I am not sure if this should go under engine or Racer section.
My brother, father nad I finished building a 408 stroker for my 72 Duster earlier this summer. We had a chance to take it to the track last Friday for test and tune. We wernt able to get more then a couple runs in but I was very disappointed in the performance and I would appreciate any feedback. I will let you know I can not give you feedback on how the car felt. It is my engine and car but I can not see well enough to drive and my brother is the driver. He didn't notice anything wrong though.
Shifting was done at 6500. according to my Desktop Dyno peak power is at 6k and pretty much flat to 6500. It didn't seem to fall off to us at 6500.
This was in Woodburn Oregon so near sea level. I think with the weather the DA was like 1500 that day.
The Engine
360.030
Eagle Cast Crank
Scat I beam rods
KB Icon pistons (O decked, .039 gasket, Compression is 11.2)
Trickflow Powerport 190
(These are the heads that have the weakest springs. 120 at seat. My heads call for 145 seat. I talked to Trickflow and they said should be fine, Two calls to Hoards once I was told it was fine and another call I was told he would feel a bit better if I shimmed. I left it alone and didn't shim.)
Howard Solid Flat Tappet 600/615 254/260 108 at 103.5 centerline
The updated Strip Dominator that shows MP for Mopar so basically M1. Whoever had it beore gasket matched
Howard EDM lifters
Lash set at .012 Cold so should be .018 area hot as is called for.
Proform 650 race carb With Proform upgrade main body so should flow right at 800cfm
68/84 with enlarged PVCR .072 and 2.5Hg High flow power valve ( We had just over 5"HG at a pretty low rpm idle so went with the 2.5. at a more reasonable idle is was closer to 7"HG)
comp Ultra Pro Magnum rocker arms 1.5 No B3Racing correction performed
Smith Brothers 5/16 pushrods
Kevko M302 5qt pan. Broke in with Lucas 30wt break in oil, Using Lucas Hotrod High zinc 10-30
TTI 1 7/8 3.5" collector race headers. 18" extensions at the track
Ignition MP distributor with initial timing adjustmnet plate, Summit ignition box with rev limiter and multi spark below 3500.
Timing 16 initial/35 total
Plugs.. are the NG that Trickflow recommends
Gap is .035
Keep adding things in edits that I forgot.
Fuel system could be a weak link 5/16 line, 5/16 pickup. Carter Muscle car fuel pump. It shows 120gph on Mancini but that must be free flow. On Summit it shows that it is stock flow at 25gph. I just ordered a Carter Strip pump, 3/8 line and 3/8 pickup and an inline regulator.
Chassis
Raceweight 3375
Manual valvebody 727 with Hughes 3500 street/strip 10.25 converter
4.10 with 28/9 Hoosier slicks
XHD Springs and Pinion snubber
CE 90/10 Front CE 60/40 Rear
Frame connectors
Best of the 2 runs we got.
60' 1.715 330' 4.859 1/8 7.515@92 1000' 9.837 1/4 [email protected]
I would have expected a much higher MPH then this. I would have expected in the 120 area. This engine shoud make in the 550 range. Watching the video to me it kinda seems like its not pulling hard in third.
We will be checking lash, checking cylinder pressure (has never been done) and doing leakdown test if we see an issue there, making sure WOT(we did of course check this before), We did tune WOT A/F with with a pull largely through second. I want to do it with a long pull through just third and make sure its not falling off. I can't imagine the vacuum going above 2.5 and closing the power valve but I guess its possible.
