1987 3.2 Carrera Backdate project - Sladeys hotrod

[210bhp]

Sticking exhaust valve on cyl 2?

Regards
Mike

[RobFrost]

Do you not have a cheap bore scope / endoscope? Ideal for poking in a spark blug hole to see which valve is open:
https://www.amazon.co.uk/Inspection-Dep ... 01NBFTAHE/

Also good for finding lost items, looking inside sills, etc.

The cam has a punch on the end which should be at the top at Z1

Cylinder two is top dead centre exactly two thirds of a turn (240 degrees) clockwise of the crank, as viewed from the back of the engine, from that point.

If in doubt about timing, it may be worth fully rotating the engine twice by hand before turning it over with the key, to avoid breaking something. Im only saying that because I'd feel bad if something happened.

[964RS]

That’s my point. They soot up and can’t self clear. Hotter will burn off the soot. I think the ones in at the minute are WR5DC+ but start with what you have and choose one stage hotter. The Bosch seemed better than the NGK. After all a simple think to try.

My 964RS ran like an absolute bag of $hite for no reason, stalling, spluttering, not firing.....we replaced a small fortune of parts and sensors that were coming up with errors only to find out it was one new spark plug that was failing and sending everything else absolutely potty and so run like crap....it's normally something stupid and cheap at the end of the day....!

[sladey]

Thanks Jason - That sounds like my symptoms but I have swapped out the plug on the cylinder that was cold

[RobFrost]

ATM I'm fully expecting the cylinder 2 intake tappet to be half a centimetre too far open! Do you recall slacking any off more than you might have expected, when adjusting them?

[sladey]

I did but that was on number 3 IIRC

Had a family week-end so won't get onto it again until the coming weekend

Got a rennline adjuster tool on the way as well

[DustyM]

If one tappet is wildly out it would generally be obvious with a quick scan along the rows of adjusters as they should all have roughly the same amount of thread showing above the lock nut.


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[sladey]

Fair point

[Nine One One]

This is getting like a Clueso mystery and needs sorted so we can all figure out what it was???

At least when it is sorted you will have the car running the best it has, and know everything about the injection / ignition system.

[sladey]

Yes that’s what is consoling me as well.

Like I said I’m not going to have a chance to get on with it until the weekend but I just popped out and took a pic of the adjusters

Right hand bank are all pretty level

But the left hand exhaust ones, not so much


Left hand intake a bit more even

[DustyM]

Yep, definitely need to revisit your valve clearances.


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[wadsworthi]

Looks like a lot more thread showing on cylinder 2 than the others!

[911hillclimber]

There is, but if there is a lot (compared to others) then that means there is a LOT of valve clearance, not too tight, just too loose, so would mean the valve will shut just not open much and produce a loud ticking as the parts impact.

All clearances need checking and again to tick them off the list.

[sladey]

Yep that's tomorrow's job....

[sladey]

Today has been a good day.

IT LIVES!!!!!!

So I did the tappets today and really took my time with them. I also ordered the rennline adjustment tool to make sure I was adjusting them accurately.



Even with the benefit of the tool it’s still a fiddly job with the engine in the car.

I’d also ordered a compression tester to help me find TDC on the compression stroke. All I used out of the many fittings in the compression kit was a rubber ended pipe that I jammed into the spark plug hole. I put a flexible pipe on the end of this and, lacking balloons, I cut the finger off a rubber glove and cable-tied that to the end.

As I was winding the crank round to TDC the finger was inflating strongly so I knew I was on the compression stroke. Happy days.

So I really took my time on this as I wanted to be sure I’d got it bang on.

A few things that came out of it
- some of the threads on the adjuster screws and locking nuts weren’t moving freely - that made it harder than expected to get the adjustment right
- I also found that when screwing the adjuster screw in, even once it hit the end I could carry on screwing.

I’m not sure what is happening there (Would need to take one out in order to understand what is happening). So for example you are screwing it in to get a baseline ‘stop’ point but you can screw past that point. I’m sure that is what happened when I did them last time - certainly on No. 3 where I’d thought it was loose and possible something similar on No 2.

To get round it I backed the adjuster screws right out so I could rock the rocker. Then I screwed it in gradually, stopping every so often to rock it again. Then it became obvious when I I had hit the end - when I couldn’t rock it any more. I used that as the base ‘fully closed’ point. I don’t know what is happening when you carry on screwing it in - but it’s not good.

The rennline tool is a nice piece of kit - very well made. Like I said though it’s still a faff - and I only used the tool for part of the process.

How the tool works is basically you screw the adjuster all the way in until it touches and using the marks on the rennline adjuster wheel you back it off from one mark to the next mark - by calculating the depth of the thread they know this is the required 0.1mm.

It was a really shock to me how narrow this turned out to be and when I’ve adjusted them previously I was leaving much bigger gaps than the tool was leaving.

Once I’d done them all and because I was surprised at how tight the gaps were (you could barely feel the rocker rocking after the adjustment) I decided to go over them all again but this time using the feeler gauge. If I could get the gauge in then all was good. On two I re-did them as I couldn’t get the feeler in at first. Re-doing them barely changed the setting at all but I could get the feeler gauge in.

My procedure was this:-

1. Loosen the locknut and then wind the screw out a couple of turns to get a decent big gap in there
2. Press down on the ‘foot’ end of the rocker (i.e. the opposite end to the adjustment screw)to make the adjustment gap as big as possible. I rocked it back and forth to confirm the gap. I then wound the screw in until it hit the stop. Not with any great pressure - just until it hits it. If you don’t hold the other end down it’s not so clear as you are continually touching the adjuster end while you are winding it in.
3. Once it was touching held the adjuster in place with a screwdriver and wound down the locknut until it was barely touching the rocker
4. Then I got the rennline tool and put it on. I lined up the current position with the adjustable marker and then unscrewed it until the 0.1mm mark was in line. Sometimes the marker itself moves so you have to keep that in place with your finger as you are unwinding it. As I said earlier it was a shock how little a gap was needed.
5. The adjustment screw is now in the right place. I then took the tool off and got a stubby screwdriver and a ring spanner. I put the screwdriver into the adjustment screw slot and tightened the locking nut by hand. Then I repeated that process but tightened it with the ring spanner - holding the adjuster in place with the screwdriver.

I’ve gone into this much detail in case I come to do the job again and in case it helps anyone else needing to do the job.

By the end of this I got into a rhythm with it all and it was going along nicely.

Once I’d done them all I then repeated the whole process but this time using the feeler guage. I did a chart to keep tabs of my progress




By the end of all this I was confident that I’d got accurate gaps on all the tappets.

I then put everything back together, taking my time with everything. Apart from a Rivnut that fought back and had to be replaced, everything went well.

I was nervous about this job because it’s basically my last chance before I farm it out to someone, so I was nervous about it not being the problem.

I needn’t have worried.

It started up fine and though it idled a bit low it was idling. The engine sounded fine - normal. This was a good start but I needed to take it for a drive.

I backed the other car out of the way and set off. It was running really well - plenty of torque and once it was warmed up I was able to get it up to 6 and 7K. The engine felt great. AT LAST!!!!

Initially, idling wasn’t always great and it cut out once, but after a while it was idling happily. I seem to remember it was a bit like that before.

When fitting the anti-roll bar at the rear I had moved it to its softest setting. However this was giving me a bit more body roll than I liked on the twisties so I’ll need to adjust that again.

Now I can do the little finishing jobs - take out that old injector loom and screw the new one in place (it’s just sitting there at the moment), make and fit a bracket for the oddyssey battery, re-fit the passenger seat. But all these jobs can be fitted in as and when - I’m going to give it a wash tomorrow and start driving it every day from next week for the rest of the summer.

I’ve also got to get the AC system working properly. I tried it briefly today but although it was blowing nicely the air coming out didn’t seem any cooler than the outside air. I’ll need to return to the manuals and the classic retrofit forum to suss out what I need to do there.

Thanks to everyone that helped out with these latest problems - especially Nige and Jon Miller - being able to share your problems and receive suggestions on the thread is an enormous help and is what DDK is all about.

Happy days


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