Unhappy 57 Fuelie

[Clem Z.]

you also need a stronger oil pan

to hold in the broken parts. all kidding aside the big problem we had back in the mid 50s with SBC engines was the flywheel coming apart,talk about noise. you were lucky if you feet did not get cut off. i have seen flywheel pieces come out thru the top of the cowl on 57 chevys.

[Mike M.]

Re: Unhappy 57 Fuelie

joe: i think most rochesters got pullled for hollys or afbs back in our youth not because the fi unit took a crap but rather because of misdiagnosed ignition problems. agree that today's units far superior functionally to the rochesters but formers butt ugly, laters lovely. mike

[Mike M.]

Re: you also need a stronger oil pan

had a friend with 57 belair with duntov cam , diaphram pressure plate, torn up floor pan/dash and missing piece of right lateral ankle. dude still limps.mike BTW clem, we'll be autoxing at cumberland airport oct 30 and 31 if you of a mind to attend.

[Tracy C.]

Dukes rod pictures

Duke,

Here is the picture you send me a month or two ago...

tc

[Tracy C.]

More of Duke's pictures for Later Model Rods

more viewing pleasure....

[Duke W.]

Re: Dukes rod pictures

Excellent! Note the "hump" of metal adjacent to the bolt seat on the "late 327" rod. Comparing them in the steel so to speak is even more dramatic. It's easy to see that the section area adjacent to the bolt seat on the early rod is THIN!!!

If you ever rebuild an engine with these early small bearing rods consider that you have a nice matched set paperweights or eight miniature boat anchors.

As a minimum, buy a new set of the later design small bearing rods. For a bulletproof SHP engine spring for the Crower Sportsmans.

The second photo are large bearing SB rods. They are definitely stronger in the big end, especially adjacent to the bolt seats, than the early small bearing rods.

Duke

[Joe L.]

Re: More of Duke's pictures for Later Model Rods

A little more info on these rods:

rod on the left:

GM #3892671----This rod was used ONLY for the 1967 Camaro 295 hp/350 cid application. This was the very first use of the 350 cid engine in a car or truck. This rod uses the 2.10" journal size, but uses the 11/32" rod bolts as used for all PRODUCTION 1955-67 small blocks. This rod is manufactured of 1037 or 1038 steel and is a forged piece. It is hardened, but not shot-peened or magnafluxed. Its design offers a considerable strength improvement over 67 and earlier 327 rods, but its not as strong as 68 and later 2.10" journal diameter 302, 307, 327 and 350 rods. This rod is quite rare but not particularly desirable;

rod in the center

GM #3916396-----This rod was used for most 68+ small block applications, except 400 cid. It has the 2.10" journal size and uses 3/8" rod bolts. It is a forged piece manufactured of 1037 or 1038 steel and it is hardened. It is NOT shot peened or magnaflux inspected at the factory. It is considerably stronger than the GM #3892671 rod described above and MUCH stronger than ANY pre-68 327 rod. However, due to its larger journal size, it cannot be used for any pre-68 small block application, except 67 350 cid. This rod replaced the 3892671 for SERVICE after October, 1969 when SERVICE inventory of the 3892671 rod was exhausted. This rod was discontinued in March, 1982 and replaced by GM #14031310, a virtually identical rod. Rod GM #14031310 was discontinued in March, 1995 and replaced by GM #10108688. The latter rod is a forged, powder-metal connecting rod which became the PRODUCTION rod for most Gen I and Gen II small blocks beginning with the 1993 model year;

rod on the right

GM #3923282-----This rod was used for 1968 Z-28 and 1969 L-46. Contrary to what some folks think, it was NOT used for 1968 Corvette L-79. 1968 Corvette with L-79 used the GM #3916396 rod described above. The GM #3923282 rod is exactly the same as the 3916396 rod except that it is hardened to a greater Rockwell hardness and it is shot-peened. It is produced from the same 1037 or 1038 steel forging as the GM #3916396 rod. This rod uses a press fit piston pin. It was discontinued in December, 1971 and replaced by GM #3973386. The latter rod was the first so-called "pink" rod and it was used in PRODUCTION for 1970 L-46 and LT-1 as well as 71-72 LT-1 and 73-80 L-82. The GM #3973386 is virtually identical to the 3923282 except that it is magnaflux inspected. The GM #3973386 rod was discontinued in January, 1982 and replaced by GM #14095071. That rod was discontinued in May, 1995 and replaced by GM #14096846. Both of these rods are virtually identical in configuration to the 3973386. Two years ago, the GM #14096846 was discontinued and replaced by the GM #10108688 powder metal connecting rod.

Another small block connecting rod virtually identical to the GM #3923282 pictured on the right is the GM #3946841. This rod is the same configuration as the 3923282 and 3973386 and is manufactured to the same standard as the GM #3973386. However, this rod is designed for use with "floating" piston pins. It was used for the 1969 Z-28 302 and would have been used for the 1969 Corvette LT-1 if that RPO had not been cancelled. This rod was discontinued in May, 1998.

Another note:

There are other small block connecting rods available from GM over the course of the past 25 years, or so, that are stronger than any of the above described rods. However, NONE of these were ever used in a PRODUCTION engine; they are SERVICE-only pieces.

[Joe L.]

Re: Dukes rod pictures

Duke and Tracy-----

A little more info on these rods:

rod on the left (picture partially cut-off)

GM #3703525 (possibly others, too)----This is an early (55-61) 283 rod. It is drop-forged from 1037 or 1038 steel, uses 11/32" rod bolts, and is used with 2.00" rod journal diameter. It was used for all 55-61 Corvette and other Chevrolet applications. This is a VERY marginal rod, not really suited for high performance applications (but, it was used for many PRODUCTION SHP applications up to an including the 1961 Corvette 315 hp);

rod in the center

GM #3784000 or GM #3815281 (identically configured rods; difference cannot be discerned from a photo)----These rods were used for 1962 283s (non-Corvette, of course) and 62 through 65 327s. They use the 2.00" rod journal diameter. The GM #3784000 was used for 1962 283s and 1962-64 250 and 300 hp 327s. The GM #3815281 was used for 62-64 Corvette SHP engines (i.e. 340, 360, 365, and 375 hp). Both of these rods are drop-forged from 1037 or 1038 steel, use 11/32" rod bolts, and have the "v-shaped" oil "squirter" holes at the cap mating surface. Both of these are manufactured from the same forging, but the 3815281 is hardened to a greater Rockwell hardness than the 3784000. Although stronger than the early 283 rods, these are still VERY marginal rods. I would NOT CONSIDER using them in any SHP engine, including a rebuild of ANY 62-64 Corvette 327. However, GM did use them in 327 engines right up to and including the 1964 L-84;

rod on the right

GM #3864881----This rod was used for ALL 1965-67 small block engines. This rod is also drop-forged from 1037 or 1038 steel, uses 11/32" rod bolts, and is for use with 2.00" rod journal diameter. Its improved design makes it the strongest of the 2.00" rod journal PRODUCTION rods. It became the SERVICE rod for all 62-65 small block applications when the above-referenced rods were discontinued and it can be retrofitted to any 62-65 Corvette 327. This rod is hardened, but it is not shot-peened or magnaflux inspected. Usually, PRODUCTION rods of this part number and SERCIE rods produced prior to mid-1967 have the "oil squiter" grooves. Later SERVICE rods of the same part number usually do not have the grooves. Although it's the strongest of the PRODUCTION small journal (i.e. 2.00") connecting rods, I would not consider using it for anything more than a totally stock rebuild. Even at that, I think that it's marginal for a 350 hp or greater small block (even though GM used it in PRODUCTION for such applications).

Since GM never offerred a really strong connecting rod in either PRODUCTION or SERVICE for any 2.00" journal application, I recommend the use of aftermarket rods for any 55-67 Corvette engine rebuild. Unfortunately, these are becoming "scarce" for 2.00" rod journal applications. As far as I know, Crower no longer manufactures any rods for 2.00" crankpin applications. The only one that I know that does is Eagle, but there may be others. I believe that many of the Eagle products are imported from the far east. Nevertheless, I can absolutely guarantee you that they're MUCH better than any original PRODUCTION pre-68 small block connecting rod. They're about $600 per set, discount.

[Joe L.]

Addendum

By the way, the rod on the right (i.e. GM #3864881) is mis-identified in the label under the picture. It was NOT used BEGINNING with mid 1966. It was first used for the 1965 model year for ALL small block applications and it was used through the 1967 model year for small block applications (except 67 Camaro 350 cid/295hp).

[Duke W.]

Re: Addendum

It was always my understanding that the 881 went into production for 1966.

Are you saying that the 881 went into production at the beginning of the '65 model year? In other words, all '65 327s have them?

Duke

[Joe L.]

Re: Addendum

Duke-----

I believe that they were likely phased into PRODUCTION during the 1965 model year. Early 1965s very likely had the earlier style rods. Later 1965, and certainly before the end of 1965 PRODUCTION, had the 3864881.

[James F.]

Re: Dukes rod pictures -Joe- Crower rods

Joe,
Ordered a set of Crower Sportsman small journal pressed pin fit rods, part # SP93200-PF, from Crower today (Mike Erns's engine escapades scared me!). Cap screw rods, four to six week wait time, bolt type rods on the shelf. Regards,