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Discussion Starter · #1 ·
Hello All,

My current 1,9l has begun blowing air/oil from the oil-filler orifice, and there has been a noticeable increase in oil pressure. I'm reasoning that a significant amount of blowby is culprit.

I have been acquiring parts to build-up an engine. Here is what I have thusfar:

  • (1) 1,9l head. Ported by Mr. Legere, with lightweight 2,2l valves, Ti retainers, racing springs-details unknown. Milling may have been done, not sure.
  • (1) Irmscher-"Sprint-Type" solid cam, powerband @ abt. 2500-6000rpm.
  • 1 set of (4) 94mm BRC forged aluminum pistons.
  • 1 set of (4) 135mm c-c (as opposed to 128mm c-c) full-floating con rods that have been lightened, balanced, and shot-peened.
  • (1) offset-ground crankshaft with a 72,4mm stroke.

Is there anything else I need to add to my list?

Would anyone know if boring of the block is going to be necessary for the sake of inserting 94mm pistons?

I've never installed a crankshaft, pistons, con rods, or bearings. Should I take the block to a shop instead?

If I take the block to a shop for the rebuild, is there anything particularly, Opelish, that I should make the machinists aware?

What year block should I consider? I have a 1970, 1972, 1973 from which to choose.

Thanks again everyone!

Scott
 

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[
  • (1) 1,9l head. Ported by Mr. Legere, with lightweight 2,2l valves, Ti retainers, racing springs-details unknown. Milling may have been done, not sure.
  • (1) Irmscher-"Sprint-Type" solid cam, powerband @ abt. 2500-6000rpm.
  • 1 set of (4) 94mm BRC forged aluminum pistons.
  • 1 set of (4) 135mm c-c (as opposed to 128mm c-c) full-floating con rods that have been lightened, balanced, and shot-peened.
  • (1) offset-ground crankshaft with a 72,4mm stroke.


"Is there anything else I need to add to my list?"

Well a new fresh timing chain and timing chain cover. keeping the oil moving around is very important.

you can mesure the head to see if it has been milled. this is important because it effects the timing. do a search here I think it is 2 degrees for per 50 thousands or something like that I found the imfo here to tell my shop..

search don't take my numbers.. bob or travis posted the right ones...


Would anyone know if boring of the block is going to be necessary for the sake of inserting 94mm pistons?

let the shop figure that all out they have all the dials and do it for a living. Just look for a shop that has a clean room and better a flow bench.. doesn't mean it is the best shop or anything but if you are looking blind like I did for an engine shop it is a good thing.


I've never installed a crankshaft, pistons, con rods, or bearings. Should I take the block to a shop instead?

If you don't know what you are doing after an investment like that I would send it to a shop. I generally do thing wrong a couple of times before i get it right... Make a mistake here and it is back to square one.

Get ready to learn how as i am about to...I now have an old engine that I am going to tear down and put back together myself to see how it is done because engine shops are expensive but the hardware you have is not the one to learn on.

"If I take the block to a shop for the rebuild, is there anything particularly, Opelish, that I should make the machinists aware?"

Opelgt source puts in three pages of Opel engine rebuild tips in with the gasket sets they sell (you will need one) make sure to ask for it when you order your complete gasket kit.


"What year block should I consider? I have a 1970, 1972, 1973 from which to choose."

trot them down to your new shop and have them magna flux them for cracks and let them choose the best one. Make sure that they clean out all the passages in the block that you choose and not just slap it together.

you are going to have a blast with that car.. especially in Texas where you have a bit of room to move...
 

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Questions & Answers

Which ever block you use pick one with a height of 208mm from the top surface to the step the main bearing caps fit in - that is the standard height.
Some blocks have heavier main bearing caps than others - the heavier caps are regarded as the strongest - another feature to choose but not necessary unless you are building a very high out put racing engine. The standard bore is 93mm so the block will need to be bored to 94mm to fit those pistons.

The piston pin height ( from the flat top surface to the centre of the gudgeon pin) should be 208 - 36.2 - 135 = 36.8mm ( block height minus 1/2 the stroke minus the rod c to c length). Check that he pistons you have are very close to that.

Are the pistons flat tops? dished? or have "pop ups" on them? The 1.9L head can give a higher compression ratio on a 2.0 litre motor but this also depends upon the piston top and how much bigger ( unshrouded valves) or smaller ( head milled)the combustion chambers are.

Get the crank, head and block crack tested before doing any machining to make sure you have good parts.

Try and find a shop that has dealt with Opel motors before - particularly modified ones as you are using non-standard parts and that really complicates matters - they will expect you to supply the answers otherwise.

I am in the middle of a stroked motor myself with 95mm bores and about 74mm stroke which is the limit without welding the crankshaft.
 

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Old Opeler
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Cost!

A set of 2.0 L Opel pistons cost at least $US380 from Opel GT Source as cars with the 2.0L motor were never imported into the US ( or New Zealand ).

That is why it is usual to use Chevrolet V8 pistons - either 305 CID ones ( 3.736" or 94.9mm) or the older 265 CID ones ( 3.75" or 95.25mm). A set of eight pistons can be as little as $US80 up to about $300 for hypreutectic specials or forged ones - this is for eight; yes 8 pistons. Chevrolet rings are also very inexpensive too.

The 265 ones can be used with Opel rods and standard stroke - the 305 ones need a stroked crank or different length conecting rods. Lots of American V8 technology and parts are used simply because they are available inexpensively and people know about how to use them - they are familiar spares that can be purchased anywhere.

Chevy V8 valves and valve springs from Chevy or Pontiac are used too.
 

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Weights & Measures

THe 265 CID ( Cubic Inch Displacement) Chevy V8 pistons weigh around 460 to 480 grammes with the piston pin weighing an additional 145 grammes. Their Pin Height is 1.805" or 45.85 mm

The 305 CID pistons are available in three diferent Pin Heights: Standard is 1.561" or 39.65mm There are two "stroker and long rod" Pin heights as well.
they are 1.433" or 36.40mm (used with a .250" stroked crank and standard rods in a 305 V8 motor) and 1.261" or 32.03mm used with a long 6" rod in the 305 CID motor.

The 1.561" piston weighs around 485 grammes with additional pin weight of 145 grammes. The 1.433" piston weighs around 445 grammes and pin 146 grammes. The 1.261" piston weighs around 420 grammes with a pin weight of 145 grammes.

The 265 Piston can be used with standard Opel rods with the pin end opened up to the Chevy standard sizee of 0.927"
The 305 pistons have the same pin size but must be used in Opel motors with different length con rods and/or with stroked cranks.

A very good site for Piston info is www.kb-silvolite.com There is an enormous amount of information and range of pistons there - but they do not have 265 CID pistons as they are an obsolete motor. Other piston suppliers do have them though. HTH
 

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OK , I think I'll manage myself to buy a CHEVY piston set for my 2.0 CIH because the original 2.0 CIH pistons weights ..............640 grams ( naked piston) so ................. I must find some Chevy pistons ( may be somebody knows a site of a company which can sell on-line).

BR

Cristian.
 

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OPEL-LESS!!!
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go to northernautoparts.com. dont bother messing around on their website tho, its very user unfriendly, just grab the number and call them for what you need. i got 265 V8 pistons from them for 46 bucks each, they're flat tops made by federal mougal (top of the line manufacturer) and i got a set of rings to do 8 pistons by sealed power for 32 bucks (also a good manufacturer). norther auto parts is a cheap place to get good quality parts. they carry parts for just about anything, even have gasket sets for the Opels 1.9 for 83 bucks!!! even includeds the correct oil pump gasket that some gasket sets dont have!!!
 

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Discussion Starter · #10 · (Edited)
My reasons for the 94mm pistons are-
  • the pistons are forged aluminum pop-top, with a comp rate of 10:1.
  • the rods connecting the pistons to the crank have been lightened, are free-floating, and shot-peened.
  • the stroked crank has had a thorough build by someone I trust.
  • all of the above is designed to fit nicely within the confines of a 1,9l block.
  • and best of all, it is available.

I'm going to have Houston Engine do the boring, fitting of pistons, crank, check deck height, clearances, bearings...

Once finished, it will be just @ 2,0l-and should still run well using mid-premium pump gas. Now, I have to find an article on recurving a distributor-Know of any?

Most online parts houses will have the pistons you want. As opposed to calling them from Romania on your telephone, might I suggest you email.

Ebay is also an option. If you need help, as some can be unwilling to deal overseas, just ask.
 

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well if you are going to do a motor over why not spend less money and go to germany and bring back say a straight 6 from a junk yard?

if you want to go the chevy route with a 1.9 go to http://www.summitracing.com/. they will have your rings, pistons, bearings and valves and be much cheaper than Europe. My pistons new were $15 that is about 12 Euro's. do it all by email.

weights and specs are listed there. I have 30 over flattops.

c
 
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