Yes, 43 ft-lbs for the flywheel bolts is correct, as they are a very fine thread and also a high strength bolt (Grade 12.9 as I recall). Also look for one flywheel bolt that has a slightly longer shoulder. I believe it goes in the one flywheel hole that is somewhat off-set in spacing from the others (or is it actually marked?), and ensures that the flywheel is closer to being at the proper "timing" position.Al Olmo said:Thanks Ron, wow that seems like very high torque, I would be afraid of breaking one of those bolts.
Thank you again.
"As for the flywheel bolts, Haynes manual says that that you should use the bolt marked with a "P" in the hole marked also with a "P", and it also says that on a new flywheel one of the six holes is a bit narrower, and this is the one that goes to the "P" marks... "
I looked for this reference in the OPEL FSM and could not find ...
"One of the six bolts has a longer shoulder; it helps to locate the flywheel to the crank. If you use it, you will be within 3 degrees of being correct. Without it, you maybe 7-8 degrees off on your indicated Vs. actual timing."
Vargos, One of the flywheel bolts should have a "P" on the top of it. This one is the guide bolt with a fatter shank under the head that fits tightly into one of the flywheek holes to line it up with the crankshaft.
This bolt will usually only fit tightly into one hole in the flywheel - the one clockwise next to the widest gap between the bolts. All the other bolts are equally spaced from each other - this is hard to see but the flywheel will only fit on in one position.
In the attached picture the wider gap is between the bolt marker "P" and thew one below it. Every Manual I have mentions marking it BEFORE removal !! :ugh:
Sometimes, really old threads are golden. I am proceeding with my engine/drivetrain assembly, and just got my rotating assembly back from the balance shop (WHOLE other thread, someday...). I was also helping John Warga (aka ftl) with his stroker CIH 2.4 yesterday, and ran up against the same question: "What flywheel bolts go where".Yes, 43 ft-lbs for the flywheel bolts is correct, as they are a very fine thread and also a high strength bolt (Grade 12.9 as I recall). Also look for one flywheel bolt that has a slightly longer shoulder. I believe it goes in the one flywheel hole that is somewhat off-set in spacing from the others (or is it actually marked?), and ensures that the flywheel is closer to being at the proper "timing" position.
Good advice, thanks Dan. This was the first Opel engine I have had properly balanced. I had done some reading and YouTube video watching on the process and requirements, so I knew some of the issues.When balancing the rotating assy. don't forget to include the pressure plate(not disc) in the mix.
Also be sure to mark it so that when reinstalled it'll be in the proper orientation.
Hmmm! I was reading about this recently and a point was made that this type of accuracy is not required! As an engineer my first reaction to almost everything is "Show me the numbers!" This article did that so let me share what they said. I'll convert to English units as most of us are more familiar with those. A pound is equivalent to 454 grams so 1 gram is .0022 lbs (.035 oz). A tenth of a gram is therefore .0035 oz (expressing that verbally is 3.5 TEN THOUSANDTH of ONE OZ.). As a comparison, 100 sheets of "standard printer paper" weights about 1 pound which means that 1 page weights about .01 lb or .16 oz. An 8-1/2 x 11 page has about 93.5 sq inches so 1 sq in of paper weights .0017 oz. Therefore, the balancing is being done to 2 sq inches of paper (that is a square of paper about 1-7/16 inches per side). Yeah, the engine is turning high RPM, yadda, yadda, yadda. The point is still the same: just because you can doesn't mean you should! The guy making the statement builds and races motors for himself and others and they win. I can't find the article now but will keep looking! I think it was in the EngineLabs newsletter, but I get quite an assortment so ??Good advice, thanks Dan. This was the first Opel engine I have had properly balanced. I had done some reading and YouTube video watching on the process and requirements, so I knew some of the issues.
I had my work done at Custom Balancing & Blueprinting and there is some good reading there.
To do a proper job, the balance shop needed almost all the rotating parts, including the crank, flywheel, pressure plate, rods, pistons (separated), all mounting hardware (front bolt, flywheel bolts, pressure plate bolts) and ALL the bits that are on the crank:
Timing chain gear
He didn't need the clutch disc, nor the rod bearings or rings, as those are not required for even-count inline engines. Even-count in-line engines (I-4, I-6 and I-8's) are balanced dynamically without the piston/rod assemblies (by definition, they are balanced by match-weighting as they are on opposing throws ).
Pistons and rods are matched-weighted to 0.1 grams, and the rods are also end-matched to the same specification.
The crank is dynamically balanced first, by drilling holes in the counter weights.
Then each rotating piece is added, using the balanced crank as a mandrel, and each piece individually balanced and marked/stamped to ensure that reassembly is the same. I believe the order was flywheel, then pressure plate, then front parts (gears with keys and even the front pulley). Each part is balanced as it is added.
Vee engines (and I presume I-3 and I-5 engines) require the piston/rod weights determined, including pins, rings & bearings. Then "bob weights" are made up using lead shot to within 0.1 gram of the piston-rod assemblies, and the bob weights attached to the crank to ensure that the full rotating assembly is balanced.
It wasn't cheap, as the cost was $50 set up, plus $50/cylinder, plus $20 per piston for rod separation/re-attachment, as mine had been pressed on when initial machining was done. All in, $330 CAD. I don't know if I will be able to tell the difference, but my rod/pistons weighed 4 grams different initially, and since I had lightened the flywheel (by 3 lbs, from 22.6 lbs down to 19.6 lbs), it had to be re-balanced in any case.