big question

I have an early MK2 8v GTi engine that I'm going fit into my mk1. It has done 100k but the head was recently rebuilt (its also a GTi engineering 8V PLUS-PAC head conversion) I want to rebuild the bottom end before I put it into the car. Also I'm toying with idea of putting a small nitrous kit onto the car (well why not eh?) What work would people recommend
1) just as a good bottom end rebuild and
 2) a bottom end rebuild with nitrous in mind?

I'm a bit unsure on a few points of a bottom end rebuild. I'm an ok mechanic but have no major bottom end experience. If I replace the main bearing for the crank do I need to have the crank re ground or anything? I know that the shells have to be matched up correctly if you remove and then refit them, so what do you do when fitting new ones??

  Lots of questions I know but I would be very grateful to anyone that can help.



 Ben  :?

Why not go for a 2.l block, I've got one in  mine and it goes well. There are loads on the scrapyards, all post 91 2.0l Passats had them and I think some Seats. They have longer con rods, oil squirter big ends to cool the pistons and a better oil pump. I paid ?20 for mine. All you need is a spacer for the exhaust  which you can make and a ring for the distributor from TSR, about ?30.

There where some new 2ltr bottom ends going at ?250 a time, seems they are out of stock right now but will let you know if i see any

I too am no expert in this area, but what I will say is that an 1800 bottom ends are virtually bullet proof.  If it has no sings of a rattle on does not use any oil I would just chuck the lot in and leave it at that. Might be worth putting a new oil pump in.

I removed my 1800 bottom end from my Mk1 after 124K last year and replaced with an 1900. I had a look at the engine once it was out and it had virtually no signs of wear.

As suggested above, if it does let go, which I very much doubt, you can  get a replacement cheaply enough.

Whats the verdict on doing just a head rebuild on a high miler? I've got 166K miles on mine, as far as I know with no rebuilds. The head needs doing I think. No 2 cyclinder valve stem oil seals I think are starting to go and when I did the valve cover gasket the lobes of the cam are worn.

However, doing the sump gasket last weekend showed (apart from a brown 'tinge' to the engine) everything looked in very good order. The sump plug had no metal 'fur' on it which did surprise me.

So quesiton is, will it be false economy just to do the head?

Again, I don't think so.  At 166K the head will definately need some work, but as for the bottom end, it should be in good condwith regular oil changes etc.

Here are a couple of things to consider  :wink:

I went to a track day at Mallory park last year and had a ride in Greame scotts (ex TSR)red Mk1 which was a standard 1800 but with 205K on the clock!. It also had a pack D head/ 4 branch/ jettex etc giving a good 160 bhp. It revved for england and was sweet as a nut.  Colin Mc intyre ( slick 50 racer!) had a Mk2 1800 there then too, almost the same spec and never had a problem with his either.  

Here is some proof of VW reliability, but it's up to you  

Cheers for tips nick - I guess a lot will depend if car comes off road for full resto or not?!