Motor was deadly consistent. Had some other issues with motor.(broke crank)replaced crank freshened motor. Decided to try some AFR 220 heads. Old heads were Iron world products. Car picked up .15 or so. I know they flow better so I jetted up some (alky). Varies 2-3 numbers now mostly from 330 on. 60 foots are consistent.
Any ideas?

Jay, two suggestions for testing;

*return jetting to the original consistent configuration.

*what was the ignition timing with the iron head package?

in some cases, methanol will like 2 - 3 degrees maybe even less, timing, need to experiment.

It was ran with original jetting. That's why I changed it trying to get better.
Timing is at 34 deg.

another thought, aluminum pulls heat away from the chamber more than iron, may need to stage at higher engine temp.

Yes....thought about eng temp last night...usually 170 at stage.
Wonder what plugs are same as autolite AR135. That's what other heads had. These heads have to have the longer with gasket. I had NGK (don't know number, I'm at work)..I put AR3910 in last week.

Post a picture of the plugs



Joe

OK...been a while since I've posted any pics...how you do it now?

I used to use accel 143 , or champion n4c both have the non- projected nose. These are 3/4 reach. In a 355 and a 406 w/ brodix track one heads on alky, temp staging was 170-180 and timing 4 to 6 less than gas and shift it early (6400 vs 7k w/ gas)

Id go to a NGK R5672A-9, if you think it needs hotter go to a 8. Autolites are no good anymore IMO.

For what it's worth my sbf stuff ran best at 31-32°. What is your fuel system setup?

I used to run 3910 on alky as well in my sbc, got tired of having issues with the plugs. switched to ngk - 8 and got much better, ended up going to an ngk - 7 was even better, and started a bunch better.

Crazy idea but any chance the broken crank did some damage to the converter or transmission? Only thing that happens between 60 and 330 is the shift.

I read that wtong you said 330 on, my bad. Is the mph consistent or does it vary like the et does?

Ngk that I was running is R5671A-7
Autolite I ran this weekend is AR3910.
Have pics...now to figure out how to post.

Oh well...went to postimage photo hosting site...not sure what I'm doing...could post pics using photobucket years ago...guess I'm getting ancient.[IMG]URL=http://s1253.photobucket.com/user/Jay_Giles/media/image_zpscvrkhfpk.j [IMG][/IMG] peg.html] [/URL][/IMG]

This message has been edited. Last edited by: jay giles,

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PICS FINALLY

Is the car in your avatar the car in question? Did you reset ride height after putting the aluminum heads on the car? I wonder if the front end is up higher and not possibly tripping the same everytime. Have you tried racing at a different track?

Yes that's the car. If it's up higher can't be much. But yes 3 different tracks.