OEM rings in the 1960s

[novadude]

Did the OEM engines in the 1960s generally just use plain cast rings, or were they using moly rings? I’m talking about the basic SBC, BBC, SBF, etc. Just curious.

[PackardV8]

The higher quality engines, especially marine and industrial, would have chrome rings. Most others came with cast rings and they were junk. In the obsolete engine business, customers will sometimes proudly bring in NOS rings for which they've paid a premium off eBay. We won't use them unless there's no current production option.

By 1967, there were beginning to be advances in OEM ring design and manufacture

https://www.jstor.org/stable/44553458?s ... b_contents

[novadude]

Thanks. So what about the performance engines? 409/425hp, tri-power 389s, Max-wedge mopars, etc? Just plain cast rings, or chrome?

[Dan Timberlake]

1959 lowly slant six intro - chrome plated top ring page 12 -
http://www.mymopar.com/downloads/mtsc/144.pdf

Attached are a couple of files with snips from SAE papers from the 60s about Dodge Hemi and "New" Buick V8.

[pamotorman]

Thanks. So what about the performance engines? 409/425hp, tri-power 389s, Max-wedge mopars, etc? Just plain cast rings, or chrome?

the HI PER 396 and 427 BBC had moly faced rings from the factory. their oil rings were not the best

[Schurkey]

the HI PER 396 and 427 BBC had moly faced rings from the factory. their oil rings were not the best

Far as I know, the Mk IV BBC was the first engine to get moly-faced top rings as standard equipment, starting in '65.

[bigmike]

I know all the BBC MK IV used moly faced top rings. I know all the SBC had a moly faced top ring by 1968. But not sure before that.

[Truckedup]

Gray cast iron rings are the best bet for engines with bores that aren't exactly round....Like in vintage air cooled engines or when the auto factories ran dull tooling to keep up with production or to save money..

[mag2555]

In regards to GM motors, by mid 1967 Pontiac was using a double Moly ring set up on all of there 4 bbl motors when they switched over fully from the Carter AFB to the Q-jet.

[Tuner]

It was the summer of '65 when the TRW rep visited and demonstrated the method of using 400 wet-or-dry over duct tape on a trapezoid glaze breaker hone to polish cylinder walls = less friction = more power. He explained that because the moly rings were (are) lapped in cylinders lined with diamond abrasive until light tight they don't need a rough wall to seat or "wear them in", they are seated in manufacture.

[hoodeng]

As some guys have pointed out already ,some manufacturers were doing top end parts for their era for performance applications , and more pedestrian products for their mass produced products.Ductile iron rings would conform and seat readily ,chrome rings were another matter ,they had to be loaded up straight away to seat or it was just not going to happen.

I have a situation where i do early V twin engines ,customers brimming with pride bring faded orange and black boxes of new old stock they have accumulated over years with the insistence that it all goes into their restoration. Some of the gear is pretty good but when it comes to rings and gaskets etc i tell them to take them home and mount them on the shed wall .Today's manufacturing is far superior to anything made in the 30's and 40's.

Replica and replacement parts made today by reputable manufacturers are not even in the same league as those of the past ,even those made by the same manufacturer ,i have some stock from the 70's that are used more for show and tell of that era .

We now machine and measure far more accurately in small independent machine shops than was done in the 60's/70's , my boring bar, vertical and horizontal hones alone would have only been a dream in the 60's and 70's, not to mention the metrology that is taken for granted today.
We are only as accurate as we make ourselves accurate , i have seen guys make instruments read what they want to see ,i have seen prussian blue applied till mating parts look good, you can kid yourself but you cant kid the job.

Cheers.

[tresi]

The 60's and 70's were definingly transition years for automotive technology and time of misinformation. More than people told me they had chrome moly rings which they were sure was 4130 alloy rings. I know for a fact I disassembled many motor from the early 70's with moly rings. I disassemble several virgin motors from the 60's but to be honest I really didn't care to look at rings that were headed straight for the trash. Some of the replacement ring were really rough, no lapping at all. Other were similar to today.

[PackardV8]

As some guys have pointed out already ,some manufacturers were doing top end parts for their era for performance applications , and more pedestrian products for their mass produced products.Ductile iron rings would conform and seat readily ,chrome rings were another matter ,they had to be loaded up straight away to seat or it was just not going to happen.

I have a situation where i do early V twin engines ,customers brimming with pride bring faded orange and black boxes of new old stock they have accumulated over years with the insistence that it all goes into their restoration. Some of the gear is pretty good but when it comes to rings and gaskets etc i tell them to take them home and mount them on the shed wall .Today's manufacturing is far superior to anything made in the 30's and 40's.

Replica and replacement parts made today by reputable manufacturers are not even in the same league as those of the past ,even those made by the same manufacturer ,i have some stock from the 70's that are used more for show and tell of that era .

We now machine and measure far more accurately in small independent machine shops than was done in the 60's/70's , my boring bar, vertical and horizontal hones alone would have only been a dream in the 60's and 70's, not to mention the metrology that is taken for granted today.
We are only as accurate as we make ourselves accurate , i have seen guys make instruments read what they want to see ,i have seen prussian blue applied till mating parts look good, you can kid yourself but you cant kid the job.

Cheers.

For true. We disassembled a Chrysler Marine flathead 6-cyl which had run for more than fifty years and the chrome rings still hadn't completely seated in some bores in some areas. Who knows what combination of poor boring/honing/piston/ring design/temperature control caused it, but the evidence was there to see.

Also for true, we have more and better machinery and metrology than the best auto machine shop I was ever in in the 1960s. I sat in a gravel pit and passed Craftsman wrenches to Don Garlits as he took parts out of the back of his pickup and off his grenaded engine and built a junkyard block into a top fuel hemi. When Plastigage came out, I thought it was really high tech.

[novadude]

Thanks, guys. Interesting stuff.

[hoodeng]

Ahh yes Packard , the venerable old 'Dodge Kew' as they were known as here, that flathead 6 was still being sold new in crates in the 70's ,they found their way into a lot of boats and were used in anything that needed somewhere around 80/100hp. I remember my brother in laws old clinker 1/2 cabin boat with one in it that was always fumy ,i mentioned at the time that if he gave it a decent workout it might clear up , he said the motor had not been over 3000rpm in its life, and saw no reason to possibly shorten its life , half litre of oil per trip and thousands of hours running attested to the engines reliability.
In the 70's i remember doing in situ rebuilds in the bush with an unhealthy amount of dust blowing around , a couple of close oil and filter changes would sort that out according to the boss.

Cheers.