Engine Health,what do you think?

[eddie c]

Back in the mid-70's,when I was in the throws of stock eliminator
racing,everyone,just as it is today, was concerned with how their
motor was performing. Yes,we all used the time card as a basis,but
weather and track conditions can sometimes throw a curve ball at you.
Anyway what alot of us did was use our Leak down tester to determine
how things were looking in the compression department.Then there
were those that insisted leak down testers didnt always tell the true
story. Dynos were few and far between back then,so most of us didnt
have them available. Of the dynos most were lab type dynos and
not the chassis type that you see today. So without trying to get into
anyones files marked Secret,what technology do you use when making
determinations of engine health? ed

[goinbroke2]

I go by rod placement.

If the rod is in the motor = motor good

If the rod is on the floor = motor not good

j/k! LOL

Nobody seems to want to be the first, so I'll start it so others can, if nothing else, criticize me. hehehe

1) Record all your runs and after X runs replace valve springs, after Y runs replace other high stressed items etc. (experience plays the biggest part here)

2)Watch your (corrected) runs to see if you are slowing down. This will tell power production but not fatigue.

3) If you are slowing down, do a leak test to see if cyl pressure loss is the reason.

4) If you scatter a motor, not only find out WHY it broke, but make note of how many runs were on the part that started the chain of events which resulted in a broke engine.
(if I only changed those valve springs at 50 passes instead of 100, it wouldn't of floated the valves which kissed the piston, breaking it and letting the rod destroy the block)

Jusy my .02

[eddie c]

My .02 cents worth, Really well though out answer,and humourous. Seems as if todays stocker engine pulls alot more RPM 's, thus your attention to valve springs.
I am not trying to regress or anything,but years back it was very rare
to see a stocker scatter an engine. Seems a little more common now,
I think. Anyway thanks for your response,I hope we hear from some more of the guys. ed

[Alan Roehrich]

Eddie,
It is typical to see close to 8000 RPM in Stock Eliminator these days, some are going higher.

Valvetrain in Stock is absolutely critical, valves, valve springs, pushrods, and rocker arms are all parts that require close attention. Of course, the new rule allowing roller rockers will help on the rocker arms, if they ever get the rule clarification done and published.

With aftermarket rods, pins and pistons, the short block life is good, especially for small block Chevy engines.

A leak down test will often "lie" to you. I've seen engines that "leaked good" that were way down on power due to blow by, and engines that "leaked bad" that made enough power to set a record. Fortunately, ring seal and ring life is a lot more of a science now, and has improved greatly.

[Jeff Lee]

Just like in the 70's...cut open the oil filter!
Aftermarket rods have helped rod bearing life tremendously and saved a lot of money for the racer.
Running the required ring land spacers and thin rings have helped with power and longevity of the rings. Don't forget the rings are usually back-cut for less radial tension but seal better with the newer facings and materials.
Stainless valves will last longer too.
Just like the 70's, check valve lash for problems.
Pay attention to MPH changes.

[ron mattson]

All the mechanical answers have been great but you can also track your performance
in relationship to your competition, get a qualifying sheet at each race and compare
your qualifying times to everyone else and see if your changing more than others. If you
have a few racing buddies you see frequently at the track you can compare et slips
from week to week and know where you stand, then if something is abnormal get out
the tools and start checking things out.