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Bad Coyote piston. Why?

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When I see melted pistons, my first thought goes to the tune or the performance of the fuel injector (cylinder goes lean if it's plugged up). I've seen very different opinions on the head cooling mod, some saying it does nothing and some claiming it helps. That being said, I haven't ever been able to find any data to back up any cooling gains and the ones that say it does something could very well be the placebo effect. I believe @honeybadger had it installed and then decided to remove it later, so you may want to gather an opinion from him since he has experience.

What you may want to consider for roughly the same price as the head cooling mod is Ford Performance M-8501-M52A. Capaldi Racing appears to currently have the best price on it.
 
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27
27
Exp. Type
Autocross
Exp. Level
20+ Years
Maryland
What you may want to consider for roughly the same price as the head cooling mod is Ford Performance M-8501-M52A. Capaldi Racing appears to currently have the best price on it.
Solid suggestion. Looks like a good idea as an upgrade in any build. Thanks
 
380
324
Exp. Type
Time Attack
Exp. Level
Under 3 Years
Bulgaria
I will put this hear but a Gen 3 car in Bulgaria melted 8th cylinder on track because of Cats. New Engine and new Cats and car is back on the road. I wonder how many of the cars with 8th cylinder failures run cats ?
 

Mad Hatter

Gotta go Faster
5,359
4,390
Santiago, Chile
I will put this hear but a Gen 3 car in Bulgaria melted 8th cylinder on track because of Cats. New Engine and new Cats and car is back on the road. I wonder how many of the cars with 8th cylinder failures run cats ?
Hmm.... I would guess it had more to do with the O2 sensors then the cats. DO NOT TRACK the car if your O2 sensors are reading funny or sending codes. Logging the car before a event is always a good idea. My O2 sensors tend to die after a season or two, always keep extras in my track bag.
 
380
324
Exp. Type
Time Attack
Exp. Level
Under 3 Years
Bulgaria
Hmm.... I would guess it had more to do with the O2 sensors then the cats. DO NOT TRACK the car if your O2 sensors are reading funny or sending codes. Logging the car before a event is always a good idea. My O2 sensors tend to die after a season or two, always keep extras in my track bag.
Тhat's first time I'm hearing such issue can you share more info what you mean by reading funny ?
 
237
211
Exp. Type
W2W Racing
Exp. Level
3-5 Years
Columbia, TN
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.

20230325_115112.jpg
 
155
171
Exp. Type
HPDE
Exp. Level
5-10 Years
Arizona
then that would be the reason for low compression in 8. Or at least a reason. Unfortunately I’m in the process of rebuilding my engine because of low compression in #8. It is the fate a few of us have face because of running pump gas at the track. Best to use is race fuel or e85. Shaun at AED warned me years ago. Kinda forgot and now paying the price.
Same deal for me. Now I run e85 or a 50/50 mix of 100 unleaded and premium if I’m somewhere I can’t get e85.
 

Mad Hatter

Gotta go Faster
5,359
4,390
Santiago, Chile
Тhat's first time I'm hearing such issue can you share more info what you mean by reading funny ?
The dead cat is probably due to a problem with the O2 sensor and would most likely be due to heat. Since the O2 sensor is part of your wideband setup its critical in keeping your engine alive and running well. I once had a bad sensor and the heat it caused, burnt a hole in my header!!!
 
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350
187
US
I lost a #8 also. No cats 105 octane in the tank. I read alot and talked to several people and the number 8 cyl had poor circulation of coolant around that cylinder. plain and simple. the piston swells up from the heat and seizes up and catastrophic failure. Gen 2 blocks were made better and gen 3s even better. problem gone in gen 3 blocks. You cant find a passenger side boss 302 head. i have a spare driver side. You cant find the stock vales for a boss either. i have an extra set now. finding good stock gen 1 heads is difficult too or they are expensive. gen 2 heads are easier to find. but do have different sized valves vs gen 1. also the gen 3 short block is 12-1 compression vs gen 1 and 2 at 11-1. I bought a new boss intake vs risk missing any metal chunks in my old intake. when the piston goes- it explodes everywhere. keep you gen 1 rear crank cover panel. the gen 2 and 3 are different where they hold the crank position sensor. you must use all gen 1 timing components. cam sensors phasers etc. gotta use gen 3 head gaskets with the gen 2 heads also i believe. good time to upgrade the oil pump and crank sprocket to billet units. trust me is adds up $$$$$$$$$. and as soon as you are done, the getrag mt-82 will fail! LOL!
 

Mad Hatter

Gotta go Faster
5,359
4,390
Santiago, Chile
When we built our Gen1/gen3 setup we could not find any stage 2 heads. So we got Gen1 stage 2 ported heads from Livernois that worked out well. They had better numbers then the Gen2 heads.


But as DrLee50 says... you are looking at something around 500rwhp and a stock MT82 is not going to like it very much.... or for very long.
 
27
27
Exp. Type
Autocross
Exp. Level
20+ Years
Maryland
I‘m thinking a budget build here. Gen3 block, move all my Gen1 stuff over. Just clean up and add stiffer (Boss 302 or equivalen) valve springs. The cost per HP seems to get too high when you start thinking about cams and head work. Since this is an Autocross/ProSolo car only, I think that will get me in the sweet spot as far as controllable power in the mid range. The block and valve springs should give me 500 more RPM, and if I need more power I can still go from 3.55 to 3.73 gears.
I‘ll add a bigger radiator and the 5.2 water pump. I’m still on the fence on whether I need the oil balance line or coolant crossover. Part of me says it won’t cause harm, so do it. The other part of me like’s simplicity. Plus I really need some good grounds on the back of the head for the Smart coils. There are 3 grounds for each bank of coils, and I need to ground the head to the chassis too.
 
27
27
Exp. Type
Autocross
Exp. Level
20+ Years
Maryland
Thought I would add this for future reference to anyone unfortunate enough to have the #8 experience and they find this thread.
I recieved my gen 3 shortblock today. Note the differences in the cooling passages. Looks a bit larger on the Gen 3

IMG_8784.jpeg

IMG_8783.jpeg
 

ArizonaBOSS

Because racecar.
Moderator
8,746
2,768
Arizona, USA
Sorry to hear that you are among the many of us that have experienced G1 Cyl8 failures. There is a litany of threads and comments on this very site about these types of issues.

Looks like a pretty massive improvement in water jacket design on the G3 SB you show above.

Get yourself a good radiator (C&R/PWR has been extremely good for me), run good fuel (at least 25% if not completely 100 octane, or E85), and make sure your tune isn't hyper aggressive. An extra 3-5whp isn't worth the cost and trouble of replacing an engine. Make sure your tuner understands that you will be running your car hard for extended periods on a road course (or autocross) as opposed to a few seconds blast on a dragstrip or dyno. Maybe worth investigating other tuners like AED, VMP, or OZ. E85 will buy you more cooling and timing options, as well--as long as you aren't concerned with the consumption rates.

Good luck with the fix and keep us posted!
 
27
27
Exp. Type
Autocross
Exp. Level
20+ Years
Maryland
Get yourself a good radiator (C&R/PWR has been extremely good for me), run good fuel (at least 25% if not completely 100 octane, or E85), and make sure your tune isn't hyper aggressive. An extra 3-5whp isn't worth the cost and trouble of replacing an engine. Make sure your tuner understands that you will be running your car hard for extended periods on a road course (or autocross) as opposed to a few seconds blast on a dragstrip or dyno. Maybe worth investigating other tuners like AED, VMP, or OZ. E85 will buy you more cooling and timing options, as well--as long as you aren't concerned with the consumption rates.
I’m in a rush to get this thing back together for Nationals at the end of August. I’m adding the 5.2 water pump, new radiator, and a conservative tune . I haven’t heard back from Fore Innovations on my E85 pump requirements that goes with their hat, so that will likely happen over the winter.

Anybody know if a GEN1 crank sensor and wheel will be ok in a gen 3 block?
 
532
505
Exp. Type
HPDE
Exp. Level
Under 3 Years
MD
Anybody know if a GEN1 crank sensor and wheel will be ok in a gen 3 block?
I have a gen 2 but was told that I will need a gen 3 crank sensor to go with the gen 3 short block. They are different shape so it makes sense. I thought a new crank wheel came with the short block.
 
27
27
Exp. Type
Autocross
Exp. Level
20+ Years
Maryland
Looks like that crossover tube gets hot. Was that under normal operating temp? Or did it overheat?
 

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