5 replies to this topic

[DJStrange]

Model: 1330 Metro Turbo Block, 940 Head, Supercharged
Year: Dunno
Description of problem (please be as in depth as possible): Engine out, gearbox & flywheel housing off, just getting ready to take pistons out to check ring alignment as it was pumping oily smoke out of the breathers. Was just thinking ahead, what is the bolt tightening sequence for the cylinder head? Also, which is no.1 cylinder, was it radiator end? And finally, what o'clock does the distributor rotor arm point to roughly when it's about to fire no.1 cylinder?

Been many years since I last stripped & rebuilt an a-series, done many other vauxhall engines since then, so a few things I used to know by heart are a bit lost amongst the other engines now!!

Just don't fancy getting the timing 180° out that's all.

And timing order is 1-3-4-2 if I remember right?



No non-standard parts affecting the job at the moment

[Pauly]

Tightening sequence is in the haynes manual but you start at number 1 in the middle and grow in a circle,

6 2 3 7

9 5 1 4 8

I think the rotor arm needs to be pointing at roughly 1:00 the its 1-3-4-2 anti clockwise round the dizzy, and yes number one cylinder is the one next to the rad.

I would invest in a haynes manual, they come in handy when doing precise engine work.

Hope that helps.

Paul.

[dklawson]

The firing order is 1-3-4-2 as stated. However, don't set the timing by eye. Use a test lamp or multimeter and set the static timing properly before trying to start the engine. If you're uncertain about this, download my PDF about it:
http://home.mindspri...taticTiming.pdf

Hindsight is 20:20. It would have been very beneficial if you had performed a compression test (and more helpful still if you'd performed a leak down test) before tearing the engine down.

[TheKing777]

After a full day of removing and stripping the engine down, we have managed to come across the problem.

3 cracked pistons in cylinder 1 3 and 4. Along with shattered compression rings in the same cylinders. Strangely cylinder two was ok.

Bores were fine, no sign of scouring or missing pieces which is good!

Anyone any ideas of what might have caused this?
Any solutions regarding choice of new pistons?

Thanks

[DJStrange]

The firing order is 1-3-4-2 as stated. However, don't set the timing by eye. Use a test lamp or multimeter and set the static timing properly before trying to start the engine. If you're uncertain about this, download my PDF about it:
http://home.mindspri...taticTiming.pdf

Hindsight is 20:20. It would have been very beneficial if you had performed a compression test (and more helpful still if you'd performed a leak down test) before tearing the engine down.

Interesting guide there, it's all coming back to me now.

Thanks for the reply. The distributor hasn't been moved, just that my brother took the ignition leads off without marking them up, and as I said - it's been a while since I last worked on A-series (distributors and points etc).

To be honest a leakdown or compression test would have been possible if I had the kit to do them with, no doubt the same outcome would have been discovered (no or very little compression on cylinders 1,3 and 4 due to broken compression rings).

What would normally cause this on a forced induction engine? Too much boost? Maybe detonation? Wrong compression ratio?

Apparently when my brother last had the car in for a check with the charger on and some miles on the new engine build, he was advised the charger wasn't running optimum because of the pipe setup (I assume this is the inlet pipe, the carb sits lower than the charger), and that it was running a little rich.

The three pistons that have gone are all broken almost identically. The first compression ring has shattered and the piston has cracked between the first and second compression ring grooves. The second rings are all sound, as is the oil control ring. There's no sign of lack of oil, no scoring on the cylinder bores, no lip to suggest a snag.

Any insight would be most appreciated.

Cheers for the help guys.

[dklawson]

Sorry, I've been away for a few days and haven't followed up on a few threads.

I can't comment on what caused the failures in your engine. I believe that your questions are better asked in the forced induction section of this board.
http://www.theminifo...hp?showforum=24