The Stovebolt Site Forums The Shop Area Engine Shop best way to blow an engine....

I think I might have asked this awhile back but oh well. I'm in charge of a fundraiser at school where we get an old car and sell tickets on how long it will last at full throttle with an empty radiator. Problem is it just slowly seizes and dies. Not very spectacular. How can I make this thing go boom? Nitrous would be great, but no money for that. Loosening head bolts, rod bolts, tapping the intake and injecting propane, acetylene, ether have all been ideas. Any other suggestions?

How about you run the engine without oil instead and fill the cooling system with gasoline?

Not much crazier than your own suggestions. I wouldn't stand within 100 feet of it though.

Depends on the engine. A little Jap 4-banger is designed to run and run and run and run on the surface of the sun before it stops. And a stock jap trap isn't going to throw a rod unless you revv it waaaaay up or loosen a rod cap.

How about using a straight 6? They're plentiful and can't take a lot of RPM. Or a furd 2.3 4-banger like used in pintos and dirt racecars. They'll revv way up and go "pop" if you run them out of oil at high RPM.

Basically if you want a rod failure, you have to find a motor design thats prone to rod failure and aggrivate it with excessive RPM, loose parts and poor lubrication. Works for my friends!

Now you can get more spectacular results using an american V8, but I'd have to kill you for ruining an engine I might need. Especially pre-77 pontiacs.

Back when I was dragracing, the 455 pontiac we had came apart when a 1" long screw fell out from under the carburator. It went through three different pistons and split the cylinder walls on two of them. It would be easy to set a 5/16" nut or washer on top of the carburator so it would vibrate in. You could tie a washer with thread wrapped around the exhaust so it would stay till the thread burnt and Boom! Joe

Been thinking of ways to speed up the engine, the higher you can rev it the faster it will blow. If you do anything like the drop the bolt trick people who buy the time spots on the board might get upset if word got out. Disconnect and plug any vacuum ports. reset the timing at w.o.t. to get the highest rpm. Remove air cleaner. If it's a points ignition remove the inline resistor for hotter spark. Since you're draining the radiator remove the fan belts. Replacing the engine oil with water would hasten the demise, but I wouldn't try it, since you would probably get people mad.

Overfill the crankcase (10 quarts instead of five, for example) and remove the valve covers...high revving will foam the oil...it'll run/spray from everywhere...

Once the thing gets hot enough, you'll throw rods and start a nice oil fire from all the dripping/spraying/foaming.

Maybe a gallon of acetone in the gas tank will make it run that much hotter.

And stay far away from the thing if you're gonna do this stuff.

Be sure you use a pre-computer car with a carb and maybe just remove the butterfly altogether so you've got absolute WOT.

These are some good suggestions, especially the bolt falling in the carb. It'll most likely be an old 70's boat with a big bock (I'll try to get a phord). We've tried draining the oil in years past and it just slowly dies. Thanks guys.

What about running AViation GAS in it?

be sure to cut the exhaust pipes off just in front of the muffler - noise is good in these kinds of events. Another sure fire crowd pleaser is to richen the mixture as much as possible and pull one of the spark plug wires so that it is pumping raw gas into the exhaust system - good for a good solid backfire on a regular basis.

AHHHH! You guys and the destruction!

Do it with a **** , I don't think they have built a good in in.... EVER!

Try sand in the crankcase along with the oil. THat outta help out things!

I don't think you want to mess with the oil or coolant at all, if you want it to die with feeling. A siezed bearing or cooked ring is quite boring and just brings the engine to a slow stop. You want the rods to stretch and the wrist pins to loosen up and send a rod or piston through the block. Run it so lean that it is sputtering but rich enough to rev high (you don't have any load on the motor anyway), advance the timing until it pings badly, and wait for the magic. A good detonation at full rpm will do some nice damage and make the pistons fall apart.

With a few higher RPMs the 460 Fruuds do the job nicely

[img]http://photo.starblvd.net/Mechainiacsphotos/6-3-2-1073306933?m=1&pg=5&ro=2&co=1[/img]

[img]http://photo.starblvd.net/Mechainiacsphotos/6-5-3-1072287155?m=1&pg=5&ro=4&co=2[/img]

Try this,drain the oil,cut a hole in the oil pan with a large sharp chisel.remove one connecting rod cap,remove the bearing shell from the cap and toss it aside, refit the rod cap, no oil required. Start the engine, run it wide open and stand clear.The rod will weld to the crank in a few minutes, break the rod and with any luck, make for a nice noisy finish like in Mechaniacs photo.

How about drain the crankcase and replace oil with 6 quarts of gasoline or coleman fuel? Use a remote starter....

Jim

Leave the coolant and oil in the engine. I agree with advancing the timing to cause it to detonate, over-rev the engine, cut the exhaust off, and let it blow. The exhaust sounds cool to the spectators. The detonation is like pounding on the piston with a sledge hammer. Either the cast piston will fall apart, or a rod will let go. Too high of RPM will speed up the process. Also, I have seen people put junk push rods in the pan positioned so that the crank will hit them and make a knocking sound, but not cause the engine to break. This makes for a good show.

Phil

I think a handful of BB's dropped into the wide open carb might spice things up a bit. Of course you'd have to rig up a way to do this from a distance...

-Boyo

.. :confused: :confused: :confused:

Ok, I'm pulling this back up because we just had the event yesterday. The car was an '80 plymouth with a slant six. I made the exhust stack come through the hood and ran the washer reservoir line into the stack using steel fuel line. I then ran a 3/16 steel brake line from the carb throat to within easy reach inside the car. I then rigged up an ether injection setup to spray directly into the carb. Then I filled the washer reservoir with gasoline. The coolant was drained from the car, but the oil left in. So I fired it up and put it to the floor, the ether going the whole time. Once it ran for about a minute and I thought it was hot enough, I hit the washer switch and the thing was belching four foot flames out the stack. At about two and a half minutes....BOOM, a rod flew out a fist sized hole in the block,......AND IT KEPT RUNNING, not a word of a lie this thing ran on one or two cylinders till it finally died at 3 minutes and 24 seconds. It was a lot of fun and the crowd loved it, but i think I have some explaining to do to the university fire safety manager though. Anyways, just thought I'd let you guys know how it turned out.

Thanks for the update. This post was a riot to read...plotting the most destructive demise of an engine.....and to think some folks manage this without doing all the planning.

Shows how durable the old slant six is. Sounds like you put on a good show, hope someone got it on video for you. I've only ever seen it done with 4 bangers, they usually don't have a spectacular blow, but some of them will go for 10 minutes without oil and water.

Next time use an old VW bug with a stinger. Crank up the RPMs and keep your ear plugs handy.
This is a big crowd pleaser at shows. They put the motors in cages at the shows due to the flying debris. It takes them a little wile to blow they can handle a lot of rpms. Every one will be expecting it to blow right away.