new piston rings fitted advice please

[boyzey]

Hiya guys after bit of experiance if poss. I have fit new piston rings to my g40 engine. Fully stripped the bottom end marked up each component for re fit in correct order. Every thing oiled up on assembly. Gone to turn it over by hand no head on so no compression but it is very tight need a ratchet to turn crank but once got it turning its fine its just the anitial getting it turning. Is this just the new rings need bedding in do we thing ? Cheers

[randombadger69]

Sounds normal.

Did you have the block honed?

As long as you checked and adjusted the end gaps and fitted all pistons and rings without damaging anything you should be alright.

[boyzey]

Hiya buddy thanx for reply. And no the bolck not been honed went on fact that it is low milage and can still see the hone marks. And buy end gaps do you mean when the rings fit in the bore u mean checking that gap in the ring?

[AdzCM]

Hiya guys after bit of experiance if poss. I have fit new piston rings to my g40 engine. Fully stripped the bottom end marked up each component for re fit in correct order. Every thing oiled up on assembly. Gone to turn it over by hand no head on so no compression but it is very tight need a ratchet to turn crank but once got it turning its fine its just the anitial getting it turning. Is this just the new rings need bedding in do we thing ? Cheers

I take it you torqued everything to spec?

What do you mean by hand? With all four pistons/rings fitted, it will be quite tough to move by your hand. As 2 pistons near the top of the stroke and 2 at the bottom, it gets a bit harder to turn. You will definitely need to use a spanner to get it moving.

[boyzey]

Yes buddy everything torqued down. Just crank and pistons/rods. And good idea buddy ill get torque rench on crank wen i gt chance but think itl be mor than 25nm. Once i get it turning its fine its just the force to crack it of and get it turning.

[AdzCM]

http://www.mgaguru.com/mgtech/engine/cs205e.htm

Read the bottom paragraph. That's where I read about the 25nm.

My cylinders were bored to fit larger pistons and honed. They bored it to spec after looking at the wossner clearance of 0.07mm so I didn't have to check the ring clearance. but I did anyway using a feeler blade and it was all good. So after fitting all the pistons and rings, I could turn it a bit by hand but mainly had to use a spanner. tested it using 25nm on the torque wrench and it didn't even come close to clicking.

Honing apparently adds additional friction, so mine should be harder to turn than yours. If its taking more than 25nm, then I don't know.

Adrian

[AdzCM]

Apologies, not 25nm - 25lb ft - so about 35nm

[randombadger69]

Hiya buddy thanx for reply. And no the bolck not been honed went on fact that it is low milage and can still see the hone marks. And buy end gaps do you mean when the rings fit in the bore u mean checking that gap in the ring?

Yes. Worth checking each ring in the corresponding bore somewhere down from the deck with a feeler guage. End gap tolerance should be listed in the haynes. If the gap is too small then they should be filed to suit.

Best method is clamp a needle file or similar in a vice and run the ring along it until it's at the correct clearance. Then de-burr and fit onto pistons.

[boyzey]

Sorry about late reply been realy busy. But yes i will get torqu wrench out today but ive got a feeling 35 may not be anough bt il let you no cheers for all help guys

[AdzCM]

35nm is quite a lot so should hopefully turn. I made the same mistake when I tested it by using 25nm, not 35nm and it still rotated easily. Nowhere near clicked.

Randombadger is right. If you have only changed your rings and its now stiff to start rotating then ring gap is worth checking. If it rotates easily once started, I wouldn't worry. Though somebody else can maybe advise.

[boyzey]

Rite i cracked torque wrench out this aft. Between 40 and 45 Nm to get it turning. Thats if i leav it for few min then go to turn it over again. But if i only leav it few seconds i can turn it fine asin like 20 Nm no problems. Its just the initial first bit that takes some duing strange. Might have to jst bite the bullet and go with theyl bed in haha

[AdzCM]

That's quite a lot mate. Is there nobody you can ask that builds engines? Maybe a forum dedicated to engine rebuilds. Can't understand why it's so stiff initially but gets easier to rotate after you finally get it 'free'...I've never installed rings that have too small an end gap so don't know for certain if they would cause enough friction to make rotation THAT difficult. Logically, I very much doubt it. Don't want you to damage anything. Keep asking around.

[boyzey]

Yes once its turning its fine i not worryed it just the getting it turning part im not sure. But yes i will have to have a word with few mor people i think cheers