Advice On Big End Cap Bolts Please.

[Moys1.9 0]

Doing an engine rebuild on my 1.9 and was just wondering how tight the bolts on the big end caps should be. Done them as tight as I can and can't move the crank by hand but can when I loosen them off. any advice appreciated? cheers

[Sandy 191]

Can you clarify, you mean the big end bolts on the con rods, not the main bearing bolts on the block?

[Moys1.9 0]

Sorry I mean the ones on the con rods. cheers

[16v205 9]

It sounds more like youve got 1 possible more on either back to front or in the wrong place and its pinching the crank.

 

Rich

[Sandy 191]

Perhaps you have the wrong big end bearings?

[Moys1.9 0]

Weel I bought new end shells from autofive. They were the ones with the groove on one side and fit pretty snug. I was also advised to put the groove on the cap at the same side as the groove on the con rod end. The caps have been kept with the pistons when we had em out and we marked them up to make sure we put them back right? Although we oiled them up alot of oil dripped out over the next two days cause we decided to time it up befor putting the oil pump back on. Could it just be a case of poor lubrication and over tightening?

The only time the pistons left my sight they were left with a well established light engineering place that cleaned them up but this was before we makred the end caps up?

[pugpete1108 62 1 Cars]

Weel I bought new end shells from autofive. They were the ones with the groove on one side and fit pretty snug. I was also advised to put the groove on the cap at the same side as the groove on the con rod end. The caps have been kept with the pistons when we had em out and we marked them up to make sure we put them back right? Although we oiled them up alot of oil dripped out over the next two days cause we decided to time it up befor putting the oil pump back on. Could it just be a case of poor lubrication and over tightening?

The only time the pistons left my sight they were left with a well established light engineering place that cleaned them up but this was before we makred the end caps up?

 

 

sounds like they have messed them about before you marked them , and they are in the wrong postions , oh dear

[Moys1.9 0]

Is there anyway of finding out the correct order, without taking the pistons out and going to get em all measured up with the caps? Don't fancy stripping it all back down if I can help it.

[Moys1.9 0]

I must emphasize we tightened the bolts up really tight.

[brianthemagical 1]

haynes states; stage 1: 40nm then fully slaken, stage 2: 20nm, stage 3: a further 70 degrees.

[Moys1.9 0]

We're loosening them all off and gonna do them in the three stages. Fingers crossed

[16v205 9]

Assuming the big ends are on the right conrod and the right way round then tightening them down extra tight will make no difference at all to how the crank rotates. The big ends wont 'compress' into the conrod with them 2 bolts your doing up.

 

If you are running the correct bearings then Ill still stick with the big ends being either the wrong way around or on the wrong conrod.

 

Take all 4 off and start at number one conrod, try the one you think fits fine first and tighten it down. Then try it the other way around, if its still pinching the crank you'll have to work through the others on the same conrod until you find the one that was originaly machined on that conrod. When you do you can tighten it up till your hearts content but the crank will still turn easily by hand.

 

Rich

[Sandy 191]

I'm sticking with the bearings being wrong.

[Veero 1]

Yeah sounds like the wrong ones.

 

The grooved bearings go in the block on the main bearings not the big end. The matching half for the main bearing cap is plain with a hole in.

 

The big end bearings are all plain bearings with no grooves in so it sounds like you have the wrong ones...

 

Even with them done up bastard tight they shouldn't bind like that, unless something has been ovalised perhaps?

 

Veero

[pugrallye 0]

sounds like you either have bearings inserted wrong way round, or have bent a rod, but if you havent touched the rods, no reason for them to be bent, so bearings are inserted wrong

[Cameron 16]

Bering caps on either the wrong way round or on the wrong con-rod, as everyone else has said.

I did this when i rebuild my 1.9, and i marked the caps before i removed them but in a momentary lapse i marked one on the wrong side which meant that when i put it back on it was turned round 180 and when i tried to turn the crank it wouldnt budge, exactly as you say. Wont be lack of oil as its designed to stick to the metal and will stay there for months. And not likely to be overtightening as they get done up fecking tight with the standard sequence.

[Moys1.9 0]

cheers for all the advice guys. It'll really help. Gonna have a look at each one, one by one this week. At least every time summat goes wrong I learn summat

[Moys1.9 0]

the caps were on the wrong ones. Changed them round to where they sat snug but had a very small bit of left and right play in them. Now the crank turns like a dream. Almost ready to start putting manifolds back on. It's 10:35 at night and we're putting it back together under a (dated) st georges style gazeebo cause its p***ing it down . cheers for the help.

[Sandy 191]

That's good news, good luck with the rest!

[16v205 9]

Thats great to hear, glad it was nothing serious.

 

rich