@ Groucho - So I was down in my office updating a laptop and waiting for the patches/updates from MS to download when I wandered over to my bookcase. I picked up a car mag that just happened to be sitting on top of the stack. Guess what it was? Yup! June, 2006 Hot Rod! As soon as I saw that 'Vette I knew it was yours! Opened up and read a nice little articel on my HAMB-buddy's car. And you were in the company of a couple SWEET '55's, too! Nice article, nice car!
I ran 12.5 / 1 compression ratio in a 301 on the street in 1970 on 110 octane pump gas. Occasionally on aviation gas. Couldn't begin to do that today when premium gas is lower octane than regular was back then. Without lead, you might have valve and seat problems with high lift cams. Those valves slam down real hard!
My camel humps were remanned with hardened seats. Someone mentioned using a lead additive. I didn't know you could get those...
i have run bouth gm cams in a road race camaro they were grate at the time the aviator has a 292 194 heads 4 sp 373 gear weight 2000lb the cam in it is a cam that was made by isky close to the 140 it needs rpm's or it will buck and learch so i have to keep foot close to the clutch at lo speed been driving it since 74 other than pushing a telephone booth down the road it has verry long legs when you lean on it
Indeed it was! Spit my coffee all over my keyboard! Now I gotta go out and get a plastic protector cover for it...
Dear johnk320, The GM factory cams were limited in lift and profile due to the factory cam grinding machines and the size of the grinding wheels. These limitations caused gm cams from the 60's 70;s to have much lower lift limits than compared to cams made in 2011 by racing cam makers. Because they were limited in lift they had to go with more duration to get more flow per engine cycle. In my oval track car i have ~ .600 lift with only 254 degrees of duration @ .050,,, GM could never get that with their production cam grinding machines. Bottom line,,buy a modern cam from Isky, comp cams, lunati,,,,, NOT a GM copy. use 2011 technology for your cam, not 1950;s tech for your cam.
If you want a racey idle with street drivability ,,,, see,, http://www.jalopyjournal.com/forum/showthread.php?t=564132
cheap cams that work http://www.competitionproducts.com/Chev-SB-Mechanical-Flat-Tappet-Cams/departments/1525/ http://www.competitionproducts.com/Chev-SB-Hydraulic-Cams/departments/315/
cheap cams that work elgin 1131 <TABLE border=0 cellSpacing=0 cellPadding=0 width="100%"><TBODY><TR><TD>Elgin, Mech. Flat Tappet Racing Cam, Chev SB, .521/.521 </TD></TR><TR><TD class=plaintext>Chev SB Lift: .521/.521 Duration: 282/292 Duration @ .050": 240/250 Lobe Separation: 106 LC Heavy Pro Street/Bracket, Oval Track 1/4-3/8 mile </TD></TR><TR><TD class=plaintext> better idle Elgin 1133 </TD></TR></TBODY></TABLE> <TABLE border=0 cellSpacing=0 cellPadding=0 width="100%"><TBODY><TR><TD>Elgin, Mech. Flat Tappet Racing Cam, Chev SB, .498/.498</TD></TR><TR><TD class=plaintext>Chev SB Lift: .498/.498 Duration: 280/280 Duration @ .050": 246/246 Lobe Separation: 108 LC Good torque for heavy car, 10:1+ comp., 3000+ stall</TD></TR></TBODY></TABLE> complete cam kits cheap,,lifters, cam, springs http://www.competitionproducts.com/Elgin-Complete-Cam-Kits/products/293/
My understanding back then that it was for valve spring life (short lift/long duration). Also I think GM knew that a lot of backyard guys were gonna sneak these cams in their cars without changing valve springs. Hell, at 18 I was one of those guys. I could put the 140 in my Z and get away without coil bind on the bigger cam with the stock Z springs. Felt like it grew 50 HP
Tricknology, the HAMB is all about period correct. This guy wants to take it to the next level, and run vintage internal parts, and I for one, commend him for that. As far as the cam choices you gave, if we want to veer away from what this guy wants and asked for, and go off on our own tangent, and start telling him how WE think he should build his car, my cam recomendations would vary considerably from what I recommended, AND what you recommended.
^^^and if you REALLY want to impress us with how much you know about camshafts and valve timing, you may want to reconsider recommending thumpr's for cars that are going to be raced.The delayed exhaust closing that makes them sound so cool does nothing but draw unburned fuel through the cylinder AND increase reversion. There are plenty of cams out there with tight lda's that DONT have ten extra degrees of exhaust duration just to make them sound cool. Read my comments on tight lda's and intake closing point back up the thread.
Oh and take a look at the second elgin you recommend, and compare it to the old school, vintage isky I recommend.
George brings up a good point here. There are several grinds that seem to be "standard" that everyone from Comp/Crane/Edelbrock/SpeedPro/Elgin/etc. seem to sell. If you check the specs, you might be able to save a few bucks and still have a "first line" camshaft. Larry T
The old 230/480/108 sbc hyd. is a good example of that. At one time or another, it has been in an Isky box, an Elgin box, a Comp Cams box, a Cam Dynamics box, and probably more that I dont even know about. Pretty decent medium street cam for SBC, but man has that grind been around.
If we were going to veer away from the sixties era theme, I would probably go with an Ultradyne/Bullet 256/263 on a 105 lda for what he is building. Used this grind several times, its what I have in my FE on 108, I have also run it in a couple of BB chevies and it is an excellent street/strip flat tappet that has a pretty aggressive lobe and makes excellent mid range. My favorite BB 10" converter cam, would also work well in a small block stick combo that is gear limited.
I am planning to do the same thing. Alot of guys dont feel this way, but to me, a period build should be a time machine. I am trying to re-create what the guys that came before me experienced.
Yeah, right! I don't want something that just LOOKS the part. I am trying to capture the look and FEEL from back then. I couldn't do it then so I'm gonna try to do it 40 years after the fact! I guess, for me, it's more of a mindset thing. Everyone has their own "thing" and that's what hot rodding is ultimately about.... for me, and this project, it's as much a time capsule thing as anything else. The only constraint for me is $$$! I don't have deep pockets so if I stray from my theme it will be because of affordability.
ok , period correct, butt it dont have to be GM,,,good idea,,, then hands down, best performing, period correct, with LOTS of 1960's wins on drags and ovals is the isky 505T ROLLER. if you got the cash,, the cat's meow in the early mid 1960's was the ISKY 505T Roller lifter cam. it is also the wildest cam that can be made to work with the Corvette 1960's mechanical FI ( but will need to be re-calibrated) the current isky catalog dont list it but they still make it. see this hamb thread http://www.jalopyjournal.com/forum/showthread.php?t=429919
Check out the Engle EP-25 Solid http://www.englecams.com/downloads/2010_engle_catalog.pdf I had this in a 302DZ motor.....Music to your ears, great performance and a wicked idle. Drag racing, circle track competition. 10 to 11:1 compression power band 3000-6800RPM .595 Lift at 1.75 280° Advertised Duration .340 Lift 244° Duration at .050108° Lobe Center
The Jalopy Journal
