Don Terrill’s Speed-Talk

The Hi Po heads in the video were what the customer wanted to use for his project. During the Engine Masters Challenge we used C5AE 2 barrel 289 castings. It was what the rules mandated. No Factory performance castings I didn’t even notice the heads in the video were hipo heads, I went straight to ...

very nice, but I have a question. Why did you use one of the best superstock castings? Its allowed 152cc's!!!! the same work could have been done on any of the 289 castings. have you got a tabular listing of the flows. I couldnt see the video plot clearly?

I have not been here in a while!!! I recently picked up a single plane Street Dominator 300-6 for a 289/302. This intake has never been a desire. What intrigued me was it did NOT have the universal spread bore looking carb pad that it is always pictured with. It was a conventional square bore carb p...

On our current rebuild, we have one cylinder not acting correctly. During the install, we noticed a line down the cylinder. We removed the piston to check for debris on the piston or ring. We did not find anything (magnifying glass used), in the region where the line appeared. ALSO, this is not a ga...

In my previous posts, i was saying that it is impossible to make any sort of assessment on whether the header pipes are large or not. Hp versus exh sizing provides little realism to the true exh need. True exh need is driven directly from the whats happening on the other side of the cylinder (intake...

Continuing---- To know if the header size is close to correct, the valve events have to be known (at seat), and even better, more additional info about ramp rate , such as .050, and .200 at the least. The hunch would say that the Burn calcs had to utilize this info, as well as Larry's Pipe Max. So f...

The flow parameters and valve events play the biggest part in header sizing, not hp by itself, or port dimensions. The exhast side is really dictated by the header dimensions (total system dimensions, on muffled set ups) therefore the velocity and volume thru the pipe are directly related to valve e...

if the motor was needing later exhaust activity and you were running the 106 LSA set-up with good success, then the earlier exhaust of the 108 may not be a good thing. It will definitely be letting cylinder pressure escape a little earlier and may not be working the overlap as nicely. However, if th...

If we are getting into exactness and accuracy within the methods, in the video, you cannot truly say that that lift at the valve equals lift at the stud. There is an additional component, due to angle between the stud and valve that is not accounted for. However, You can say lift at the valve can be...

I liked the video too. I have never done it that way beither. the midlift 90 deg is the point of tangency to the valve line of action. this is the same thing that is accomplished with the narrowest wear pattern. By definition, the narrowest wear pattern is as near to tangency that can get. Scott's m...

Buddy , I'm not familiar with that part number. Did you see it in one of their old catalogs? I'll do some looking. I am not sure any more. I cant find the source that got me inquiring on this cam. Somewhere along the line, I came across a replica of a ford cam that was a solid lifter measured aroun...

I have ran calc after calc on the tunnel port heads, and I have no idea why the huge slow moving port was cammed the way it was. That combination had no business running cams with those sort of durations paired up with late of exhaust events(narrow LSA). Its exactly what was needed on the convention...

Does anyone know why the car magazine guys seem to always recommend either making the pushrod longer or shorter to get the sweep in the middle of the stem? The magazine articles don't seem to have a problem with how wide the sweep is. I have seen pictures in the articles that show the sweep and som...

the formula for height (chord height) of an arc is h = r- [(r^2)-((BC/2)^2)]^.5 BC= Length of segment BC (chord length). For these purposes, the valve lift is the equivalent measurement r= is the radius of the arc. For these purposes the rocker arm sweep radius h= the height (chord height) of the ar...

Guys, I got some good info cleared out on the tunnel Port Cam, thanks for that. I have another question that some of you may know. Shelby had a solid lifter cam S1MS-6250-2 that was supposed 289 deg, .500" valve lift for the 289/302. Its does not match the Lemans cam, becuase it never ends up a...