Bad Coyote piston. Why?

[ESP41]

“I thought a new crank wheel came with the short block.”

Nope. I got an oil filter, oil pickup tube holder,and a pilot bearing in the goody bag. No crankwheel. MMR billet wheel is only a few more pesos than the stamped FM one. I will probably try it.

 

[biggsy]

“I thought a new crank wheel came with the short block.”

Nope. I got an oil filter, oil pickup tube holder,and a pilot bearing in the goody bag. No crankwheel. MMR billet wheel is only a few more pesos than the stamped FM one. I will probably try it.

View attachment 96859

Good to know. Which crank position sensor are you using?

 

[ESP41]

“Good to know. Which crank position sensor are you using?”

The gen 3 one. I am controlled by a Haltech Nexus R5, so I just need to tell it what is there.

 

[sldghmr]

Looks like that crossover tube gets hot. Was that under normal operating temp? Or did it overheat?

Normal operating temps....but before I had hood and fender vents. Now w/the vents it's difficult to get coolant temps over 200-210

 

[Fabman]

I did the oil balance lines and the MMR cooling mod on my car when I swapped the clutch. It was nice, I had full view, but it was still a pain. I can't imagine trying to do this job over the top only by removing the intake. For me it was crucial to have the transmission out as I was over and under the car to get the freeze plugs, and oil plugs out, and the new fittings and lines it.

Does the cooling balance line work... well only one way to know and that is drill, tap, and install temp sensors in the back of both cylinder heads and the block. Run the car and datalog the temps. Install the cooling mod and then run the car again on a similar track and ambient temp to datalog temps again.

I know a respected engine builder posted a video saying this makes no difference, he also improperly stated the cooling paths in the engine saying the coolant is forced to go around the bottom of the cylinders, around cylinder 8 and then back across the top of the cylinders to while flowing up through the head gasket, which is completely incorrect. Personally, from my experience, there is zero downside to the cooling balance line across the back of the head and only up side.

Here is a pic from my car.

View attachment 96227

Yup, this is what I used on my gen 2 and now my gen 3 motors. (Water crossover)

There is also one from power by the hour for the front of the block if you are more race than street and don't need a heater.

I road race so heat management is a big deal and I have had good success.

 

[Dave_W]

So just spitballing here, and I haven't done a deep dive on coolant routing, but the hose at the rear seems to just balance the coolant pressures at the rear of each head - not sure how much flow there actually is. Since it's the #8 cylinder that seems to be an issue (at least on Gen 1), I'm wondering if this could be modified to promote more coolant flow at the back of the head. You could cut the balance hose in half and insert a tee fitting, then run a hose from the tee to somewhere with suction from the water pump (maybe the outlet fitting on the block?). May need to use a smaller hose to not have too much flow in this new direction. Not sure what that may be "stealing" coolant from.

Has anyone considered something like this?

 

[Fabman]

So just spitballing here, and I haven't done a deep dive on coolant routing, but the hose at the rear seems to just balance the coolant pressures at the rear of each head - not sure how much flow there actually is. Since it's the #8 cylinder that seems to be an issue (at least on Gen 1), I'm wondering if this could be modified to promote more coolant flow at the back of the head. You could cut the balance hose in half and insert a tee fitting, then run a hose from the tee to somewhere with suction from the water pump (maybe the outlet fitting on the block?). May need to use a smaller hose to not have too much flow in this new direction. Not sure what that may be "stealing" coolant from.

Has anyone considered something like this?

According to Shaun at AED this hose does nothing.
However, I went with it anyway just in case the flow was slower through the back of the block and it could exit with the flow on the opposite side of the block.
That's a big maybe, for sure, but I had already installed it and the motor was in the car, so I went with it.
My cooling system both water and oil has been so effective with the mods I've done I just kept it on there.
Why mess with success?

Would I do it again....? Probably.

As to your suggestion of splitting the hose.....yes, that is how sprint cars are done. Everything on the motor is an out.
Front of both heads and rear of both heads are plumbed to the radiator via A/N Hoses. (no upper rad hose as is typical) Super efficient system.
That was how I was going to do my Coyote at the first sign of overheating but its run so cool I haven't had to change a thing.

 

[misterpeanut]

We have sold a lot of no water head gaskets for guys to externally plumb cooling line for the cylinder head and block. It looks really cool too, it's a bit of tedious work... and as always it's a risk. Sprint Car guys run a big ol cooling line up in between the siamese exhaust ports on they SBC platform and it prevents over heating and kicking/cooking the head gasket out.

I'd be more inclined to add a small and same size cooling port as the Gen 3 gasket has at the 2 o'clock position on cylinder 8 (and 10 o'clock position on cylinder 4), and slightly increase (as in percentage) the cooling port size right where the faint carbon tracking is which is also in line with the torched part of the piston.

There's too much questioning of the balance lines across the back of the heads doing something. They absolutely do something and if someone plugged in the instrumentation to measure, the results would be really interesting. This is an old trick done on BBC's as well, just a small 1/8" to 1/4" line and it stopped HG issues, and plenty of other engine platforms.

Usually, at teardown, if you don't wipe off the gasket and you stand back looking at the head gasket as a whole unit searching for color change you can start to pick up where it got hot.

I am just about certain a Gen 3 hg will work on a Gen 1 & 2 from everything I've seen. There are some small holes that will be along for the ride, but that doesn't matter. I have two junk Gen 1 blocks here and 1 set of cylinder heads. I'm ordering a set of Gen 3 hg's...

 

[Fabman]

Sprint Car guys run a big ol cooling line up in between the siamese exhaust ports on they SBC platform and it prevents over heating and kicking/cooking the head gasket out.

So this must be an update with modern heads....my oval track days ended in the early 90's so front/back of the heads were the way it was done back then but regardless, same idea, same result.

 

[misterpeanut]

Seems to be the thing now.

https://content.speedwaymotors.com/ProductImages/12141000_L1600_9763243b-9e73-46e8-8d1d-99477068e0cc.jpg

https://kistlerengines.com/files/2016/11/IMG_7228.jpg

https://th.bing.com/th/id/R.3a5c23ba64ddaabd3245842827ff6da7?rik=of4G4OTqT67zfQ&pid=ImgRaw&r=0

 

[Fabman]

Seems to be the thing now.

https://content.speedwaymotors.com/ProductImages/12141000_L1600_9763243b-9e73-46e8-8d1d-99477068e0cc.jpg

https://kistlerengines.com/files/2016/11/IMG_7228.jpg

https://th.bing.com/th/id/R.3a5c23ba64ddaabd3245842827ff6da7?rik=of4G4OTqT67zfQ&pid=ImgRaw&r=0

Yeah, I looked that up too. Times they are a changin'......lol.
Back in the day we just tapped into water at the back and front of the heads where the intake manifold landed on the water port and sent it to the radiator with 4 separate hoses.

 

[ESP41]

That is some impressive cooling engineering. Pretty sure I don't need it for three (or 6 with a co driver) 60 second runs spent mostly in the engines midrange. That being said, I want it anyway......

This site and its contributors never fails to impress me. thx.

 

[bauern]

I'd be more inclined to add a small and same size cooling port as the Gen 3 gasket has at the 2 o'clock position on cylinder 8 (and 10 o'clock position on cylinder 4), and slightly increase (as in percentage) the cooling port size right where the faint carbon tracking is which is also in line with the torched part of the piston.

The Gen3 only has this hole on the pass side gasket.