Don Terrill’s Speed-Talk

Those heads may be the bottleneck but they sure seem to be punching above their weight.

I went the other direction recently on an AMC 258. The guy had larger valves installed, 1.8? x 1.5 and the conventional wisdom seems to be 112 to 114 LSA. The Comp we replaced was, if I remember right, 218/226 (?) on a 110. We did a custom from Howard's Cams that was a mere 211 @ .050 on a 107 LCA, ...

All I've got in this drawer here is the sheet that came with them listing 259 at .500 and I'm guessing that's from their development port on the best day, lol. I don't remember if their website had more data or not. It looks like I was on the way to a decent head before it took a swan dive.

That's correct, Kevin.

My DARTs didn't post flow numbers above .500 either and rolled over hard just above that. I didn't touch the ssr because I had no way to know what it was (velocity across it) to begin with nor test along the way. A part of me was somehow panic-stricken over grinding that bolt boss out of there and l...

To do all of the things you're wanting, it sounds like some sort of boost is in order.

I think you're fine with the shorties there. I'd do an h or x-pipe and some good super turbos. I know from personal experience that an h-pipe really helps pull the snap out of loud mufflers. Maybe that'll be your Goldilocks.

I just installed an x-pipe into 2.5 inch duals, into 3 inch Dynomax Super Turbos tapered back down to 2.5 inch tailpipes and the damn thing is quieter than stock. I actually kind of like it. It sounds good when you powerbrake it with the door open because I've got too much sound-deadening material i...

That's just all kinds of badass.

Any Super Victors in here? I'm curious what guys are doing with the runner entries.

I just heard back from tech on those turbos and he stated that at 12psi of boost, I could likely expect 20psi of backpressure. I was sure hoping for less but I'm guessing my idea of a cam on a 110 is no-go. Stick with the apparently ubiquitous 112? I sure don't want to get hung up on the lsa; just ...

I'll see if I can find it. Thanks

I just heard back from tech on those turbos and he stated that at 12psi of boost, I could likely expect 20psi of backpressure. I was sure hoping for less but I'm guessing my idea of a cam on a 110 is no-go. Stick with the apparently ubiquitous 112? I sure don't want to get hung up on the lsa; just a...

Eric Weingartner did a video awhile back where he tested lift measured with the actual running spring as opposed to the usual light test spring. The lift lost on an aluminum rocker was pretty bad. I don't know if that factors into your decision or not.

Regarding these turbos (.82 a/r T4) on that 1 5/8ths header I linked, anyone happen to know the exhaust/inlet differential that could be expected assuming I don't screw it up downstream? I've got an email out to the company but I think it's usually wise to double-check the salesman. https://turbo4le...