Opel GT Forum banner

1 - 14 of 14 Posts

·
Member
Joined
·
789 Posts
Discussion Starter · #1 ·
What years did opel make the following components forged(otherwise cast) in a 1.9??

pistons

rods

crankshaft
 

·
Super Moderator
Joined
·
13,812 Posts
azopelnut said:
What years did opel make the following components forged(otherwise cast) in a 1.9??

pistons

rods

crankshaft
pistons....never seen forged in a 1.9

rods....at least until '73 they were forged, I've seen some '74's with forged rods, some with cast. Only seen cast rods in '75.

crankshaft....always seen forged, even later Euro 1.9's

Just my experience.
 

·
Member
Joined
·
240 Posts
Forged or cast (Rods)

I have a disassembled 75 FI motor so I know what cast rods look like(at least I think I know what they look like).

What are the visual clues that would identify a rod as being forged?

Garry
 

·
Member
Joined
·
789 Posts
Discussion Starter · #4 ·
cylinder wall thickness after over bore

Hello Bob
Good to see you online here.
I am looking at doing a .130 overbore on a 1.9 block.
My machine shop said that this would be fine as long as the remaining thickness(cylinder wall to water jacket) is not less than .180 on one side only and .200 to .220 on the remaining sides.
Do you know if the 1.9 block would have enough thickness with such an extreme overbore??
 

·
Member
Joined
·
149 Posts
Just my personal experience. Forged components have a thicker flashing, perhaps a quarter of an inch wide. Cast components have a thinner flashing due to the difference in manufacturing process.

Darrin
 

·
Super Moderator
Joined
·
13,812 Posts
Re: cylinder wall thickness after over bore

azopelnut said:

I am looking at doing a .130 overbore on a 1.9 block.
My machine shop said that this would be fine as long as the remaining thickness(cylinder wall to water jacket) is not less than .180 on one side only and .200 to .220 on the remaining sides.
Do you know if the 1.9 block would have enough thickness with such an extreme overbore??
Only if there's no core shift, and you have a 'thick' block. At .065" material removal per wall, you will have anywhere from .185" to .160" remaining.
 

·
Old Opeler
Joined
·
5,564 Posts
Opel Rods

Here is a pic of the two types of Opel Rods with the forged one on the left ( see notch in the cap) and the cast one on the right.
Note how much 'chunkier' the cast one is with much more metal in it to make up for the lower strength of the material.

On the far left is a fully worked forged rod - much effort gone into lightening and polishing.

Pic from OpelTuners.
 

Attachments

·
Super Moderator
Joined
·
5,883 Posts
Bob,

I bought a used set of rods to replace the spun rods on the Ascona engine. They seem "chunkier" like the cast rod shown above, but they have the "notch" in the cap. Here is the photo. What do you think they are, cast or forged?
 

Attachments

·
Super Moderator
Joined
·
13,812 Posts
Definitely cast rods. The notch is a locator of sorts.... the notch in the rods faces the rear of the engine, the notch on the pistons (OEM anyway) faces forward. Reason? This ensures the piston oilers in the rod beams are facing correctly.

Bob
 

·
Senior Contributor
Joined
·
730 Posts
R.bob, is the setup the same as US motors? I usually have the shops put my rods & P. tops together, so I've never checked for a notches end-cap, just made sure the side markers matched up.
:confused:
Barry
 

·
Super Moderator
Joined
·
13,812 Posts
Per the factory service manuals, all CIH Opels are built this way. All that happens, if you put the rod notches facing forward, is a lack of piston-cooling from the rod oil sprayers.
 

·
Senior Contributor
Joined
·
730 Posts
Tanks, I need to remember that when I pull my old engine apart. The notch actually is the slinger and part of the system.
 

·
Old Opeler
Joined
·
5,564 Posts
Notch!

The notch in the cap is a viual indicator - the oil spray is a hole in the rod through from the bearing (which has a matching hole in it) to the outside of the rod above where the rod bolt screws into it. Shows up in the RH Rod in Kwilford's pic above - a round, chamfered hole inside the rod bore at about 2 o'clock.
 
1 - 14 of 14 Posts
Top