Rover Engine - Help Needed With Valves

[AndyW]

I'm getting way out of my depth here, and could really do with some advice and/or help.

 

I suffered a broken shock absorber in my Super Spec (see thread http://www.rhocar.org/index.php?showtopic=44368&hl=) and as a result the flying spring snapped the ancillary drive belt, crushed the lower timing cover, and also snapped the cam belt inside. All this gradually came to light as I worked my through fixing everything. Bit of a sorry story and unfortunate chain of events :-(

 

The engine is virtually new - Rover t-series DOHC 2.0L non-turbo, and only done 3k miles in its 20 year life.

 

I've now replaced the cam belt and aux belt, and have done a compression test. I get 250 psi on #1 and zero on the other three cylinders. Not a twitch on the gauge. Does this mean I've knackered the valves on these 3 cylinders or is something else wrong? Are there any other tests I should do to find the extent of the problem?

 

This is my first time taking an engine apart, so my expertise is nil. Everything I've done so far is by following the manuals, so I could really do with some expert advice and help. Is there anyone in the Bedford area who'd be willing to assist?

 

[Guest 2b cruising]

sorry but no other thing for it now.

Your cylinder head needs to come off, get stripped and carefully examined for other damage such as broken guides.

If I lived nearer I would come and help as it is quite an involved job if it's your first time.

If you don't already have a manual, I would advise you to get one for it.

Just steadily work you what through it section by section and you will be fine.

Thing like loosening and refitting the head bolts in the right order are a must, so study the job before you start stripping anything.

If it all seems to daunting to you, get a quote from a local garage before giving them the go ahead.

Unless you have money to burn, don't use a dealership, or engine tuning specialist for this type of work.

Shop around first.

Really sad to hear of your bad chain of events and I hope you get through it before it's too late to get some good fun out of your car.

Ken.

[tractor]

I might be able to come Saturday will have to check with the wife first

[AndyW]

Ken & CMA - many thanks for your encouragement. I do have the Haynes manual and also Rover's own T-series engine overhaul manual, which is good for clear step by step details.

 

I guess I'll have to take the plunge and get the head off. I just wondered if there was anything else I could check before doing that.

[AndyW]

I've taken the cam covers off and had a look at all the valve tappets as the engine is rotated. #4 inlet valves and #2 & 3 exhaust valves sit too low and don't appear to close properly. When the cam lobe is rotated away there is a gap of 1-3 mm between the cam circular part and the tappet, and the tappets don't rise up to the same level as the others with respect to the surrounding casting.

 

I presume that means at least 6 valves are bent stopping them seating in the head properly, and would account for the zero compression on those 3 cylinders.

 

Do I need to replace all 16 valves or assume (hate doing that!) that the other 10 are ok?

 

CMA - afraid I don't have an engine stand, hoist or even a garage that I can work in. Doing it all in the car on the driveway. (Actually I do have a small garage but it's filled with gardening stuff and storage).

[AndyW]

Tractor - I'd very much like to take you up on your offer and to learn from someone more experienced. If you're free on Saturday and you're allowed of course! But don't bother if it's wet as I'm working outside on the drive. PM me nearer the time.

[Guest 2b cruising]

As CMA states, take things a bit at a time logging either in the grey matter or on photoes.

Bent valve are easy to determine in or out of the head.

Poor some thin liquid into the combustion chamber and if it doesn't leak out, you are ok.

16 valve is a fair bit of work to go through so use a Pisces of cardboard to pop the valves through and keep in the same possition they came out as.

Onepce out you can roll the valve stems along a flat surface with the valve head hanging over the side.

If bent you will see by the movement from a true circular motion or the stem lifting off the bed if that is bent.

Check for broken valve guides in that they sometimes crack if a bent stem has been forced through them by the camshaft still turning after the initial damage has occurred.

If the top of the Pistons have been marked, you should clean off any proud marks or sharp edges as these will form hot spot and possibly cause either pinking or pre ignition run on.

If you do decide to remove the engine (I would not unless obvious heavy damage up top. Each to there own though), it would be better to at least remove the sump and have a visual inspection. Preferably by someone with previouse experience.

Tractor is a class person so I hope he can get to you.

[Peter Bell]

You have a PM

[richyb66]

Just get another head and drop it on. That way you can still use the car and consider overhauling yours at your leisure.

 

When you start pricing up the valves and factor in possibly needing guides and the machining work, you might go off the idea.

[Guest 2b cruising]

+ 1 for above.

If you can get a good matching head you should be able to replace it in a couple of days then do the other head at leasure. (If you wanted to)

If you do get a second hand one, it would be worthwhile getting it checked for flat.

Edited July 9, 2016 by 2b cruising

[AndyW]

Huge thanks to Tractor for coming down this morning to assist. I learned an enormous amount watching and doing as we dismantled my dohc head and removed the valves.

 

6 valves are obviously bent so need to buy a set of replacements. A couple of pistons have very small marks so we think those will clean up. Everything else seems ok. Then I have to remember how to put it all back together again in the correct order!

[Guest 2b cruising]

Well done to both of you.

Chris really puts himself out to help other members and deserves an award.

Especially as he is fixing his own car at the moment.

[tractor]

you could have given me gold stars Ken

[Longboarder]

Amazing train of events. You couldn't make it up.

 

Nigel

[Guest 2b cruising]

If I'd had them I would have given them.

you could have given me gold stars Ken