[nobody]

I was looking at a stock 1.9 with a manufacture date code of 1 31 70. It's been replaced into this car. Anybody know final date for the high compression Build cars.

 

[tekenaar]

German Model year

Since the German model year ran from Jan. to Dec., I would think that all engines with '70 cast dates would have flat top (HC) pistons, though those closer to the end of the year may be suspect due to model year changeover. In this case, cast date is a more reliable indicator than the car model year because of conficting US model year start date (Sept.).

 

[opelgtworld]

Engines with the marking 19 S have high compression pistons and
19 SUS have low compression pistons.

Wasn't that like that?

 

[GTJIM (R.I.P.)]

Change Time

To quote "Norbert" from Germany in a previous post:

"From Chassis number 226 5862 the dished pistons and hydraulic cam were used."

Looking at the Official Buick Motor Division "OPEL and GT PARTS BOOK" in the Model Chart #77 226 5862 is listed as the start number for the 1971 GT chassis numbers. It also notes that: "1971 Models identified by letter "M" on vehicle identification plate."

So it would appear that ALL 1971 onwards GTs were SUPOSED to have LOW COMPRESSION engines. But since the Euro motors were exempt from the US emmission standards they continued to have 9:1 compression ratios and it is not beyond the bounds of possibility that some of the high compression motors found their way into GTs after 1971.

Indeed it has been rumoured that GTs were retro-fitted with flat-top pistons by dealers from time to time due to complaints about lack of power after the change over to low compression pistons.

Also lots of motors have been swapped from Opel to Opel and been rebored - it is reasonable to believe that the higher compression pistons/motors would have been the ones chosen in these circumstances.

The trick is going to be matching engine number up to chasis number to know after which engine number lo-comp pistons were used.
To this end, could anyone with a 1971 GT please record here their Chassis number (starts with "77" - ) AND Engine number (Starts with "19S" or perhaps "19US"). Enquiring minds would love to know!

 

[opelgtworld]

Since the German model year ran from Jan. to Dec...

Hi Otto,

the term "Modelljahr" covers the period starting from the Opel factory holidays in summer up to the next factory summer holidays. Thus about September to July of the next year.

Norbert

 

[greensmurf20]

my 71' GT was made in september of 70 according to the sticker inside the door, numbers as fallows.

chassis no. 772288663
engine no. 19S-058977

casting dates on the block, trans, bellhousing, timing chain cover, every casting date is 70, but still has low compression and hydraulic lifters.

 

[nobody]

A clue was the lack of start up clatter as the lifters fill. I didn't get a chance to pull a plug to have a look see but that date of January of 70 makes me think it is flat top.

 

[bozkm]

My 71 has the following numbers:

Engine - 19s-0696800
Chassis - 772447229

Have no idea what type pistons it has, but do know it has hydraulic lifters.

 

[GTJIM (R.I.P.)]

Thanks!

Great info guys! Looks like the "19US" engine designation for lo-comp motors may be a myth and they simply had "19S".

My 1972 Model has a production date of 24.04.1972
VIN 77 2858052 Engine Number 19S 0940070

Now we need some data from 1970 models with hi-comp and solid lifters to see if there is any way that the Engine Numbers identify which type of motor has hi or lo compression pistons and when the change occured.

A GT with a VIN close to - or ones either side of - the suposed change at #94 226 5861 and #77 226 5862 would be a definite bonus!

 

[nobody]

Bozkm, look for the manufacture date code by the starter. I'll doube check the 1 31 70 next chance I get. Jim the mix and match of cars and motors over the years makes it hard to tell. Vin on the car begins with OY07 so that's not that accurate. It was listening to it and checking manufacture date as well as original color that tipped me off. I know it's 19S but will work on the rest of the numbers.

 

[GTJIM (R.I.P.)]

Extrapolating ...

By collecting Vin numbers and associated Engine numbers we should be able to establish when the change over from hi to lo compression took place.
Already established is that motor number 19S 058977 from a GT produced in Sept 1970 is a lo-comp motor. So any motor with a number after that will almost certainly be low compression.

It will just take a bit more "zeroing in" on earlier 1970 motors to be able to say a motor before number 19S XXXXX will probably have been and original hi-comp and a motor after 19S XXXXX + 1 will probably have originaly been lo-comp.

It will be interesting to see if lo-comp pistons, cast rods and the use of a hydraulic cam happen to start being used in the same engine!

See the feindish plan!

 

[soybean (R.I.P.)]

I looked at 6 of the 7 engines that I have. Out of the 7, 3 are High Compression. Flat top pistons. The first one was a 1 owner known 70 model engine, Block nos. *19S-0473836* , the other one is Block nos. *19S-0812336* , that came with the 69 I have. What does that mean if they quit with block nos. 19s-04xxxxx? It doesn't appear to be rebuilt, I have no way of knowing. The third was in my original Manta, rebuilt as per the C&D article. Didn't get the block nos., as it didn't count. One other (69), was covered up with a tarp and I didn't want to go to the hassle of pulling it off as it is still covered with ice. The only common denominator I could see was the blocks that had the *s, before and after the block nos., had flat top pistons with notches for the valves. I did not pull the valve covers off the above two to see if they had solid lifters. I'll pull the valve cover off the 70 block tomorrow and check to see if it has solid, or hydraulic lifters. Jarrell

 

[nobody]

Jarrell, I think you found it. I have 2 here one a 73 # 19S 1206898 dated 12 M 73 that I know is low comp. I also have a known high comp. here # *19S 0674983* date is 1 12 70. I wondered if they pulled a block regardless of SN and built it as needed then stamped the asterics? Thanks Jarrell

 

[greensmurf20]

anybody else with low comps only see one asterik after the engine number, but not before as my low comp engine? maybe its all in the asteriks, 1 asterik low comp, 2 of them high comp.

 

[EJprovost]

High compression engine

I have this and its a high compression *19S-0678061*

 

[bozkm]

Sorry guys, just came in from the garage after I read this post. My "supposed" low comp engine has both the asterisks.before and after. I say supposed because as I stated above, I know it has hydro lifters, but not sure about the pistons...so I can only assume is has dished pistons cuz I believe both of these were changed at the same time, but not positive. Sorry dave, couldn't find an engine manufactured date during my brief stint in the garage..my block isn't the cleanest in the world.

 

[nobody]

Kevin, check for original color or signs of a rebuild, It may be an early block that was rebuilt.

 

[bozkm]

I was told it was rebuilt by the original owner. I can only assume it was the original motor. Does the color of the block supposed to match the original color of the car??

 

[soybean (R.I.P.)]

The blocks that I looked at that were low compression, had no *s, before or after the casting nos. I'll try to take pictures of the blocks and nos. tomorrow.
1, ( 1 owner known 70 model engine, Block nos. *19S-0473836*) is in the shed now and if I can finish cleaning up, I'll try to pull the head by the weekend and post pictures.
On another note I found a neat little light at Lowes with a flexible head that fit right in the spark plug holes. On all the engines that I was able to look into, all spun, except 1, and I looked in all the spark plug holes and could see the pistons with no problem. Jarrell

 

[GTJIM (R.I.P.)]

More Info!

Thanks Guys & Gal for the input - looks like we may be on to something there with the "* "

My 1972 engine has a "71" Cast date and the number is 19S - 0946070* It was lo-comp but had flat tops added by the dealer when quite new to increase power.

I have four later 1.9 Opel motors as used in Holden Toranas - two I could get at in the dark this morning at 1.30am!

"75" Cast Date Engine number 19S* 1303380 with nothing after it.

"78" Cast Date Engine number 19S* 1595656 with nothing after it.

The first two are still asembled so have no idea of internals as yet but I have dismantled the "78" Cast Date motor tha came from a 1978 Holden UC Torana.
It has flat top pistons and a three bearing solid lifter cam. The rods are cast.

This is getting interesting!