Fatal Mistakes....

[coolchevy]

one of my favorites was during building a Buick 455 engine way back. Engine was ready for priming and since we had a stubborn 20 gallon oil drum with oil I usually used a cleaned 5l Valvoline oil container to fill oil from drum into it and then into engine.

All done, I prime engine and suddenly tons of bubbles comes out the valve covers !
well I did not know that the night before my friend used that container to pre-mix an extremely aggressive cleaning agent to clean up the work shop floor. One which is known to break up oil in no time. What I did not know either was that when it does that it gums up and converts any oil spills into a easy to remove rubber like jelly.

You can imagine how the engne looked inside all, gummed up jelly..........I had to completely take it apart and painstakenly clean every little nook and cranny and oil hole, it took me weeks to do so..............

most embarrassing, one of my early girl friends and I take her out with my pride a 68 Camaro with a souped up 327 SBC. That old Porsche comes along, too bad her former friend too, and we gun it, I could not let him win that would be face loss. I rev the shit out of the car and pass him and blow his doors off with close to 7200rpm...........seconds after engine lost power, 3 rods left through the oil pan, one through the hood and one through the fender. The only thing salvagable from engine was one breather...........but I killed him, manhood restored, girl married......

[jobes]

A big block chevy uses two front oil galley plugs with small weep holes to bleed oil onto cam gear and thrust.I accidently got one of those plugs and installed it in the BACK of a small block chevy! Instant oil leak while priming after the motor was installed OUCH!

[MrWOT]

I was only supervising on this one but a buddy of mine with an awd Mitsubishi pulled the engine/trans and tore down the motor, built it up and popped it back in complete with new harness. Fired it up and it ran GREAT!.... Then we went to move it and realized very quickly that it was OUR clutch disc sitting on the shelf

[airrj]

I have a few to add. The first rebuild that I ever did was for a friend that had a street stock asphalt car. He had all of his money tied up in a 400 SBC that was rebuilt. First race he never had good oil pressure and he shut it down. Took the motor to the builder and he threw my buddy out and called him a lier. From there he comes to my house and says that he needs a favor (this motor got me hooked and I am still at it 18 years later, not a bad favor.) Of course I have never rebuilt a motor before at this point.

I open up the motor and all the rods are burned up, and the mains aren't far behind; this thing was a few revolutions from throwing rods. So I order parts and start cleaning things up. But why didn't the pressure build up properly??? I went to put the new pump on the block while I was mocking things up, and it rocked back and forth on the cap. I looked closer and the rear main cap had been dropped at some point and there was a big 1/8" burr sticking up on the mating surface for the pump to the cap. The oil was bypassing the entire motor and was going back to the pan. I still to this day can't believe that I found that one on my first try.

The other mistake that I have seen several times which isn't immediatly fatal, but quickly fatal is leaving out the plug under the rear main on a SBC that diverts the oil to the oil filter. No plug=No oil filter and you don't know it.

R.J.

[Roadknee]

We were developing a supercharged 304 ci Studebaker V-8 for a land speed attempt at Bonneville a number of years ago. Upon starting the engine for the 3rd or 4th dyno run of the day it wouldn't spin over. I went back to wiggle the battery cables while the operator hit the ignition switch. I got wet with a fine spray of water. One of the hogged-out paper-thin intake ports sprung a leak, filled, and hydrauliced the cylinder. Fortunately, with Arias pistons, Carillo rods, and a pretty stout block we didn't damage anything but the head gasket.

We tore it down for repairs. We were proud of the time saved with the Stude design which has a valley cover, making intake removal/reinstall very quick. we removed the intake/pushrods, and hauled the head back to the shop for repairs (a bit of Gasoila fixed the pinhole). Anyway, we put it back together the next morning and fired it off. Once it was warm we started a dyno pull. Fortunately our operator was on top of things. He noticed HP was off about 6,500 rpm and aborted the pull. The engine was knocking.

Upon teardown we found one of the H-style roller lifter tie bars had come off and one of the lifters had rotated on the cam. The cam was toast, and the cylinder immediately under the failure had been sprayed with shavings; it was in bad shape as well.

It took a while to figure out why the tie bar had fallen off. When we pulled the pushrods after the hydraulic incident, the engine oil created enough suction to pull a lifter high enough to release the tie bar. Since the Stude uses that valley pan (which we never removed) we never saw the fallen tie bar.

We really should have sleeved that cylinder, but we just had it honed the best we could and cleaned/reassembled with new rings, bearings and cam.

That engine went on to make 638 HP. We set a land speed record later that year - first ever 200+ mph Stude powered Avanti.

[murre]

frend of mine use to work at gas station. one day a customer purchase 1gallon oil. came back 10min later buy 1 gallom more. when he came after third gallon. then my frend have to ask him what he did. he whas checking motor oil level and whas upset becuse they obviously did not fill oil in last servise.whell he fill oil in right hole but try to fill up to Valve Cover Breathers.

one more. my frend forget Wrench on crankshaft at a race. broken radiator. and next time he left a motor too Balanced Rotating Assembly. they ask him if balanced with or without wrench

[rq375]

I purchased a set of World iron sbc heads for a stock rebuild because the origionals were cracked. The engine ran for about two weeks and started knocking, lost pressure. Upon teardown I found little bits of spring steel everwhere. The heads had tapered guides for umbrella seals, but the shop hand crammed viton seals with the spring bands on them, and they were in hard contact witht the spring dampers. I'm suprised it ran as long as it did. (and thats what I get for not tearing the heads down before running them)

A local "engine expert" who had only done SBCs previously built a 302 for a mustang, torqued the rod bolts to 50 ftlbs. (stock rods and bolts)

Had a block bored and honed when I was in HS, I am looking it over and see that they had de-burred the saddles with a carbide cutter in a die grinder, apparently when the guy doing this pulled back out he hit the lever and the carbide spun around the fresh bore and made a nice cork screw pattern of divots up the bore. The shop then honed it and told me it won't make a difference and happens all the time.

I rebuilt the pump on a jet boat for a guy one time and he asks me to install a T fitting on the pressure port for the cooling system. He was installing a set of Hooker over transon wet headers and needed a water source. I told him to make sure he installed a control valve, He says if he needed a control valve, it would have been in the box. He spit two rods out of the 460 first trip to the lake when it hydrolocked.

I installed half of a SBC rear main seal backwards once, pumped all the oil out pretty quick.

[technicaltom]

a friend of mine was trying to trace an oil leak at the back of a fiat engine.so he removed the gear box , then had a look behind the flywheel.still not sure of oil leak source, he put on flywheel with two bolts.then started the engine and raised the car on the car lift to have a look with a hand lamp.Before he had a chance to get near, theres a bang ,and i see my friend running out of the workshop closely followed by a flywheel still spinning quite fast along the floor.

[Mr. P.]

....3 rods left through the oil pan, one through the hood and one through the fender. The only thing salvagable from engine was one breather...........but I killed him, manhood restored, girl married......

SHEESUS CHRIST DUDE! Great story, two thumbs up!

OK my failure story, 16-years old with a 77 GMC truck with 350-SBC, driving down the freeway notice 0-psi on the oil pressure gauge, apparently I put the oil drain plug in the pan but for some reason didn't actually *tighten* it. ??? DOH! So this led to first rebuild, I bought a cheap re-man kit and tore the motor out and apart and get hard to work on the floor of the barn (yes hay and all, kid you not). Finishing touch, instead of installing the head gaskets clean and dry I slathered Permatex copper bond (from the can!) with a brush all over the head gaskets and hell even on the deck of the block for good measure, it seemed like the thing to do at the time??? Torque everything down. and start the motor for 1/2-hour run-in... check the oil and it's FULL of copper. Motor ran two more days and finally wouldn't start anymore. Kicker was, after we got the motor out again, we could not remove the heads from the block even with air chisel and pry bar. After that incident I got educated real fast and have not had a fatal incident since.

But I WAS going to take that secret with me to the grave until you guys opened-up in this thread, now I don't feel so alone LOL I can laugh about it now!

Freakiest thing I've ever seen underhood was during 3-years of demolition derbying - After a demolition derby mulligan heat in northern CA, the forklift (log loader) carried out an early 50's Ford wagon that was totally creamed and still running (dieseling) hahaha we laughed our butts off joking to the driver that his car was posessed; mind you the derby had been over about 5-minutes by that point. After the car is on the ground we have to use a cutting torch, sledge hammers, and 6-ft pry bars to get the hood off and the motor is STILL dieseling, even with the battery cut. I look down and grab the shirt-sleeve of my friend to show him, the crank pulley was spinning backwards... he threw his shirt over the carb to choke it out.

Mr. P.

[MadBill]

When I was about 17, I did a rebuild on the engine in my rust-bucket '57 Karmann Ghia VW. I had it all back together and was setting the valves when something shiny on the floor caught my eye: A main bearing shell!
In an air-cooled Vee Dub, the very first step in engine assembly is to fit the main bearings to one crankcase half, then set in the crank, the other case half, etc.
Before tearing the whole %$# apart again, I briefly wondered if an engine might run OK down one bearing...

[ou812]

When I was about 17, I did a rebuild on the engine in my rust-bucket '57 Karmann Ghia VW. I had it all back together and was setting the valves when something shiny on the floor caught my eye: A main bearing shell!
In an air-cooled Vee Dub, the very first step in engine assembly is to fit the main bearings to one crankcase half, then set in the crank, the other case half, etc.
Before tearing the whole %$# apart again, I briefly wondered if an engine might run OK down one bearing...

Yes, ha ha! Isn't it amazing what goes through your mind for just a brief moment when you realize a problem and don't want to fix it!!!!

[wikd69]

Hi all, new guy to the forum.

Many, many years ago I was a diesel mechanic up in Oregon state, probably 21 or 22 years old then, and did my very first full in-frame overhaul on a 335 Cummins. New rings, bearings, sleeves, etc. I had not been into a wet sleeve motor before and had heard all sorts of stories about water leaks around the buna o-rings on the sleeves. So to make sure there would be no leaks I used plenty of silicone sealer on each of the sleeve o-rings prior to stuffing the liners into the block.

I finally buttoned it all up, did a static time, ran the rack and then grabbed the shop foreman to watch me proudly fire my new motor up for the first time.

I fired that big puppy up and it ran perfectly. At first.

I was *so* proud. Then as it started coming up to temperature it started squeeking. A little at first, then a *lot*. We shut it down and did a fault analysis. After some discussion we determined that I needed to pull the motor all the way back down and replace the liner o-rings, *without* silicone this time. Under heat, the siliconed o-rings swelled to the point they crushed the liners enough to pinch the rings, making all the noise.

D-uh....

[Greezer]

Have a Nice Day

[speedmachine]

I needed a helper to help get engines ready for the dyno, so we hired a kid fresh out of a famous tech school.(I wont name names cause this guy does not reflect what the school puts out) All I needed him to do was top off the long blocks so that I could dyno them.
He told me how he used to build circle track engines and how good he was at it. His first test was simple. Put on a single plane intake and a water pump. When he was finished he told me how big of a piece of sh** my Edelbrock water pump was for rubbing on the balancer. I inspected it to find that he had it on upside down! I looked at the intake and it was on backwards also! WOW
He was dismissed after that. So much for my great engine builder.
I didnt even think that was all possible!

[s/c 266]

This is funny. Taking confessions is what it is

I'm not about to confess on here