Engine ID 472 cid help!- with picture....

[Stampie]

Ok I went out and cleaned up my pad to see what it says.  As you can see it is 66Q813718.  So ... I know this engine had later heads and I was told it was a 76.  I never saw the actual car it came from but at least we have two engine with the 66Q.

Stampie

[Stampie]

I just looked at the other pictures I took and I think it's actually 66Q213718.

Stampie

[Geert-Jan]

Okay, good work Stampie! Thanks to your better half  Does it mean it's an 76 engine? And can you tell me something about the cilinders?

Tomorrow (it's now almost 08:00 pm here) I'm gonna try the metal pin in the spark plug hole trick.

I keep posted!

Best regards,

GJ

[Stampie]

I'll check tomorrow but if I remember correctly this one was pretty straight up stock.  With your early heads and what appears to be the same block beginning numbers as mine I'll assume you have a mix of parts.  As Thomas pointed out you wouldn't be liking it if it was a stock bottom end with early heads.  We could get lucky and have someone with a known original engine from 76 post their numbers.

Stampie

[STDog]

I need to eat some crow.
I was bored today (took the wife top a craft store), so Having seen the spots for the engine SN, I grabbed a rag and cleaned the spat.
I'll be damned, the number was there on my '70. I know I'd looked before and never found it, but I was looking in the wrong place.
Matches my VIN w/o the letter for the body style (J = Coupe DeVille).
I mis read the last digit, but after checking the VIN, I looked again and it is probably correct.

Wasn't able to get a picture as I didn't have the camera and it was raining when we got home.
It's dark now (and still showers) but I'll try in the morning.

But it is on my 1970 car, contrary to the previously mention page saying it's not there. Just like the FSM says, the VIN minus the initial letter. This car was built the 4th week of March, 1970 so it's pretty late in the model year, but it is there.

[STDog]

And can you tell me something about the cilinders?

What do you mean? The block is the same from 1970 -1976.
What matters is the pistons, and making sure they match the heads and crank.

Tomorrow (it's now almost 08:00 pm here) I'm gonna try the metal pin in the spark plug hole trick.

Did you get chance to measure the stroke then?

That'll tell if it's a 472 or a 500. But you'll have to see the pistons to know what the compression is.
Well, you could try running 89 or 87 octane (U.S. R+M/2 specs) in it an see if it knock/pings. Would recommend against that though.
Too easy to damage something, and not worth the effort at this point.

If pump gas doesn't knock, it not a 74-76 flat top piston, so it's at least a piston for your 76cc heads. If you ever rebuild it you'll buy pistons for the compression you want, and the current pistons won't matter (just the 472 or 500 info).

[STDog]

Wasn't able to get a picture as I didn't have the camera and it was raining when we got home.
It's dark now (and still showers) but I'll try in the morning.

Got some pics. Hard to get a good angle but these two look pretty good.
VIN is J0271892.
All except the J is there (the last 2 is hard to read)

[Geert-Jan]

Okay, I just got out of my garage.

To get the stroke was very tough to do: parking break, shift in neutral, unplug all the sparks, hydraulicly raised the front end, crawled under the car and pulling like hell at the two belts going from the power steering pump pulley to the crank pulley. Then go underneath the car and look if the wooden rod in cilinder # 1 has raised or lowered. Mark the level and repeat the above about 30 times (you wouldn't miss the TDC or the BDC). Checked and dubble checked. The maximum lenght top-bottom was between 10.3 and 10.4 cm, which is about 4.06 inch.

So, my engine turned out to be a 472.... Another mystery solved.

What do I have now?

Serial number: 66Q192082 => 76 block
Heads: 1497902 => 71-73 heads (76 cc cylinders?)
Stroke: 4.06 inch => 472 crank (could be 68-74).

The only mystery are still the pistons....

Best regards,

GJ

[STDog]

To get the stroke was very tough to do:
The maximum lenght top-bottom was between 10.3 and 10.4 cm, which is about 4.06 inch.

Definitely a job you want a helper for...


I'd have cheated and use the timing mark for TDC,  and a riller through the center to find 180^o away, and lined it up with the timing pointer for BDC.

Serial number: 66Q192082 => 76 block
Heads: 1497902 => 71-73 heads (76 cc cylinders?)
Stroke: 4.06 inch => 472 crank (could be 68-74).

Sounds right. Oh, that's 76cc chambers

The only mystery are still the pistons....

What octane fuel do you use? What have you tried?
Do you know if the rating is ROM, MON or the average (like in the US)?

Could give some clues as 10.5:1 ('68 & '69) and 10.0:1 ('70) pistons won't run on US grades of 87 or 89 octane.
(might get 89 to work at 10:1 if the timing is pulled way back, but I couldn't do it in Mississippi summer heat).

[Geert-Jan]

I'd have cheated and use the timing mark for TDC,  and a riller through the center to find 180^o away, and lined it up with the timing pointer for BDC.

The timing mark is on the front side of the crank pulley (right?) and it was quite dark under the car and laying on your back (head to the rear) you're facing the back of the crank pulley. Although it was hard pulling (and have grazes on my arm now) this was the easiest way.

What octane fuel do you use? What have you tried?
Do you know if the rating is RON, MON or the average (like in the US)?

Could give some clues as 10.5:1 ('68 & '69) and 10.0:1 ('70) pistons won't run on US grades of 87 or 89 octane.
(might get 89 to work at 10:1 if the timing is pulled way back, but I couldn't do it in Mississippi summer heat).

In Europe we have a different system in rating octane. To clear the differences I copied some info from Wikipedia:

"The most common type of octane rating worldwide is the Research Octane Number (RON). RON is determined by running the fuel in a test engine with a variable compression ratio under controlled conditions, and comparing these results with those for mixtures of isooctane and n-heptane.

There is another type of octane rating, called Motor Octane Number (MON) or the aviation lean octane rating, which is a better measure of how the fuel behaves when under load. MON testing uses a similar test engine to that used in RON testing, but with a preheated fuel mixture, a higher engine speed, and variable ignition timing to further stress the fuel's knock resistance. Depending on the composition of the fuel, the MON of a modern gasoline will be about 8 to 10 points lower than the RON. Normally fuel specifications require both a minimum RON and a minimum MON.

In most countries (including all of Europe and Australia) the "headline" octane that would be shown on the pump is the RON, but in the United States, Canada and some other countries the headline number is the average of the RON and the MON, sometimes called the Anti-Knock Index (AKI), Road Octane Number (RdON), Pump Octane Number (PON), or (R+M)/2. Because of the 8 to 10 point difference noted above, this means that the octane in the United States will be about 4 to 5 points lower than the same fuel elsewhere: 87 octane fuel, the "regular" gasoline in the US and Canada, would be 91-92 in Europe. However most European pumps deliver 95 (RON) as "regular", equivalent to 90-91 US (R+M)/2, and even deliver 98 (RON) or 100 (RON).

It is possible for a fuel to have a RON greater than 100, because isooctane is not the most knock-resistant substance available. Racing fuels, straight ethanol, AvGas and liquified petroleum gas (LPG) typically have octane ratings of 110 or significantly higher - ethanol's RON is 129 (MON 102, AKI 116)."

In the Netherlands the regular gasoline at the pump is delivered at 95 octane (RON), so that will be equivalent to 90-91 US octane (R+M/2 or AKI) and most pumps deliver also 98 octane (RON), equivalent to 93-94 US octane (R+M/2 or AKI). We pay also a price for it. The gasoline prices are now, due to the high oil prices and all the war going on in the Middle East, at their highest in history: â,¬ 1.48 a liter. This is equivalent to (hold yourself tight now) $ 8.29 a gallon......
So that's why I have a liquified petroleum gas (LPG) installation built in in the Caddy when I bought her. Extra evaporator on the carb, a pressure valve and some extra hoses under the hood and an extra tank for LPG of about 21 gallon in the trunk. That's it. The price of LPG is now in wintertime also high (because of a higher butane:propane rate) and cost about â,¬ 0.61 a liter, in summertime about â,¬ 0.45. This is equivalent to $ 3.42 a gallon in wintertime and $ 2.52 in summertime. So think twice before you start complaining about raising gasoline prices over there....

Although I have to admit the performance is slightly better on gasoline I drive mostly on LPG and about 10 at every 200 miles on gasoline.

So besides me driving on LPG most of the time no chance for me to test a lower octane rated fuel....

Best regards,

GJ

[STDog]

In the Netherlands the regular gasoline at the pump is delivered at 95 octane (RON), so that will be equivalent to 90-91 US octane (R+M/2 or AKI) and most pumps deliver also 98 octane (RON), equivalent to 93-94 US octane (R+M/2 or AKI).

That rules out that idea. You don't even have access to US regular unleaded. (90-92 RON).
The compression of 76cc heads and flat top pistons would be fine on LPG, and maybe do alright on the 98 RON (not sure there)

It'll take a look at the pistons to know more. That means either pull the head or a bore scope, and I don't think it's worth the effort/expense at this point.

FYI, bore scopes look sort of like this.


But they aren't cheap.
$230 http://www.eastwoodco.com/jump.jsp?itemID=12446&itemType=PRODUCT
$382 http://www.usatoolsinc.com/index.asp?PageAction=VIEWPROD&ProdID=17233

This is equivalent to $ 3.42 a gallon in wintertime and $ 2.52 in summertime.

That's not much mope than I pay for LPG actually (just paid $2.55/gal), and in some areas it's higher than you pay.
I guess it doesn't have all the added taxes that gasoline does.

You won't see me complaining about gasoline prices. I know how we compare with other countries as well as other ways of looking at the price (like % of income to drive 1000 miles) which shows how cheap it really is.

[Geert-Jan]

I agree it's not the effort worth at this point. The person who did the piecework on my engine did a very good job because it's running very smooth, absolutely no complaining at all.

Maybe I can ask the garage where I have my Caddy maintained (for the yearly tag and in case of big trouble) if they have a bore scope and will take a peak for me the next time.

Best regards,

GJ