505 stroker, stealths, full TTI exhaust, 830 quick fuel, perfromer RPM Comp hydraulic roller XR280HR-10 2800 Stall 4767lbs race weight 3:23 gear with detroit locker 275/60/15 M&H racemaster drag radials
This is frustrating, anyone have any ideas?
UPDATE: Played around tonight, the trans is shifting weird. Its taking about 2-3 seconds between the 2-3 shift. I will mess with it to see if it was part or all of the problem.
UPDATE/UPDATE Got the trans back in finally, and went to the track last night in the 100+ degree heat. As always I drive 70 miles, swap to the drag radials and get in line.
The first 2 runs the car vapor locked at 2/3 track.
I let the car sit for 3 hours with the hood up till I could touch the manifold and radiator without discomfort.
Car went:
12.67 @ 105.9 MPH 60 foot 1.725
I still think the car should be faster with the CNC'd heads. The plugs show it to be a bit rich, but i am ok with that for now. I set the cal-tracs at 1/4 turn of preload. I did fab and install sub-frame connectors since the last time I was at the track.
Joined: Thu May 01 2008, 11:15AM
Location: Chicago,IL
Posts: 2868
Sounds like you didn't get the kickdown linkage put back correctly when you put the engine back in. The trans needs to increase line pressure as engine output climbs to not slip
Joined: Fri Mar 13 2009, 11:21AM
Location: San Marcos, CA
Posts: 713
I wonder if the jetting needs to be changed. The lower trap speed says you don't have as much horsepower. Were you shifting at the same RPM or higher due to the higher flow? The porting may have have made the motor loose bottom end torque so it is not gating as hard as before. I'd try messing with the timing and jetting, maybe try higher shift RPM.
Joined: Sat Apr 29 2006, 05:11PM
Location: Cincy
Posts: 269
Ok - not enough information to fully help but I have some comments:
- I think that is a good 60 foot for your combo - what are you revving the motor to at the track? My experience with hydraulic rollers for mopar big blocks revving much over 5600 (5800 max) is a no go. They float like crazy at low rpms - mine floated bad by 6000 rpm. - the et versus mph is about right - my calculator comes up with 465 hp - that is pretty light but I don't know if my calculator works well with such a heavy car - what is your actual compression? - that cam is a bit light for a 505 and decent heads - what was the actual flow of the heads before and after? - sure you are not running out of fuel? - what is your total timing?
Closest I came to your car was my 67 Coronet street car with AC - weighs 4025 lbs with me in it. 440 with my home ported 906 heads at actual 9.05:1 compression. Very similar hydraulic roller cam to yours (just a touch more lift and duration), 3.55 gears with 255/60-15 tires. 9.5 inch converter was failing. 750 DP carb. 1 3/4 headers with full stockish 2 1/2 exhaust.
Car ran 13.30 @ 101.75 mph with zero tuning and the converter failing. Pretty sure it would have gone high 12.90's in good weather.
So given your weight disadvantage versus my car I put your engine in my car about 0.9 - 1.0 seconds faster but you have many more cubes and much more head so that may or may not be great.