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Roller Timer Geometry

Posted: Wed May 24, 2023 4:00 pm
by GeorgeHounslow
Hi All,

I have gone to replace my roller Timer with a new one on my car, I have followed the timing procedure on here but the car will not start, and just occasionally coughs.

On checking the rollers themselves side by side, the geometry seems different - meaning when #1 cylinder was firing with the original roller in place, #3 cylinder was firing with the new roller in place. It still won't start however, with the old roller and new cap, but I will try timing with the complete old timer again tomorrow and see if the car starts as it did before.

I was wondering if anyone has had this or similar problems when replacing a roller Timer before?

Many Thanks
George

Re: Roller Timer Geometry

Posted: Wed May 24, 2023 4:05 pm
by Jerry VanOoteghem
Look at your camshaft. Does the hole for the roller locating pin go all the way through the shaft or is it a blind hole. If it goes all the way through, it's possible to have the rotor 180 degrees off location, (firing on exhaust and not compression).

Re: Roller Timer Geometry

Posted: Wed May 24, 2023 4:39 pm
by John kuehn
If your old timer would give you a good start and the car would at least run time the car back to the way it was when you were using your old timer. Make sure you have the wires on your new timer on the same terminals as the old timer and compare the new roller to make sure it will go on the same way and location as your old timer did.
I know this sounds simple but it’s a good way to compare timers. It could be that that the roller is installed improperly if it has the pin hole is all the way through the cam.

Re: Roller Timer Geometry

Posted: Wed May 24, 2023 6:00 pm
by TWrenn
I'm voting for what Jerry said.
All too common to overlook whether the cam has a "full" or a blind hole. Put the pin in the wrong way and it'll never start.

Re: Roller Timer Geometry

Posted: Wed May 24, 2023 6:02 pm
by Humblej
George, how did you check and set your timing?

Re: Roller Timer Geometry

Posted: Thu May 25, 2023 6:03 am
by Allan
George I note you are in England, and your car is likely RHD. This means the timer will be installed with the pull on the bottom. If you wired it according to a set of LHD instructions the timing will be 180 degrees out. This is a common mistake made by RHD owners when following the colour codes for LHD installation.

Hope this helps.
Allan from down under where we drive on the correct side of the road.

Re: Roller Timer Geometry

Posted: Thu May 25, 2023 7:11 am
by Kerry
Profile lists a 15 and 16 T's so if original they will have cams with the pin hole going through so 180 degrees out is easily done.

Re: Roller Timer Geometry

Posted: Thu May 25, 2023 4:43 pm
by GeorgeHounslow
Thank you to all of you! I turned the roller through 180 degrees and the car started right up, better than it ever has. I do feel a bit of a fool for missing such a simple thing, so I do apologise!

The car is a left hand drive model just to note, but that is interesting what Allan says about the right hand drive models.

The timing procedure I followed was the one posted when you set the crank pin at "half way between 3 and 4 o'clock", with the no 1 cylinder on the firing stroke, then adjust the timer so no.1 cylinder's spark plug starts to spark and then back it off a little.

Thank you all again for your help, it is much appreciated.

Re: Roller Timer Geometry

Posted: Thu May 25, 2023 5:45 pm
by TWrenn
GeorgeHounslow wrote:
Thu May 25, 2023 4:43 pm
Thank you to all of you! I turned the roller through 180 degrees and the car started right up, better than it ever has. I do feel a bit of a fool for missing such a simple thing, so I do apologise!

The car is a left hand drive model just to note, but that is interesting what Allan says about the right hand drive models.

The timing procedure I followed was the one posted when you set the crank pin at "half way between 3 and 4 o'clock", with the no 1 cylinder on the firing stroke, then adjust the timer so no.1 cylinder's spark plug starts to spark and then back it off a little.

Thank you all again for your help, it is much appreciated.
Don't apologize! Live and learn. Thats why Jerry & I thought what happened cause it's very easy to do. Next time you pull the rotor for service take a paint pen and make a dot next to the hole immediately after you pull the pin and rotor and you'll know where to replace it!

Re: Roller Timer Geometry

Posted: Thu May 25, 2023 7:20 pm
by Art M
Before I loosen the nut holding the rotor, I turn the engine so that the rotor pointing downward. This insures that the locating pin will be at the topside.
If the pin is on the down side, it will fall out as soon as the retaining ring is removed. I always keep spares on hand just in case.

Art Mirtes

Re: Roller Timer Geometry

Posted: Thu May 25, 2023 10:35 pm
by Dennis_Brown
I will bet turning the timer roller 180 degrees is a lot easier than flipping a ring gear 180 degrees.

Re: Roller Timer Geometry

Posted: Fri May 26, 2023 10:42 am
by Art M
When the timer cap was changed, the wires might have become mixed. Easy to do

Art Mirtes