1G 1st engine build questions

[1990dsmkid]

Hey guys! This is hopefully gunna be my first engine rebuild.

I'm tearing down my old engine from the 90 TSi AWD I used to have. I'm just looking for stock rebuild. This engine was suppose to have been rebuilt before, so I was told anyways. Does it have balance shaft delete done already? I have parts from years ago to redo the head.

I'm looking to see if I can get away with just new bearings and engine rings. I felt and saw no scratch on cylinder walls. Just a ring of rust towards the top. Hopefully these pics help. Its all i have right now. Just looking for help/info. Thanks a lot guys

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[1990TSIAWDTALON]

It looks like it should clean up well and make a good motor again.

 

[97egl]

As Marty said above it looks like it will clean up well. Since this is your first engine build I'm not sure what tools you have at your disposal.

As far as the cylinders, in a "proper" rebuild you would want to measure the bore of each cylinder with a bore gauge to make sure it is not out of round or tapered. But if the car ran ok before with no slapping/banging/knocking noises you'll probably be ok to just hone and re-ring it. (This can be the difference between a 50k mile rebuild and a 200K mile rebuild) I would recommend honing the bores with a ball hone as opposed to a tripod/stone hone. The ball hones are much easier for a beginner to use.

For redoing the bearings you'll need a set of micrometers to measure the main and rod journals on the crankshaft. If any of them are out of round you'll need to have the crank turned or find another crank. If you can't afford micrometers and the bearings look good I would recommend just re-using the bearings over putting new ones in if you are going the route of not measuring. If the bearings are worn I would definitely suggest measuring the crank or bringing it to a machine shop and have them measure it and let you know if it just needs to be polished or if it needs to be turned down.

The headgasket looks like it was good so you probably are ok with head and deck flatness but it is always a good idea to check them with a flatbar. You need an actual flatbar/machinists ruler to do this. I've seen guys put carpenters squares against cylinder heads to check flatness and there's no point to doing that unless you have verified it is actually 100% straight and most are not.

For the valves I'd pop them all out and clean the carbon off. (Be sure to label them so they go back in the same hole they came out of) Then wash the head well in a parts washer and lap the valves into the head. If all the valves lap in then your head should be good to go.

On top of rings and bearings be sure to replace the timing belt unless it recently replaced. You may already be planning to do this but I always bring it up because so many of these engines die due to timing belt failure. I'd also replace all the seals in the engine since you already have it apart.

 

[1990TSIAWDTALON]

Ball Hone video HERE, in case you need it. I agree with @97egl on all of his points. I put new oil pumps and water pumps in all of my rebuilds. Not necessary but it is the heart of the motor so I always replace them with good replacement items if not OEM. On the timing subject, new timing tensioner and pulleys if not recent. OEM tensioner if available.
If you want to follow along, I am doing a replacement shortblock build over on my profile page thread of my Red 90 TSI HERE.

 

[1990dsmkid]

Ill see what the bearings look like and go from there. I dont have set of micrometers but my buddy might. The engine as been sitting on stand for at least 6 yrs. When it was in car is ran but compression was low. Burned oil some exhaust valves i can tell were leaking. I have all new parts to have head redone so thats not a problem. Timing belt and water pump have prolly 5k miles on if that but like i said been sitting on stand so i will see and decide. Thanks guys

Part of me now wishes i would have done a leak down test. I might have been able to just get the head redone and go. At same time though with my luck if i would do that the bottom end would give out not long after.

Do you guys recommend a certain brand for new rings?

 

[1990TSIAWDTALON]

They should come with any pistons you purchase. If you are keeping the stock pistons, I use Nippon like THESE.

 

[1990dsmkid]

Yea im keeping stock pistons. Just need/want it running again.

I saw rockauto has some. Hastings was one. Dont remember other. Havent done much more looking

 

[1990TSIAWDTALON]

Hastings is a very good brand name. I have a Roller Motor 350 SBC build going with Hastings rings. I trust them. They've been around for along time.

 

[1990dsmkid]

Maybe tomorrow ill get the crank and pistons out. Check them over and post pics here

If old bearings look good could i plastigauge them to get clearance to see if i could get away with new bearings or still too much risk without measuring?

 

[1990TSIAWDTALON]

Really need to use a micrometer. The old bearings are wore so no accurate measurements but hey, plastigauge is cheap so it won't hurt if you want to check it out!.

 

[1990dsmkid]

Very good point. I did not completely think that through. I guess ill wait and see what i find

 

[1990dsmkid]

Well this has been and will continue to be on hold. I dont foresee it happening this year

 

[steve]

Better to wait and collect the tools and knowledge to get it right than learn the hard/expensive way. Even once you have the tools it takes awhile to use them correctly.

When we talk about measurement tools there are various types. I can't comment on the quality or accuracy but here are some examples that won't cost major body parts.

Outside Micrometer-

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Micrometers

Shop Shars Tool today and see why customers choose our high quality micrometers at a great value, same-day shipping, and dedicated customer support.

www.shars.com

Bore Gauge -

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Bore Gages

Shop Shars Tool today and see why customers choose our high quality bore gages at a great value, same-day shipping, and dedicated customer support.

www.shars.com

Caliper -

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Caliper

Shop Shars Tool today and see why customers choose our high quality calipers at a great value, same-day shipping, and dedicated customer support.

www.shars.com

 

[1990dsmkid]

I know about the tools. Just have yet to get any. The main issue comes down to time and money. Work is slow. Was suppose to be a busy year but now its not looking so. Just put on back burner and see what happens.