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.

[FED 387]

Ditto on changing stressed parts at regular intervals eliminates many problems
check oil & filters for particles
leak down test as well as blowby testing to check ring wear among other things
do not be afraid to take off the valve covers and give it all a good lookover for particles,broken springs ,rocker arm alignment , water leaks,etc--also turn engine over by hand while looking in these areas
check valve retainer/locks/caps appearance ,spring condition and pressures

dynos only tell you part of the story track performance is the true test--check chassis/tires etc regularly too

compare your performance with another similiarly classed car if possible see if when you do make changes if in relation to the other cars what happens faster/slower

keep records on every run-- your engine settings/weather etc so you can go back in future situations to compare that performance against a known condition in the past

[BlueOval Ralph]

Buy a quality blow-by meter carry with you to the races very easy to use with wet sump system, little harder with dry sump, any thing over 2 cfm take engine apart and fix it.

[Chris Hill]

Originally Posted by BlueOval Ralph

Buy a quality blow-by meter carry with you to the races very easy to use with wet sump system, little harder with dry sump, any thing over 2 cfm take engine apart and fix it.

Use going down the track or just at idle in the pits. Never thought of it but good idea.

[BlueOval Ralph]

The way we used it was in the pits, just plugged one valve cover and hooked it to the other valve cover, it was the way Ted Flack & John Worley from Chrysler advised use to do. If engine was really bad the float in the meter would bounce when spinning it over on the starter. Difference on a 358 CID modified engine between 2 cfm and 6 cfm was about 60 hp this was engine that made 680 to 690 when everything was perfect. Most times on a 6cfm engine leak down would be in the 5% range with the old style Sun leak down tester. The meter was a Fisher Porter flow meter not some cheap deal like Hamburger use to sell.

Originally Posted by Chris Hill

Use going down the track or just at idle in the pits. Never thought of it but good idea.