Separating Flysh.. From Pepper

[Mike McKown]

Simple Question: How many of you are running your original 11-1 (or thereabouts) stock compression ratio and what adjustments or otherwise are you doing to accomadate same.

Next simple question: What have been your successes and failures?

Next simple question: What is the difference between a re-stamped block assy and a block assy with the "wrong" pistons in it? Or a wrong Harmonic Balancer? Or a wrong Intake? Etc, etc.

For example: I have these engines in my stable. Run pump gas. I don't hold them wide open through all four gears or try to attain max top speed. I don't lug the engines at all. I downshift before they are pulling hard. I cruise mayy highway miles. I seem to have no problems.

I am "no rookie"! I was running 12.5's @ 112 with my bone stock '65 Nova SS in 1965. Of course, bone stock meant it had a "bone stock" 327/375 with the fuel injection unit on it. I still have the car. With the original pistons.

So, just wondering what some of you guys think. I'd like to hear from you.

[John H.]

Re: Separating Flysh.. From Pepper

Mike -

I have a stock/original '69 Z/28 with 11:1 compression, and it runs fine on 93 octane pump gas (now); it didn't used to with the original factory-spec base timing and advance curve, but it does now. Factory spec was 4 degrees BTDC with 32 degrees centrifugal advance and an inadequate vacuum advance can with ported spark; now it's at 8 degrees base with 24 degrees centrifugal and a vacuum advance can that provides 16 degrees at 8" Hg., on full manifold vacuum, and it runs like gangbusters with nary a ping. The stock 30-30 cam helps due to its wide overlap and late-closing intake valves.

I also have a stock/original '67 327/300 with 10.5:1 compression which I run with 12 degrees base timing and 20 degrees centrifugal, and the vacuum advance can provides 17 degrees at 17" Hg., on manifold vacuum. I would expect it to have more of a ping problem than the Z/28 due to the earlier intake valve closing (which builds more cylinder pressure), but it runs like a champ and doesn't ping at all on 93 octane - go figure.

[Mike McKown]

Re: Separating Flysh.. From Pepper

Thanks John:

I knew you guys were out there hiding in the bushes. This is the kind of response we need.

By the way, I used to have an original 69Z, blue with a white skunk stripe. The next owner put a Cowl induction hood on it. It went to Michigan. Could this be the one you have?

Mike

[Jim T.]

Re: Separating Flysh.. From Pepper

Still driving my original owner 68 327/350 that has 11:1 compression ratio and burn 93 pump premium. No problems so far and have 94K on the car. I also don't lug the engine shifting when necessary.

[Mike McKown]

Re: Separating Flysh.. From Pepper

You're my kinda guy! Thanks!

[Joe L.]

Re: Separating Flysh.. From Pepper

Mike-----

As far as the judging issue goes it's really quite simple: NCRS (and NCCB) judge engine block casting numbers, engine block dates, and engine block stampings. Regarding these 3 parameters, a great many total judging points are involved. NCRS (and NCCB) do not judge pistons or, for that matter, virtually any other aspect of INTERNAL powertrain configuration. Largely, this is because it's TOTALLY impractical do do so, regardless of the merits of being "all-inclusive" with respect to judging vehicle originality.

NCRS (and NCCB) judging is designed to be VERY "non-invasive". Very few owners would consent to a complete (or even partial) diassembly of their cars in order to verify that every internal component is correct and/or original.

Being a "configuration guy", I've said for years that I feel that too many points (and WAY to much general emphasis and interest) is placed upon engine block "numbers" of all varieties. Numbers are part of configuration, but a VERY small part of configuration and their point-value should be proportionately and appropriately so-weighted. Obviously, the majority of folks, apparently, disagree with me. In any event, NCRS has a more-or-less rational approach to block stampings and the point value assigned does not, I believe, preclude someone from achieving a top flight award with an incorrectly or non-stamped block. An incorrect block casting number or casting dates, however, does essentially preclude top flight certification.

Notwithstanding the above and, especially, not withstanding my feelings about configuration, I would be the last one to suggest that judging standards should be revised to include the correct internal configuration of powertrain components. Like I say, it's impractical to ascertain the presence or absence of original internal configuration so, for all practical purposes, the issue is academic and moot.

[John H.]

Re: Separating Flysh.. From Pepper

Mike -

Nope, mine came from Canada (where the original owner stored it indoors next to his pool table from 1978-1993), and it's Fathom Green; lucked out finding one that was sold new in Canada, as I now have the GM of Canada letter which fully documents the car as-built. I think it may be the only one left that hasn't been tubbed and slammed with a blown Sonny Leonard Mountain Motor sticking through the hood


The "Green Hornet"

[Mark Ring]

Re: Separating Flysh.. From Pepper

I am not an NCRS expert but I will take a stab at the last simple question. The NCRS does not judge the pistons inside an engine. Others have said this before and based on what the judging manual says, it seems to be pretty well spelled out. From the Corvette judging reference manual; "Cars are to be judged to the standard of vehicle APPEARANCE, and as equipped, at the time and point of final assembly by Chevrolet Motor Division of General Motors Corporation. Presentation for judging is to be in the condition normally associated with that of a Corvette which has undergone the then-current standard Chevrolet Dealer New Car Preparation for delivery to a purchaser, exclusive of any dealer or purchaser inspired additions, deletions or changes."

Even though the pistons are changed, they do not "appear" to be different when looking into the engine compartment. The car needs to LOOK new, not have original pistons. It could have wooden pistons and plastic connecting rods and still earn full credit. It would not be all original but it could still get a Top Flight award. The NCRS judging point system just does not recognize the internal engine components.

-Mark.

[Dale Pearman]

With Exception

An operations judging team will deduct points for an engine that sounds of a hydraulic cam when a solid lifter cam was original. Also, some of us can judge by the exhaust note for high compresion pistons. I have never deducted points in these areas BUT why not do things right in the first place.

The use of Rhodes lifters will deceive most judges since they cause the engine to sound (up to about 2500 rpm) as if a solid lifter cam is installed and this technique is used on occasion. Also, mechanically advancing a hydraulic cam causes the exhaust note to resemble that of a high compression engine.

Dale.

[Donald O.]

Re: Separating Flysh.. From Pepper

Mike,
I have a stock 67 L79, with original cam, pistons, valves, carb, and no hardened valve seats. Though I do add some lead from Jack Podell in the 93 octane, I also run the timing at 14* initinal and 41* total. I don't lug it, but I will bang some gears with it. Hasn't pinged yet. Gosh it runs sweet over 3500 to red.
Don

[Mike McKown]

Re: Separating Flysh.. From Pepper

You're a guy after my heart, Don. Thanks.