connecting rod

Post by **T'Onion** » 03 Jul 2006, 09:00

can i swap a connecting rod without spliting the engine ??

Post by **T'Onion** » 04 Jul 2006, 09:32

anyone?

Post by **Tex Ritter** » 04 Jul 2006, 09:59

I've never worked on a VW engine yet, but if it's anything like the subaru you can't get at the big end nuts because of the opposing con-rod.

You have to split the casing to get at the BE nuts or bolts I should GUESS?

Tex Ritter

Post by **T'Onion** » 04 Jul 2006, 12:35

cheers tex
i can get a socket on the two nuts just wondered if it was do-able
I may just have a go

Website · Post by **CovKid** » 04 Jul 2006, 16:04

Con rods are matched weights to ensure balance - likewise flywheels. Mismatches in the bottom end can shake the hell out of an engine - seen it many times. You have to decide whether its worth it if the engine has already clocked up substantial miles. Its perfectly possible for an amateur to rebuild an engine but a reground crank, new bearings and preferably a linebored case are really your starting point - for reliability anyway.

I have on occasion replaced ONE valve in a VW lump where the owner was really strapped for cash but it wasn't long before other parts of the engine followed suit.

I see no reason why you can't replace a single conrod but do bear in mind the above. Theres an element of luck when you replace single items in matched sets.

Post by **T'Onion** » 04 Jul 2006, 16:52

Cov Kid
cheers for the advice
will look into it a lot more now

Website · Post by **CovKid** » 04 Jul 2006, 17:07

Tis no problem. You may just get away with it but theres a lot of force going on in that case which is why the manufacturer aims to get everything reasonably balanced. If its around the 140,000 mile mark or just shows signs of having worked a lot (ie rough running, oil leaks etc) then you might just consider a general bottom end rebuild, just so you can forget that side of things.

Alternatively if you've nothing to lose, swap the one conrod and have faith in Ferdinand Porsche

Post by **T'Onion** » 04 Jul 2006, 17:10

Alternatively if you've nothing to lose, swap the one conrod and have faith in Ferdinand Porsche

hehehe nice

Post by **HarryMann** » 04 Jul 2006, 17:39

Whats up with the conrod in the first place - did ya say?

Can always match it weight for weight if the new one is heavier, just remove metal of an unstressed part of it.

Support about gudgeon pin centre and weigh t'other end
Ditto vice versa.
Match as best can do..
Aim for 1/5 gram match

Personally, doubt if I'd even bother on a VW flat four, they rev so slow...

Post by **T'Onion** » 04 Jul 2006, 18:10

i bent it Clive

its out by 5mmish so when the piston is in its sleeve theres no way its goin home

lesson learn't was never heat up a piston to remove the gudgeon pin

hopefully will be getting another rod soon so will take the bent one out and weigh them up (on't kicthen scales)

Website · Post by **CovKid** » 04 Jul 2006, 19:17

He's right. If you remove another conrod you can compare weights then:)

Post by **T'Onion** » 04 Jul 2006, 19:28

cheers will do . and will let you know my finding

Post by **Tex Ritter** » 04 Jul 2006, 20:10

T'Onion wrote: lesson learn't was never heat up a piston to remove the gudgeon pin

Why not?

We always used hot water to remove/refit gudgeon pins with no problems...aluminium expands at a faster rate than steel.

Removing a piston that is sticking out of crankcase; wrap a very hot towel around it and keep pouring boiling water on it 'til the gudgeon pin moves.

To fit pistons to rods; get a largish bucket of hot water to put your pistons in (in our case 6), plenty engine oil on your small ends and fit your pistons/pins to con-rods using finger pressure only.

Removing pistons from con-rods: put your pistons and con rods in hot water (remember to take a circlip out) give them a minute, remove from bucket and slide gudgeon pin out. Simple as that!

Just remember to fit the pistons the correct alignment to the big ends.

Tex Ritter

Post by **T'Onion** » 05 Jul 2006, 17:49

Tex i'm sure you way is correct and doesn't cause any damage , mine was to take a blow lamp to it and bend it a little,,,

Post by **Tex Ritter** » 05 Jul 2006, 18:46

T'Onion wrote:Tex i'm sure you way is correct and doesn't cause any damage , mine was to take a blow lamp to it and bend it a little,,,

Oh dear, say no more.

TR