burst panels blow out

what are the reasons burst panels blow out on a basic alcohol fuel system
( no timers or 6 shooter used ) with a 526 KB and psi blower .92 over/ mag 44 .
Is it possible to blow them out if engine is to rich and not just rich but realy rich ?We have no heat on plugs but burst panels blow out exhaust temps are 700 max thanks danny

 

You don't say how many runs this happens at. Do they blow out or just crack and open up slightly?

 

burst panels

it blowing the one in the blower or on the manifold and on the blower are you running the double burst panel set up?

 

burst panels

Hi yes they blow out every run ( wide open ) and we have the dual system on the blower and 1 in the intake.This is happened on 5 runs we did so far and all the time 3 burst panels popped out complete.We have to go to a race in Sweden next week and have to solve the problem.Is it possible to blow them out when the engine is far to rich and there's to mutch pressure in the intake?? thanks danny

 

Is it possible that you are so lean it will not build heat?

Is the engine popping or banging?

Who flowed your fuel system?

EDB

 

burst panels

we have fuel coming out of the exhaust don't think its to lean, we even reversed the hi -speed to keep the fuel in but they keep blowing out.We checked the intake valves they are ok,27 ° ignition on the 44 mag the barrel valve is set @ 80 %,bae fuel style heads.We also have alcohol in the puke tank like 1.5 L after each run, we can use the plugs over and over again because they stay new( we put new ones in every run ).The engine sounds ok on the stands but is running like a super comp car no fun @ all grtz danny

 

are you peddling the car? if you are in and out of the throtle it will cause this.dave

 

burst panels

Hi Dave no we are not peddling because @ the moment i can have a smoke during the runs,it's running like a super comp car no fun @ all i'm going home now because we have to triple chek everything before next week.grtz danny

 

Fuel shutoff

Hey Danny,

Could it be your fuel shutoff vibrating partially closed? We wrap the shutoff with one wrap of duct tape 1/2" wide right at the pump to make sure this does not happen. It has happened before to many a good racer and this solved the problem. Just a suggestion.

 

All of the above are good suggestions. Mechanically a weak or broken intake spring could cause this. If you have the large pro cap on the mag it could be out of phase. Check to the wire condition esp on cyl 5 and 7. Easiest cyl to have inductive crossfire. You don't say if you have a flowmeter on the car. It could also be a pinched fuel line or leaking fuel pump. Wrap a paper towel the back of the pump then plastic wrap to hold fuel residue in if the rear seal is leaking. Thats if you have to run without finding anything and have no computer readout on pressure or flow. Fuel coming out the pipes other than at stage seems really rich with a 44. Do you have clearance around all the pushrods to the headgaskets and reliefs in sleeves. Some you have to clearance. this is also assuming the leakdown is good and you don't have a leaking intake valve.
Just more questions and thoughts.....

 

boooom

Start with the simple stuff first ,check the valve springs and lash.

Make sure that you don't have any debris in the port nozzles .

Make sure that your ignition wires , coil wires , and plug wires aren't shorting out or breaking down.

What are you using for a mag kill ?, Is the mag kill capable of handling the pro mag or is it shorting out internally?

 

I don't think it's lean since it has fuel coming out of it.
Plug gap?
When you say like a Super Comp car do you mean it is popping like it is on a throttle stop or do just mean it is slow...
Do you have a pump saver or something coming open at the wrong time?
EDB

 

its sounds like the intake vavles are not seated. or the cam timming is wrong to blow the burst panels if all 3 panels are blowing if its fat that wont do that is has to have a vavle open when it fires or the cam timming is wrong

 

that sounds like a real good possibility, put a top dead center stop in #1 plug hole and make sure top dead center is correct at 0 degrees on your hub and degree wheel, then check and see where the degree wheel is at .050 lift on #1 intake, you should be between 32-38 depending on your combo.
if this stuff is correct i would recomend taking your fuel system to a flow bench i had a problem years ago where the car was fine on the jack stands but when i stepped on the pedal to do the burnout it would blow the panel, after replacing almost everything i took the whole fuel system to bill barrett. we put it on the flow bench and at 5000 rpm you could see the main line to the barrel valve pulsate. he said it was an airleak. we traced it to a bad fitting under the pump. it wouldnt leak fuel but it would suck air. you need to also make sure your fuel tank is well vented because air needs to go in as fast as fuel goes out or it will cause a vaccum in the tank and prevent fuel from leaving the tank.
good luck
.

 

If it's blowing fuel out the pipes then I don't think he has a lean-condition problem, but, I do also agree with the cam timing being off, a retarded cam could create excessive intake pressure blowing the burst panels. I would also check for wiped cam lobe(s).

Good luck,

 

You might check your crank hub. I have seen the pin that holds the digree wheel on the crank hub shear can cause lots of problems until you find it. Just a thought.

Good luck. Rick Hanna

 

Better tell him what side of the rocker the mesurment is from. I forgot

 

Eli, I have a hard time telling when you are being serious vs sarcastic...
Don't you measure the 0.050 at the pushrod side of the rocker?
EDB

 

hey guy use a dial ind. on the push rod or if you have what we have it has it's own push rod...dave

 

Raised cam or standard cam block?
48 or 45 degree cam?