Camshafts seized or timing way out?

Road-race engines and ancillaries - general discussion
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twincamspit
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Camshafts seized or timing way out?

Post by twincamspit » Sun Jul 14, 2013 11:54 pm

Hi all,

My camshafts have absolutely no movement/play in them even without the timing belt on .
I'm not sure if they're seized, or whether the timing is possibly 180 degrees out or something? Hopefully someone can advise from these photos and my description.

I know about the crankshaft pulley timing mark and where it should align with the mark on the timing cover. (it does, even though it is a replacement crankshaft pulley - I locked the flywheel though the access cover before changing the pulley, and the dowel definitely didn't move).

I also know about the 2 locations for cam pulley timing marks, on the end of the water elbow AND on the camshaft housing itself.
Both pulleys line up as expected, and as far as I know, the camshafts haven't been rotated - although the previous cambelt change was done by the previous owner some time ago and I can't remember if the engine has actually run since then. And just to complicate things, I've changed the cam pulleys over too, but they also have equivalent alignment holes which also line up.

My first problem was, while following Guy's book, trying to turn the engine over by hand using the crankshaft pulley after changing the cambelt, the crankshaft starts to turn, but then hits a strong resistance almost immediately - and Guy's book says to STOP if there is any resistance.

The resistance seems to be caused by the cams. Both the inlet and the exhaust camshafts will not move even half a mm, forwards or backwards, even with the cambelt removed. Now is time to admit that I let the oil drain totally from the engine for several weeks due to an oil change that I didn't get around to finishing due to an emergency elsewhere.

I've eliminated the possibility of the new cam pulleys 'catching' on the cam housing by putting one of the old solid pulleys back onto the inlet side, and just doing it finger tight. The problem remained, can't rotate it even half a mm either way, feels absolutely solid.

So my immediate question is: are both camshafts likely to be seized, or is the timing a long way out somehow, even though the markings 'look' right?

I know that pistons in cyls 1 and 4 are very close to the top compared to 2 and 3 - using the 'wooden spoon handle thru the spark-plug hole' technique; also all markings are where they *should* be, but is it possible that I'm trying to set things up 180 degrees out or something?

I remember reading somewhere that on the combustion stroke for cyl 1, cyl 1's inlet and exhaust camshaft lobes should be pointing 'upwards', but when I removed the cam covers I found that cyl 4 lobes are the closest to 'upwards' out of all of them (see photo).

I've filled the cam carriers with 15/40W oil in the vain hope that it might somehow free the camshafts if they've just dried out and seized up, but I'm still concerned that even with the camshafts able to turn slightly that the timing might be 180 degrees out anyway!

Any thoughts anyone?
2013-07-14 13.22.22.jpg
Timing marks on pulleys circled in yellow
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Attachments
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2013-07-14 22.05.49.jpg
Old cam pulley back on, same issue
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Guy Croft
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Re: Camshafts seized or timing way out?

Post by Guy Croft » Mon Jul 15, 2013 9:47 am

If it's a 2 liter it might be the fuel lobe on the aux d/s fouling no.2 con rod...

G
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twincamspit
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Re: Camshafts seized or timing way out?

Post by twincamspit » Mon Jul 15, 2013 1:21 pm

Sorry Guy, I forgot to say it is a 1756cc from a Fiat 132, the aux ds has been modified (lobe cut off that drives the old mechanical fuel pump)
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Guy Croft
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Re: Camshafts seized or timing way out?

Post by Guy Croft » Mon Jul 15, 2013 2:58 pm

This is quite serious.

Before you wreck the engine: take the head off, strip it down and assure free-rotation of the cams without and with pulleys.

Time up the cams from 1st principles and maybe do a 'dry build' - see attached.

G
Attachments
Cam timing and dry-build_with photos.doc
(491.5 KiB) Downloaded 141 times
Guy Croft, owner

twincamspit
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Re: Camshafts seized or timing way out?

Post by twincamspit » Mon Jul 15, 2013 11:20 pm

Thanks Guy. Not what I wanted to hear, but fair enough .. Will be another learning experience!
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Re: Camshafts seized or timing way out?

Post by twincamspit » Mon Jul 22, 2013 10:16 pm

** UPDATE - Some progress, and further question **

Tonight was my first chance to get back out to the garage since my last post, and while I was contemplating the £100 cost of a new head gasket set, I thought I'd try quickly try something cheaper...

Firstly, I tried to 'waggle' the pulley wheels again, as they'd been sitting in oil for a while. No change, still rock solid.
Then I removed the "cambox end caps" (probably not the correct name for them - I mean the things below circled in yellow)
gc-800.jpg
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I'd removed them previously to lock the camshafts, and then painted them and refitted them with new gaskets made from Weetabix card; I wondered if I'd somehow b*ggered something up during that process.

With the 'endcaps' removed, it leaked a little bit of oil, but I could move the pulley wheels / camshafts slightly at last.
I've ended up fitting the timing belt, and was able to do 3 full engine revolutions quite easily by hand using the front pulley nut and a 38mm socket and small wrench; the cams turned perfectly with the 'end caps' removed, so I then refitted them and tightened them up enough to stop the oil from dripping out.

HOWEVER - having done so, the engine no longer turns over by hand again - there is quite a resistance with those 'end caps' on.

Does anyone know what I've done wrong?

Have I over-tightened them? (tried slacking them off slightly, but it started dripping oil again) - is there a correct torque setting for them? I used 10f lb ft.
Perhaps they're handed, and I've put them on the wrong camboxes? yes, I'm clutching at straws here!

Guy, do you sell the correct gaskets for them, as maybe my Weetabix card efforts are the problem?

Thanks!

Richard
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twincamspit
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Re: Camshafts seized or timing way out?

Post by twincamspit » Tue Jul 23, 2013 8:53 am

The reason I used card is because all of my gasket papers were much thinner than the original ripped gaskets that came off, and I know that cereal packet card is used by many people as gasket material!
Do you sell the proper gaskets?
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Re: Camshafts seized or timing way out?

Post by Infectus-Guy » Tue Jul 23, 2013 9:24 am

Blimey, i hope you just made them out of cardboard for testing purposes!!! I wish i'd seen this before because i could have taken you straight to the problem as i've encountered this before. You MUST fit the correct gaskets! I tried making them from gasket paper too and it locked the cams up, the proper gaskets are very thick and have wire mesh sandwiched in them to give the correct thickness. The inlet end on my reverse head HF turbo has the same steel plate as yours and i managed to reuse that gasket with some sealant (my usual supplier ran out years ago) but its holding up fine. The exhaust side has the alloy adaptor plate for the dissy and what i did was machine the thrust face allowing for the thickness of liquid sealant that i used in place of the gasket. Guy can confirm as I don't have the figures to hand, but from memory camshaft thrust free-play of .003" to .009" is allowable. With the OEM gaskets i guess you torque the nuts up until you have the required thrust free-play. Guy will confirm.
Guy
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Guy Croft
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Re: Camshafts seized or timing way out?

Post by Guy Croft » Tue Jul 23, 2013 12:48 pm

No offence taken Richard but you really knocked me off my chair with that one.

yes I have the 'proper' gaskets!

G
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twincamspit
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Re: Camshafts seized or timing way out?

Post by twincamspit » Tue Jul 23, 2013 12:57 pm

Infectus-Guy wrote:Blimey, i hope you just made them out of cardboard for testing purposes!!! I wish i'd seen this before because i could have taken you straight to the problem as i've encountered this before. You MUST fit the correct gaskets! I tried making them from gasket paper too and it locked the cams up, the proper gaskets are very thick and have wire mesh sandwiched in them to give the correct thickness. The inlet end on my reverse head HF turbo has the same steel plate as yours and i managed to reuse that gasket with some sealant (my usual supplier ran out years ago) but its holding up fine. The exhaust side has the alloy adaptor plate for the dissy and what i did was machine the thrust face allowing for the thickness of liquid sealant that i used in place of the gasket. Guy can confirm as I don't have the figures to hand, but from memory camshaft thrust free-play of .003" to .009" is allowable. With the OEM gaskets i guess you torque the nuts up until you have the required thrust free-play. Guy will confirm.
Guy
That's great info thank you... and I'm relieved it's not just me that's done it too!
I'll order correct gaskets from GCRE and give it a whirl, thank you.
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twincamspit
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Re: Camshafts seized or timing way out?

Post by twincamspit » Tue Jul 23, 2013 1:13 pm

Guy Croft wrote:No offence taken Richard but you really knocked me off my chair with that one.

yes I have the 'proper' gaskets!

G
I've emailed my order to you now Guy, thanks
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twincamspit
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Re: Camshafts seized or timing way out?

Post by twincamspit » Mon Aug 05, 2013 1:56 pm

Just a quick update - installed the real gaskets supplied by GC, tightened the caps up just enough for oil not to seep, engine turns over by hand absolutely fine now.

Thanks GC and "Infectus-Guy", lesson learned - I must always use the correct gaskets.
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Re: Camshafts seized or timing way out?

Post by Guy Croft » Mon Aug 05, 2013 2:07 pm

sorry they were slow coming, bogged-down with book editing.

Very nice to have a successful follow-up, thanks!

G
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