Thinking of DIY rebuild....

[Alexw]

I'm putting some serious thought into doing a top end rebuild of my S2, to save on serious costs at my Indy, so I'm doing some investigative work. I'm not sure exactly where my oil is escaping but I'm pretty sure its either rings or valve guides as there far too much oil being consumed for me not to be able to find it externally. I've never touched anything to do with timing on a car so am a bit hesitant though. I'd probably do a major service at the same time, waterpump, chain etc.
How many on here have done this before and how difficult was it?

 

[TTM]

I haven't done this but if you can replace valves guides in your kitchen with basic tools then I'm all hears

 

[pauly]

ORIGINAL: Alexw

I'm putting some serious thought into doing a top end rebuild of my S2, to save on serious costs at my Indy, so I'm doing some investigative work.  I'm not sure exactly where my oil is escaping but I'm pretty sure its either rings or valve guides as there far too much oil being consumed for me not to be able to find it externally.  I've never touched anything to do with timing on a car so am a bit hesitant though.  I'd probably do a major service at the same time, waterpump, chain etc.
How many on here have done this before and how difficult was it? 

What previous experience have you had and how mechanically capable are you ?.

 

[tref]

I have certainly done this type of work on an 8 valve, but gave the head to a locally respected machine shop for replacing the guides themselves. Everything else is pretty standard procedures, except that everything has to be "right". If you want instant gratification, it is the type of job that could end in disatser; if you are thorough, take your time, and look to do it "right", Then it is a real pleasure to work on.

Hope this helps...

 

[edh]

ORIGINAL: Alexw

I'm putting some serious thought into doing a top end rebuild of my S2, to save on serious costs at my Indy, so I'm doing some investigative work. I'm not sure exactly where my oil is escaping but I'm pretty sure its either rings or valve guides as there far too much oil being consumed for me not to be able to find it externally. I've never touched anything to do with timing on a car so am a bit hesitant though. I'd probably do a major service at the same time, waterpump, chain etc.
How many on here have done this before and how difficult was it?

Before you start, I'd suggest a bit more investigation - a head refresh is one thing, but if it needs rings... no point in putting the head back on to find it's no better.

What is your oil usage like? (and what grade of oil? - I know this might be a contentious issue right now, given other posts recently [], but could be a factor)

Rule of thumb is: smoking under heavy load - rings, smoking on startup / overrun - guides.

If you can't see any smoke yourself, get someone to follow you. Also find someone who can do compression and leakdown tests.

 

[satancom]

ORIGINAL: pauly
What previous experience have you had and how mechanically capable are you ?.

This is probably the most important question. I had never done much engine work until last year. But had gone as far as changine a timing belt. Last year I sat down an stripped and rebuilt (nut and bolt) a rover V8. It helps if you take it apart in the first place and have somewhere you can spread your work out! I used the spare bedroom, the misses loved it!

 

[tref]

The biggest problem I think is recognising when a component is acceptable to re-use, and when it is u/s. Fine for something which is obviously broken, but not so obvious when the whole engine is worn, just to varying degrees.

 

[Neil Haughey]

ORIGINAL: satancom

ORIGINAL: pauly
What previous experience have you had and how mechanically capable are you ?.

This is probably the most important question. I had never done much engine work until last year. But had gone as far as changine a timing belt. Last year I sat down an stripped and rebuilt (nut and bolt) a rover V8. It helps if you take it apart in the first place and have somewhere you can spread your work out! I used the spare bedroom, the misses loved it!

Definitely do it then, my brother has really impressed me in this regard in the past. He has rebuilt a few engines for ppl, a few years back he rebuilt, including some tuning a Cosworth turbo engine, in my parents old garden shed. Basically it belonged to a mate who blew it up big time and couldn't afford to get a top pro rebuild. The car made 380 Bhp on the rollers and AFAIK is still going strong several years latter.

As Tref said you can get local machine shops to put the guides in and do other such critical machining. As an example my brother and I built an A series engine that required the edge of the cylinder walls to be machined out to give clearance for the monster valves. We used the local college as they had proper engineering teachers and charged very little money (ISTR 40 quid), I remember it well as it was the only engine build that I did any of the work on myself. Happy days, have to do a similar project again as I had to do several critical calculations for that rather special motor.

 

[Alexw]

I completely forgot I made this post... I'm starting to worry myself...

I'm reasonably capable - amature and immature [] I took the cam cover + intake manifold off to get at the AOS this winter and replaced all seals and o-rings i could, plus the vacuum pipes, thats my experiance with this engine. My biggest worry on this is screwing up the timing, I know some special tools are required to lock everything in place. My Dad is also an ex engineer so I can always lean on him for help and info

I was thinking of passing the head to a local machinists to sort out the valves and stuff.

I think its the rings at the moment. Compression is fine on all cylinders but it can smoke like hell under hard acceleration, oddly enough though it doesn't -always- smoke, unless I'm not seeing it. The car stinks of burning oil as well, can smell it behind the car and inside when driving along.

 

[satancom]

I was thinking of passing the head to a local machinists to sort out the valves and stuff

Then the rest is pretty much spanner work. I would say giv eit a try, as long as your not in a hurry and don't rush you should be fine With regards to timing, uif you get it wrong and try to start it you can do all sorts of damage, however if you simply tun the engine over by hand first (ratchet on crankshaft pulley) you will do no damage if the timings out as the engine will juct lock up and not let you turn it futher. Then you have to do it again

I have done timeing on a couple of cars now, got it badly wrong on one, but as I turned it over by hand first I found out before any damage occured and rectified it. By the end I could time that engine blinfolded

 

[edh]

ORIGINAL: Alexw

I think its the rings at the moment. Compression is fine on all cylinders but it can smoke like hell under hard acceleration, oddly enough though it doesn't -always- smoke, unless I'm not seeing it. The car stinks of burning oil as well, can smell it behind the car and inside when driving along.

I believe a compression test will only test the top ring - so you can still have good compressions with ring problems. If the car smells of oil, then that may be coming from the crankcase - check the breather

Of course the other option is an oil leak onto the exhaust....i wouldn't rule it out

 

[tref]

Agreed... there are three rings - two compression, and one oil control ring - their name should give away the fact that two can be doing their job fine, and the third not - guess what the result is!!!!

Oil leaking onto the exhaust is a regular problem on the 8v from the cam box... I know that there is a cam cover oil leak issue (easily prevented if correctly fitted) with the 16v, so I guess teh question is does the oil from this go onto the exhaust manifold?