How much can u bore the coyote block

[KenB]

Not true. There are at least 3 others that i know of that have broken the oil pump gears.

Mike @ powerhouse has broken 3 blocks as well. there is a bit of a weaker area in the water jackets above the cylinders. Those issues could possibly be tuning related, but who knows.

that said, i am 10 over and have put lots of street miles and nearly 100 1/4 mile passes this year without issue.

There are reason those blocks broke.


pump gears break from harmonics like 19COBRA93 said. One of the biggest causes of harmonics like this is detonation.

Valvetrain instability can also be another issue but I don't think that is the case on any of the Coyote failures.

 

[19COBRA93]

Not true.

I wasn't making a statement that could be considered true or false.

If you'll really read what I said, you'll notice I said things like "that I've heard of", and "suggested", and then I asked some questions. Unless you're refering to what I'm suggesting as boost level having nothing to do with broken pump gears. I'm just not finding the relationship there.

I'd like more details on those broken blocks before it's suggested that they're weak. You could probably fill a warehouse with broken race blocks that are out in the world, and it's not because they're weak.

I'm not trying to argue with anyone, I'm just looking for accurate information based on facts.

 

[beefcake]

I wasn't making a statement that could be considered true or false.

If you'll really read what I said, you'll notice I said things like "that I've heard of", and "suggested", and then I asked some questions. Unless you're refering to what I'm suggesting as boost level having nothing to do with broken pump gears. I'm just not finding the relationship there.

I'd like more details on those broken blocks before it's suggested that they're weak. You could probably fill a warehouse with broken race blocks that are out in the world, and it's not because they're weak.

I'm not trying to argue with anyone, I'm just looking for accurate information based on facts.

again, like i said, mike broke 3 with stock bore.

i'm 10 over and ran the car for the last 8 months with probably around 100 passes with no issues

 

[19COBRA93]

again, like i said, mike broke 3 with stock bore.

Broke what? Mains? Split it down the middle? Any details? Technically I've broken 4 blocks and not a one of them had anything to do with their structural integrity.

 

[stkjock]

I spoke to Mike at NMRA Atco in April. He showed me pics of one of the blocks, the bore was deformed and "out of round". The pressure pushed the bore out by the water jacket as I recall.

 

[KenB]

I think we should leave it up to Mike to discuss why the blocks broke if he wants to.

 

[Trbosvt]

It's funny that i had someone ask me this morning if i had heard of the oil pump gears breaking. i told him i had not.... other than adam's car which he stated was per the balancer he was using. Now we start seeing other people starting to break more of these.

With all the older modular engines you heard of people breaking oil pump gears also, but i never broke any!!! I made plenty of power and have built over a hundred mod motors. I don't know what's going on but there's always two sides to every story, and with everyone trying to be first to everything and be the fastest with these motors you're going to start leaning on parts and breaking stuff.

Another thing to factor in is installer error...you have alot of people installing their own parts these days and that could be another factor in the equation. I'm in the process of building a motor for our shop car now, and will be installing a set of billet gears in it. there's nothing wrong with our motor now, but i know it won't take what we're going to try to do with it.

When i take the stock block out it will be going to my machine shop and we will be trying to get some darton sleeves in it. i see the weak part in the deck but it's only halfway up the deck that's hollow between the cylider bore and the block. We've done a ton of darton stuff and have never had any issues.

I agree with Ken that alot of these issues are more than likely tune up related. I also agree with Adam that it can be boost related, not the fact that it's too much boost...but blower speeds start getting higher and the blowers start getting harder to spin and create more loads on crank snouts which in turn creates more issues. we have all experienced this with all the gt500 and 03-04 cobras. as soon as you start over spinning the blowers you start getting belt slip.

 

[luillo]

if you got the pocket for it I think Mike at L&M can build one similar.

Here is the reply from L&M

Luis,
I don’t buy the excuse, the cranks or balancing is too expensive, lots of folks use custom cranks and the cost is about the same for all.
The proper excuse, I feel, is the engine is too expensive for more than a few folks so we decided not to produce it.

I have not done the engineering for a Coyote of this size, but have looked at the bore and stroke requirements.
Without conducting a study I would have to make an educated guess based on our 40 years of experience that it would cost around $40k-$60k with us supplying all the castings and parts.

I hope this helps you.

Take care, Michael

 

[stkjock]

So Luis.... how many did you order?

 

[luillo]

So Luis.... how many did you order?

LOL, None... I didnt thik it would cost that much.. My Plans are to run High compression with mild boost. I think Livernois or JPC Will do or i might get back to L&M.

Right now the air force is moving me from Kansas to Idaho and i cant afford to put any more in the car at least until i get back in 1 or 2 years.

 

[stkjock]

L&M builds very good motors. They have built several 5.0s for Evo that have seen 1000+ to the tire. I highly recommend him

 

[Adam@ST]

Guys Ive lost 2 oil pumps and blown a block apart. I have nothing to hide, nor do I keep failures a secret. Thats how we learn. All the locals here know of my trials and errors. On the tune issue...any wrong tune will kill and engine. Detonation will kill an oil pump..but I assure you..15 psi 20* on c-16 with an 11.5 afr...there is no knocking going on. I lost a pump in this scenario . I have some theories.
Bottom line...these engines have not proven to be as durable as the older 3v yet. If you are gonna play...be prepared because sheet can happen. Racin is breakin ...