Assembling an Engine… any tips?

[tdstuart]

I know they used to use 0 weight. That was back when they had qualifying engines. They would use the 0 weight for qualifying then when they put the race engine in the car it got 40 or 50 weight.

I've been running Valvoline VR1 Synthetic 10w-30.

So many debates on oil that go nowhere. Only thing I have decided for sure is that 30-weight oil is probably the better oil for the coyote than the 20-weight. I just chose the vr1 because it has a lot of additives, enough that you can't run cats, so hopefully that means its better for my engine...

Sponsored

 

[GregO]

@tdstuart
Was there issues with the heads in the first place ?

10w in a 4V VVT DOHC V8
Man you are just full of all kinds of surprises.

You want robust oil for 4V DOHC VVT and Catless then Rotella T-6 5W-40 or their newer T-6 0W-40.

Now, who will be the first to jump my shit with that advice ?

 

[tdstuart]

@tdstuart
Was there issues with the heads in the first place ?

The original reason I pulled the motor was that it detonated really bad (likely from the bad tune I was running). The piston melted, the spark plug melted, and the piston rings melted to the piston. The piston was just rubbing up and down the bore so the bore is heavily scratched.

I took it to the machine shop and they said it's pretty likely the head got warped from all the heat and it would be best to machine it. So I am having them machine the head and check all the valves and valve seats. Also having them throw in some upgraded springs for my cams.

 

[WildHorse]

I know they used to use 0 weight. That was back when they had qualifying engines. They would use the 0 weight for qualifying then when they put the race engine in the car it got 40 or 50 weight.

Comment wasn't directed at you. And they use 0w20.

 

[K4fxd]

Comment wasn't directed at you. And they use 0w20.

What team?

20 weight thins out a lot at the oil temps a cup engine runs at.

 

[GregO]

The original reason I pulled the motor was that it detonated really bad. The piston melted, the spark plug melted, and the piston rings melted to the piston. The piston was just rubbing up and down the bore so the bore is heavily scratched.

Melted like the picture below ?
Just one of 8 pistons were damaged all 7 others were unharmed ?

 

[tdstuart]

Melted like the picture below ?
Just one of 8 pistons were damaged all 7 others were unharmed ?

Just the one cylinder. That piston has been through it haha. Mine isn’t nearly as bad. Don’t have a photo of the rings melted to the side of the piston but here is the piston and cylinder wall.

 

[GregO]

Just the one cylinder. That piston has been through it haha. Mine isn’t nearly as bad. Don’t have a photo of the rings melted to the side of the piston but here is the piston and cylinder wall.

Very interesting !
Only one piston, all the others are fine ?
You posted on another thread about your 2M header bolts loosing up.
I’m wondering, does the damaged cylinder exhaust port gasket show signs of exhaust gas leakage or soot trails ?
There’s more going on there than detonation. There’s evidence of a localized hot spot.

I’m going as far as saying that picture shows me no evidence of detonation. Especially if the other 7 holes are not damaged.
IMO what you have there is a hot spot from an extended full power run, stuff got to hot, expanded, the oil film failed from excessive heat and poof, in an instant metal to metal contact and the reciprocating parts came to a grinding halt.

Who told you that piston in the picture is detonation ?

 

[tdstuart]

Very interesting !
Only one piston, all the others are fine ?
You posted on another thread about your 2M header bolts loosing up.
I’m wondering, does the damaged cylinder exhaust port gasket show signs of exhaust gas leakage or soot trails ?
There’s more going on there than detonation. There’s evidence of a localized hot spot.

It could have been the headers I’ll look when I have a chance. The engine shop did say it looked like it happened near the exhaust port.

Keep in mind fuel correction was like 30%+. I was doing a very mild pull and the engine wasn’t very hot.

If anything I would have expected it to blow when I got the engine super hot and went 176 like a week before.

I think the car didn’t fuel correct and the car went lean during the pull but I could be wrong, I don’t know a ton.

And yes all others appear fine. I did a compression test and all the others were within 10 psi of eachother in like the 190 range. This cylinder was at like 30.

 

[GregO]

It could have been the headers I’ll look when I have a chance. The engine shop did say it looked like it happened near the exhaust port.

Keep in mind fuel correction was like 30%+. I was doing a very mild pull and the engine wasn’t very hot.

If anything I would have expected it to blow when I got the engine super hot and went 176 like a week before.

I think the car didn’t fuel correct and the car went lean during the pull but I could be wrong, I don’t know a ton.

And yes all others appear fine. I did a compression test and all the others were within 10 psi of eachother in like the 190 range. This cylinder was at like 30.

Overall gauged Coolant system temperature readings are irrelevant when it comes to identifying localized hot spots.
You said your headers were loose at the flanges so that would means your wide band O2 was sampling incorrectly due to exhaust gas leaking at the header flange.

The piston I posted failed due to localized coolant flow issues. I won’t bore you with how we fixed it but the jetting, EGT’s, fuel, timing curve and coolant gauge temp reading were all spot on ! So the question was how did just one of 3 cylinders fail so horrifically and the other 2 cylinders were text book perfect right down to the piston wash band.

 

[tdstuart]

Overall gauged Coolant system temperature readings are irrelevant when it comes to identifying localized hot spots.
You said your headers were loose at the flanges so that would means your wide band O2 was sampling incorrectly due to exhaust gas leaking at the header flange.

The piston I posted failed due to localized coolant flow issues. I won’t bore you with how we fixed it but the jetting, EGT’s, fuel, timing curve and coolant gauge temp reading were all spot on ! So the question was how did just one of 3 cylinders fail so horrifically and the other 2 cylinders were text book perfect right down to the piston wash band.

I’ll check the headers and see if I can see anything obvious.

When I was driving I made a small pull. Started probably around 60-70 and got up to 110-120. Heard a small boom or “poof” and said damn that’s not good and then my check engine light came on. Car was misfiring hard due to the lack of compression and spark plug damage.

Spark plug tip was completely gone, and you saw the pictures of the piston.

Found a photo of the plug:

 

[GregO]

I’ll check the headers and see if I can see anything obvious.

When I was driving I made a small pull. Started probably around 60-70 and got up to 110-120. Heard a small boom or “poof” and said damn that’s not good and then my check engine light came on. Car was misfiring hard due to the lack of compression and spark plug damage.

Spark plug tip was completely gone, and you saw the pictures of the piston.

Found a photo of the plug:

To be honest, IMO this isn’t a bad tune that took out this one cylinder and piston. This is a case of header bolts backing out creating a leak and a wide band O2 sensor misreading the exhaust gas and a localized cooling system hot spot.
That piston turned molten. Detonation doesn’t melt pistons it jack hammers the head squish band and piston dome.

 

[Jackson1320]

https://www.rosspistons.com/piston-coatings/

 

[Jackson1320]

He should have never took it apart. The only proper way to rebuild a gen 3 block is to sleeve it or buy a new one.

i like using a new block but you can have the cylinders redone now. so there's options. and it's cheaper than sleeves

 

[Jackson1320]

@tdstuart
Was there issues with the heads in the first place ?

10w in a 4V VVT DOHC V8
Man you are just full of all kinds of surprises.

You want robust oil for 4V DOHC VVT and Catless then Rotella T-6 5W-40 or their newer T-6 0W-40.

Now, who will be the first to jump my shit with that advice ?

mobile one 0w40 or 5w50 ether one European blend

Sponsored