Mustang and Ford Performance Forums banner
1 - 16 of 16 Posts

·
Registered
Joined
·
61 Posts
Discussion Starter · #1 ·
This is not an 2003 -04 Cobra.
It's a Lincoln MKVIII with turbo and E85.
First I used the Techsid block 0.010 bore, gibtec pistons with early version 03 Cobra heads.
I think I have a multiple problems.

During the first tuning one of the #1 cylinder exhaust valves get cut like a torch thrue the valve.
It was found that the injectors which was tested prior to install they was good, now was showing way off.
That was Bosch 2200 cc LNG injectors.
Due to that I built a new engine reused all except the block exchanged to Nemak from 2005 Mustang and replaced some bad pistons.
New injectors Ford motorsport 1500 cc.
Second session of tuning then nearly the same thing happened, now it was the #8 cylinder exhaust valve.
The one that's redoing my heads is telling me that he can see evidence it have been really hot.

I have done the simplified cooling system with thermostat in upper cooling hose.
The thermostat have been drilled with 4 holes each with 5mm (0.2 in).
Lincoln MKVIII cooling fan working properly, the temp stays within limits.

Few things I think I have done incorrect with cooling system.
Thermostat, used a 180 deg instead of more preferable 160 deg.
I have deleted the heater core and therefore plugged the return to water pump under the intake.
I only connected the cooling at the back on the heads.
I didn't think about to connect it back to prior the thermostat, which I'm doing now.

Still I don't think this will cure the problem.
One thing that might get much more flow is to use the Ford GT 2005-06 GT500 2007-13 water pump with the front feed.
Can this be a good thing to do?
I know that usually the water pumps are either short or long, but the front feed is that either or another length?
 

·
Administrator
1965 Superformance 427 Cobra, & 2022 BMW M850
Joined
·
9,477 Posts
Stefan,

Selectively burned pistons and torched exhaust valves and or seats are not cooling system problems they are tuning problems, Stefan. Whoever you are using to tune your engine does not know how. I would replace him with someone that is more knowledgeable about tuning. Additionally while it is possible to tune these engines with the OEM computer it is much easier to tune them with a good aftermarket ECU. My personal preference is the MS3Pro PnP system.

If 2200 cc injectors were the correct size for the first build then 1500 cc injectors are the wrong size for the second build! If you are going to fiddle with the cooling system the only modification I would recommend is going to a thermostat in the top radiator hose and using standard radiator to water pump inlet plumbing on the bottom and discarding all the OEM emissions inspired plumbing including the lower thermostat Ford put in the OEM cooling system. Anything else and you are potentially creating a cooling problem.

Although the engine can be run w/o rear exit coolant plumbing on the back of the heads, I would discourage it even if you use a vacuum refill tool to fill the cooling system. Use some sort of plumbing to get the coolant flow at the rear of the head up. Read this post for a better understanding, click here => Head Cooling

If you keep doing what you are currently doing you are going to continue getting the same unhappy ending. Whoever your tuner is he is definitely not up to the job at hand and needs to be replaced.

Parting thought, new injectors that flowed correctly and then did not, can be telling you something about your fuel system and it's plumbing — it is dirty! If you aren't, you should start using fuel filters. If you are, then replace the filter elements with new clean elements.

A brand new injector that flowed correctly and then after an engine failure does not, was clogged by foreign particulate matter in the fuel system. A typical fuel injector is designed to run a 100,000+ miles on a daily driver with a properly maintained clean fuel delivery system. Your accelerated failure points to other problems.


Ed
 

·
Administrator
1965 Superformance 427 Cobra, & 2022 BMW M850
Joined
·
9,477 Posts
Stefan, say something. What's happening?

Ed
 

·
Registered
Joined
·
61 Posts
Discussion Starter · #4 ·
Long time without any update.
Most likely have found the problem.
Dwell time to long for the chevrolet D585 coils.
They shall have max 4ms dwell time, if the dwell time gets to long then might fire to protect the coil (good for the coil but not for the motor).
I'm quite sure this is the reason due to I started to get blow out after changed the max dwell time.
I had to get closer gap on the spark plugs.
Currently running with very low advance 14 deg just to have some fun during the summer.

Background.
I'm using Maxxecu aftermarket ECU.
I have setup all the basic functionality and made it run then the tuner made his "magic" to it.
Nearly no tuners tuners in Sweden are familiar with these motors due to so few are present.
The Bosch 2200 cc LNG injectors are notarious to change flow due to they are not really compatible with the E85.
Therefore my tuner suggested the Ford motorsport 1500 cc injector which will work good with E85 and will be more than enough for my application.
I changed the thermostat to 160 deg and modified the cooling system with plumping from rear of the heads to just in front of the thermostat.
The dwell time I set to 4ms, but there was a table that I didn't see.
That table increased dwell time at boost, very bad.
 

·
Registered
Joined
·
433 Posts
I would not waste my money on a head cooling product because it's not going to solve your problem. It is normal for the tune up to be correct and then have exhaust valves on a turbo or any other power adder engine to be subjected to a significant amount of heat and thus fail.

The cure for the burning valve issue is to use an exhaust valve and seat that are made out of a more durable material. Manley offered "extreme duty" exhaust vales that are designed to handle high operating temperatures.
Manley valves.
 
  • Like
Reactions: mercenvy

·
Administrator
1965 Superformance 427 Cobra, & 2022 BMW M850
Joined
·
9,477 Posts
Stefan,

A 4ms dwell time for an ignition coil (especially all the time) is excessive. It will overheat the primary coil in the Ignition coil, boiling the oil and eventually bursting the plastic enclosure. Aside from the mechanical damage to the coil the oil from the inside could catch fire if it found a sufficiently hot surface to land on.

Your ECU should provide you a way to ramp up dwell time as the load the engine sees increases. At max dwell you should not exceed 3.5ms dwell. At low engine speed and low load you do not need to use long dwell times. You can easily idle on a 1ms dwell and linearly ramp the dwell with engine load but stopping at 3.5ms max.


Ed
 

·
Registered
Joined
·
61 Posts
Discussion Starter · #7 ·
Ed
The ECU is capable to setup tables for nearly what ever used.
I agree that the dwell time can be much shorter at low rpm, whoever this not the way GM have done it.
GM actually have slightly higher dwell time a low rpm and taper off at higher rpm.
I have run the car for over 1000 miles, the longest run during a day was over 260 miles.

Cobra racer
I do beleave in the head cooling mod.
Every way to make better cooling will get a happier engine.
I have invested some money and time to build my own head cooling mod kit.
 

·
Administrator
1965 Superformance 427 Cobra, & 2022 BMW M850
Joined
·
9,477 Posts
Something to keep in the back of your mind Stefan is that GM is driven by the EPA's focus on oxides of nitrogen in emissions certification testing. To minimize the amounts of unburnt fuel and oxides of nitrogen in the exhaust at lower engine speeds, hotter sparks are your friend. By increasing coil dwell time you will optimize the spark energy available at ignition producing a more complete burn with reduced nitrogen oxides.

For guys like us, we tend to focus more on power development than emissions. Reduced dwell in high load environments will produce reduced power. High dwell all the time can damage ignition coils when it exceeds 3.5ms on a continuous basis. The idea of matching dwell times to engine load can provide predictable and reliable high power outputs even under high load conditions.

Ed
 

·
Registered
Joined
·
61 Posts
Discussion Starter · #9 ·
Ed
Thank's for the explanation.
Actually I never thought that's the reason for GM dwell times.
 

·
Administrator
1965 Superformance 427 Cobra, & 2022 BMW M850
Joined
·
9,477 Posts
I know what you mean Stefan. A lot of times I will look at something Detroit is doing, scratch my head and think gosh, that's sure counter-intuitive! Then after some digging around in their published tech papers, the pieces of the picture slowly start to come together.

This is a graphic from a paper on removal of Nitrogen Oxides in lean burn conditions that was published in 1992. The paper was focussing on the benefits of using Platinum Group metals in catalysts to further reduce the Nitrogen Oxide content. In the body of the paper they published this chart (the red annotations are mine).
175712

As a curious aside, look at where HP peaks. It is around 0.85 lambda or 12.5 AFR. A boosted engine will be a bit richer around 0.8 lambda or 11.8 AFR for gas w/o ethanol. E-10 fuel has a stoichiometric point of 14.1 which would put it's max power AFR at 11.1(0.79 lambda because of ethanol presence). E-85 (which you are running) has a stoichiometirc point of 9.765 which would put it's max safe power point at an AFR of 7.32.

The 7.32 AFR equates to a lambda of 0.75 because of the higher ethanol content. The max safe power points are not the upper end of the rich limit for the engine they are the lower end of the lean limit and you don't want to go leaner. I would venture to say your tuner is not even close to a 0.75 lambda Stefan.

Back to the chart and the answers to the why question! The chart illustrates the nose dive that Nitrogen Oxides take after an unthinkable (for us) 16:1 AFR. This percentage of NOx reduction is/was nirvana for the Detroit crowd, especially in light of the continually moving goal posts, emissions-wise, that California and the EPA were demanding be met.

The rub was the unstable combustion that came with AFRs in this range. Suddenly you needed a long (time-wise), fat, hot spark to prevent the lean mixture from self-extinguishing. Presto here come the long coil dwell times with the long, fat and hot sparks they deliver — the exact same type of ignition event we like for dense (boosted) mixtures at high loads!

The question I don't have an answer for is, how did they get away with always using these long dwell times without bursting coils from boiling the oil inside of them. I think the OEM electrical systems may have been a bit weaker than the performance ones we use with high output alternators. It is also worth noting they pulled back the dwell times as engine speed increased, which would help coil life.

What I am certain of is that continuous long coil dwell times of 3.5ms or more on our engines risk bursting the coils from boiling the oil inside them. More significantly, we don't need the spark energy at low load and low engine speeds and of course we aren't using lean burn technology, in fact quite the opposite.

Didn't mean to rag on but thought I would add a little more depth to the answer.



Ed
 

·
Registered
Joined
·
558 Posts
One red flag to me is blocking off the return to the back of the water pump under the intake.
I would run your current cooling mod plumbing to the back of the water pump. Just get a Y block and run the flow from the back of each head to the back of the water pump. There are fittings available. Since you deleted the heater core anyways.

Running from the back of one head, and then into the back of the other head is just sending hot coolant from one head, to hot coolant In the other head. There is very little flow and very little cooling taking place.

The modular water pump gets its coolant flow from 2 places. The oil filter adapter through the front of block and front of heads, and the back of the water pump itself that comes from the rear. The cold water comes from the radiator to the oil filter adapter.

With a deadhead at the rear of the heads, and flow blocked off at the rear of the water pump, it's possible that the cold water comes into the oil filter adapter, then just gets pumped up into the crossover tube and then goes straight to the radiator, not really cooling anything.
Temp sender is in the crossover so temps seem fine.

If I understand it correctly, you have deadheaded the coolant flow from both heads, while also cutting off 50% of the flow. That is bad.
Now you are relying on the water pump to only use 50% of its flow to cool 100% of the engine.
In an engine that is known for not great flow to begin with.

I'm not saying that the coolant flow is the cause of your problems, but i can say that your cooling system is not really plumbed correctly, and i'm not surprised to hear that your engine shows signs of running hot with the gauge reading fine.

This is just my opinion, i could be way off.

a picture of your setup would helpful, I might be misunderstanding things.
 

·
Administrator
1965 Superformance 427 Cobra, & 2022 BMW M850
Joined
·
9,477 Posts
A couple of thoughts mercenvy,

Your "Y" block idea is an excellent way to handle exhausting the hot coolant from the rear of both heads. It is worthwhile remembering that the preponderance of the force that moves the coolant from the rear of the head to the radiator inlet comes from block coolant that is forced up through the coolant holes in the head gasket. Without any other escape coolant will be forced up through the coolant holes in the head gasket and forward in the casting to exit through the coolant ports on the front of the head and then out to the radiator. By pulling significant quantities of coolant out the back of the head we reduce the coolant pressure in the head that forces the remaining coolant out the front of head.

The block's internal coolant path is from the front of the block to the rear of the block. The head gaskets provide progressively sized holes that allow a portion of the coolant to rise into the heads and get pushed forward to the radiator. The coolant flow is driven by progressively more and larger gasket coolant holes as you move towards the rear of the gasket, causing increased fluid pressure at the rear of the head and reduced pressure at the front of the head. Fluid flow will always be from high pressure to low pressure.

The coolant exit ports at the front top of the head are fed by the coolant rising up through the coolant holes in the gasket and moving towards the low pressure area at the front of the head. The coolant manifold on the front of the engine routes the coolant to the radiator to be cooled and reused.

The water pump nipple in the valley between the two cylinder banks is just a convenient way to handle the coolant the heater uses to heat the cabin. The nipple on the water pump does two things, both of which were attractive to Ford. The first was a clean economical way to handle the coolant exit from the heater back to the main cooling system and the second was a way to more quickly warm up a cold engine helping with the emissions mandate the cars had to meet.

The water inlet at the lower driverside front of the engine is only connected to the low pressure side of the water pump. As such it has no way to enter the cooling manifold on the top of the heads and return to the radiator without first going through the engine.

On balance Stefan's cooling system is plumbed fairly well and with some of his modifications performs as well as the OEM system, possibly a whisker better notwithstanding the usual emissions considerations. The write up on head cooling that is hot linked in post #2 above gets to the basic cooling problem of the head design fairly well. BTW if you share a first name we will use it instead of your screen name.



Ed
 

·
Registered
Joined
·
61 Posts
Discussion Starter · #13 ·
This is the way I have plumbed my cooling system now.
Which to my understanding is one of the preferable way to do.
I found a this picture on the web.
175775
 

·
Administrator
1965 Superformance 427 Cobra, & 2022 BMW M850
Joined
·
9,477 Posts
I am still of the opinion you have done a very good job Stefan.


Ed
 

·
Registered
Joined
·
558 Posts
This is the way I have plumbed my cooling system now.
Which to my understanding is one of the preferable way to do.
I found a this picture on the web.
View attachment 175775
Yes, i stand corrected. I did not realize that you ran the coolant from the back of each head to the remote thermostat housing.
What you posted is indeed the correct way to plumb it.
Sorry for the confusion, i misunderstood. My bad.
 

·
Registered
Joined
·
61 Posts
Discussion Starter · #16 ·
No problem.
I actually had it incorrectly plumbed as I indicated in post #1.
Just between the heads in the back without the return to the front of thermostat.
I then realized it was wrong and have corrected it with return to front of thermostat from the back of the heads.
 
1 - 16 of 16 Posts
Top