Stock Fuel Rails, why they don’t keep up

[Jack_Toepfer]

Hellcat cam verse a tool steel Demon/Redeye cam. Gun drilled, it’s a pound and a half lighter then original cam. View attachment 38650

Looks about an inch longer too!
haha

 

[16GoManGoHC2]

Looks about an inch longer too!
haha

Optical illusion from camera angle. Every dimension short of the lobe geometry is exactly the same as the stock cam including the length to the thousandth. After FAS screwed me with a bogus ready to install inlet plate I QC EVERY part I get from now on. Lobes you can noticeably see the duration difference, from egg shaped lobes to oval lobes.

 

[Jack_Toepfer]

Optical illusion from camera angle. Every dimension short of the lobe geometry is exactly the same as the stock cam including the length to the thousandth. After FAS screwed me with a bogus ready to install inlet plate I QC EVERY part I get from now on. Lobes you can noticeably see the duration difference, from egg shaped lobes to oval lobes. View attachment 38748

Just messin with ya bud... great tear down, sucks to see the tranny falling apart.

 

[Speedy!]

Yeah that cam is WAY different. Explains a lot of what I've seen, and felt, in the Redeye motor upgrade on my car.

I hope you're getting bigger injectors

 

[16GoManGoHC2]

Yeah that cam is WAY different. Explains a lot of what I've seen, and felt, in the Redeye motor upgrade on my car.

I hope you're getting bigger injectors

Someday, Just not yet. I have to see if the fuel system modifications actually gave me some fuel back or not or it’s all been in vain. OST Mike says I’ll be OK on injectors still, as long as I’m not running in 20°F or colder weather LOLWhich by the time I get this thing back together after fighting Covid for the last three weeks and still doing such it’s not going to be that cold anymore LOL

 

[Speedy!]

Well, hope you're feeling better.

Have you taken a look at your rods to see if there was any signs of them bending? You were leaning on those stock rods pretty hard.

 

[16GoManGoHC2]

Well, hope you're feeling better.

Have you taken a look at your rods to see if there was any signs of them bending? You were leaning on those stock rods pretty hard.

Yes, I inspected them. at first I thought #2 had a slight bend from scuffing on position side but upon total disassembly all rods where fine. Piston 7 the ring butted and knocked the exhaust valve relief brow out. Top ring gap on all rings was between .018 and .020, second rings .028 to .030. Top ring gap of .018” is pretty tight for a blown engine with rings so close to the piston tops, it’s is their weak link for sure especially built so tight. Add in increased boost and possible hot ambient temps and higher inlet temps and it’s a recipe for disaster. This most likely occurred one day when I forgot to turn the AC on and my killer chiller was in HX bypass mode and my LTR coolant temp got to 130F and I had a large timing retard event during a long up hill pull. I decided to tear my engine down because of excess blow by found during a winter inspection. Cylinder 2 was a problem cylinder from a bad fuel event that occurred 2 years ago so I started with it, I was surprised that it recovered even more and leak down was 6% from 11 from 18 2 years ago, I would have kept running it. I started with cylinder 2 expecting bad news then cycled through the cylinders by firing order from there. All where .5% to 1% leak down, I was happy until I got to the last one # 7, to my horror it was 25% , engine was coming out when that was found. What’s amazing is it made 935 wheel on 2 hurt cylinders on the dyno just a few miles prior. What I found on disassembly is top ring for cylinder 7 ring Gap was right under the popped exhaust brow. Upon inspection it was evident that ring was butting, its ends where polished, 2 others, 2 and 8 where showing signs of butting as well. This is probably where the HP limit starts to kick in in these engines and piston snd rod problems start, butted rings will tear a piston top off in a heart beat if it goes catastrophic quick, as when rings butt they start to get hot quick and expand even more and get tighter in the bore until usually at the top of the exhaust stroke they stick there and the top of the piston stays there while the rest continues down the bore for it’s last time as when it reverses it’s all over. Usually wrist pin gets ejected through the side of the block and rod folds over and snaps under the pin area. I’m glad mine didnt get that far and I still have a good block to work with.

 

[Speedy!]

Interesting. Sounds a lot like what happened to mine. I wonder if Demon/RE ring gaps are larger.

 

[16GoManGoHC2]

Interesting. Sounds a lot like what happened to mine. I wonder if Demon/RE ring gaps are larger.

My wonder as well. I’ve read suggestions on engine builder forums of guys tearing down new and perfectly good engines to check and most times increase ring gap before leaning on them harder. I’ve read the Redeye engine has 30 microns more piston to wall clearance then a standard Hellcat engine and they are also torque plate final honed, hopefully they opened up the upper ring gap as well to accommodate the already engineered for increased stock boost level over a ordinary Hellcat engine. Short of a tear down for inspection Only someone in the engine building department would know this. I’ve tried getting revision information from dodge for various engine parts from what was put into my 16’s engine to today’s latest revisions and so far have heard nothing back. For instance, lifters. I’ve read they where revised in 2018 to the still latest AD version to which pins and bearing needles received hardening via nitriding and the rollers cryogenically treated to increase toughness and wear characteristics but no one at dodge would confirm this. So what did I do? I upgraded to the latest AD version to go on the new Demon/Redeye camshaft. Same with oil pump, it was revised the same time head gasket oil orfice holes where enlarged, was an oil flow increase then needed as well? Again, boo from dodge so for $125 I upgraded to the latest version pump. I called Melling, they dot even make a pump rated for the 6.2, they make one that will bolt on but cannot confirm it is of the correct flow rating. So being I’m planning on using VVT yet Mellings recommendation was to use the latest Chrysler version pump put out for the Redeye which I did. Short of a ring set of choice I have all the parts on hand to start the rebuild but it all starts with honing of the block to which I’m waiting on a torque plate to have that done with. I’m going with chrome nitrided gas ported total seal rings on the 9.5:1 Diamond pistons which are going out to have a special coating total seal recommend to have applied to their skirts to tighten up piston to wall clearance to help quiet it down during cold startup and reduce piston rock. This coating will make the piston almost seal to the bores it self and more so acts as a oil sponge to help lube and more importantly cool the piston buy helping it transfer its heat to the cylinder walls. A buddy of mine just dyno’d his build last night and made 1400 rwhp on a mustang dyno with a small 200 shot of spray. Yesterday was only its first day on the dyno, his goal is to be in the 8’s. He Should be at the track Thursday so we shall see soon track results verse dyno results. I think he’s going to get there as his spray system can deliver allot more juice if the need arises and his tuner will be with him on site. I Have my fingers crossed for him, car looked and sounded VERY impressive from dyno videos and graphs he shared with me last night. I can’t wait to start putting mine back together!!!

 

[Hpindy]

My wonder as well. I’ve read suggestions on engine builder forums of guys tearing down new and perfectly good engines to check and most times increase ring gap before leaning on them harder. I’ve read the Redeye engine has 30 microns more piston to wall clearance then a standard Hellcat engine and they are also torque plate final honed, hopefully they opened up the upper ring gap as well to accommodate the already engineered for increased stock boost level over a ordinary Hellcat engine. Short of a tear down for inspection Only someone in the engine building department would know this. I’ve tried getting revision information from dodge for various engine parts from what was put into my 16’s engine to today’s latest revisions and so far have heard nothing back. For instance, lifters. I’ve read they where revised in 2018 to the still latest AD version to which pins and bearing needles received hardening via nitriding and the rollers cryogenically treated to increase toughness and wear characteristics but no one at dodge would confirm this. So what did I do? I upgraded to the latest AD version to go on the new Demon/Redeye camshaft. Same with oil pump, it was revised the same time head gasket oil orfice holes where enlarged, was an oil flow increase then needed as well? Again, boo from dodge so for $125 I upgraded to the latest version pump. I called Melling, they dot even make a pump rated for the 6.2, they make one that will bolt on but cannot confirm it is of the correct flow rating. So being I’m planning on using VVT yet Mellings recommendation was to use the latest Chrysler version pump put out for the Redeye which I did. Short of a ring set of choice I have all the parts on hand to start the rebuild but it all starts with honing of the block to which I’m waiting on a torque plate to have that done with. I’m going with chrome nitrided gas ported total seal rings on the 9.5:1 Diamond pistons which are going out to have a special coating total seal recommend to have applied to their skirts to tighten up piston to wall clearance to help quiet it down during cold startup and reduce piston rock. This coating will make the piston almost seal to the bores it self and more so acts as a oil sponge to help lube and more importantly cool the piston buy helping it transfer its heat to the cylinder walls. A buddy of mine just dyno’d his build last night and made 1400 rwhp on a mustang dyno with a small 200 shot of spray. Yesterday was only its first day on the dyno, his goal is to be in the 8’s. He Should be at the track Thursday so we shall see soon track results verse dyno results. I think he’s going to get there as his spray system can deliver allot more juice if the need arises and his tuner will be with him on site. I Have my fingers crossed for him, car looked and sounded VERY impressive from dyno videos and graphs he shared with me last night. I can’t wait to start putting mine back together!!!

Torque plate eh ..... You must be copying me !lol

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[16GoManGoHC2]

Torque plate eh ..... You must be copying me !lol

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Something like that LOL. Hurry up and get home from your escapade LOL

 

[Hpindy]

Something like that LOL. Hurry up and get home from your escapade LOL

We are working on it ........ Starting tomorrow lol

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[16GoManGoHC2]

We are working on it ........ Starting tomorrow lol

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Just kidding, take your time snd enjoy every minute, not often adventures like you embarked on happen in peoples lives, ENJOY it while you can !!

 

[Hpindy]

Just kidding, take your time snd enjoy every minute, not often adventures like you embarked on happen in peoples lives, ENJOY it while you can !!

True ..... But I can't wait to start working on my car .......

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[16GoManGoHC2]

True ..... But I can't wait to start working on my car .......

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So your garage sick aye? Not home or wife sick??

 

[Hpindy]

So your garage sick aye? Not home or wife sick??

I'm hellcat sick ........( I can say this because my wife doesn't read this forum lol )

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[16GoManGoHC2]

Interesting. Sounds a lot like what happened to mine. I wonder if Demon/RE ring gaps are larger.

Take a look at factory ring gap data in this chart, mine where all right in this range. Even more troubling look at a 6.4’s top ring gap data, .0118 to .0157”. No wonder when people put pro chargers on them and push them a bit to hard they pop pistons or fold rods over. I don’t think the pistons and rods are the weakest link in these engines, I think the tight top ring gap is starting the trouble and the piston is getting stuck up top when rings butt hard and the rod is yanking the bottom off it and the rod is taking the blame as being the weak link when it breaks on the next up stroke. I see evidence in my engine, top of the bores some ring scuffing marks are seen which most likely was from them butting as this was seen in the tops of the bores of 2,7, and 8, the pistons whose rings showed signs they where touching intermittently and 7 popped a brow and ended up with excess leak down.

 

[white1]

Take a look at factory ring gap data in this chart, mine where all right in this range. Even more troubling look at a 6.4’s top ring gap data, .0118 to .0157”. No wonder when people put pro chargers on them and push them a bit to hard they pop pistons or fold rods over. I don’t think the pistons and rods are the weakest link in these engines, I think the tight top ring gap is starting the trouble and the piston is getting stuck up top when rings butt hard and the rod is yanking the bottom off it and the rod is taking the blame as being the weak link when it breaks on the next up stroke. I see evidence in my engine, top of the bores some ring scuffing marks are seen which most likely was from them butting as this was seen in the tops of the bores of 2,7, and 8, the pistons whose rings showed signs they where touching intermittently and 7 popped a brow and ended up with excess leak down.
View attachment 39147

Agreed. Ive been saying the same. Its not due to weak pistons, its due to a crazy tight ring gap. When I did the drop ins in my Ram, out of curiosity I measured stock. I thought I had measured .011, but it might have been ,015

 

[BULL]

@Speedy!

Wasn't it #7 in your engine that pooped on itself?

 

[Jack_Toepfer]

The problem isn’t the top ring, it’s the 2nd ring. It’s been suggested that the 2nd ring gap is too tight, and the pressures exerted on it are forced up to the bottom of the top ring which is the wrong direction, because there is next to no material above the top ring.
When you build the race motor I think you open the 2nd ring even more than the first to help prevent that.