MSO documentation

[PhilS]

I'm trying to figure out the meaning of the horsepower (SAE) rating found on MSOs. My theory is that the rating is max built to spec per cylinder. I noticed on the Daytona Yellow COPO Chevelle at B-J the number was 55. On a Camaro bought by a friend the number is 53.6. This car is supposedly a 375 hp car. I think Zs are 48. Kurt and Daniel have been trying to help but Kurt says an SS350 is something like 51 which might blow the theory. Charley thinks someone has already figured this out but doesn't remember who. I would like to see more MSOs to get a better understanding. The number on a new Vette is around 51. I think a Viper is in the same range. If anyone has an MSO for a 67-69 Camaro I'd appreciate your info or thoughts.

Thanks

[bilede]

53.6 is a 396 but wouldn't tell you which of the 3 versions of that motor it would of been originally.. 325hp, 350hp, or 375hp or even L89 aluminum headed engine.. tach or other clues maybe.. keep looking.

[Chevy454]

We talking about the "taxable hp" rating? Seems like we dug into this many moons ago on this...

[COPO]

We did talk about this several years ago on this board. It is one method to help determine what displacement engine came originally in a car. I have seen a number of discrepancies with solely relying on this method. I found quite a few examples of highly documented BB's with a taxable HP listed as a small block. I think the old thread talked about the formula for this calculation. It is displacement only.

[Chevy454]

Here is the formula...

Diameter squared times number of cylinders divided by 2.5

[PhilS]

Thanks for the help guys but I'm curious about this formula. More than one displacement can have the same bore so I'm not sure how it works. Does the SAE number apply to more than one engine size? Also when I ran through the numbers I wasn't getting a match to the MSOs I've seen. I'm assuming that the number actually has relevance but maybe not.

[Belair62]

Phil my Y Camaro MSO states 53.6

[Mr70]

When I did a VIN search in 1995 on my car,the Missouri DMV sent me pages of 1970 Chevelle VIN's that were numbered around my cars VIN#.(They were pretty loose back then)
I was able to ID a few of the cars to their current owners today.
As was mentioned earlier,there were human errors when reporting these numbers,but they show my L-78 Chevelle as 51 taxable HP,an L-34 Chevelle as 48 taxable HP,and an LS-6 Chevelle as 54 taxable HP.

[mchriscad]

This is very interesting. I have to admit I have never heard about this. I dug out the copy of my MSO on my 67 Vette L89 and it says 57.8. Thoughts?

[PhilS]

Multiplying by 8 would give you 462.4 hp. I think this would be pretty close to correct for a blueprinted engine. Years ago a friend who had held some national records with small block Chevys told me that a blueprinted 302 would make about 380 hp. I think the MSO rating on Zs is 48. That comes to 384 hp. I looked at a bunch of new MSOs at a friends GM dealership recently and the nembers seemed pretty consistent. I'm certainly not sure of anything about this and that is why I'm seeking more info but if it is valid then it might provide another way to document cars without other paperwork. It seems that there might be too many inconsistencies though. More investigation needed. I'd like to see an MSO for an L-72 Vette.

[Enoch]

Just wondering which 67 L-89 you have. I know of the blue AIR coupe, yellow coupe, green coupe maroon vert, silver vert. So there a 11 I don't know of is yours one of those or another. What other paper work do you have for it?
Those cars are super http://www.yenko.net/ubbthreads/images/graemlins/cool.gif.
Thanks, Rich.

[mchriscad]

My car is Black with a Red stinger and black interior. I have the original tank sheet, copy of the MSO, dealer order sheet, NICB owner history report (this is where the MSO copy came from) Thanks, Chris

[Enoch]

WOW, thats the first I heard of a black-black 67 L-89. I'd love to hear more about the car!!! IE: options, how long you had it, previous owners. You can PM me if you wish not to put that out on the web. You are a lucky man to have one of those.
Rich.

[COPO]

What is contained on the NICB owner history report? I am only familiar with the one that lists the original dealer and shipping date.

[mchriscad]

I bought another 67 L71 that had the NICB report which included: orginal dealer, copy of the MSO, and a copy of every title back to 72.

[LS6 RAT]

57.8 is in the box Horsepower on my original State of Illinois Certificate of Title. This is for a 1971 LS-6 Corvette.

[mchriscad]

That would make sense since the formula would use the same number for a 427 (4.251) as for a 454.

[PhilS]

Why then would the number 55 be on the MSO of the Daytona Yellow COPO at B-J? I'd like to see some of the low horse bb numbers.

[GeorgeLyons]

The yellow COPO was mine, yes the SAE HP was 55.0. While in Phoenix I saw one of the other Westminster Chevrolet COPO Chevelles, Red 4spd (Was spec paint, Buick Riviera Gold), now owned by Tommie Lee Austin. It too had an MSO copy showing 55.0. Interesting sidenote: Tommiie has a letter from the orig owner of his car talking about a friend of his buying a new Yellow Automatic 427 Chevelle from Westminster.........that would be my Yellow car. Pretty cool, huh ?

[PhilS]

I've recently found 57.8 hp on a 71 Hemi Challenger title. I'm still looking for more info on some of the low hp big block cars. I'd really like to know if all 396s are 53.6 or just the l78s, Same question for the 427s. At least the l72s and l89s are different. Anybody?

[budnate]

what about the really low hp 396 "copcar" motor in 69???? its in colvins book, never saw one until I pulled one out from under a guys bench and ran the numbers..something silly like 210hp...??? cant recall and to lazy to walk out to the shop right now.

[COPO]

I have an L-78 w/bullet proof docs. with 52.0 shown.

[Racefan]

[ QUOTE ]
what about the really low hp 396 "copcar" motor in 69???? its in colvins book, never saw one until I pulled one out from under a guys bench and ran the numbers..something silly like 210hp...??? cant recall and to lazy to walk out to the shop right now.

[/ QUOTE ]

I actually have one of those "fleet" 396s-- from what I understand same internals as a 325hp, but with a 2 bbl intake and small carb. A 2bbl intake for a bb is pretty interesting looking.