Recent content by K1tom

Hi Allan, Actually I do remember you. You bought your parts from Dan at Performance Only. I am glad we were able to work things out to your satisfaction. Thank you for the kind words. Tom

C and A made some ok parts but always seemed to have problems with getting the bearing notches correct. Look at the photos and you can see the notches do not look deep enough and maybe not long enough for the tabs on the bearings to fit into without reworking. If the notches are not deep enough...

Mike, I may have found something that was machined out of tolerance and could have caused or at least contributed to your problem. I am trying to confirm before I say anything else. Tom

Very good questions. Regarding longer strokes, lets say you have two engines. One with a long stroke and one with a short stroke and both engines have the same cylinder pressure due to fuel burn. The engine with the longer stroke will have compressive load on the rod because the crank will...

Since most of the spooling done before the race even starts, within reason, it doesn't really make much difference does it? Also keep in mind that heavier parts that are spooled and in motion are stored energy and actually help launch the car.

NASCAR engines are now in the 800-850 HP range and have a minimum rod weight rule of 525 grams and the rod must be made of steel. A 525 gram rod looks scary enough but when you see one that has as much weight trimmed off from the pin end and rod beam as these do, it becomes even scarier. These...

A lot of people do not realize that rotating weight is mass that is mass that is already in motion and only is only accerated. Reciprocating weight must be stopped and restarted twice every stroke. Imagine tying a 8,000 pound weight to a steel cable and dropping it off from a bridge. It takes...

The simple answer is, an H-beam is more prone to bend in one axis and the I-beam is more prone to bend in the other. Like I said earlier, MOST rods do not break in compression they break in tension. In a case of detionation or an actual overload / buckling failure, the rod will bend in the...

You are right and I agree but you should hear the phone calls I get from people that won't use a rod that is 20 grams or a crank that is 2 pounds heavier than a different brand because they think they will never win with the extra weight. When trying to move 2,500-3,000 pounds of car, a few...

Regarding the triangle shaped beam, the simple answer is NOPE. In 30 years of examing rods both broken and unbroken, in 99+% of the cases where a rod broke and there is no sign of detonation, the rod fails just below the wrist pin. Detonation tends to break them off just above the big end...

The swinging motion stress comes from the starting and stopping of the side to side motion and in some cases is refered to as beam whip. Compared to the other forces being so much greater, I do not worry about this. Tom

LOL! That is an antique. Yes, that is one of the old beam designs and I have seen a few of them blow the center right out of them and that is on a n/a Busch engine with a 390 CFM 4 barrel. Based on what I see in the picture, it is an old Busch Grand National rod circa 1986 or 1987. Did you...

All parts in the engine will vibrate when excited at their natural frequency and different parts of the rod will vibrate at different levels due to the different amount of mass. I.E., the cap will vibrate at a different frequency than the beam. This becomes a real can of worms due to the...

Mike, You are correct about changing from a 2X4 to a 4x4 but you have also doubled the amount of mass. From a rod design point of view, no one wants a 1,400 gram connecting rod. I am not trying to convince you one way or another and you found something that works for you so don't change...

You will always get some vibration at the natural frequency of the part. The ideal goal is to never stay at a RPM where this takes place for any length of time. As for the taper beam rod, this design looks real cool and you would think it would even out the stress around the big end but...