Since moving to ports......

[gregm784]

Fuel distribution / plug reads are nice. It just feels like i'm having to use more mag to get it to run than years past.

Could it be a low pressure deal? i'm running right at 100psi, used to run 150-160psi. (Enderle 600 pump)
My MSD points box is <1 year old, but it could be taking a crap i guess. i will put my spare in and see if it changes.

If it were the mag, my plug reads would be rich i suspect, and they aren't. 1/2 crown on my plugs.

WHen i went to ports, i kept my jet area almost identical (within a few 10/1000).

8 x 32 in hat
2x31, 5x35, 1x39 in manifold, 95 main, 60 in HS @ 66#
8.91gpm
4% under on a 6:71

It was running 7.50 at 27*. up 2 * to run same #s now.

Something changed........

[gregm784]

Here are my numbers.
Ports:
.031 .0007548 2 .0015096
.035 .0009621 5 .0048105
.039 .0011946 1 .0011946

Hats:
.032 .0008042 8 .0064336

Ports: .0075147 54%
Hats: .0064336 46%
Total: .0139483 100%

Hats only .012164 (8 x .044)

13% more jet area with ports

Obviously, i'm going to pinch my ports down some to get my jet area & system pressure back. I bet it picks back up.


oops.......

[32bantam]

How old are the plug wires? The BBC blown T/S car I help on had a issue with a cylinder not firing consistently.  We ohmed the wires twice and all was good. We chased it for two days...even put my whole ignition system on it...but not the wires...and still had the problem. As a last resort we put a spare set of wires I had on it and fixed it!!!!!

[JrFuel Hayden]

We had the same problem , couldn't find the issue, we changed plug wires, and picked up 2 tenths, won our 1'st JF race with the Hemi, the wires and ends were shorting out in the Hemi plug tubes.

[gregm784]

I found a broken converter.
I have new plug wires and i think i'll cycle them in. I can't see any dead holes on the onboard camera, but that doesn't mean it isn't squashing the flame front

[Paul New]

I bet you had issues at the first race with ports and that was your ET slow down

[JrFuel Hayden]

Greg, what broke in the converter and how did it brake ? I have never broke any of my A-1 converters, what were the signs that it broke ?
I assume you have either 8" or 9" converter, if you'd like to try a 7", I have some I could sell  cheap.

[gregm784]

9.5" (stamped on case), i thought it was a 9". 

Broke the stator. 

60's tanked and killed the fluid.

[Paul New]

Have they cut it apart yet

[gregm784]

Nope.  i'm pretty sure it's gonna be junk.  i get my Spec-Right saturday.

[Paul New]

Oh excellent all new!

[JrFuel Hayden]

Greg, you might ask your converter guy if your stator blew because you might be taking too long of a burn-out.
A-1 told us 20 years ago to get off the throttle when the tires hook, and not past the tree. It's too hard on the converter.
I'm still surprised you are running a 9.5 converter, while you are running 7.60's, making under 1000 hp, but then again you are running those TF tires, another question for your converter guy.
The only team I know that is running a 9.5 is Dennis Murphy in his NA/F blown Brad  motor trying to run low 6's and 220 mph.
Your 9.5 is heavy rotating weight, using up HP to spin that stuff. I think another blown Alan Johnson  combo I know , I think is using a 9" and he has just run 6.08, 225 mph  in NA/F.
I know you don't want to run better than 7.60, it seems it could be hard on parts.
Jon