Have I screwed the pooch?

[Tmac897]

Hi,

I may have done things a little out of sequence, although I thought I had verified the sequence both by talking to DBE and by reading posts on this forum, but I still may have gotten myself in a pickle. I assembled the bottom end of the engine, and then put on the front cover and the oil pan, while I waited for the head to come back from the machine shop. I know in Rohan's post on gasket sealants, he generally leaves the oil pan for last. Not having an engine stand though, I thought it would be rather difficult turning the engine over once the head was installed, so I opted for buttoning up the bottom end first.

So as I prepared to install the head, I had the 'Oh [poop]!" moment as I realized I couldn't really tell how the timing chain looked between the jackshaft sprocket and the crank sprocket, and whether there was any slack there, or whether the chain was high-pointed on the crank sprocket. I made an effort to avoid that as I installed the chain and the front cover, but my x-ray vision fails me now.

Any ideas on how to handle this, or do I have to pull off the pan and front cover until the head is semi in place?

Best,
Tony

[skelteanema]

I just recently replaced a failed water pump and had to remove engine and then dismantle and reassemble much of the engine, including head, sump, and front covers. I reinstalled the front cover, then the sump and finally the head. I don't recall any issues with the timing chain, although I did nook it up with a wire before installing front cover and sump. For me, the chain was such a tight fit that I don't think I would be able to get the cam sprockets with chain on if it was high pointed, and the jackshaft sprocket spins quite freely so any slack should be taken up.

[Billmack]

Should not be a problem. Before I put the chain on cam sprockets I skipped the distributor around till it was pointing in right direction with the piston at TDC and cams approximately in right place. All fine car is being driven whenever weather permits owner has big grin.

[Tmac897]

Thanks. DBE has been incredibly helpful with this restoration; but sometimes it seems like the prior conversation never took place. Shakes my confidence.

[Slowtus]

I truly wish I could remember what I did when assembling yet another of these engines.

Honestly, I used a Haynes Manual (if and when I actually referred to one) and used to bang these things together on an all to frequent basis.

Why so frequent - was this because of NOT rebuilding properly?

No, just abuse...but they all ran sweetly after each rebuild.

Maybe I was blessed.

[skelteanema]

I am happy with my rebuild as engine is running sweetly as well. Water pump failure forced me to address a few issues around oil leaks, and I am pleased to say that the car has much reduced (but not eliminated) oil leaks now. I don't think any leaks are from the rope seal, but I get a small amount of oil accumulating on the end of the block/head interface at the rear left of the engine. Don't know where this is coming from.

[rgh0]

Timing the cams with the sump on is just a pain to get the timing right as you need to ensure the chain it correctly sitting on the crank and layshaft sprockets and tight between them. You need about 4 hands to pull up the chain, pull it tight on each side and then fit the exhaust cam with it tight from crank sprocket to exhaust cam sprocket and then fit the inlet cam correctly with the chain tight to the exhaust cam without it dropping of the crank sprocket. it can help to pull the chain up on the crank sprocket and support it on the head on the exhaust side so it does not drop off when fitting the exhaust cam sprocket.

This is why it helps to to leave the sump off when fitting the head and doing cam timing. But it is not impossible just takes a little longer with a higher risk of false tries where you end up a tooth out.

Stopping it falling off the crank sprocket is what's important as ultimately you can move the jack shaft as needed to take up the tension between crank and jackshaft sprockets

cheers
Rohan

[pharriso]

Isn't what you are doing no different than changing the head with the engine in the car? I am currently in the middle of changing my head so I'll be watching for others' feedback:

[Tmac897]

Yes, except if you didn’t move the crank or rotate the distributor after you removed the old head, your timing chain tension and orientation at the bottom of the engine should not have changed. So when you pick the chain back up to engage the cam sprockets, it should be in the right place, if I am visualizing this correctly.

Others probably know better, though, so don’t take my word for it.

[Craven]

Isn't what you are doing no different than changing the head with the engine in the car? I am currently in the middle of changing my head so I'll be watching for others' feedback:

IMG_2685.jpg

Almost guaranteed you will lose the ignition timing, so in my experience remove the distributor, note its’ basic position first, and refit and time after you have done cam timing.
Never had any problems in ‘fishing’ the chain up.