Not my fault the motor blew! Machine shop messed up!

I've heard this a million times with rebuilt engines.

I'm not sure I've ever heard anybody admit they made a mistake putting the engine together, it was always that damn machine shop that didn't xxx.

Any machine shop guys have a story? What is it that amateurs seem to always do wrong? Or what's the biggest mistake a guy has brought an engine in for your to fix?

Does anybody ever take responsibility for not checking clearances or something?!?

I have heard more than once the radiator being blamed for overheating, causing the engine to ...., FWIW

 

Well "my" machine shop mixed the pistons, so the valve cutout did not fit properly.

Causing a valve to hit the piston and break the head of the valve and the valveshaft punched a hole in the piston 15 seconds after the startup..

A human error that ive could have done but they did it, and they fixed it.

 

my first machine shop built the engine to tight. burned the bearings up in under 1000 miles. 2nd machine shop did an excelent job.

 

The machine shop / engine builder left a connecting rod nut off of the #1 cylinder....he didn't fix it either....I've always wondered how high do you have to be to miss a rod nut / bolt while torqueing the bottom end.

 

I bought a short block SBC from a now out of business shop. When I went to install lifters...one wouldnt go and I looked into the block and huge chunks of casting were gone. It had been grenaded.

I did however get all my money back.

 

Had an engine built but lost confidence in the shop. Took it all apart and found the oil passages in the crank completely pluged with crap. The reason I was skeptical is because they had put the rods in backwards. The cam bearing had not been changed and they were probably one of the main oil pressure problems. I was charged for putting all five of them in the flathead. I also was charged for the freeze plugs and installation in a 59AB. Name of shop in San Antonio by request. I was able to get some money reduced but I sure was bent over.

 

I never had a problem with the ones I built! And I built many!

 

No problems ,The machine shop put the pistons on the wrong connecting rods ,Was wondering what was going on ,Straightened that out ,Thats all I have ,Ive been lucky ,,,,

 

I learned a long time ago to torque each rod as it is installed and rotate the crank one full turn to make sure nothing is binding up before installing the next piston.

 

have a great machinist and shop. he is slow but very good. never had a problem with any of the weird stuff I have had done.

 

We use to rebuild lots of engines in my Dads garage back n the day. Regrinding cranks , boring blocks we did it all. We would not do just a little of the work. We did it all or none, because some one will always blame you for there mess up. We had one engine come back that we messed up. One thing I would never do is talk to some one while working on a rebuild and I would always go back over all the nuts and bolts after it was done.

One time I had this young guy come in with his 265 chev engine all apart. He never put the rod caps back on the rods,or marked them, so they were all messed up. I give him a good lecture on this, to this day he reminds me when I see him. He turned out be be a good mechanic.

 

This is a long story,but........
I had a customer come in with a "new" engine rattling and no oil pressure. They had bought the rebuilt engine from a machine shop 500 miles away and had another shop here in town install the engine. When they cranked the engine and it knocked, the mechanic shut it off and told the customer it was her problem and rolled it out the door. I told them I'd look at it and dropped the pan. Seems that the builder had turned the rod journals on the crank .020 and put ..010 bearings in it. He sent me the right rod bearings and a check for rolling a new set of rod bearings in. No major catastrophy, but it could have been a shipwreck.
Larry T

 

I had a machine/race shop build a pulling truck engine years back,$23000 engine and the assembler left a shop rag in #1 cylinder! When they went to crank it and do the breakin/dyno pulls it grenaded.They did build me a new one and found me an engine to use while they fixed thier boo-boo.Good thing that came of it was the guy wound up sponsering me so that was the last engine i had to buy

 

I never could afford to have someone build my engine. Had the machine shop do the required machining and assembled it myself. (Then you KNOW).

 

had an engine rebuilt at a local voc tech years ago on a 1961 ranchero (6 cyl), when I got it started, it wouldn't produce any oil pressure. When I tore it down I found they used the wrong lifters. They had a good 1/16" of clearance all around. Apparently they got lifters for a small block chevy if I remember right. I put in the correct lifters and, luckily, it ran great for years.

 

I always built my own.
I have taken apart and checked over a few other shops work and found plenty of errors over the years.TO much or to little clearence, parts in wrong ,, wrong parts,even saw pistons that was welded after an improper balance job : o
We all make errors or oversights, just odds of doing this much work for so many years .
One popular machine shop here always blames the timing for detonation and causeing failures ( insert eye roll )

 

a pretty well known phx. area shop dropped my buddies 400 sbc and broke the ear off the back/lower part of the block where the starter mounts and then welded it back on and pitted the weld with a pick hammer to make it look like cast iron. when he noticed it and called them on it, they told him they didnt drop it and there was a crack there so they fixed it for him for free but forgot to say anything....yeah right. after that it took a mountain of shims to get the starter lined up, til the motor blew.

 

This is a very good piece of advice!

A buddy had a local machine shop put an engine together for his dirt car, it went one lap and came apart. The builder put all the rod caps on finger tight and was getting ready to torque them, one long cell phone call later the pan gets put on. The builder did fix it at his own expense addmiting the error.

 

I build my own also. I've had to send cranks back for proper clearances also.
My favorite machinist retired now

 

I think most of the machine shops will add about 10 pounds to the customers right foot...

 

I prefer two at a time so they won't twist

 

I ran a machine shop for 5 years, lots of guys putting motors together that shouldnt have been. and im talking the customers, i ran the shop by myself and if i wasnt happy with it it didnt leave the shop. We didnt do any assembly, you can probably understand the liability in putting motors together for people, i would have been very comfortable doing it cause i was really picky when i built my motors.

heres a few that customers did,

Rod caps all mixed up (spun rod bearings)

Overtightening rod bolts (this one never ran as he tried to torque them down to the main cap specs, snap!)

leaving out cam retainor out of a 302 ford (it was a repair shop too!)

I could go on and on, those are just ones off the top of my head.

I always felt a ran a tight ship, happy customers where everything, when they heard we were closing they were very happy, what can you do.

JEFF

 

My machine shop dyno'd the engine and was paid to properly break in the engine and put it through it's paces. They had a problem during this process and ate the cam. This machine shop unwisely decided to send out the engine as good never suspecting that I would have to pull the pan and swap in another for clearance issues discovering all of the metal shavings in the bottom of the pan. When I went back to the shop the owner stated that I must not have broken in the engine properly and proceeded to tell me how stupid I was for damaging his master piece. He wanted the engine left at his shop so he could comb through it to asses the damage I had done through my ignorance. I promptly took it to another shop and paid the gentleman an hourly rate to disassemble and document all of the parts as they came out of the engine. Absolutely none of the parts that I had been invoiced for were present, the block and heads were not even my original parts, he used all stock junk on every bit that was within the engine and put some roller rockers and guide plates on the heads. Far short of the racing engine that had been contracted for. When confronted with this information he first denied that he had done anything wrong and called me a liar and a thief, then blamed some poor kid who worked there and fired him on the spot, the kid spilled the beans on him and his parts scamming operation. Luckily my credit card company returned my money to me. He went out of business within six months but opened a repair shop a year later. Always check another's work, parts etc. A good guy will be happy to show you his work. A bad guy not so much.

 

I do that too, but wind up measuring everything before and after so the "shop math" adds up. One piston-rod gets assembled and clearance is checked with clay first... with the head on loose just in case.

I had a set of heads come back once, looked beautiful until I flipped one over and glass beads poured out of a port. Those went back for the shop to take apart and make right.

Even though everything is hot tanked and cleaned... I spend as much time as it takes chasing every thread, cleaning every galley and blow it all out followed by a thorough solvent rinse.

Bob

 

I've been using the same machinist for many years. When I assemble the engine, I'll ALWAYS check all tolerances, piston/rod mounting etc. I've only caught him in one small mistake on my latest Pontiac engine. He was supposed to drill/tap/plug the old original oil galley passage up to the old rocker-stud oiling because I was later cyl heads with pushrod oiling. I noticed he forgot to do it and took 15 minutes to do it myself.
The later head gasket may have contained the oil pressure and blocked off pressure to the studs but I didn't wanna take a chance.

 

I am just paranoid but I do one journal at a time and have both rods on before torqueing. I am afraid of distorsion. I do snug them down and rotate as I put them on as suggested.

 

a friend of mine runs a G hydro boat with a 427 chevy motor in it. Had a local race shop put the motor together for excess of 30k. Was suppose to be the best shit available because he winds the motors out. Fired it up, warmed it up, and took out for his test lap. Got on it and it grenaded.

Took it apart and it had stock valves, stock springs, stock pushrods, cast pistons, and stock rods on a grooved crank. Dunno what he did about it but i would have been pretty upset.

 

We bought a factory rebuilt 436 IH diesel. Installed it on our combine, no oil pressure. Took it to the IH dealer, he pulled it off there and dropped the pan. They mic'ed everything, all "Within Specs"! The crank was at minimum spec, the line bore was at max and the bearings were the thinnest they could be and be "On Spec". The cumulative total was somewhere around .007 main clearance! They were going to put it back in the hole! I soon veto'd that idea. We eventually got a replacement engine.

 

Machine shop Screw ups the biggest reason to buy a crate motor. 290 HP Ram Jet Chevy your best.

 

Years ago, my buddy had an engine shop. He rebuilt a nice 390 Ford for a non paying customer, so he put it up for sale. Sold it to a couple kids to replace a wore out 406 in a 61 Starliner. They dropped in the 390 and it quickly locked up. Called my buddy raising he**! I went with him to check it out. Black tire marks all up and down the street where they had been trying to kick start the car after the engine locked up. Turns out the 390 had a large vacumn nipple on the intake manifold for the PCV valve or something. Guess where these genuises hooked up one of the heater hoses?? LOL
They were able to save the engine and apologized to him for his troubles....