Ooops! did it again.... RIP Coyote....

[Coz]

They're all forged cranks. I think the 2013 Boss crank and damper were weighted a little differently than the GT crank.

 

[Mad Hatter]

Thanks Coz. been thinking about the valves. Did not appreciate that the Gen 2 valves are so much heavier then the Boss ones... the total difference is 320g!!!! Seems huge to me.. Disappointed to see that the Manely valves are also quite heavy.


I imagine that going to heavier 37.3 valves will have less high rpm reliability if we don't go to a stronger valve spring.

 

[Coz]

I don't know how heavy they are but the Gen2 does rev higher than the Gen1 and closer to the Boss.

This is a good reference regarding the differences across the generations of the Coyote.

https://performanceparts.ford.com/download/pdfs/Gen_2_Coyote_Technical_Reference_2-16.pdf

Unfortunately, while it refers to improvements to the Gen2 that were inspired by the Boss, it doesn't have a separate column for it.

I believe among the differences is that the Boss head was a slightly different alloy with more copper for heat dissipation. Also, the comparison column states that the Gen1 intake valves are hollow and exhaust valves are sodium filled. I thought they were solid and only the Boss had the hollow/sodium valves.

 

[Mad Hatter]

Double checking the valve weights, made a mistake... The gen 2 valves are 54/43 grams and the Boss valves are 48/40 grams (intake/exhaust). So its only 144 grams more total valve weight.

For reference these are the weights we have from the shop.
Gen 1 55g 37mm intake. 42g 31mm exhaust
Gen 2 54g 37.3mm intake 43g 31.8mm exhaust
Boss 48g 37.1mm intake 40g 31.8mm exhaust.

 

[Coz]

There's discussion at this post and a few prior to it that recommend the Livernois springs.

BOSS 302 Race Car Build Thread

 

[Mad Hatter]

I went over the posts on springs and am still undecided about the stock Boss springs or an upgrade... I would have thought that LM intake cams would be fine with the Boss springs?

Talked to Modular Head shop about the Wiseco pistons and their take is that it could have been a badly placed circlip that made the second groove... I really do not know... any opinions??

 

[TMSBOSS]

I was thinking the same. A clip which was not properly seated could have been making its own groove before the failure. Are there any signs of the clip wearing on the cylinder wall?

 

[Coz]

went over the posts on springs and am still undecided about the stock Boss springs or an upgrade... I would have thought that LM intake cams would be fine with the Boss springs?

How high are you reving your engine and for how long? I think you're fine on the intake cams since they are still 12mm lift. I think the concern is on the exhaust paired with a heavier valve and high sustained rpm.

 

[Mad Hatter]

I was thinking the same. A clip which was not properly seated could have been making its own groove before the failure. Are there any signs of the clip wearing on the cylinder wall?

Yes, you could see very clear marks on the cylinder wall, But just one set that look like they happend before the just before the "event"

 

[Mad Hatter]

How high are you reving your engine and for how long? I think you're fine on the intake cams since they are still 12mm lift. I think the concern is on the exhaust paired with a heavier valve and high sustained rpm.

I have my cutoff at 7850. Usually dont spend much time at the rev limiter... Well sometimes as long as a second or two... still mulling springs over

 

[Fair]

There is a false sense of "high RPM reliability" with Coyote/Voodoo based engines. The internet likes to perpetuate these false narratives, too. You have to get that out of your brain and work within the limitations of these engines. Making any road race engine that lasts at high RPM is THE MOST EXPENSIVE THING YOU CAN DO. It adds as many problems as boosted track cars, which are a total nightmare.

I cannot count how many GT350 track bois I have seen that have lost engines on track. Many of them multiple times. What do they do even more than Coyote and Boss302 owners? Rev the engines even higher. It's engine suicide.

Watching the OP's HPDE video I saw more than a few "overrev" moments on downshifts. Touching 8000 rpm in a Coyote is a recipe for disaster - they don't live long up at that range. I would be a little more careful and downshift later in the corner to avoid the mechanical overrevs that can happen when you are downshifting early. No electronic rev limiter can prevent a mechanical overrev. We have seen customers touch 10K revs on some of our built-to-7500 rpm LS engines, and they don't live long like that either.

I get that the Boss302 intake doesn't make as much power at lower revs. Its a pretty terrible manifold, actually, and when you port it they likely get even lazier low RPM flow. Ever wonder why the GT350 doesn't have an intake that looks anything like the Boss or CJ? If you want to avoid the higher revs and make the engine last longer, switch to the Gen III Coyote intake, which will help retune the engine to make maximum power under 7000 rpm. Then shift at 7K instead of nearly 8K. I bet the engines last 5x longer. Our Coyote had 18K miles on it when I sold it, and almost all of that was track miles. 5 seasons of abuse, 16 track records, 75+ wins. It made peak power at 6800 rpm.

So in short: Keep it NA. Keep the revs under 7000. Tune the intake/cams/EFI to make peak power under 7000. This is how you make a Coyote live.

Cheers,

 

[Grant 302]

Thanks for saying it Terry. I've felt like a broken record...especially about the mechanical over-rev part and the need to downshift later.

A 4-3 downshift at ~6,800 rpm jumps to 8,700...

Even shifting at 6,300 jumps up to over 8k.

----

The other thing I keep harping on...are the oil squirters. Why else did Ford include them for ALL Coyote variants AFTER the Boss? (Excluding crate engines)

---

My understanding/interpretation is the stock Boss valve springs barely prevent float with the stock lightened valves. I wouldn't pair OEM springs with heavier valves.

/rant

 

[Coz]

The other thing I keep harping on...are the oil squirters. Why else did Ford include them for ALL Coyote variants AFTER the Boss? (Excluding crate engines)

I thought they were deleted in Coyotes sometime in 2012 and have not been reintroduced since.

 

[Grant 302]

I thought they were deleted in Coyotes sometime in 2012 and have not been reintroduced since.

Common misconception. They're only missing for part of MY13 production. Definitely back in for ALL Gen2+ starting with MY15 cars.

 

[Mad Hatter]

Thanks Terry will digest what you said... Due to Grants harping I have dialed back "some" of the over reving but looks like I am still touching 8000 rpm on several downshifts. Will work on that.

Following your thoughts... If I built my engine up using the stock Gen1 engine I bought recently (rods and pistons that look to be in great shape).... and went for a 7000 rpm build??

With the Boss manifold have won lots of races using the +7000rpm range but would really like to have a a longer lasting engine..

The original Boss motor spoiled me... I abused and mistreated that poor thing at the track for some 5 years before it gave out on me.. Since then not been so lucky....

I understood that the Gen 3 manifold was a pain to tune for the gen1 pcm setup?

Sadly, oil squirters don't fit with many after market rods and pistons.

 

[Coz]

Did your newly acquired 2014 block come with squirters?

 

[Mad Hatter]

Nope. its with out squirters.

 

[Coz]

That's what I thought. My 14 isn't equipped with them either.

 

[TA28]

A 4-3 downshift at ~6,800 rpm jumps to 8,700...

I find that hard to believe. almost 2k jump in rpm. I know different car/motor but fr500c on down shifts I see 1k jump and that thru most gears. Watkins glen back straight 4.11 in to chicane 5th to 4th 1k increase 4th to 3rd 800 rpm increase.

I know most of you guys like to stay in direct drive gears . taller gear use od gears?
I also agree banging a coyote to 8k your asking to go

when I bought the car off dean martin he warned me to watch down shifts.chris

 

[Coz]

My table only goes up to 140mph and it's based on a 27" tire. But you can see that dropping 1 gear at speed can result in a money shift.