65 396

[John H.]

Re: 65 396

I seem to recall reading somewhere that the orders to lower the HP rating came from within GM, although possibly to appease the insurance companies. The story alluded to a "rule" or agreement within GM to not have HP numbers exceeding cubic inches. Hopefully, someone on the board can elaborate. Chip.

Paul -

The "reason" cited on the Engineering Change Recommendation to reduce the advertised horsepower numbers and release new air cleaner stickers with lower ratings was "Management Direction".

[William F.]

Re: 65 396

Joe, you sure that '65 Chevelle 375 hp 396 has hydraulic lifters? I know the later ones had solid lifters. My best friend had a '69. And Larry, you're right about NHRA classifying the 375 hp up to 425hp.

[Carl N.]

[Joe L.]

Re: 65 396

Joe, you sure that '65 Chevelle 375 hp 396 has hydraulic lifters? I know the later ones had solid lifters. My best friend had a '69. And Larry, you're right about NHRA classifying the 375 hp up to 425hp.

William-------


Absolutely positive. The 1966-69 L-78's did have mechanical lifters ( I once factory ordered and owned a 1968 Chevelle L-78). However, the 1965 Chevelle Z-16 was equipped with hydraulic lifters. I always thought this engine was designated L-78 but it could have been something else as Carl mentions.

[Joe L.]

Re: 65 396

my 5 cents worth on the topic of the 1965 Z16 SS vs L78
Under the hood is the source of the 396 confusion. The Z16’s engine was rated at 375 hp, and since the legendary solid-lifter L78 375 hp 396 became available on SS396s as of mid-year 1966, and was also the top engine on Camaros and Novas during the 1967-1969 heydays, I — as well as probably a few others–mistakenly assumed that the Z16’s 375hp engine was also an L78. Not so!
It was actually an L37, made only for those 201 Z16s (as far as I know). The difference? The L37 had a hydraulic lifter cam, somewhat less aggressive in its lift and duration too. Someone correct me if I’m wrong (again), but it appears that the only difference between the 375 hp L37 and the 360 hp L34 was that the former had 11.0:1 compression and the latter had the a more civilized 10.25:1 CR. Which makes me wonder if the they had the same heads? Did the L37 have the rectangular port heads, and the L34 the oval-port heads? Or did both of them have oval-port heads? Chevy “L” experts; where are you in our moment of need? Exhaust manifolds, intake manifold, carb and ignition were not the same as utilized on the L78 Corvette application. The 375 hp rating may have been understated.
A bit more info on the Chevelle"Chevy also wanted in on the mid-sized action, where the Pontiac GTO had created a whole new genre. Their response was the mid-year 1965 Z16 SS396, of which only 201 were built. They were never advertised, although they got plenty of publicity otherwise. Dan Blocker (“Hoss” in Bonanza) was one of its big fans. Why Chevy didn’t put the SS396 into production in 1965 is a good question, and I’m surely not the first to ask. It was a wickedly fast machine, and those that got their hands on one were highly enthusiastic.
The ’65 Z16 was a much better car than the actual production ’66-up SS396. It was built on the reinforced convertible frame, and had unique chassis components including the biggest brakes from the full-sized Chevy line. The ’66 SS396’s chassis was mostly unchanged from the mild regular V8/SS coupes, and was decidedly not renowned for its handling or brakes. It was built to a price, to undercut the GTO." Another feature unique to the Z16 is the 160 MPH speedo and there are others ----- but this is a Corvette Forum ---- so mods don't flame me.

Carl------


The 1965 Chevelle Z-16 with whatever the engine was designated was virtually identical to the 1965 Corvette L-78 except for the following:

1) camshaft and lifters;

2) oil pan

3) exhaust manifolds

The Chevelle L-34 (I bought one of these new, too) used oval port heads and a cast iron square flange (Holley) manifold. The Z-16 used rectangular port heads and an aluminum, square flange manifold (same as Corvette L-78).

[Carl N.]

Re: 65 396

Agree intake manifold was square flange but had a heat sink for choke much like later 396 in passenger car applications (different p/n) and carb had different choke provision (thus different list #) as exhaust manifold did not have tubes for choke hookup on passenger side exhaust manifold which was\is unique to Corvette. Neither would have any effect on HP rating.

[Patrick B.]

Re: 65 396

There is a twist to the story of 201 Z16 SS396 Chevelles. The 200 Z16 hardtop SS Chevelles had an "IX" pad suffice and the hydraulic cam. The 201st car was not a pillarless hardtop but rather a 2 dr pillar coupe (hence not an SS) with an "IY" pad suffice and the Corvette solid lifter cam. I once owned this IY code block, and I showed a rubbing of the pad to Alan Colvin who recognized its significance. He used the car vin derivative sloppily handstamped on the pad to locate and purchase the car. By the way, the block was very rusty and I bought it in the 80's from Bob Jorjorian by way of a magazine ad. I do not know Bob personally but maybe he remembers the block.

[Joe L.]

Re: 65 396

Agree intake manifold was square flange but had a heat sink for choke much like later 396 in passenger car applications (different p/n) and carb had different choke provision (thus different list #) as exhaust manifold did not have tubes for choke hookup on passenger side exhaust manifold which was\is unique to Corvette. Neither would have any effect on HP rating.

Carl-------

From what I can tell, the intake manifold was the same as 1965 Corvette. If it was a manifold with a choke stove, then I don't know what manifold it could have been. The first aluminum manifold with a choke stove was 1966 L-72/L-78.

As far as I can tell, the Holley 3310, used for 1965 Z-16 Chevelle, did not use a divorced style choke (i.e. the type used with a manifold choke stove and manifold-mounted choke thermostat).

[Wayne M.]

Re: 65 396

The Chevelle L-34 (I bought one of these new, too) used oval port heads and a cast iron square flange (Holley) manifold. The Z-16 used rectangular port heads and an aluminum, square flange manifold (same as Corvette L-78).

I've got one of those BB cast iron "Holley" oval ports; part # 3866948, cast E_24_5, with choke stove provision (although I have it on my 961 block mentioned above), but I use a LIST 3124 carb with the hot air choke tube on the 301/302 exhaust manifolds.

[Keith B.]

Re: 65 396

There is a twist to the story of 201 Z16 SS396 Chevelles. The 200 Z16 hardtop SS Chevelles had an "IX" pad suffice and the hydraulic cam. The 201st car was not a pillarless hardtop but rather a 2 dr pillar coupe (hence not an SS) with an "IY" pad suffice and the Corvette solid lifter cam. I once owned this IY code block, and I showed a rubbing of the pad to Alan Colvin who recognized its significance. He used the car vin derivative sloppily handstamped on the pad to locate and purchase the car. By the way, the block was very rusty and I bought it in the 80's from Bob Jorjorian by way of a magazine ad. I do not know Bob personally but maybe he remembers the block.

thats a new one. In the Chevelle circle everyone believes the odd ball number is a convertible that was for a GM executive. The car is believed to have been crushed years ago. Have you spoken to Jeff Helms about it?

[Carl N.]

Re: 65 396

From the 1973 parts book

The LIST-3310, part number 3878261 is correct for a 1965 Chevelle (396). The LIST-3130, part number 3869933 is for a full size Pass. w/Sp. H/Per. (396) to quote the parts book. I do not believe either of these used the same choke arrangement as the 3124.

[Joe L.]

Re: 65 396

From the 1973 parts book

The LIST-3310, part number 3878261 is correct for a 1965 Chevelle (396). The LIST-3130, part number 3869933 is for a full size Pass. w/Sp. H/Per. (396) to quote the parts book. I do not believe either of these used the same choke arrangement as the 3124.

Carl--------



I know exactly what the GM #3869933, list 3130 configuration is; I have an NOS example in the box [not for sale]. It uses a choke identical to the 1965 Corvette L-78. The 1965 passenger car with SHP 396 (i.e. L-78) used the same exhaust manifolds as the Corvette L-78.

[Patrick B.]

Re: 65 396

thats a new one. In the Chevelle circle everyone believes the odd ball number is a convertible that was for a GM executive. The car is believed to have been crushed years ago. Have you spoken to Jeff Helms about it?

I don't know who Jeff Helms is. Alan Colvin seemed to be very well informed. He is the author Chevrolet by the Numbers Books and must have some good GM sources. If the odd car was just a Z-16 convertible there would be no need for a different engine code. Does the Chevelle circle know about the IY code 65 Chevelle engine?

[Keith B.]

Re: 65 396

I don't know who Jeff Helms is. Alan Colvin seemed to be very well informed. He is the author Chevrolet by the Numbers Books and must have some good GM sources. If the odd car was just a Z-16 convertible there would be no need for a different engine code. Does the Chevelle circle know about the IY code 65 Chevelle engine?

Jeff Helms owns Z16 number one the pilot line car and a bunch of other cars. And runs the Z-16 registry. I'm sure a few does.

[Patrick B.]

Re: 65 396

Jeff Helms owns Z16 number one the pilot line car and a bunch of other cars. And runs the Z-16 registry. I'm sure a few does.

Keith--- I still have a copy of the rubbings I gave Alan Colvin with the VIN derivative of the IY code car. I would like to give the info to the Z-16 Registry if they do not have it already. However, I cannot find the registry with a google search. I did find references to Jeff Helms as owner of the pilot car. Also I found a Camaro website with a engine suffix decoder that listed "IX" as 65 Chevelle Z-16 and "IY" as C.O.P.O. 65 Chevelle Z-16 which gives some credence to Alan Colvin's version of a COPO Z-16. If anyone knows how to find the Z-16 registry please let me know. I also have another Z-16 block that is lightly decked but still has some traces of the stamping.