webered 289 output

tblackgt350 · #1 (**permalink**) 09-05-2002, 07:33 PM

To all you guys running 289s that have dynoed your car-

What kind of numbers are you getting? I have a 289 hipo with 48 IDAs running just under 10:1 compression. My rear wheel HP on pump gas is right at 300. The only thing I have yet to do is play with the air correctors a little more to see id richening up the top end may help a little. Should I be making more power?

Thanks,

Tim

Jeff Frigo · #2 (**permalink**) 09-05-2002, 07:38 PM

Need more specs. Who's heads, ported or out of the box, what cam, which intake?

acaskie · #3 (**permalink**) 09-06-2002, 06:53 AM

Given the drivetrain power loss, you are around 365 HP at the flywheel. As I recall, the original motors running 48 IDAs and 12:1 or so on the compression with heavily ported Hipo heads were making around 380 HP-- I don't have the cam specs. So you're probably in the right neighborhood.

I have a mild 351 with 48 IDFs, 9.25:1 compression, .477 lift and iron GT-40 heads. In current tune it makes about 330 HP at the flywheel, with a bit more possible.

In all, I would think you're pretty close to where you ought to be.

Charlie Conner · #4 (**permalink**) 09-06-2002, 09:15 AM

Are any of you measuring the fuel air mixture at the individual exhaust ports to determine optimum tune for each cylinder? My headers have 1/4" bungs in each tube and i'm looking for information on testing equipment that will fit there. I just installed 1" billet risers under my idf's so that i can easily get to the idle air adjustments, hopefully it will improve performance a little too. i will dyno again after i change to gt40 polished and ported heads, i'm running a stock 95 302 crate from ford, my horsepower isn't worth mentioning yet, i'll report back after the head and rocker change. I posted an image of these in my photo gallery.

acaskie · #5 (**permalink**) 09-06-2002, 12:01 PM

Charlie,

You are very diligent to try to measure individual cylinder exhaust outputs. Please post whatever you are able to determine as a result.

What cam are you using? If it came with the crate motor, it may not be ideal for the Webs, and all the tuning in the world won't get you where you want to be.

If you haven't already put your car on a dyno, it might be good to do so before you make all the changes, just so you have a base-line for comparison purposes.

The spacers are impressive. IF they make a significant difference other than in ease of tuning, that would be worth posting as well. Good luck.

427Aggie · #6 (**permalink**) 09-06-2002, 12:45 PM

Actually CalMetal told me a trick for setting them right...you have to get them close and then run then and read the plugs...check to see which cylinder is burning the best...

Then you use a laser temp meter to measure the temp of the header for the cylinder that was burning good....adjust the other carbs to get the same temp on all 7 of the other exhaust headers...

Other than an O2 sensor in each header I don't know what you will get from the setup you have.

Matt

tblackgt350 · #7 (**permalink**) 09-06-2002, 05:04 PM

I also have heard of the pyrometer trick; run the engine up to 5000 rpm and then cut it off. Check all the plugs, looking for at least one that is "malt brown" in color and take your pyro reading off that header, then adjust the other cylinders to the same temp.

I'm running a 289 .030 over, 10:1 compression, solid cam of actual duration 236, lift 528. The heads are stock 289 iron ported and cut to accept 1.6/1.9 valves. I'm running blue thunder's weber intake with 48 IDAs. I'm using the stock tri-y headers and 2 1/2 in exhaust with Dr. gas crossover.