Balance guy tells me Mopars are sloppy motors?

[The70RT]

On the 50's vettes when they restore to specs they overspray the exhaust manifolds with with engine paint because the engines were painted after installed. The old T-Birds may have been the same. 18 grams light on one rod? I may have switched that one out? Were they 6 pack rods?

[1969chargerrtse]

On the 50's vettes when they retore to specs they overspray the exhaust manifolds with with engine paint because the engines were painted after installed. The old T-Birds may have been the same. 18 grams light on one rod? I may have switched that one out? Were they 6 pack rods?

Wow, thats interesting about the vette and T birds.  I didn't know that, gee that sounds " sloppy ".    Normal 440/350hp C body short block, he just had to take 18 grams ( maybe it was 13 grams? ) off each of the others.  Keep in mind it probably ran fine from the factory, but I was paying the guy to balance things out.

[andy74]

im pretty sure thats why it was such a big deal to balance and blueprint motors back in the day,all the car makes were know for sloppy tolerances and builds, if you check the ccs on a head from any make of 60s and 70s car,they are almost never what the specs say in the books,its not a coincedence,we have all seen it at one time or another,

the cars we love and enjoy now came down the assembly line hundreds an hour,and most of the guys building them didnt give a shit,it was just a job,and they were just cars!when you read old road tests and mag reports almost all of them talk about the "blue printed"rides for a reason,most of the guys i talk to that were line mechanics in the 60s and 70s tell the same story,none of them were perfect from the plant,and most had to be adjusted/messed with right off the carrier!

[Challenger340]

Very Nice Camaro !   

Yeah, your guy is right. The factory Mopar balancing was terrible, but, keeping things in perspective, whats 13-15 grams on a 2400 gram bobweight back then ?
2200 gram bobweight ?
Etc.

Keep in mind also, that the factory was doing whats called a "dynamic" balance with the parts installed in the block, and then an electric motor spinning the assembly for a strobe correction.

It was "good enough" for the intended application, and most were "production" passenger grocery getters,
and,
without getting too technical, other than the HEMI, the first real destructive harmonics for them was deemed "above 6800" with those imbalances.
Far above where most of them would rev with the factory Cams/Internal hardware.

Just my opinion, Bob out.

[superduperbee]

Have rebuilt numerous Mopar engines. Having an ounce or more difference between rods is pretty common. I always grind and polish rods, also parting lines on crankshaft,  then have everything re-balanced to cut down on stress of parts and chance of vibration.

[1969chargerrtse]

I think the real point from the start got a little lost.  He wasn't bad mouthing Mopar by any means and he even wasn't saying much on the rod that was off like it was anything terrible.  Just that the crank had burrs on it and there are areas that normally get deburred etc...  and Mopar stuff back then was known for that kind of stuff.  That's it and I was curious if you guys heard the same.