[81 GP]

I went to milan dragway Friday night with my new KRE heads. My best last year was 12.57 at 106 with a 1.72 sixty ft. The only things changed were the heads, port match the intake, and set the timing back to 30deg. The end result was a 12.26 at 110 with a 1.66 sixty ft. We didn't have any time to make any changes because the track was packed, only got two time trials before eliminations. I talked to a friend whose similar GP runs 11.0's and he gave me three ideas to try if jetting and timing changes don't help. #1 performer intake too restrictive,[ try an RPM or Torker],.#2 switch from spreadbore Holley to squarebore[ better fuel distribution]. #3 is my Ultradyne 288/296 H10 cam not the best to use with these heads,[try a single pattern cam]..Maybe I'm let down because that 12.57 was run with a blown front power valve and a burned #8 exhaust valve on a set of 6x-8 heads. I hope there is a cheap fix here, budget is getting tight! THANK YOU.

[Goathead]

new KRE heads

What are the flow #'s on the heads and what drivetrain do you have?

[71 Ventura II]

What engine? Combo?

How did the weather match between last year and this year?

Timing at only 30 degrees you must be running a 455+, otherwise you would need more.

A 1.66 60' and 4 mph gain is pretty good without tuning for the better airflow! Give up some details so we can try and help. JD

[Fast 82]

I too have a Grand Prix mine is a 82 with a 455 with the same cam Ultra Dyne 288/296 Hydraulic cam with 1.52 rockers my heads are #64's ported by myself 221cfm intake and 200cfm exhaust. I run the Performer RPM intake with a Barry Grant 850 Speed Demon. I had mine at the track it ran 13.11 at 101 mph with a 60ft time of 1.77. My first run was a 13.51 (i had trouble getting out of second gear. Driver error). When I left the line I left off the brake both times. My goal is to run in the 11's. I didn't lower the tire pressure; i'm running MT 28x12.5x15 and the timing was set at 12 degrees initial. I have a 9" Ford rear with a 3.70 gear and 3200-3400 PTC stall converter. I'm running the Ram Air shorty headers that have been opened up to 2.5" on the collecter with 2.5" full exhaust. my rear suspension is Hotchkis boxed upper and lower control arms and a anit-roll bar, Eibach springs with C/E 3 way adjustable shocks. I need help also. i'm looking at changing my heads to KRE's or Edelbrock, but I would like to get the car close as I can to the 11's before I make the switch or can I run 11's with cast iron heads. i also drive it on the street.

[Croaker]

Originally Posted by Fast 82

I too have a Grand Prix mine is a 82 with a 455 with the same cam Ultra Dyne 288/296 Hydraulic cam with 1.52 rockers my heads are #64's ported by myself 221cfm intake and 200cfm exhaust. I run the Performer RPM intake with a Barry Grant 850 Speed Demon. I had mine at the track it ran 13.11 at 101 mph with a 60ft time of 1.77. My first run was a 13.51 (i had trouble getting out of second gear. Driver error). When I left the line I left off the brake both times. My goal is to run in the 11's. I didn't lower the tire pressure; i'm running MT 28x12.5x15 and the timing was set at 12 degrees initial. I have a 9" Ford rear with a 3.70 gear and 3200-3400 PTC stall converter. I'm running the Ram Air shorty headers that have been opened up to 2.5" on the collecter with 2.5" full exhaust. my rear suspension is Hotchkis boxed upper and lower control arms and a anit-roll bar, Eibach springs with C/E 3 way adjustable shocks. I need help also. i'm looking at changing my heads to KRE's or Edelbrock, but I would like to get the car close as I can to the 11's before I make the switch or can I run 11's with cast iron heads. i also drive it on the street.

There should be a LOT left in that combination, honestly. Either your car is a lot heavier than I would guess or you're down on power.

[screamingchief]

If I were looking for issues with the UD cams,first thing that comes to mind is degreeing,absolutely all UD cams need to be degreed,they are the biggest offenders of being "off" of all the cams I've done,at least two were off by 9 degrees,both were the hydraulics,and have heard of plenty of others,good cams,but they gotta be degreed IMO.

As for the first combo (81 GP),yeah,loose the performer,and the spreadbore holley,if you want a spreadbore,use a Q-jet with the RPM.

Single pattern cam is likely gonna do nothing to help if the cams specs are roughly the same.

The mild KRE-D heads did'nt really "add" that much,so I would'nt have expected big changes with just that change.

Fast 82,was your UD cam degreed?

[smagnotti]

Well lets use some logic here!, you put on better flowing heads, and then went racing, so if the weather that day was about the same as you best run with the other heads, how can you expect to go all the much better with out jetting up for the better flowing heads.Assuming your carb jetting was in the ball park before, I would have jetted up 2 jet numbers off the bat, just to be on the safe side of not melting something!
For your cams power range the RPM performer is the better choise.

[70 lucerne lemans]

You picked up about .3 and 4 mph thats about 30 hp,I think thats pretty good for no other changes.Now you just need to optimize the better flowing heads.

[Ron H]

You probably need an RPM or better intake to utilize the flow on the heads. If they are ported an rpm will even choke them unless very well ported.
Need more info on combo as noted above, exhaust, converter, gears, tires.

[Ducks Goat]

Did you check for proper pushrod length? When I went from my home ported 6x's to unported KRE's I had to use a longer pushrod.

[Ron H]

I had to go to a longer push rod as well.

[Fast 82]

Originally Posted by screamingchief

If I were looking for issues with the UD cams,first thing that comes to mind is degreeing,absolutely all UD cams need to be degreed,they are the biggest offenders of being "off" of all the cams I've done,at least two were off by 9 degrees,both were the hydraulics,and have heard of plenty of others,good cams,but they gotta be degreed IMO.

As for the first combo (81 GP),yeah,loose the performer,and the spreadbore holley,if you want a spreadbore,use a Q-jet with the RPM.

Single pattern cam is likely gonna do nothing to help if the cams specs are roughly the same.

The mild KRE-D heads did'nt really "add" that much,so I would'nt have expected big changes with just that change.

Fast 82,was your UD cam degreed?

Yes my cam was degreed; The engine is balanced and blue printed. And yes the cam was off by 2 degrees. I am also wondering if my carb is the problem because it kind of lays over going into 2nd. It just dawned on me that it maybe because the carb is vacuum secondaries?????

[Ron H]

Originally Posted by Fast 82

Yes my cam was degreed; The engine is balanced and blue printed. And yes the cam was off by 2 degrees. I am also wondering if my carb is the problem because it kind of lays over going into 2nd. It just dawned on me that it maybe because the carb is vacuum secondaries?????

Have you upgraded your fuel system?

[Fast 82]

Originally Posted by Ron H

Have you upgraded your fuel system?

Yes I have a 140gph pump with -8 braided line from the tank to the regulator and -6 from the regulator the carb.

[Ron H]

1 -6 an line with a dual feed or 2 -6 lines from the regulator?
What is your total timing?
What are your shift points and trap rpms?

[JSchmitz]

Which spreadbore are you using? A 650 or an 800? Single or dual line? I've gone 12.22@ 110 with a dual line 800 spreadbore double pumper. I think I would do the intake upgrade first and go from there. It's definitely the glaring mismatch in your combo.

[Fast 82]

Originally Posted by Ron H

1 -6 an line with a dual feed or 2 -6 lines from the regulator?
What is your total timing?
What are your shift points and trap rpms?

I am using a single -6 line going to a dual feed. My shift point is 5200 rpm.

When I dynoed the engine my combo made power up to 5250 rpm and the total timing was 40 degrees. I know 40 seems high but the engine took it. Every pass I made I adjusted timing and the engine picked up more hp and tg my final numbers with a Q-jet and a cast iron manifold with the shorty ram air headers was 421hp and 532 ft lbs of tq and that was at 40 degrees total timing.

[Ron H]

Originally Posted by Fast 82

I am using a single -6 line going to a dual feed. My shift point is 5200 rpm.

When I dynoed the engine my combo made power up to 5250 rpm and the total timing was 40 degrees. I know 40 seems high but the engine took it. Every pass I made I adjusted timing and the engine picked up more hp and tg my final numbers with a Q-jet and a cast iron manifold with the shorty ram air headers was 421hp and 532 ft lbs of tq and that was at 40 degrees total timing.

What rpm are you running at the end of the track? You will probably pick up a bit if you shift below that rpm.
You should have 2 separate lines from the regulator.

[Goathead]

I am using a single -6 line going to a dual feed. My shift point is 5200 rpm.

I'm with Ron, dump the single feed and get two seperate lines to the carb. Not so sure about that shift point either, but, without seeing a dyno graph, it seems low to me for that setup.

[81 GP]

Originally Posted by Goathead

What are the flow #'s on the heads and what drivetrain do you have?

Standard KRE 85cc D-ports advertised at 261/220 matched intake port to gasket TH400 w/ manual valve body, est. 3200stall TH350 converter 8.75 chrysler rear w/ 3.55 posi, 900-28 goodyear slicks {I noticed when I use my 275/60r15street tires I pick up 1mph even though my 60 ft slows to 1.90-2.0 - maybe 3.73 gear needed?].