Carb Intake question

[elzrcmch]

Due to the lack of of parts for a 307 (which i got mine rebuilt 10 years about and barely put 10,000 miles on it) I was thinking of upgrading the "computer" chip and I wanted some input on it.

http://www.jegs.com/i/JET/561/58606/10002/-1

Also I was thinking an Edelbrock performer intake but I got an 86...why does it stop at 85??? Would i regret it if i bought it?


http://www.jegs.com/p/Edelbrock/751403/10002/-1


Thanks Fellowship of the G-body pals

 

[dan2286]

I have heard that using chips on a car with a computer controlled carb really does not make a difference. The most it will do is advance the timing a little bit when at part throttle. At full throttle the chip wont do anything since the computer does not control the carb when at wide open throttle.

The intakes stop at 85 because 86+ cars use a differently designed head. The edelbrock will bolt on, but the intake ports will not match up.

 

[88ss408]

yeah if i where you i would hold off on the ecu chip.but i would find a set of80-85 307 heads and clean them up and swap the heads and then get the edelbrock intake. does your 307 have the stainless exhaust manifolds ??

 

[joe_padavano]

Due to the lack of of parts for a 307...

What parts are you lacking? Most everything that fits a 350 Olds also fits a 307.

I have heard that using chips on a car with a computer controlled carb really does not make a difference. The most it will do is advance the timing a little bit when at part throttle. At full throttle the chip wont do anything since the computer does not control the carb when at wide open throttle.

Dan is exactly correct. The chip market is grossly over-advertised. There is very little margin for adjustment that won't violate EPA requirements. As Dan correctly points out, you can simply change the metering rods in the secondary side of the carb since it is not computer controlled. On the other hand, without other mods to the engine to improve airflow, all this will do is make the car run rich and waste gas.

The intakes stop at 85 because 86+ cars use a differently designed head. The edelbrock will bolt on, but the intake ports will not match up.

This and the roller lifters are the two big differences on the 86-90 Olds 307s. The ports in the heads are optimized for low RPM flow. A popular swap is to use either the 5A heads from an earlier 307 or heads from a late 60s/early 70s 350. The latter won't have the A.I.R. ports drilled, which may be a problem if you are required to pass a visual inspection for emissions. The other problem with the CCC system is that the distributor advance is controlled by the computer. The only way to change the advance curve is to burn a new chip. The available aftermarket chips are unlikely to have an advance curve that will make much of a difference. There are several firms that will burn custom chips.

 

[elzrcmch]

First all thanks..
ah, ok but if i can't find reasonably priced heads..ffff-it I'm find a 350


I think its stainless steel

 

[beeterolds]

i sold a set of good 5A heads for lil over 100bucks.. running ready to go.. thats plenty reasonable.. keep looking..or try to score a running 350 olds..it bolts right in

 

[Blake442]

I've got a set of 5A heads that came off my '85 442, as well as the matching factory aluminum intake if you're interested.

 

[88ss408]

any junkyard should have a set of 5A 307 heads for a cheap price.and you should get a set of exhaust manifolds as well as the stainless ones look good . but they have small ports and would hurt performance.

 

[megaladon6]

the one thing the chip would be good for is more timing advance. stock timing is extremely limited. but since it's a 307 you won't get much. however, if you changed the heads, intake, etc. it might become worthwhile, if you're not worried about emissions. but if you're not, it's much better and easier to just get a non-computer carb and vac advance dist.

 

[foxtrot]

The Jet stage 2 chip (part no. 58603-s) is a good choice and it's ~$125... Make sure that you check the part number because the stage one chip bearly changes the timing profile.

You can also bump up the base timing to 22 degrees... Also make sure to watch for detnonation once you start messing with the timing...

You can also modify the secondary’s on the carb so that they open all of the way. Also can change out the secondary metering rods.

These mods along with a free flowing exhaust and air filter will wake up the motor some.

It's all about your goals and how much time&&money you're willing to spend. Before getting too deep it's always good to start out with the "easy" mods. Don't expect any miracles with the simple mods but you can definitely feel the difference in the seat of the pants.

Here are two good sites:
http://performanceolds307.tripod.com/
http://www.442.com/oldsfaq/ofe307.htm