Dialing it in - Carb issue and a bit of fun?

[KFreddy]

I've gotten just beyond the break in period with a ZZ454, about 650 miles on it now. I'm now trying to dial the motor or more appropriately dialing in the carb. I started with a stock 3310 Holley jetted 72F and 76R and 32 degrees of timing. Needless to say not enough timing, engine felt flat all around. I then advanced the timing to 36 helped out alot, smoothing out the idle, cruise and WOT. No knocking or pinging so I've left it locked at full advance 36. But the power still felt flat. Switched to 74/ 82 jets motor woke up abit but the plugs blackened within 10 miles. Went to 68/ 81 jets, no more black plugs, there was a slight hesitation at cruise to light throttle and a definate bog off the line at WOT then the engine would run like a raped ape after the bog. (*see below) I figured it was the accel pump cam or the squirter so I went from a green to a blue cam. This took care of the off idle to WOT bog but now the motor feels flat again above 4200 rpms. I know I need to just keep playing with different combos, but any input would be great.

ZZ454, Th400, stock converter 3.08 rear, Accel HEI

(*)So I'm cruising around town, 11p on a 2 mile strech 4 stop lights coming off the beach in North Miami. Stop the first at a light and a Chrysler Crossfire pulls up next to me, I think nothing of it. Light goes green and the guy just pegs the hole shot. Now I'm thinking I'll be dammed. We hit the second light and it's obviously on... I'm not power braking it, light goes green Crossfire jumps out of the hole, as I'm nailing it my truck jumps forward, bogs terribly then does the raped ape thing. Now this guys got no sh$t 5-6 car lengths on me and not letting off, truck rips 1st gear, nails 2nd, doing about 70 and I'm right up on his flank at about 5000rpms at about 80 or so I'm passing right by his door and the rear tires on the truck are spinning as I'm blowing by him... I let off. Stop at the next light and he looks over at me with this, somewhere between, bewildered and uncomprehensible look. I'm doing all i can do not to be a giddie school girl I'm so darn happy. So safe to say that a '72 with a 454 can easily lay waste to a 14.50 1/4 car... My joy has just begun

[dmsteele92831]

Nice burn, but there about a 14.7-14.9 car but once you get that carb tuned you'll be down right dangerous!

[bryanw1968]

Originally Posted by KFreddy

I've gotten just beyond the break in period with a ZZ454, about 650 miles on it now. I'm now trying to dial the motor or more appropriately dialing in the carb. I started with a stock 3310 Holley jetted 72F and 76R and 32 degrees of timing. Needless to say not enough timing, engine felt flat all around. I then advanced the timing to 36 helped out alot, smoothing out the idle, cruise and WOT. No knocking or pinging so I've left it locked at full advance 36. But the power still felt flat. Switched to 74/ 82 jets motor woke up abit but the plugs blackened within 10 miles. Went to 68/ 81 jets, no more black plugs, there was a slight hesitation at cruise to light throttle and a definate bog off the line at WOT then the engine would run like a raped ape after the bog. (*see below) I figured it was the accel pump cam or the squirter so I went from a green to a blue cam. This took care of the off idle to WOT bog but now the motor feels flat again above 4200 rpms. I know I need to just keep playing with different combos, but any input would be great.


ZZ454, Th400, stock converter 3.08 rear, Accel HEI

(*)So I'm cruising around town, 11p on a 2 mile strech 4 stop lights coming off the beach in North Miami. Stop the first at a light and a Chrysler Crossfire pulls up next to me, I think nothing of it. Light goes green and the guy just pegs the hole shot. Now I'm thinking I'll be dammed. We hit the second light and it's obviously on... I'm not power braking it, light goes green Crossfire jumps out of the hole, as I'm nailing it my truck jumps forward, bogs terribly then does the raped ape thing. Now this guys got no sh$t 5-6 car lengths on me and not letting off, truck rips 1st gear, nails 2nd, doing about 70 and I'm right up on his flank at about 5000rpms at about 80 or so I'm passing right by his door and the rear tires on the truck are spinning as I'm blowing by him... I let off. Stop at the next light and he looks over at me with this, somewhere between, bewildered and uncomprehensible look. I'm doing all i can do not to be a giddie school girl I'm so darn happy. So safe to say that a '72 with a 454 can easily lay waste to a 14.50 1/4 car... My joy has just begun

68 sounds about right on the front. You might try a little bit smaller than 81 in the back. Maybe more in the 78-80 range. I'm a believer in having it be a little fat on the back end just in case my foot gets a little to heavy

Sounds like you're real close though.
Good luck.
B

[jhow66]

Change pump squirtor to next size until off line bog goes away (put stock pump cam back in first).

[KFreddy]

Originally Posted by jhow66

Change pump squirtor to next size until off line bog goes away (put stock pump cam back in first).

Sounds like a great suggestion, trouble is the 3310 had a green cam in it when I got it, I have the blue one in there now, so my question is what is the stock cam color, I have the kit so I can do it right away.

I'm also trying to figure out why the above 4500 power dropped off a bit per TTT

[jhow66]

Pink cam is the stock one. 3310 should have a 25 shooter in stock form. Go to a 28 to start. As far as being flat above 4500, sounds like the secondries are not coming full open. Here how to check them: With engine off put a paper clip on the secondry rod up apainst the pod. Now go out and give it a test run. Stop and see where the clip is. If they are opening the clip will be pushed down the rod. If not the vacumn pod probably has a leak.

[68GMC454]

sounds like a blast, but a pink cam..

[KFreddy]

Thank you