1984 GTV 2.0 camshaft clarification

[steampunk10]

Hi to all AROCA. I would like some clarification of the correct Camshaft rotation. I have a suspicion that the crowd the re-honed my head have swapped the cam shafts over!
I'm slowly increasing my confidence in DIY and this is the first time ive removed the head (something i believe will come in handy regularly when owning a 2.0 : ).

The dismantle and reassembly has gone according to the instructions until ive rebuilt the engine and tried to start it. No go and an occasional backfire. Fearing id misaligned the timing chain by 1 link i checked the camshaft alignment marks at TDC - all good... but noticed the cams were pointing inwards - where the manual said they should be pointing outwards.

I feel this is an easy mistake for a novice but will be less than impressed if this is something done by the 'professionals' who checked and honed the head 

I havent been able to find any images showing correct placement and my weary brain feels that this is the problem (according to basic knowledge of the 4-stroke function) but id really appreciate a second or third opinion.
I'm also hoping that because it's exactly 180 degrees out there will not have been any damage caused by the clashing of valves and cylinder heads?

Great appreciation in advance - Andrew.

[colcol]

You may have the camshaft timing out 180 degrees, the crankshaft and camshaft timing marks all line up, except they are on the wrong stroke, i don't think you would have caused any damage, but you are getting the backfire and flame out of the carby.
I have done this with the 33, so i know how easy it is to do it, also check that the distributor is timed properly as well, Colin.

[steampunk10]

HI Colin. Thanks for the prompt response.

I think i've found it - thanks for your advice.

I assumed (a very dangerous thing ) that there was only one alignment mark on the cam shaft. I just went and rotated the engine and found there's two. So I think your right that i've go the shafts over rotated by 180.

I'll go and rectify the situation and l see what happens.

Thanks again. andrew.

[Alan Hopla]

Andrew,
Remember that the crankshaft turns twice for every revolution of the camshaft.

You might've find that if you turn the crankshaft until the timing mark aligns on the next revolution, that the cams will then be aligned.

When the timing mark is aligned both cylinder 1&4 will be at top dead centre.
One will be at the top of the compression stroke about to fire, the other will be finishing its exhaust stroke.
To check which is which, when the timing mark is aligned you need to take the dizzy cap off and see which plug lead the rotor button is pointing at 1 or 4.
When doing the cam timing you want it pointed at the lead for 1.

Regards,
Alan.

[steampunk10]

Hi Alan. Thanks for the info - very helpful in clarifying my understanding. I found the cam shafts have two alignment marks and have rotated them to the correct placement.
Unfortunately, in the process I've found one of the bearing cap studs has stripped out of the head. So it's off to the Helicoil shop on monday : )

cheers, andrew.

[Cool Jesus]

Andrew, I'm very concerned that you weren't aware of each camshaft having a timing mark. Please be very careful and follow a shop manual (if you don't have one source it). Check on here of course for any advice and confirmation of your work. Oh, make sure you turn the crank over by hand twice and double check timing, just to be sure 

[steampunk10]

Hi Jesus. I do have the manual and read it a number of times and checked continuously as i went. The only thing i wasnt aware of was that there were TWO alignment marks on each shaft (not mentioned in the manual : ) It was only a note in a separate section that mentioned the cams pointing outwards that lead me to check. thanks for your concern - i think i'll have to keep learning the hard way : )
Regards, Andrew.

[Cool Jesus]

It's all good mate. Would be heart breaking to kill an engine after doing the work. I'd suggest you find a manual that does mention both timing marks. This is a basic technical requirement for the Alfa engine, if not any DOHC engine. Look forward to getting your automobile on the road.