Engine Break-In

P

Phoenix

Member # 013
Location
Saint Louis
First Name
Karl
Last Name
Schoenefeld
Anyone think that Randy's engine was too new to run on the dyno, and that might have contributed to the damage? Maybe too tight and needed to run a couple of thousand miles to loosen up? I know that some car manufacturers recommend a break-in period. In fact, I drove a new Mazda RX7 turbo one time at the dealer, and that engine would not operate at full output until it had a certain number of miles on it. It was limited by the computer. I know that BMW also does this. I have heard others say "don't take it over 4,000 for a few months."
:confused:
 
The dyno didn't break the car. It was already broken when he showed up. If he would have driven it for any length of time further, he would have trashed it completely.
 
a good engine builder will actually run the engine, and break in periods are not as long as u think. just a rear wheel dyno can sometimes mess with a tranny. u never know the tranny
could of been the problem definitely a break in period too.
chrysler actually dynoed their early Hemis' prior to putting them in the vehicle.
but a dyno can now a days really be an engine analysis
my opinion it didn't
and when u get a new play toy with as much power u are really wanting to let it rip
and sometimes things can go wrong too soon.
anything can happen anytime
its like shooting a gun, windage and elevation>the engine air,gas and fire.....;)
 
Anyone heard from Randy or has he heard from his engine builder? Wondering if a "free" rebuild was offered. To my understanding, the dyno isn't any harder on the engine as driving around. Not sure about the tranny. Didn't hurt mine.
 
I talked to him. Southern Automotive will be picking up the car and taking it back to ATL for a tear down and re-build.
 
But..... Even though a dyno is no worse than driving the car, you shouldn't drive a car too hard on the road either until it is broken in. Run-in on a flat tappet cam is about half an hour at 2,000-2,500 RPM or the cam can get ruined.

If the damage was already there, what does that say about Southern Automotive's engines? Bad cam -- maybe a factory defect. Bent valves? Where did they come from? There is no way a piece of the camshaft could make it into the combustion chamber. Sometimes things get in through the intake.

Something just doesn't add up here.... We may never know, but I sure hope Randy gets the straight scoop. As far as I can tell, it could not have been Randy's fault in any way.

Randy, if it is not too painful, please keep us informed. This applies to all of us.
 
Sorry -- now I see there are two threads, and Randy's specific situation is being addressed where it should be -- on the other thread.:o:o:o:o:o
 
From what I understand (being second-hand information) the push rods on cylinder #1 were broken and bent, and the cam was wiped at cylinder #1 too. So, the question is - if the push rods break, does that wipe the cam? or, vice versa - if the cam is damaged does that break the push rods? Or, is there another component cause?

So, he has been running on 7 cylinders the whole time. Omer knew the problem was deep after the first pull to 3K RPM. He tried the usual things first, timing, dist, carb, etc - but after pulls to 4K RPM and the same problem - he stopped.
 
I was there the day after and i helped Omer move the car to a place where it would be safe, but out of the way inside. When we looked at the engine, you could clearly see where three other push rods had fractured at their base. One of them being on cylinder #8. Like I said before, I was heart broken.
 
I agree with what Mark is saying, the dyno run didn't cause the problem, it just highlighted that something was wrong.

Not sure about other auto manufacturers, but at Honda, we dyno test every car that comes off the assembly line. These confirm a car or truck is performing correctly before it is staged in the lot awaiting rail or truck shipping to the dealership. But, these are production line products built over and over again to the same spec. A little different than a high performance custom engine.
 
I've been behind the Corvette plant when they come screamin out of the plant sideways and hammer it for two miles behind the plant. Break in is for engines under warranty. Otherwise, DILYSI (driveitlikeyoustoleit) :D
 
Broke push rods ???

Valve sping coil bind, valve geometry , piston to valve clearance , valves installed in heads dry or inferior parts . Need to find cause before correction is made. My years of racing never used p c valve seals felt they starve valve for oil always use nylon umbella like big block gm used years ago
 
mike w said:
Valve sping coil bind, valve geometry , piston to valve clearance , valves installed in heads dry or inferior parts . Need to find cause before correction is made. My years of racing never used p c valve seals felt they starve valve for oil always use nylon umbella like big block gm used years ago
Click to expand...

ur right Mike
piston to valve clearance?
head gasket thickness?
no pre-lube
and one other cam degree of the engine
but the big one someone putting an inferior part in which isn't their fault, but the manufacturers'
just a cheap part can screw up a good build.
 
Speaking of prelube never ever take the following parts out of the package and expect to use with out soaking in oil, roller rocker arms, timing chains , roller lifters and remember don t forget to lube wrist pins in pistons have seen failures cause by this. I always get out my drill and prime the motor before starting
 
When priming the engine, make sure you know the proper rotation of the dist. If you just turn the drill on and assume you are pressurizing you could be in for trouble. Oil pumps only pressurize in one direction. Case in point: SB Fords have the dist run counterclockwise. IF you run the drill clock wise you are not getting pressure to all the engine even tho you will feel resistance on the drill. If you are turning the motor over by hand or starter while priming, you will probably wipe out most bearing surfaces.
 
You must log in or register to reply here.
Back
Top