Need Advise Re: Engine Builder

[agro1]

Here's the story - Motor comes from engine builder and is installed by a reputable shop (HOC).
I ask builder, "How should I treat the motor since it is new ?"
his response, "Drive it like you stole it..."
Rear main won't stop leaking - Motor comes out, back to builder. They fix it and pay for it to be put back in by HOC. No prob.

Right side head gasket blows. Heads come off, and go back to builder. After inspection, nothing wrong with heads. Gasket builder used was a graphite OEM style replacement for a motor running 12:5.1 compression. I paid for and my build sheet says, "Fel-Pro gaskets throughout".
Heads back at HOC to get put back on and engine builder says he will not pay for the head work done by HOC. Builder says the motor was detonating (I run 100 octane only). I said if the motor was detonating the carb wasn't adjusted properly when it came from you and you told me to drive it like I stole it. Builder tells me once it was installed in the car it needed to be "re-tuned under load", which was never done. Builder states they tuned it on the engine stand while running it in, but after it went in the car it needed to be tuned again under load. He said the installer should have known this.

Am I missing something here guys ?? Is this standard practice ?? Should my motor have been tuned again once it went in the car ? I spent close to $12k on this motor alone and would think the builder would stand behind it. The simple fact is an inferior gasket was used and the builder is trying to say because the motor was detonating he will not warranty the work. Mind you - HOC said the motor was NEVER detonating and the build sheet said "Fel-Pro gaskets throughout" and another gasket was used that failed. I do not want pi$$ them off in case there is a problem with the motor down the road, but I also feel as though they are not honoring their warranty. Any thoughts on how to proceed ? Thanks in advance.

[coyled]

Put the fel pro head gaskets on it for sure. I would find out if the block was decked and the heads were milled. A flat surface should eliminate any head gasket failure do to poor gaskets. Take a picture of the pistons and also keep the plugs. The tops of the pistons and the plugs for that matter, will usually show pitts if there was severe enough detonation to blow a head gasket. A magnifying glass will be needed to see the pits if there are any on the plugs. Once the motor is going again, I would take it to a rear wheel dyno that has an air/fuel ratio exhaust sensor. This will tell you if it is to lean and pinging. 12.8 to 1 or fatter should be safe, with 100 octane fuel . Also, check the timing. With lots of compression and good heads, it is not neccesary to run 38 total to gain the best power. Running less(32 to 35) timing will be easier on the motor and still make as much power. The builder may be telling you right now that the warranty is over. If the evidence shows that there was no pinging(plugs, pistons), maybe the builder will reimburse you for some or all of the repair bills with out getting into a legal battle which is almost always more time, money and trouble, than its worth. Good Luck, Scott.

[agro1]

Scott - thanks for the reply...But what I am wondering is if when an engine is installed, does it need to be re-tuned since it is now under load ? That is what the engine builder is saying DIDN'T happen and the basis for them not covering the repair work under warranty.

[dscott]

Agro1, In your case I would say yes. What surprises me is that the engine builder didn't take the time to have this engine dyno tested. To break an expensive engine in on a stand wouldn't satisfy me. When I sell a motor it is always dyno tested which allows us to break in the cam and rings properly, set timing curve for best results and tune carb. We have exhaust temp probes to tell us how the fuel mixture is at the entire rpm band. We know when a lean condition is happening.

The carb should have been retuned but this would only be necessary if a problem was found (pinging). Sounds like using the cheap gasket could have caused the problem. A good Fel-Pro and this problem probably would not have happened. With the cylinder pressure that a 12.5:1 motor makes any detonation would blow a cheap gasket. With detonation the cylinder pressure can increase 3 to 4 times over normal.

In my opinion the builder should have had this motor dynoed for his own safety. He should have used the proper gaskets. Then and only then would I have said "run it like you stole it". I think the builder should be required to assume any costs involved in the repair.
Don

[agro1]

Don - my sentiments exactly.

[scottj]

Agro1,

Scott and Don are right on.

Regarding compression; I was running 11.8:1 in my 434 sm block until today.
My engine builder assured me that 9.5:1 would be more than I needed with that many cubes and with the cam he was using it would still have that nice "pop" that high compression has at idle. He was right. We dynoed this morning on pump premium and using AFR 210's it made 600 ft/lbs @ 4500 and 620 HP @ 6500.

I'm one happy camper!

[coyled]

I agree with Don in that the best way for the builder as well as the client to get a motor is after it has been dyno'd and broken in. Usually when you get it from the builder, he will leave the fuel curve on the rich side. To fine tune it, you then can modify the fuel and timing curve to suit. In my opinion, the best tune will be under the weight(load) of the vehicle. scott

[Jack21]

Never take a freshly built motor and drive it like you stole it!

The cam has to seat, the rings have to seat, the valve guides and rocker arms have to seat, the bearings have to seat, etc., etc.

Got to baby it for awhile. Any fresh engine, not just Cobra.

[agro1]

Jack - Some may agree with that school of thought, but understand that there is also one that ALL of the drag racers and most engine builders subscribe to - When they rebuild a fresh drag motor they do a burnout and run it WIDE OPEN. Granted, they rebuild them after each run, but they sure as hell don't baby their motors.

[cobrashoch]

Interesting the approaches guys use to break in a motor. How a motor is clearanced is the desiding factor. That is a direct function of your engine build. A racing motor is usially clearanced loose and can indeed be pushed hard but the backside of that is those motors don't last much over 60k miles or even less for street use. A tight engine does need to be brought up to speed more gradually, say 5000 miles or so as a rough guess. My advice is more practical. I haven't ever seen the perfect engine build yet. Even very good engine builders make boo-boos. There is always something that needs addressed it seems. Breaking them in graduially will bring out any problems in most cases, before you gernade a motor by pushing it. And that philosophy will work on a so called racing motors in most cases too. Dyno work for me is later, after I have some degree of knowledge of the motor and I have set up some sort of rough tune.
Agro1 - your engine builder should replace the gaskets, but in most cases the tune should be made on the car itself after the engine install. Very rare indeed is the engine builder that can get it right the first time, every time. And the money you spent usially has nothing to do with it. Your engine builder should repair this simple fix if he is worth worth his salt. LOL
cobrashock

[Mr.Fixit]

FACT: You paid for Fel-Pro gaskets throughout the motor, invoice says so. Cheap substitutes were installed instead, and failed.

Builder had the motor back after running it for a while, if there was detonation, the upper rod bearings ought to be shiny spotted from being hammered. The sparkplug insulators would be chipping or or otherwise showing evidence of detonation as well. I would expect the engine builder to cover the gaskets, and necessary machining to repair the damage, labor to remove/reinstall, maybe not. That motor is brand new, one would expect them to cover their own @sses a little better with a new customer. If all this happened a year from now, you would be outta luck. Unfortunately, warrantees on racing motors are usually nonexistant.

[coyled]

Mr. fix it, that shiny spot on the rods could also be from too much timing in a high compression motorn that was not pinging. I have seen that on BB chevy's. He did pay for fel pro and got brand x. scott

[Mr.Fixit]

I don't think they saw any shiny spots. No evidence of detonation other than the blown gasket.