Need help decoding VIN & TAG of 66 Riviera

[NewSteffland]

I am looking into buying a 66 Buick Riviera in Germany. The car seems to be one of those rare copies which were produced for the European market. This one originally went to Switzerland.

Since I heard some rumors, that there are some minor and major differences between the models for the US and European market, I thought it would be a good idea to ask the seller for the VIN and TAG in order to decode them to find out what car I am actually dealing with.

Well, it might be a shame but I am not able to decode the given data. But I am pretty sure someone here can, right guys...?!

Thanks in advance from over the ocean

<span style="font-weight: bold">emailed data</span>

motor 445cui wildcat chassis 494876H934802 motor 6H934802 tack 02D st:66-49487 EUC 156269 body UU paint TR:653 B XT 2G 3B 4F 5K

<span style="font-weight: bold">photo gallery</span>

some pictures of the Buick Riviera 1966

[1965rivgs]

No problem...

445 is the torque rating of the motor-not cubic inches. There is an engine code which is located in the same area as the VIN number which you listed but on the passenger`s side. If you are kind enough to supply it we will no doubt have a very interesting discussion about your car and others built for export.

494876H934802 This is the VIN and breaks down as follows...49487-model number....6 is the year of manufacture..H indicates the car was built in Flint Michigan...934802 is a sequential serial number assigned to the cars as they were produced.

Motor 6H934802 This sequential number matches the number assigned to the body and tells us this is the original motor installed in your Riv

02D indicates the body of your Riv was produced in the second month (Feb) and the fourth (D) week

66-49487 is the model number

EUC indicates body production in the Euclid Ohio Fisher Body plant

156269 is the number assigned by Fisher to your body

UU paint indicates your exterior color should be Riviera Plum top and bottom

TR 653 B indicates the interior TRim color is Dove (off white) bucket seats

X power windows

T 4-way power seat

2G Full length shifting console

3B rear window defroster

4F Remote control outside rear view mirror

5K Door edge guards

Hope this helps. I`d be very curious to know what your passenger side engine code is. Sounds like a gorgeous car, Plum exterior and Dove buckets. Interestingly equipped also, no tinted glass, no A.C. (unless you left out a character) and a rear window defroster. Must have been ordered for a cold climate!

Tom Mooney

[NewSteffland]

Tom,

Thank you very much so far for your time. I really appreciate your help on this. I already emailed the seller for the engine code and as soon as I get it I will post it.

In the meantime I have set up a photo gallery with some pictures of the Riviera. Hope you enjoy it

The seller told me the interior is in good/excellent condition, the exterior in good condition (chrome excellent but car needs a new paint job) and technically in good condition, too.

Oh, and he stated that the car allegedly has A/C. Well, can you see an air conditioning compressor anywhere on the pictures?

b rgds

STEFF

[RivNut]

Steff,

Tom, Tim, or one of the other gurus can either back me up on this or correct me, but if the orginal engine is in the '66 Riviera, it should be a 425 (465 lb. ft. of torque,) with the one year only intake manifold and a Rochester Quadrajet carburetor. If so, it should be coded MW.

Other 66's may have had 401's (445 lb. ft. of torque) and they would have come with a Carter AFB carburetor. High compression 401's have a T code to go with the year (M for '66) Hopefully, someone has just put the 445 lid on the air filter housing and there's truly a 425 under the air cleaner. Good luck

Ed

[RivNut]

Steff,

I just looked at the pictures. All Riviera engines for 1966 were painted red - the first year for a color other than the teal green.

Ed

[Guest Riviera66]

Full points, Tom, a perfect decode.

It appears to be a metric speedometer though the photograph is a bit small to see for sure...so that'd substantiate the European specification if so.

It has some differences from when it left the factory

1) Plum paint is now some other color

2) Red engine is now a bluish color

3) The taillights are missing their center end pieces, which also support the license plate frame. This car has a strange holder fashioned to attach to the trunk lid (NOT original at all).

4) Small red reflectors have been added behind the taillights... not sure how they provide more reflection than those in the factory tail lights.

The car is definitely a non-AC car... no doubt about that.

Darwin Falk

1966-70 ROA Technical Advisor

[Guest Riviera66]

A close examination of the interior photo confirms the speedometer is registering in kilometers... so it is a continental European-spec auto. (For those of you who read my article on Exports, you'll see this is the only year exported without a speed alert...not available).

It occurs to me that someone probably removed the rear side brackets to allow the longer Euro license plate to be more easily fitted (instead of the non-standard more square ones also available). German plates are extremely long though.. the plate would've covered up the backup lenses and almost been enough to cover the built-in reflectors (hence perhaps why the reflectors were added). Still seems like a squared off plate would look way better on the back...

Darwin Falk

1966-70 ROA Technical Advisor

[1965rivgs]

Ed, Darwin and Steff,

I suspect we are looking at the original engine in this particular `66 and it is and always has been a 401.( See my comment in the first paragragh of my initial response to Steff ) As we all know, shade can vary due to light conditions, etc,... we are looking at the original Buick green.

Several years ago there arose a discussion on the Riv list about a foreign member`s `66. I cant remember where he was located? Anyway...his was also a `66 and (if my recollection is correct) he claimed he had a 401 engine and the engine was marked with the MT 401 code, numbers matching just like Steff`s car. There was much insistance the engine must have been changed, blah, blah, blah...and the final conclusion was Buick made a mistake stamping his block and that his car, did indeed, have a 425 engine with the 401 code stamped into it. I suspected all along, because his was an export model, Buick built his `66 with a 401 but I bit my lip...there were others principal to the discussion who were MUCH MORE familiar with the `66`s than I at the time and I have personally found a misstamped LX block in a `65 GS!(Buick initially stamped an LT into it and blotted out the T and added the X!)

I believe we have yet another `66 Riviera built for export with a factory installed 401. Should be interesting to hear what code Steff comes up with. I`ll bet it`s MT or a code we are not familiar with.

Tom Mooney

[RivNut]

Darwin,

You made a contribution to the Buicks.net web site on engine identification that's proven to be helpful in identifying 425's that are missing codes or miscoded. Would it do Steff any good to look for the J shaped 425 alignment lugs on the bell housing?

Ed

[NewSteffland]

Ed, Darwin and Tom,

Again thank you very much for your helpful insights.

Unfortunately the seller seems to be still looking for the engine code, so I do not have any new information on this particular point. In this connection I really do not know how hard or easy it is to find it.

Anyway.

Because I am not a real car enthusiast but rather an enthusiast of beautiful things I do not know what the main differences between a 401 engine and 425 engine might be. Maybe it is like always: the higher the number, the better. Can anyone explain it to me in very simple words, please?

I already read the article "Evolution of the Riviera - Year 1966" at http://rivowners.org/features/evolution/evpt66.html but now I am a little bit confused because - if I understood correctly – it is said that the only engine offered was the (Wildcat 465) 425ci, 340 hp, code "MW", with a single 4 bbl Quadra-jet carburetor. And until March '66 there was a special dealer option that allowed you to order the same engine with dual 4bbl carburetor which means you had 360 hp instead of 340 hp in the end, right?

But a couple of posts above Ed wrote that some 66's Rivieras may have a 401 engine what would mean – according to what is said in the previous paragraph – that this is not the original factory installed engine, wouldn't it?

And last but not least, for my better understanding of how different engines could optically look like, do you think that this could be a 425 SuperWildcat with dual 4bbl?

an auction on ebay

b rgds

STEFF

[RivNut]

Steff,

Too bad the owner hasn't gotten back to you with info on the engine code. If you need something to help him find it, let us know. There's a link on the Buicks.net website with pictures of where the code would be stamped. If the VIN on the engine and and cowl are the same, it is the original engine for the car. What is to be determined now is what engine Buick put into export Rivieras.

In 1966, Buick built both 401's and 425's, the latter having an addtional 1/8" larger bore for the additional 24 cubic inches. As I've heard said many times, "There's no replacement for displacement." You get more horsepower and torque from more cubic inches. My 1966 Chassis manual list the following codes for the "nailhead."

MT - Standard use - 401 cid, 10.25:1 compression ratio, 4 bbl carb.

MW - Standard use - 425 cid, 10.25:1 comperssion ratio, 4 bbl carb.

MV - Export - 401 cid, 8.75:1 compression ratio, 4 bbl carb.

I think that in March of '66, you could finally get the 2X4 option installed from the factory. The code for that engine was MZ. Otherwise, you're correct, the 2X4 option was dealer installed.

401's and 425's are identical from the outside. Darwin has posted some pictures on Buicks.net that show some casting lugs that are on most 425's that were there so the boring machine would know which bore to put into the block. But there are exceptions to that as well.

Based on the VIN numbers matching, I don't think I'd be too concerned as to whether the car had a 401 or 425, they both have enough power to move the car comfortably. From the driver's seat, I doubt if you'd be able to tell any huge difference.

Keep after that seller for the engine code if it's really important to you.

Ed

[NewSteffland]

The seller informed me after another reminder for the engine code that the car was sold to Finnland a couple of days ago. Well, I guess I asked to much inconvenient questions and were not his first choice, but I can live with that...

Thanks again to everybody, you were really very kind and helpful.

From over the ocean

STEFF

[ericw]

Steff, sorry to hear that you didn't get the car. Thanks for the question and thanks to those who answered. I learn a lot from here. Good Luck on your car search. Eric

[RIVEST66]

Hi everyone in this discussion!

As a new owner of this 66 Riviera I discovered web space to find useful information about Rivieras.

I may say that that 66 Riv is not forgotten to somewhere but is in new home in Estonia.

As it is said before by Eric I found from here lot of useful. Thanks you all.

About the topic:

The engine code in this Riv is MT and 4 bbl carb. But now I'm confused - Rivnut wrote:

MT - Standard use - 401 cid, 10.25:1 compression ratio, 4 bbl carb.

MW - Standard use - 425 cid, 10.25:1 comperssion ratio, 4 bbl carb.

MV - Export - 401 cid, 8.75:1 compression ratio, 4 bbl carb.

In Buick.net engine identification chart data is:

401 MW

425 MT

So which engine really is in this 66 Riv?

About Riv's condition:

- exterior - bad white paint -

- interior - leather good, floor mat worn

- body quite good

- chassis good

- engine good

Of course because highly original condition car needs total restoration to be perfect ...

best regards,

Urmas

[RivNut]

Urmas,

Here's a link that will let you see where you can look to determine which engine you have. All '66 Rivieras that were delivered in the states, that came with one 4 bbl. carburetor, were the 425 engine - code MW; if the car came with two four barrels carbs from the factory, it will be coded MZ. The 425 is easily identifiable by the Rochester Quadrajet carburetor. The other 66's had a Carter AFB carb. You can look at your engine and probably enlighten us as to which engine it is. You can probably determine if it was exported for a dealer or later by an owner. Let us know if your speedometer reads in Miles Per Hour or Kilometers Per Hour.

http://www.buicks.net/shop/reference/engine_ident_where.html

No Riviera's after '63 came with leather interior, what you're looking at is a high grade vinyl (unless someone has reupholstered in leather.)

Keep us posted.

Ed

[RIVEST66]

Hi Ed,

So I made a better look into engine compartment ...

Production code # is MT (no digits)

Engine serial # according chassis #

Rochester 4jet carb

So I suppose that engine is 425!

In carb is tag with designation: T026040 AM5LA51 - what's this?

And speedometer reads kilometers per hour.

About interior - may be that is some vinyl - but feels very leathery . Like pigskin.

See pictures

http://www.usaraud.ee/index.php?id=5_5_20_1058

br,

U

[RivNut]

Urmas,

Your engine is a 401 with the Rochester 4GC square bore "4Jet" carburetor. All Rivieras built for the U.S. would have been engine code MW, the 425 with the Rochester 4MC spread bore "Quadrajet" carburetor.

If your statement "Engine serial # according chassis #" is telling us that they match, then the car was built with a 401 engine in it at the factory. Perhaps other Europeans who own '66s can tell us about there cars' numbers and see if the same data is true for them. If it is, then we can probably assume that Rivieras built for export to Europe were fitted with the 401 engines rather than the 425 engines. Is the engine painted red or green?

I looked at the picture you sent of the interior and it's a very nice looking original vinyl interior.

Regardless of which engine it has or what the material is on the seats, it's a very nice car.

Ed

[rivgs]

Ed, On your leather statement, you forgot to add " until 1974 and later"

[Guest Riviera66]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: RivNut</div><div class="ubbcode-body">If your statement "Engine serial # according chassis #" is telling us that they match, then the car was built with a 401 engine in it at the factory. Perhaps other Europeans who own '66s can tell us about there cars' numbers and see if the same data is true for them. If it is, then we can probably assume that Rivieras built for export to Europe were fitted with the 401 engines rather than the 425 engines. Is the engine painted red or green?

</div></div>

Ed:

That won't help. As I presented in the "Export" article I wrote in the May/June 2007 Riview, 541 '66 Rivieras were exported, but only 238 were ordered with a low compression engine. At the time I wrote the article, I believed the low compression to also be a 425 for 66 (based on the way the reports were worded...), but additional information now indicates that there was only a single low compression engine each year and that it was of the smaller displacement. We haven't encountered one yet, but a '64 would also have a 401 low compression engine I suspect. Based on the Euro cars I've documented so far, Europeans didn't order low compression engines (probably since they had as high or higher octane there than we had in the US)... if this car was originally sold into Eastern Europe, that'd probably explain a low compression fitment.

Darwin Falk

1966-70 ROA Technical Advisor

[RIVEST66]

Hi,

Thanks Ed and Darwin!

I'm not disturbed about my riv's technical data, it's great car. But knowledge about it is interesting.

I found fax with car's certificate from Switzerland (dated '74 probably 2nd owner), there is displacement 6,569 l -> which is 401 cid.

I think it's true.

Now compression rate. I'll try find some solution to make it sure. Maybe some suggestion (w/o engine disassembly)

Engine color is green, no marks of repainting.

br,

Urmas

[RIVEST66]

Hello Darwin,

I keep wondering number of different options of Buick Rivieras engines.

This topic is interesting. You seems most skillful in this. I looked your story article and look my Rivs engine closely.

I discover that my Rivieras engine code is MT 338, block cast # 136 705, head cast # 1374603, "casting rectangle" true rectangle w/o J or L shape hook part.

So - again the question - 401 or 425?

See pictures. pics

Other data: Buick Riviera 1966, vin 494876H934802

Best regards,

Urmas