Ok everyone, I don't know if you have been following the ups and downs of me trying to refreshen my 408ci windsor, but I've been working on this since last year............missing a lot of racing action! Anyway, the motor is mostly together for the third time and will be going on the engine dyno late next week. For the person coming closest to the actual dyno numbers I will donate in their name $50 to the forum...................on one hand I am really excited and on the other I am really nervous as I've spent twice what I had budgeted on just refreshing this motor, not counting the new trans, front disc brakes..................and the list goes on. So, what do you think??????? So, lets go over the specs; 71 351 block w/4blt mains on 2/3/4 mains, bored .030, 13.5:1CR with Ross forged pistons, Total seal rings, Eagle H beam rods, Eagle billet crank, Crower special grind solid roller cam (my own specs) intake duration 310degrees@.712 lift, exhaust 312degrees@.714 lift. I am using Comp Ultra 1.6 roller rockers with 3/8 Trend pushrods and Probe stud girdle on the 7/16 studs. Springs are tool steel which are 200lbs closed and 680lbs open, tool steel keepers and titanium retainers. Intake/exhaust ports on the Super Victor Jr. with 1" spacer(which is matched to the intake) are matched to the heads, MagnaFuel regulator with #10 in and #8 to the Holley 850 that was refreshened by The Carb Shop and flows very close to 1020cfm with #92's on all four corners and block'd power valves. The pump is a Mallory CP 250gph pump with 1/2" line from the pump forward. Headers are Dawson, 1-3/4 into 1-7/8 stepped 31" tubes into 13 degree merge collector and reverse 3"/12" megaphone. Heads are some old Roush/Yates cup heads, TF Twisted Wedge R heads that have a very weird exhaust port configuration. Has a new CSR electric water pump..............timing will start at about 36degrees and everything will be in before 3000rpm................so that's about how it will be setup on the dyno...................any guess at to HP and Tq??????????????????
I am going to say 688 HP and 595 Torque on an engine dyno. If you are going to run it on a chassis dyno then it will drop 20% or so. I think it should pull to about 7000. There are a lot of things left out on the description but I think that should be close. When is the dyno run?
If it makes that kind of HP I may have to rethink the chassis setup. The motor will be run on an engine dyno to break it in (no pun intended...hopefully) and then we will spend the rest of the time doing some fine tuning so when I put it in the car I can hit the strip with a half way decent tune. So, how much HP at the crank????? I am pretty sure the motor should pull over 7k (but I'm going to take it to 7500 at least once) and know the cam/valve train is good for around 8k... but I really only plan on 6.5k racing...........or maybe 7k.......we will see. What other things would you like to know...............????? The dyno run should be either Thursday or Friday of next week.
I can't wait either.............on one side I'm really excited..................on the other I'm really nervous............what turned out to be a simple refreshen has turned into a full blown (no punn intended......hopefully) build and I've spent twice as much $$$$$ as I wanted to. I have put a lot of thought and all my knowledge on the line................... certainly not to prove anything to anyone but myself..........I guess that's why I am nervous..................I hope I haven't set my sights too high.........................we will wait and see.
Don't be mad at me but I'm going low at 580 since it's untuned, get it broke in and tuned Ill go a couple hundred more.
I will be spending about half a day on the dyno. First thing is to warm it up and check for leaks..........and break it in..............then check the valve lash after it's hot to find out how close we were when we set them cold. Then it will be making maybe 3 to 4 pulls optimizing timing.....changing jetting if neccessary.......so by the final pull we should be somewhere in the ball park......................the motor will have a good dyno tune..........then into the car.............break the new trans in.............then to the track.
You are putting me on the spot...............but I would be happy with 725 and really happy with 750 at the crank............we will see.
