I think some people pick a cam with no information at all. Threads asking for a cam recommendation are pretty common. Most provide almost no information about their combination, or what they really expect from their car, including the OP of this thread. If others seeing this thread need a cam recommendation, hopefully, they provide more information.
Have had several jobs where the owners did know as much as anyone else, after all they were the ones who started it and were still working, they just needed help because there business was growing and they couldn't keep up, but there knowledge certainly hadn't degraded one iota? In fact those have been some of my favorite jobs. We're not talking about a Boeing 747 with dozens of different complex systems..that I understand. We are talking about one part made the exact same way for thirty or so years.
Thank You, Larry for explaining that about the Heads. I was told that by Jim Weise when I wanted to run the Lunati 241-241/112° Hemi- Killer cam with Iron Heads. I believe You as well as Bruce Wilson chimed in on that...Thanks,JIM, BQUICK and THE WIZARD . Mr. Jay B.Britt,Jr.
exhaust flow is less important than intake flow. 6* extra exhaust is fine. with 15* split you will start getting reversion = exhaust going into the intake and carb. the 15* extra exhaust duration will keep the hp hanging on longer after peak hp rpm BUT at the cost of losing low end torque. good for a race motor I guess. now put that on a 116 lsa which will also KILL bottom end. don't forget to buy a 3500 stall converter to help with that cam. your talking about cams designed over 50 years ago.
I have posted this link dozens of times. It isn't the only consideration, but it is an important one, http://cochise.uia.net/pkelley2/DynamicCR.html Look at the KB 118 cam. Probably one of the most popular cams back in the day. It has 19* more exhaust duration than intake, and, it's on a 118* LSA https://www.taperformance.com/proddetail.asp?prod=TA_C118-455 It closes the intake valve relatively late, so it wants at least 10:1 true static compression. I ran 12.11@112 MPH with the 118, my Stage1SE heads @ 10.4:1 SCR, SP1, Holley 1000, Switch Pitch (3000/1800 12" converter), and 3.73 gears.
Thank You Larry, at the risk of being redundant, I was going to ask you to explain ( again ) about Dynamic Compression Ratio vs. Static Compression Ratio. Thanks again for looking out for the students, even the 66 year olds. Mr. Jay B.Britt, Jr.
great newsletter thanks for proving my point with trade offs with more duration hurting bottom end and idle and needing converters and gears which will hurt street driving. but reading the rest of your post i don't understand why you ran a wide spread duration and wide lsa with your after market free flowing heads and not having stock iron heads ? was that built years ago ?
I bought my GS in October of 1999. All iron 462 with untouched Stage1 heads, Forged Speed Pro Pistons, KB 118 cam, Quadrajet, MT headers into 2 1/2" exhaust Added X pipe later, switch pitch ST400 with 12" 3000/1800 converter and stock OO 3.42 rear. My best was a 13.22@ 101 MPH. In January of 2006, I purchased a set of TA Stage1 SE heads from Greg Gessler with his level 2 porting. Greg milled the heads .040", which resulted in 59cc chambers. My all iron engine calculated out to 9.4:1 SCR. The smaller chambers increased my SCR to an aluminum head friendly 10.4:1. Greg also mildly ported an Edelbrock Performer Intake. That along with my Quadrajet, immediately put me in the mid 12's at 106-107 MPH. I then added a built 8.5 10 bolt with 30 spline Moser axles, matching Eaton Posi, and Yukon 3.73 gears, an SP1 intake, and AED Holley 1000 HO carburetor. That netted me my best 12.119 @ 111.998 MPH. Around the Spring of 2010, I gave Jim Weise a deposit to build me a 470 short block. I sent him a .030 SF block, and crank that I got with my car. I took my TA heads, SP1 intake, and AED carburetor off and shipped them to Jim. I put my iron heads back on with the Performer intake, and got my car running again. Good thing too, because the first motor Jim built me was used as a test mule, with my consent, for different cams. In total, it went across the Dyno around 35 times. That revealed a block weakness in the number 4 main bulkhead. That engine with a roller version of the TA413 made 608 HP/596 TQ before it revealed the weakness. Here are the cam card specs, Card specs @.050 235/247/113 - 365/365 lobe lift This cam was part of Jim's Cam Degree thread, along with the other 2 cams tested in my 1st block, a Lunati fast ramp and TA413 flat tappet. Other degree specs for roller cam #1, 234 duration again, with an ILC of 108.5... half a degree more than recommended on the card.. We will run it there. Other specs measured Exhaust duration at .050 247* Intake lobe lift- .359 Exhaust lobe lift-.366 Advertised duration (.006) 290/317 Lift at valve - .574/.585 @ .050 overlap- 16* Advertised overlap- 83.5* Jim then got me a nice 76 block and built me a second engine with a smaller roller cam. It made 602 HP/589 TQ. So I waited until August of 2012 for my new engine. Of course I was happily driving my GS around for the 2 years it took for me to take delivery of my 470, so I didn't care one bit. Jim took the opportunity to do a bit mo out the motorsre porting to my TA heads. They ended up with 61cc chambers, and better numbers. Had the motor delivered to John Csordas at his shop. Drove my GS up there, swapped the motors over 2 days, and ran new 1/2" line for my fuel system. Sold the iron headed motor to another NE GS/GN clubmember. Later went to 3" X pipe exhaust with Magnaflow mufflers, and N25 tips. So there you have it. The history of my GS. It has gone a best of 11.54@ 116 MPH at 4100 lbs. race weight. Been together 11 years now and runs great. Fun street car with Drag Radials. For those interested, Motor 1 build and cam tests, https://v8buick.com/index.php?threa...totype-specs-and-testing-larrys-motor.221289/ Motor 2, https://v8buick.com/index.php?threads/tsp-level-2a-r-larrys-motor-complete-and-dyno-tested.252641/
