Don Terrill’s Speed-Talk

I would think the camshaft will depend on what the heads flow and where. If your flow maxes out at 0.500”, then a cam much bigger than that won’t get you anything. If your heads flow well to 0.700” and your cam tips over at 0.500”, then you are leaving something on the table. That said, its about h...

289nate wrote: ↑Mon Mar 04, 2024 4:12 pm I thought .575” lift was low lift by todays standards?

It's moderate for a HR SBC. Nothing to be concerned for longevity about.

The whole reason for going roller is for more lift with minimal time spent doing it... .575" is nothing to be concerned about stressing your valve train about, .480" is a waste of money for the components used. Use a quality spring and stable pushrod and forget about it. What my point her...

I've been looking at hyd roller cams. Howards shows some profiles with .480 lift and 268° duration. Then, they show .575 lift and a similar duration. Both of these have rpm range of 2000-6000 rpms. I know it's the ramps, separation angle, etc . that makes them hold the valve open for the proper tim...

Received these in the mail today. Sending them back out tomorrow, absolutely unacceptable! You'd think Howards would take a bit more pride in their quality control! These are their #91112 lifters. Also, checking them on my Fowler gauge stand shows they are totally unsymmetrical around the circumfer...

Speaking of L98s here's the heads. I did a set of those once years ago trying to help out a broke customer and trying to learn more about porting. Managed 245cfm @ .550ish with the stock 1.94". They went on a budget 406 with Mahle pistons and a XE274S in a 3rd gen, 12:1 on E85, RPM AG and a 75...

Speaking of L98s here's the heads. I did a set of those once years ago trying to help out a broke customer and trying to learn more about porting. Managed 245cfm @ .550ish with the stock 1.94". They went on a budget 406 with Mahle pistons and a XE274S in a 3rd gen, 12:1 on E85, RPM AG and a 75...

It's designed to use the regular FP pushrod and stock gear, just like a flat tappet camshaft iron core.

How much could you mill from these heads before you got into intake sealing problems? I was hoping to get them down to 115 cc, now they are 122 and I'd like to get around a 10.5 to 1 pump gas comp ratio. I know there is variables and I haven't measured how far the piston is down in the bore yet. Th...

You're betting a $2800 block and set of custom pistons vs a set of 50 year old stock rods so you can save $300 or so. Do not sway my people. I want to buy a new motorcycle .... :D I'd like to see the bobweight for 4.6" x 1.650" CH pistons work with a stock external balance crank..

wilson1970 wrote: ↑Thu Oct 26, 2023 9:32 am I am assuming building a 421 would be more clearance friendly

Yes, stick with a 3.875" crank, it isn't worth the work for a 4" crank in standard block layout.

Worst type deal, received the parts from the customer, not in a complete SCAT kit, but the parts seem to be correct. ICON pistons, etc . The bobweight comes in at 1609 grams. The new crank, with no drill holes whatever, spun up on our Pro-Bal, the left (flexplate) end is 221 grams out and the right...

Taper crack repair pins and then drill a .060" bleed hole if you feel it's needed.

I'm sure it varies from block to block and manufacturer to manufacturer, but does anyone have any data on what type of gains have been achieved by blueprinting lifter bore locations? Thanks, Joel Ron Flood/Cedar Machine did a 383 SBC test a few years ago, the thread might be in here somewhere. http...

But say a guy wants an aftermarket block? That rotating assembly is only 200 bucks more to go say 454 inches. So the extra on the block.. why go 406 or 377. Just go 421,434 etc t hen you can't get a big enough head for any street use. My personal opinion is for a stock cam location, stock deck heig...