duplex timimng chain - Road Test today

Post by **RogerRust** » Sat Feb 04, 2006 5:38 pm

I'm going to replace my chain this week. I've ordered a kit from ESM.
Can anyone help me about countersinking the bolts. I've heard that you have to do this - I presume its the two bolts below the crank shaft. How much do they need countersinking? If I mask it up carefully can I do this in situ? Will it be ok to use a half inch drill for the job?

Any helpful suggestions are welcome.
Roger.

Post by **Willie** » Sat Feb 04, 2006 6:34 pm

Yes, it is the two bolts which would foul the new double cogwheel which have to be replaced by countersunk
screws. Obviously the countersinking should be done with the proper tool.
It is possible that you can do a good job with a drill which has a slightly wider
diameter than the screw head if the angle of the point is the same as the
angle on the screw head but the resultant countersink is not usually very even as the drill tends to bite too much. Depends on your delicate touch really. Do take care to align the two cogwheels properly (shims).

Post by **les** » Sat Feb 04, 2006 8:00 pm

I agree that a proper countersink bit should be used, you will find that a drill bit will produce an uneven coutersunk hole which will prevent the screw head from making contact all round.

Post by **RogerRust** » Sun Feb 05, 2006 9:45 am

I've taken the water pump off. Do you think the solid type by-pass hose is more robust than the original flexi one. I've got to replace it so only want to do the job once!

Post by **bmcecosse** » Sun Feb 05, 2006 1:07 pm

YES - never use the horrible flexi type except as a roadside emergency repair.
The duplex countersinking must be deep enough to get the screw heads completely flush with the front plate. It can be done in-situ, just plug all the holes and wipe up carefully afterwards - I use a strong magnet to grab all the little bits, and i put the csunk screws in with Loctite. Look carefully at the new chain - some have a 'joining link' - with slightly longer through pins on one side - the chain must be put on with these longer pins facing away from the front plate to make sure they cannot catch.
Why are you fitting duplex ? Are you fitting an upgraded camshaft while you are in there ?

Post by **RogerRust** » Sun Feb 05, 2006 6:17 pm

I need to replace the existing worn chain, so it makes sense to upgrade to the duplex. The smaller sproket was really tight I hope the new one goes on easier. If not I'm going to put it in the oven and heat it up before I struggle to get it back on with the chain in place.

Can I change the camshaft from the front? Is there a useful ungraded profile to use with standard carb and exhust?

I will definately use the "solid" bypass hose its only £1.50 from ESM.
I'm going to replace the waterpump while I'm in there although it looks ok.

Post by **KirstMin** » Mon Feb 06, 2006 1:19 pm

I took the plate off and carefully used a pillar drill with drill bit. If I were doing it in situe I would definitely purchase a c/s bit for the job.

Post by **RogerRust** » Mon Feb 06, 2006 10:37 pm

I've taken the front plate off and bought a proper countersink bit to go in the pillar drill. I had to fight all the way with the engine mounting tower bolts, but I won!
Glad I decided to do the job. most of the bolts on front plate were loose including the two under the crankshaft, which explains the oil leak at the front.
Oh well just got to put it all back together now and flush the heater and cooling system.

Post by **RogerRust** » Tue Feb 07, 2006 10:35 am

There is a big felt washer in the duplex kit do I need to fit this to a timing cover with an oil seal?

Whats all this stuff about centralising the cover, I can't think how you would adjust it if it was wrong.

Post by **ianselva** » Tue Feb 07, 2006 12:26 pm

I can't think what the felt is for except for really early engines .
Its only about putting all the bolts in loosely and let the oil seal centralize the cover on the crank, then tighten all the bolts . It's probably not really neccessary with modern seals .

Post by **bmcecosse** » Tue Feb 07, 2006 7:37 pm

Natural upgrade is the MG Metro camshaft - but snag is it has a different oil pump drive - so it's engine out to fit it. Bonus is the newer oil pump is much better! Otherwise maost of the Mini places sell upgrade cams - and can supply to suit the Minor pump drive. But if nothing else is getting changed - may as well stay with the standard cam. Simpler (and cheaper) upgrade then would have been to fit the single chain with tensioner assembly from a Mini - this is much quieter than the old (rubber band) system and fine for standard camshafts. The duplex chain can still rattle - but it's much more reliable when driving a high lift cam usually with stronger valve springs - and at higher revs.

Post by **ianselva** » Wed Feb 08, 2006 11:41 am

bmcecosse wrote:Natural upgrade is the MG Metro camshaft - but snag is it has a different oil pump drive - so it's engine out to fit it. Bonus is the newer oil pump is much better! Otherwise maost of the Mini places sell upgrade cams - and can supply to suit the Minor pump drive. But if nothing else is getting changed - may as well stay with the standard cam. Simpler (and cheaper) upgrade then would have been to fit the single chain with tensioner assembly from a Mini - this is much quieter than the old (rubber band) system and fine for standard camshafts. The duplex chain can still rattle - but it's much more reliable when driving a high lift cam usually with stronger valve springs - and at higher revs.

You should also fit new cam followers with a different cam - It all works out quite an expensive change.

Post by **RogerRust** » Wed Feb 08, 2006 2:43 pm

Here are a couple of pictures;

I'm lucky to have a nice big garage

Post by **RogerRust** » Wed Feb 08, 2006 2:52 pm

and one of the countersunk screw so you can be sure I did it properly!!

Post by **Pyoor_Kate** » Wed Feb 08, 2006 4:02 pm

Shiny...

*jealous of garage*

Post by **bmcecosse** » Wed Feb 08, 2006 8:08 pm

Mg cam from ebay - £5, and brand new followers also from ebay(from Andy Barton - well know and extremely successful Minor then Mini racer from 40 years ago!) were £8 I think. Excellent value.

Post by **RogerRust** » Sun Feb 12, 2006 6:19 pm

Its all back together now and sounds like a sewing machine. The timing is much less erratic and it runs beautifully.

BUT I noticed a few drops of clean oil on the floor. Eventually I traced it to the coil - its leaking I must have disturbed it. I'll get a new one during the week.

AND when I was tidying up I found a little rubber washer on the floor looks like a half-inch tap washer. When I road tested it there was a new rattle. I have now traced it to the front wing, which now rattles! Two hours later I've managed to squeeze a bit of rubber trim into the gap between the wing and the sill finisher and all is quiet again. I guess the washer fell out when I was shaking the engine to get the front plate off the engine mount.

While I was at it I flushed the cooling system including the heater, changed the oil and filter and put a magnetic sump plug in.
By the way I used Castrol Classic 20w 50 interestingly enough the oil is more viscous as measured by the time it takes to run trough my funnel than the Halford's 20W 50 I also had in stock and smelt better too. Perhaps it really is better I'll let you know how the oil consumption goes.

Post by **bmcecosse** » Sun Feb 12, 2006 6:42 pm

Excellent close-up picture of the c/sunk screw - how did you get that ? Is it a special lens ?

Post by **RogerRust** » Sun Feb 12, 2006 7:41 pm

No, it’s an Olympus c-40 zoom digital 4Mpix. It’s only a compact but it was the best compact on the market three years ago. It has an excellent macro set up.

Not a Morris just a few beetles!

Post by **Matt** » Sun Feb 12, 2006 8:29 pm

Not a Morris just a few beetles!

oh ha ha ;)