Don Terrill’s Speed-Talk

You really need to match your hone job to the expected use. The heavier the hone deep grooves, the more oil that is left there to lubricate and then possibly contaminate the combustion process. Total seal has a lot of great reference material out there. In my opinion a straight 180 grit deglaze is n...

The timing turned out to be 32 degrees total, so I was pretty close on the initial static setting. It liked it immediately when I bumped it up to 35. They plan to test it on a chassis dyno in the near future. He was running race gas, but I am not sure what brand, It has a triple pass radiator in it ...

I had something happen tonight that I still can’t believe. We broke in the camshaft on a limited late model engine, which is basically a Bmod engine with a 4 bbl carb. We fire it off and take it straight up to 3,500 rpm. I start messing around trying to get a timing light to work and finally give up...

The taper runs out near the nose to increase the area supporting the spring load from what I have observed. You should see a thin line around the lobe up to the peak where it widens out over the nose, then quickly goes back down to the thin line. The tapered lobe induces spin so the contact patch mo...

The 0.006” lifter lift number is the SAE reference lift number for duration rating. Many of the cam companies preferred the 0.020” lifter lift number as it took out the ramp and more clearly identified the nature of the cam. Most engine builders use 0.050” lifter lift as that seems to approximate th...

Although my head hadn’t hit water, it was severely damaged and needed being built up prior to fixing the seats. The area between the seats was about 3/16” low, so I used cast iron welding wire with Argon gas and welded the head up. It was able to be machined down and have seats put in the previously...

My experience is that you bring your own known good MSD box or other ignition system to the dyno. A bad box will shave 50 to 100 hp off the engine and be unnoticeable otherwise. The power supply to the box is also critical. A well sorted dyno operation will have all of this taken care of. I would li...

E85 MUST be mixed at home to be 100% certain of what you are getting. There are kits, hydrometers and such that you can buy to test the ethanol content of your fuel. The best way is to drive over to the ethanol plant with a 55 gallon barrel with the right amount of race fuel in it and mix your own, ...

The block prep is where a lot of people miss the mark. Between that and part selection, they leave 30 to 40 hp on the table. Ring/piston selection is where many of them miss it.

Thanks for all the comments. In the end it doesn’t matter how it broke as the block will be repaired and another attempt at destroying it will be made. It’s still on the living side of race engines.

Inclusion (slag or other contaminant, "dirty" iron) in the iron the cap was poured from? You'd think they'd have heard the cap pop if it cracked during engine assembly. (Maybe they did, and ignored it?) Oldsmobiles are known for breaking the #4 cap. My understanding is that the 18436572 f...

Wow, we couldn’t see the broken cap as the crack was closed up tight in the assembled engine. This wasn’t a gorilla of an engine as the pistons were 0.050” below deck. We are going to fix that along with the main cap. I just finished a rebuild of his brother’s USRA Bmod engine which prompted this ad...

I get a kick out all these holier than though responses about using a ridge reamer. Get over yourselves. You aren’t all that and a cup coffee. If you were, you would be in a professional organization and not posting on this website. The main reason I have used one was to get one more use of parts I ...

These photos are from a small block Chevy engine I am advising on. This is the center main of a 4 bolt block. The cap has a ductile fracture just outside of one of the main bolts. There’s absolutely no evidence of fatigue in the fracture mating surfaces. My working theory is that the cap was fractur...

Proper bolt and nut engagement requires a softer nut than the bolt material. This allows the nut to seat the bolt threads completely. As long as a sufficient amount of thread is engaged on the bolt, the nut material isn't as important. It is only stressed from the top thread down progressively, wher...