dean51267

scenario:

Motors get super hot and one spins a main from a faulty or mis-installer thermostat.

Rebuilt two very mild motors, 454's, dart heads, mild Comp Roller cam, elderbrock intake and carb, lightening headers, builder have built thousands of motors.

Install motors, they run like schit, one breaks an INTAKE valve and bends push rod on one cylinder, other valve hitting pistons. Motors only ran 10 minutes or so.

Oil coolers have been flushed, but motors have oil in them, also water. Cylinders and rings are rusted. Motors were SUPER clean prior to assembly, bearings show wear after just the 10 minutes.

Not sure what has happened, And ideas?


Second question - what oil and filter is everyone running in these motors?

rdoactive

"one breaks an INTAKE valve and bends push rod on one cylinder, other valve hitting pistons"

Sounds like that's your problem.
Know one guy who installed bigger valves and bigger cam on a 454. Never checked the valve to piston clearance. All the intake valves were hitting pistons.
Gary

SB

iTrader: (1)

Guides too tight, hanging up valves ?
As mentioned, not enough valve to piston clearance ?
Valves adjusted totally incorrectly ?
Retainer to guide clearance not enough ?

Rust:
No sealant used on head bolts ?
Exhaust leaking water ?
Busted valve guides ?
Wrong headgaskets ?
Leaking intake gaskets ?

==================

Something seriously wrong with this build.

Did the 'builder' assemble the engine complete or just as shortblock and someone else did the rest or.............?

MESABALANCING

As an engine builder I don't see were the customer has a problem the engine builder has a problem stuck valve guide piston to valve interference dirty oil cooler or other crap get the engine builder to do what I do get off his a s s and fix the problem at any cost and make it right when there is a problem we all have problems and how we handle them is what makes customers come back.

articfriends

iTrader: (1)

sounds like a damn abortion. Are you sure pistons weren't in backwards with valve reliefs in wrong spot? Was it a mild roller cam or hyd roller cam? A "mild" hyd roller cam shouldn't come no where near hitting pistons. I doubt the guides were too tight,valves probably all bent a little then stuck in the guides from not moving freely any longer.Was it intakes,exhaust or both? Maybe cam was off a tooth or something. Let us know what you find in the end and how its resolved,Smitty

rmbuilder

Dean,
What pistons were you using? What cam part or grind# (ICL and LSA if you have them), and intake valve size with the Dart heads?
Bob

customryder

did you have any breathers on the engines? I was told you ran the boat with NO valve cover breathers. maybe just hear say....

dean51267

this is a half truth....

The motors were run without breathers for an initial run (10 minutes), the one that resulted in a spun main from the thermostat problem. Part time mechanic thought this would be acceptable, at that time I defered to his judgement, should not have, but it was 10 minutes, and not the source of the problem.

There were breathers already ordered, but not yet installed, they are installed now.

Sounds like someone is telling half truths.... wonder why someone would do that....

dean51267

The pistons are stock, forged, flat tops, fly cut .030, all are new. They are installed correctly (I know this from first hand experience).

There is plenty of valve clearance (found this out last night, was so much it was not necessary to measure).

The cam is the Comp "Extreme Marine" cam kit to retro fit a Gen V, it is a mild hydraulic roller. 540 lift, 260 duration... nothing extreme at all... The dart heads have the larger valves in them, I do not have exact size, but they are the larger of the 2 sizes with this head. 309 runners I think... I will check specs and confirm when I get to office... The intent was to build a motor that runs comfortably and makes power to about 5500 rpm. Before thermostat problem motors made 440hp/400lbs torque on dyno...

Engine builder has stepped up to the plate 100%, while I wish it were not messing up, the builders acceptance of responsibility has been reassuring. I would take him another one based on how he has addressed this. This is not a "vendor screwed up" issue, it is a "how do I prevent this again" issue.

My concern is mostly with the metal in the oil after the coolers had been flushed, and water in the engines. Of course everything is put together with marine gaskets and all. I have one going back to Dyno shop today or tomorrow.

Valves could have been adjusted to tight, but not so tight it eliminated valve clearance, builder was with me to splash boat with intention of adjusting valves after motor ran with a load on it. The second time motors went into boat they did not go to dyno shop first.

dean51267

agreed...... builder and installer have been exceptional, even after this problem I will use them in the future, sometimes schit happens, like you said, it is what happens next that exposes a mans character, and I have only positive comments in that regard....

BUT - I am wondering if there is something else, one of those "you do not know what you do not know" deals...