Sal,
I agree with you 100%. My reply is not a response to your post. You beat me to the submit button. Quick reaction time!!

 

Plain and simple, have to agree with LightningBoy, HP is exceeding design limit. There are some abuse exceptions but the limits of design are beginning to come into play. These aren't bad parts. They have design limits though. These engines seem to handle about 75-100 extra HP fairly consistantly. After that I think you are on your own.

 

I personally feel that the reason why a lot of motors are starting to blow is due to some tuner's programs simply being to lean. Denotation from what I can gather puts additional stress on the rods becasue the combustion does not occur when the rod is fully extended which puts additional stress on the rods. Combined with 75-100hp over stock and it's just a matter of time before the rods fail!

 

Have to agree & 1 other thing is the maintance being stepped up to go along with he stress on the parts professonal racers change plugs & oil alot

 

I would have posted on this subject earlier, but have been so busy havn,t been able to keep up. I do see there are certain individuals who want to say a (certain Chip) caused the motor to throw a rod. I don't even want to start blaming this chip or that chip for these motors throwing rods. i know of around 5 motors that blew running my chip. and about 6 of another tuner's and about 4 of anothers and i know of 3 that were bone stock! . and we know that 1 of us tuners had a rod break also. So do we say well since his rod broke he tuned it wrong? No! and i never came on here blaming the *tune* for it. We will never know. I have talked to guys who motors threw a rod and they had mechanics inspect their engines for the cause. the valves were good the plugs were burning good the pistons had no signs of detonation or lean signs at all. The rod just flat out gave out! I have many 11 sec. lightnings out there and many of 12 sec. lightnings running everyday without any issues. I have had *serious*detonation with my 10 sec. 93 cobra on different occassions when i was building the 5.0 engines and racing with it. however with some *serious* detonation. we blew head gaskets and on 1 occassion we hammered the piston. we could clearly with no doubt see that we had detonation problems. but we *never* broke rods! and this was on the *stock* rods in the 5.0 which aren't suppose to be 1/2 the rod that are in these trucks.( but i believe different). I beleive the bottom line here is a *rod* issue these rods are a production rod and a long rod at that.(Designed for the *stock* h.p. levels) i believe once we get past the 450 h.p. mark we are pushing the limit! This might not be the case with all the *stock* engines but i believe were pushing these *stock* engines to the Limit! You take a 4,700 lb. truck and push it into the low 12's were makin some *serious* power. So my advice to all of us if we plan on running in the mid to low 12's this year then we should consider putting some *good* rods in the bottom end to prevent the possibility of breaking a rod. I know of many trucks who have decided to do this including myself. which i believe anyone who is running mid 12's and faster should consider doing this.We can only expect so much out of these already High H.P. & Torque Monsters! I wish none of us would have things go wrong and break rods and other things that go wrong. but this is *racing* and this unfourtantly is the chance we take the moment we decide to mod our vehicles. my 99 lightning has had more *hard* runs on it than what i would even want to mention but Never gave me any problems. but beleive me i had my fingers crossed everytime i made a pass....JL

 

Drag racers always find the weak link in the chain. In our case, it's the rods. They are sintered, not forged. There is a difference.

If you modify the truck enough, you will exceed the tensile strength of the material and process that is being used. It's simple. Couple that with a long stroke, and a raised RPM shift point, and you will eventually create a problem.

There is a larger side force on these connecting rods due to the long stroke. If you raise the RPM capability, the force increases dramaticlly. The weight of the piston will try to pull the rod apart as it goes up on the exhaust stroke, and reverses direction to begin intake. Couple that with the large side force, and you have potential for fatigue to set in.

Also, detonation will rarely cause connecting rod failure, because it a compressive action. Most of the damage from detonation, manifests itself in the top end of the motor. Burnt pistons, plugs and valves are indications. You can also see evidence in the bearings.

I think most of our problems stem from the fact most of us have a major horsepower jones. We can't get enough of that blower screamin, push you back in the seat acceleration. We will modify until the manufacturers designs have been exceeded. That's why there is an aftermarked full of manufacturers who will help you strengthen the stock parts by replacing them with stronger ones.

I think that the survey results should include a column. It would be the percentage of blown stock engines, compared wit blown modified engines. That would be a more accurate indicator.

I don't think it's fair to compare tuners/chips either. All they are doing is what WE ask them to do. Every truck and driver are a little different. They do the best they can, given the huge number of variables available in the PCM. It is up to us to decide what is working and what isn't.

You must put it in perspective. We are using high output, SUPERCHARGED engines. When someting goes wrong, it does in a big way, very quickly. If you hear detonation/pinging, shut it down, and get the problem fixed. The problem is, if you hear the detonation, you are already way into it. You cannot hear it when it begins.

 

can anyone confirm that our internal components....rods and pistons ect.....are balanced before assembly. With all the compression, boost, heat in our engines...i've been told something as simple as unbalanced components could lead to instant destruction. I've heard this from more than one engine builder. What are you guys thoughts on this?

 

As stated the weak link in the motor is the rods! Theses rods are stock 5.4 rods that are put in a supercharged engine.There is no way in the world they are gonna hold up under the normal stress we put them under when were racing.If the MFG Ford would spend an extra $300 per motor and put better rods in the Lightnings they could cut their repair costs ! They advertise all the drag racing ,and motor cross SVT events but if you take them there and they blow, you loose.
I guess what it boils down to is if your gonna race get an engine race ready,new rods a good balance and then you can throw some boost at it. I also believe and we all know these engines all run very differently.they are sluggish in the hot humid weather and run faster than heck in the cool weather.I think you have to be careful to not run the engine real cold,let it warm up to 150 or so then hit it.I think the blowers will handle some extra boost,how much depends on the bottom end of the engine.If it's stock about 4 lbs is safe with a good tune....anymore than that and as a local track owner said to me don't leave here on a hook!!
Just my opinion, but they do blow, and the engine might be to powerful for the rods that they put in em,and definitely get a good tune.....I've been to hell and back with my Lightning as far as engine problems, but if you look hard enough there are solutions...Just my .02
J MAN

 

What would one expect to pay for replacing the stock rods with Manley type rods (including installation)?

 

With rods that are 6+" long, it doesn't take too much more looking for your weak link.
These, so called, forged stock rods are not up to the task that many of you are asking.
Stop looking for the "common denominator" in the chip brand, weather, gasoline type.
The common denominator is a 6+" rod reving close to 5600 or more rpm in a 4700+lb vehicle w/~400rwhp. That 6+" rod revs 93.3 times per SECOND. I cannot find my programs anymore,

Is there anyone that can calculate the critical loads on the rods at 5600 rpm?

 

JMAN -- how is the blame with Ford? For the most part, the rods work fine with the design of the stock truck... When you push stock, you have to make sure all the pieces in line follow.

How many people have now rebuilt their clutch-packs because they are not rated for the higher torque?

It just comes with the territory.

Daniel

 

Amen Pawn

 

Ride on Pawn. Any automobile or truck manufacture when they give you the specifications. They are the maximum specs. Bob.

 

One of the questions asked should be transmission mods as well. Converters, and other tranny mods change engine loads.

Also should ask what gear they blew (just shifted into 2nd, 3rd, OD)..

There is a ton of stored energy in the transmission...
Just my .02

Jeff

 

manley rods are onsale at $400. You'll have to pull the engine and rebalance the crank/rods/piston assembly. Put it back together and put the engine back in the truck. Depending on who does the work, I could see the total being around $2500 - $3000 depending on the labor. I wonder what the shop rate is for pulling an engine and putting it back in?