Don Terrill’s Speed-Talk

N20mike is on the money. Usually not concentricity.

It's usually worn valve guides or cams that have design flaws around max lift. Causes valve to whip

Sounds like a bad rpm pickup sensor. Is there one on the brake?

Tried sending you an email. This is perfect for my size engines.

Run it with 2 stroke oil in the fuel. 32:1 or 24:1. See if that helps. Would be a fun quick test

I didn't even notice this was a super old post... my bad

Production GSXR Suzuki's had a service bulletin and special tool to check squish in early 90's.

If it was .028" you were good. If it was .026" you had to put a new head gasket on.

So yes, there was some tight squish stock

FYI, this dyno is capable of up to 300hp.

It comes with an test stand, or can be used directly on the end of a snowmobile tapered crankshaft.

Land and sea dyno 9" water brake.

Full dyno, water tank, computer. $5800.

williamsmotowerx@gmail.com

Email me, will send pics

Ryobi. They're amazing and cheap. I use my 1/4 and 1/2 everday for 7 plus years. Just recently had to buy new batteries. Ryobi has best prices on batteries too.

What happened to page 10? There was a bunch of posts deleted?

Dwelling over the nose is the most stressful thing you can do to a valvetrain.

You see it all the time in cam grinders who try to manipulate a copied cam.

And obviously you've never designed a cam or measured one.

Those are not infinite design errors. Those graphs are of a measured cam. Those that have ground a cam or designed a cam know exactly what's going on in the "not smoothed enough" graphs

As designed you don't you smoothing.

When you measure a cam as ground, you use smoothing sparingly to interpret the profile.

When you have a spike at peak lift it's the cam dwelling. Which causes the valve head to shake like a cold chihuahua. Pop goes the daisy

joe 90 wrote: ↑Tue Jul 24, 2018 12:45 am Acceleration is ALWAYS zero when at peak lift and zero velocity. So due to the sampling rate and lack of smoothing, that part is wrong.

Lack of smoothing? Why do you need smoothing for zero movement?

That's what you're saying when you have zero accel and velocity.

Running engine, what gets hot first? Piston

Heat travels to cold.

One of the jobs of cylinder is to absorb heat from piston and give it to air ir water.

Your test had both objects same temp. Not the case in running engine

I think it has to do more with control, what you use for porting tools, how you hold the head.

I'm #2