Don Terrill’s Speed-Talk

Did I understand you to say that the heads were breaking of your valves? I was thinking you might be having valve float. Jon, the engine is roller rocker very similar to the 32V Ford 4.6 in layout. The rockers are perched on top of the (solid in this case) lifters on a ball head. The ball of the li...

:-k ... Hmm. I might find out decisively why the Mitsubishi 6G72 cams we used last time throws the rockers.. and even snaps the lifter heads off :shock: .. study time, I think. Do you have a machine to measure and software to graph the cam? Jon, I do. I measure cams with regularity for simulation p...

... Hmm. I might find out decisively why the Mitsubishi 6G72 cams we used last time throws the rockers.. and even snaps the lifter heads off .. study time, I think.

I have built several 2JZ at the 750whp level using the lower spectrum of the stock clearances. If you are to rev way past 8000 or add 400 hp to it, or both, we are talking of just a slight increase needed. The doubling of the factory specified clearances I see advocated is for 250+ hp per hole engin...

Thanks guys, but even the mildest of those are miles more "racey" than the stocker. Stock one has just 0.238" and 0.249" valve lifts - including the 1.56:1 rocker - on said 230 and 220 degree seat to seat durations (if the factory really had that). The original cam hardly has a b...

One potential downside my minds-eye could see occurring in the chamber would be the possibility that even a .020" centerline offset of that sharply transitioned divider "COULD" lead to a slight flow bias from one valve curtain area compared to the other. Add an intake manifold that n...

And it's not very recent either. So, anybody ever measured a 1970's Honda CB175 Twin camshaft? The original specs as reported in the shop manual says just 220º inlet and 230º exhaust durations. Sounds ok until you realize that they say it is seat to seat durations.. about 180 degrees at 0.050. Sound...

Ooooold post, but I weld up those narrow coolant channels between the cylinders with regularity. Never had any noticeable movement, then again I use 4043 there...

As mentioned, an Audi valvecover who rested standing up in my dip tank at 70ºC overnight using the PartClean NC 1:20 solution mentioned above.
One might notice which part was in the air and vice versa.

I use a product from Chemsmart called Parts Clean NC.. in a heated dip tank you can put in a valve cover so dirty it looks like it is enameled black on the inside. Then take it out shiny the next morning... I'll post a photo of the result when I get to the computer who holds my pics.

MadBill wrote:What, you mean the seventy five thousand RPM part?

5000 is idle...

How about if you pass it through your kidneys first? :D Bill, I'm not sure I'd like to work on a head after taking a wee in it.. :P But seriously. Alcohols are severely underrated as cutting fluids when you work on aluminium. Try it and become a convert. It leaves no residue either. And you'll be a...

I would seriously consider the use of Vannik's 4t engine simulation program. It provides a worthwhile insight to turbo performance. A comparison to Performance Trends results would be most interesting. Even with all the boxes ticked in EA Pro you will find that any decent build - I.e. less backpres...

Vodka. Seriously...

Tight squish out over the rings... tapered so it opens up the closer to the spark plug you go. In many cases that lets you eat the cake and keep it.