We need more threads like these. Love the good knowledge that is being thrown around.

 

My order for one goes in on monday although I have a Darton sleeved iron block which I'm sure would do the job.....I figure I'll go ahead and take advantage of the 100lb weight loss.
Dale

 

I got this idea from the Yamaha Vmax world. When you start boreing and stroking that already long-stroked motor (V-4), head lifting begins to become an issue when you get to 1600cc+, supercharged and pumping nitrous. The block twists like a screw, and the decks twist along with it, but the thick heads don't, and the weak point is the headgaskets - pop! Always from the same side.

To combat this, engine builders close the decks, weld in reenforcementing metal plates to add rigidity, go to solid motor mounts and brace the motor. With our blocks, I know Ford added more metal and webbing to the 03/04 5.4 blocks, adding about (20?) lbs to its weight, for the purpose of making the block more rigid - so it must be a known issue. Perhaps bracing the motor, or using solid or lower-compliant motor mounts on the engine and transmission would help, and reduce the block twisting by pushing the torsion loading back on to the frame. Johnny Lightning is running the fastest now, and he's lifted a few heads in his time, perhaps he's combated the issue and has a solution???

 

i've heard bad things about iron/sleeved blocks. and i gotta believe most of these guys running big boost dont have an adequate fuel system to back it up. it may be adequate on the dyno where there are no G-forces and loads in effect but on the track its a whole different animal. just like a dirty fuel filter would inhibit fuel flow imagine what the inertia does to it.

i'd bet most are lifting their head due to lack of fuel be it in the tune or the fuel system itself. lack of fuel also would explain all these guys burning up there spark plugs as well.

Rob Staley

 

It could be fuel related, but Cobra's have fuel problems too and really push them to the edge on the tuning.

I've been running mine closer to mid 11's(11.4~11.6) A/F instead of the ol upper 11's(11.7~12.1) that a lot of people try to run. Might be hurting a little power, but it's not burning up plugs when it's onrace timing.

 

good stuff. I have heard of people lifting the head and still drivng it

 

Ding, ding! I doesn't matter how hard you hold down the head if the chamber is too weak. The 4v head has a WAY stiffer chamber because of the ports. Look at a 2v head. See that flat area that the cylinder pressure pushes against? Think there's much behind it to support it? Nope. The 4v heads don't have that problem.

 

hummm so what do you think about this.
would the pistons not comming up to the very top of the bore also help in letting detonation happen? i know when i pulled my 302 out of my stang a few years back the pistons were right at the top but in our motors there is like an 1/8 of an inch space from where the pistons stop comming up and the deck. just a thought

 

do any of these trucks have spark plug inserts? Just checking to see if they are more prone to detonation.

 

Ive thus far mildly and severely detonated 2 sets of CP pistons. I have a modified fuel system with bigger line -8 and -6 return, rails etc etc. and though my block is 0-ringed with reciever grooved heads I have not blown any more head gaskets @ 23#s, so I think my problem lies with fuel delivery, especially volume.

 

the block being o-ringed and the heads shaped to match are keeping your cylinder walls in shape at high rpm's?


how are you gonna get more volume to the cylinders? maybe two feed lines?

 

I have a fuel cell now with a Magnafuel 2500 hp fuel pump -12 feed and -8 return.