Stroker specific cams (Part 2) cam reveal
A while back I asked for recommendations for a 408 Magnum based stroker. If you want to read through 8 pages of discussion , I will link that thread below. So, with that said, I decided to do a second reveal thread instead of adding to a rather lengthy one. First I'll recap my requirements/ specifications so everyone is on the same page. The engine is going into a 1973 Challenger, it will never see a drag strip, and is truly a street car that will see a wide variety of road types including spirited driving on twisty road, to long freeway drives. It has a A518 automatic overdrive transmission, with 3.73 gears, and 26 inch tall tires. The top end of the engine will have TFS 190 heads, RPM Air Gap intake, and Holley Terminator X Stealth TBI fuel injection. I decided I wanted to keep the hydraulic roller lifters, plus wanted to be able use a stock distributor/oil pump drive. Compression is 10.17 to 1. My goal is to have a fun car to drive, while being reliable. It will also have power brakes, and A/C.
So, now to the cam selection, and how I got there. After emailing various vendors, I ended up having Mike at B3 racing engine figure out the cam for me. I had actually called him on another matter, but after talking to him, it was obvious he had a better grasp of what I wanted. Plus, he actually had real world experience with the TFS heads to go by, instead of just numbers on a sheet of paper. This is the cam he cam up with:
Intake
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[email protected]"/ Lobe lift .350/ lift at valve .560 with 1.6 rocker arm
Exhaust
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[email protected]"/ Lobe lift .347/ lift at valve .5547 with 1.6 rocker
Lobe separation angle is 112 degrees, with 4 degrees advance on the intake centerline.
I know there are few that will think this is too small, but he figured in that with my overdrive, the engine will be "on the cam" at cruising speed this way. Also, while others thought a single pattern cam was the answer, Mike said the the TFS head need a little help on the exhaust side, but not a great deal. Notice that here is only 2 degrees difference in the duration numbers @.050. The lobe separation angle is a little wider to play nice with EFI, and should help vacuum for power brakes. Mike did make one point that with heads this efficient, a bigger cam is not needed so much for a street engine as mine. This should be a fun engine with good drivable wide power band, and that is what I wanted. Just for the record, he does do race engines with close to .700 lift on these same heads. Finely, I would like to thank Mike for coming up with this after several phone calls. He has earned my trust and business in the future. I will be buying my heads, rocker arms, and correction kit from him when the time comes. He was kind enough to grant me permission to post this, so please do not drag him into this if you have a disagreement with his recommendation.
First thread for reference:
Stroker specific cams?