VR6 engine block problems

[grassy 4]

just stripped the head off my vr6 it has clocked about 100 miles, it was a new block but it started knocking (very early stages)

 

i looked inside the bores and all the cross weave scraches have been removed and has glaized over already and has scored the bores in places, you can just feel them catching your finger nail. (only just feel them fairly light)

 

it was a new genuine block with new pistons and rings all new and genuine!

and the whole thing needs rebuilt again,

im going to turbo it so ive already bought forged con rods just need the pistons.

 

can i repair the bore just by honing the bore to put the cross weave back on or will i need a rebore.

 

a few problems have both resulted in this i think

 

> not having the engine balanced

 

> not checking the crank tolerances for the bearing sizes for the knocking

 

> not having installed the oil jets as i didnt know what they were or where they went, i thought they were just a dowel but i kept hold of them, (recon this is the main culprit here) my stupid fault for not asking. not this this type before and this is the most modern engine ive worked on with very basic details no proper manuals

 

> a knock sensor coming loose while driving, thing was hanging off and i torqued it to spec, seems to be holding up fine on this second vr i put in for the mean time 600 miles in, but im having problems with that too.

 

> ecu may have stored a code from knocking and retarded the ignition, the ecu was part of an engine conversion i got for my mk2, came from a guy that had ruined his engine, block was cracked and sold to me saying it had 60k on the clock and was a good runner.

didnt find out till i stripped it to change the head gasket. but it worked on the 2nd vr engine sounded fine and it went well.  not sure if i should get another ecu to use just incase.

 

> had some engine parts powder coated and i think the stuff they use to blast clean them hasnt been cleaned out well enough, found it inside of the dip stick tube and on the end of the dip stick for pulling it in and the rocker cover had trapped some in the breather area so it basically peppered the engine. 

 

(ill be using the plastic rocker cover this time)

 

ive got plenty of time and patients with it, this time i just want to have it done right as my car will be able to get me about with this second vr. didnt have a car for 5 month doing this engine build and conversion

 

 

 

 

[Jimjon 28]

Hi mate, 

 

You pm'd me a while back about the vr6 block, (i bought one of them as well)

I took mine up to Stealth racing yesterday to have it built up using my old crank and rods.   Vince told me balancing isn't worth while and not to bother (so I'm not)

I mentioned someone from the internet told me about the oil jets (meaning you) and that you hadn't installed them, was told that would cause a lot of problems and probably seize the engine if they aren't fitted.  I think that is probably the main culprit.

[grassy 4]

Hi mate, 

 

You pm'd me a while back about the vr6 block, (i bought one of them as well)

I took mine up to Stealth racing yesterday to have it built up using my old crank and rods.   Vince told me balancing isn't worth while and not to bother (so I'm not)

I mentioned someone from the internet told me about the oil jets (meaning you) and that you hadn't installed them, was told that would cause a lot of problems and probably seize the engine if they aren't fitted.  I think that is probably the main culprit.

hi mate, yeah i remember talking to you. there another block on ebay now apparently this is the last one!

the balancing was just a possiblity on mine i thought that they balance them at factory and to change the pistons would be a different weight.

ill have to have my engine balaced this time as im using aftermarket internals.

i knew as soon as i took the head off that the jets will of been the cause but there so many things that can cause problems.

i havent bought the pistons yet so if i cant get it repaired ill over bore and get 2.9 pistons put in. luckily still have the jets to put in.

personally think the amount of things that went wrong all added up, glad i didnt push the new engine at all or it could have ended worse.

i found a decent machine shop so ill have to get a price for all the work, ill get the head ported and polished too while im at it.