500rpm.  Visit a real track, there's 350s out in autoland exceeding 9,000rpms. 

5.  "If 350 is SO great, why are there so many articles on how to DE-STROKE a 400 to below a 350?"  The primary reason one would de-stroke a 400 is to take advantage of the resulting large bore/short stroke combo and still meet a class cid restriction.  Note that I stated "large bore."  Something 307s don't seem to have. 

6.  "I've done my homework.  Wish you people would to."  Again, as my daughter would say... whatever.  Pal, you might think about getting your head out of the magazines and get it under a hood of a real car (not a cyber car).  Try expanding your knowledge beyond just the magazines.

Suggestion for next time... if you're going to debate, ensure you have more factual knowledge contained within your posts.

"PLEANTY" of dyno sims.  Looks like you forgot English when you were doing all your "homework".  It's spelled p-l-e-n-t-y. I would have chalked that up as a typographical error if you didn't take the time and care to put it in all capital letters.  I wouldn't exactly call dyno sims homework anyway.  You could type in a Briggs & Stratton with a supercharger, .900 lift cam, and 25:1 compression ratio and say it makes 700 hp but so what?

I say "whatever" to your 350.  Come on, what are you, a 14 year old girl?  You may as well have typed "talk to the hand".

I'm sorry about the weight issue though.  I didn't realize you were talking in terms of reciprocating mass.

Also, it should be "Wish you people would too."  Not "to".

You guy's aint worth my time. If your only argument is 2 misspelled words, then just shut up.  I told you it's how the engine is built. Not wasting any more time.

Ok, ok, ok!!!   I was just trying to get some help.......  Let me give you a little more background....

This little ole 307 is in my 71 Chev pickup that I bought brand new!!!  Yes, that's right, brand new.  So you can probably figure out, Im not a teenager fixing up my first car.  But, I don't have a lot of experience in the high performance field......

I just change redid my suspension.  2.5 " drop spindles in the front, and a 4" drop in the back.  I replaced the old 4 speed "granny" with an M-21 and now ready to attack the engine.  But, I don't want to replace it.

I have purchased a set of headers, plan to change the 2bbl carb and obviously the intake.  I did see the Horsepower TV show this weekend, and it looks like a new cam, timing gears/chain and lifters would also help. 

So, I would take any suggestions seriously, as long as they are not about replacing the engine....

P.S. - I did enjoy the comments back and forth, until they started getting personal....

Thanks for your help....

Let me tell you what I did to my 307, and why I think it is a good choice. I'll also include my issues with jegs and summit for only supplying parts for 327 and higher...

First off my engine is a 1970 307 block which someone before me fitted with 882 76cc heads. They left a GM 4bbl intake and Quadra-crap (holley rebuilt) with stock exhaust manifolds.  The engine smoked like a mother till I tore it out, reringed it and put it back in.

I am working on it again, putting better rings, and a new crankshaft since I never replaced it and it needed it. Rear main seal has never sealed up, so I figured it's time to get a crankshaft kit (12330 from advance auto) with matched bearings.  I purchased an acrylic mr. gasket rear seal from jegs.  The performance parts I put in this engine is as follows :

Edelbrock RPM manifold, 600 CFM Performer carb (1405) added electric choke to it,  put a set of flowtech longtube headers, Energizer 280 cam, Mallory Unilite distributor, Accel CD style 48k coil, Accel 8.8MM race 300 wire, proform 6" harmonic balancer, K&N filter and a double roller timing chain.

My current modifications are using the above mentioned components but going to a 305 57cc head with 1.85/1.5 valves from an 83 Z28. This changes my CR from around 8.4 to 10.5 (give or take) Also putting on a new 2000-2600 stall converter and flexplate.

I have found the Crane Cams PowerMax 260-2 cam is more optimal for this engine as it moves power and torque down to 2000k but still is making close to 360HP at 6K like the 280. I am thinking of switching to this cam to see if it does work like my software shows. It puts 50TQ more at 2k than the 280 cam. On this engine, with slightly less torque than a 350, getting all you can will help.

Problems with the 307 are that no one sells performance parts such as, pistons or rings or crankshafts for the 307 like the 350. Jeg's and summit both lack any piston sizes smaller than 4.000 and rings for a 307 are +.030 over and thats the only choice. Other than the internals, everything you put on the 307 including cam will swap to the 350 if you so chose.

This is the parts I have chosen and recommend them. I think a 307 is cool since they are harder to find and it's cool to get them running as good or better than 350's. But like I said, it's all about how it's built.  Every engine runs better with turbo's 

As stated in my earlier post... 307s can be modified into a nice little combo.  Just understand that they have inherent limitations, and set your goals appropriately.

Sounds as if you're just looking to freshen up your engine with a couple of simple mods.  If so, here's my suggestions:

1.  Rebuild the short block, with a new set of pistons/rings, bearings, etc.  Replace the oil pump while you're at it (cheap insurance policy by doing so).  Keep compression near 9:1.  Re cam selection... go with a hydralic set-up.  But, call several cam manufacturers and ask for their reco.  Here's why:  Most cam descriptions for the sbc are based on installation in a 350.  A given cam will act as if it's a "larger" grind in a 307 than a 350.  So check around with a couple of different tech lines.

* You'll probably find that a cam in the range of 0.450" lift and 220* at 0.050" will work well and give you a little lumpy idle. 

2.  Clean up the heads (e.g.; valve job, fresh springs, etc.).

3.  Up top, install a nice looking dual-plane intake and saddle it with a small vac-secondary carb (e.g. 600cfm).  You won't need anything larger.  Install a good HEI ignition system. 

4.  With your headers, add a set of quality 2 1/2" mufflers and full length pipes. 

With this, you'll end up with a nice running and sounding little small-block.