Don Terrill’s Speed-Talk

I'd be focusing on intake opening and closing points, not the resultant LSA that's still dependant on your chosen exhaust events. That’s how it’s done but I’m still curious as to what makes some of these TPI cars peak at 4900. Others peak at 5900. That to me is telling me there’s something that’s n...

I ruined a set of morel lifters in my bbc on the street running near 300 seat 800 open. .842 needles. I was gonna go bushed but changed cam lobes and spring package to take over half the load off and been fine so far ever since. I was told with that much spring load you are goin to get a failure wit...

Agree, it's just significantly less consequential, than what's on the valve side of the rocker fulcrum Regardless of rocker ratio It's still inertial mass that needs to be accounted for. The old "rev kits" that had springs in the valley acting on the lifter took a lot of load off the valv...

Ive had some turbo cams straight up or 1-2 deg advanced, and one 3.5 deg.

Had one tight lsa sbc cam with 1 deg advance. 108 icl 109 lsa.

Seems like icl is chosen based on desired events

Give JHE a call and see what they think

GM never used a valve larger than 1.85 on the 305 bore, even though they'd made zillions of 1.94 valve cylinder heads previously. Wild guess: A 1.94 valve clears the bore...but is so shrouded that there's no point. There's an ancient Trick Flow 2.02/1.60 head that will similarly clear a 305 bore, a...

They will work. Theres also a 305 vortec head i think its the 059 castings that may be looked into as an alternative

Ive had 11:1 383 run fine on 93. No issues but it was efi and well tuned. Ive had 9:1 400” run fine on pump 93 as well with 24 psi boost lol. 1000 hp. Also efi lol. I think 93 can go along way

“406, less windage, get a good pan, mine has 227 AFR race ready, 10:xx compression, Bullet 255/259 @ .05 cam, Victor Jr, with a Mark Whitener aka jmarkaudio (Lightning Racing Carbs) carb, and made 646hp@ 6800 you have a good block. Just get the rest of the good parts, my combination was from Mike Le...

https://www.chevelles.com/threads/pump- ... ds.347846/

Heres another

My buddys 406 made 521 whp thru a t56 6 spd. Trapped 127 mph in a 3300 lb trans am

Ported old afr 195’s that flowed 300 cfm at 208 cc
Single plane efi intake i think a eddy victor efi
Cam i believe was a comp 248/254 solid roller.
10.5:1 roughly. Ran strong for a basic combo

Def needs boost if you want it to run with a 509 bbc, although those bbc builds sound mild if running 11’s A typical 11:1 406 with a 250 deg solid roller and afr 220 head approaches 600 hp and runs 10’s in most 3200-3400 cars. Def rowdy idle though although very drivable well tuned. Efi helps alot h...

Shp is setup for oem hyd roller setups so you can do the dogbone/gm lifters and step nose cam plate. Else you can do link bar lifters if need much more than .600” lift or so. Should be doable for those power goals

Theres really no reason to get away from stock rocker systems on hyd roller ls stuff. Unless ofcourse its super max effort exceeding the range of lift stock rocker systems are designed around. But you rarely see a hyd roller that big, only solids usually

Ok. So a cam produces a lift curve which is related to velocity and more importantly acceleration rates. Your valve, spring, retainers, and locks have mass. Also your rocker arms. So with mass and acceleration you get a force required. The spring will have that force in terms of rate and total loads...