Don Terrill’s Speed-Talk

There's been a lot of talk about using resistor vs non-resistor plugs with common distributor HEI ignitions, and also with restive plug lead vs copper wire plug leads. A lot of it boils down to how much electrical interference you and your car can tolerate. What about using non-resistor plugs with a...

The retardation of the timing with a magnetic pick up ign is an electrical issue, not a mechanical one. It is caused by distortion of the AC sine wave generated by the pick up & the distortion increases with RPM. Geoff, see also my post here -> https://www.speed-talk.com/forum/viewtopic.php?p=9...

Some years ago now while messing with home made ignition boxes I found that magnetic trigger distributors were sensitive to how much resistance is placed across the pickup coil by the module. Lower resistance interacts with the inductance of the pickup coil and causes a phase shift that effectively ...

Tuner wrote: ↑Sat Oct 21, 2023 12:01 pm The distributor weights and springs act as a torsional absorber, which of course they cannot if hard against a solid limit.

In that case there would be some merit in adding rotating mass to the rotor button. Offbeat for sure, but it may help.

The muffler hangers are a factor too. Yep. A piece of hanger strap that is bent into a 90 deg curve has flexibility in all three planes. If the strap is straight there is very little give lengthwise and that can transmit conducted noise to the bodywork, especially if connected to a flexy part of th...

HQ, Have you noticed the trend in recent years is to thin out the leading edge of the divider to almost a sharp edge, rather than have a bull nose shape. Supersonic planes have sharp leading edges. Normal subsonic planes have rounded leading edges. So with a manifold divider it would depend on the ...

I have never saw a factory block that was right. Probably best case scenario is find a block that has ran and shifted or settled ,then fix it. Most are horrible,angles off,location etc Would an inline engine be more likely to have accurate lifter bore positions ex factory given the ones I have seen...

Yes. If the elastomer did not dissipate the energy the peak to peak movement of the outer ring would increase to infinity! The losses in the elastomer dictate the Q factor or sharpness of the resonance. Whether it really digs in over a narrow rpm range or has a lesser effect over a broad rpm range. ...

Also, why does the inertia of the crank damper have to be coupled trough rubber or a viscous oil? Wouldn't just the inertia of a heavy pulley absorb the harmonics like a second flywheel? Adding rotational inertia to the front of the crank in the form of a second flywheel will lower the fundamental ...

A piston on the downstroke working against say 18” of vacuum at cruise absorbs quite a bit of energy. Try pulling the plunger out of a blocked syringe of any decent diameter. Then calculate the force of 2/3 atmospheric pressure on the underside of a 4 inch diameter piston. About 120 pounds. Pull th...

There must be something to the heat thing, all of my sbc powered cars gain 1-2 mpg when the weather warns up. Power goes down accordingly. At first I thought it to be related to the choke, but a manual choke, or in some cases no choke proved it to not be much of a factor. My afr gauges say the rati...

Whenever I hear of grooved lower half bearings it always makes me think of the difference in behavior between a grooved and a bald tyre on a wet road. There may be some degree of correlation.

They all do AFAIK.

Would be fun and games balancing one of those things. Pretty cool though.

I am so over aluminum heads that warp and allow the head gasket to quit at the first sign of overheating, and the consequent expense and inconvenience of repairs. ](*,) Both of our late 90's Camrys have needed this in the last 2 years. If one had the resources to produce a cast iron replacement head...