Timing chain frustration

[bob-ashton]

Dear All,
I am currently in the final stages of a full re-build of my twincam engine, at least, I thought I was! I have spent several hours over the last couple of evenings trying to fit the new timing chain to the existing cam sprockets, but without success. The crank sprocket and chain were replaced as a matter of course but I have noticed that when I turn the crank on the pulley bolt, if the pulley is fitted, the chain is pulled into the timing case on both sides, as if the pulley is locking it onto the sprocket with the oil slinger. When I remove the pulley and turn the crank simply on the bolt, this does not happen. Whichever, way I do it however, the chain has insufficient length to fit onto the inlet sprocket after mounting on the inlet with the relevant marks aligned. I am satisfied that all parts are to specification as they are supplied by Mattys
I am hoping that I am committing some elementary mistake but am concerned that I may not have pressed on the crank sprocket far enough onto the crankshaft and will need to remove the sump and timing covers etc.all over again. I was fairly satisfied that I had properly seated the sprocket although this was some time ago now. Any views or experience of this area would be greatly appreciated. Many thanks.

Bob Ashton

[Elanman99]

Bob

I dont quite understand 'pulled into the timing case on both sides' but tightening the bolt would certainly fully seat the crankshaft sprocket.

Maybe the oil slinger washer is facing the wrong way?

Could you fasten a small bit of mirror on a stick and try to see down there?

Ian Phillips

[lotusanglia1965]

Are you sure someone hasn't sold you an ohv crank sprocket?-they look very similar,but proper lotus one has teeth offset to front,to clear timing case.I think tightening pulley/bolt would seat sprocket up against crank.
good luck,
Martin

[types26/36]

Bob,
Dont know if its possible but could you have fitted the crank sprocket the wrong way round? as Martin said the sprocket is "of set" bringing the teeth forward (1/4" I think)

[bob-ashton]

Ian/Martin,

Thanks for the prompt replies, when I said it was pulling both sides of the chain down, I meant the top loop of the chain is pulled down into the timing case, which will eventually cause it to lock up. I think the oil slinger is correctly positioned and agree that the pulley should press the sprocket on if it were not fully home. I hadn't considered the OHV sprocket though. Oh well, it looks like I'll have to drop the sump off again, I'm on my third set of gaskets now.

Regards,

Bob

[bob-ashton]

Brian,

Regretfully I think you may be right, I thought I had fitted it correctly but that sounds most likely......... schoolboy error really! Thanks for your reply.
Regards,

Bob

[Elanman99]

Bob

I see you are located NW England, Are you anywhere near Cheshire?

Ian

[bob-ashton]

Ian,

Yes, I live in Bolton, I am intending to pop down to the CLOG when I get the S4 back on the road. I blew the head gasket on my way home from Donnington this year so as I get the engine running again I'm hoping to get some mileage racked up.

Regards,

Bob

[elansprint71]

Bob,
Look forward to seeing you at CLOG (come in another car if the Elan is not ready).....

"I am satisfied that all parts are to specification as they are supplied by Mattys "

Do not ever, ever, ever, contemplate going there for a wiring loom!

Cheers,
Pete.

[bob-ashton]

A brief update for anyone who may have ben as puzzled as I was; I dropped the sump again yesterday and found the pulley was effectively clamping down on the oil slinger thus locking the chain onto the side of the crank spocket. The items were correctly assembled but he slinger had lost its dished profile, I can only assume I either trod or dropped something onto it when I stored it in the workshop. Happily, I was able to rectify the fault without removing the cover by the judicious use of a hammer and large flat bladed screwdriver. The result was the cam sprockets went on easily and I have spent today timing the cams - the end is once again in sight.
Many thanks to those who left suggestions.

bob