16 replies to this topic

[Safely]

Evening All,

 

Can you fit a timing chain tensioner to an A series (not A+) 1275? I was told you could, but I am not sure how / if at all. I have the 'bigger' timing cover, but the seal also doesn't seem to fit the block very well.

 

Any wise words very welcome!

 

Thanks

 

Safely

 

 

Attached Files

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[nicklouse]

You need to used the A+ front plate and cover and gasket.
 
 
 

Edited by nicklouse, 11 September 2022 - 08:55 PM.

[Safely]

Thanks Nick,

 

I have the bigger gasket and cover available. You can put the timing chain tensioner plate on, but there appears to be no bolt hole for the slipper pad to be screwed into? So I can fit the plate, but nothing obvious to hold the slipper pad in place to me?

 

Cheers

[nicklouse]

Thanks Nick,

 

I have the bigger gasket and cover available. You can put the timing chain tensioner plate on, but there appears to be no bolt hole for the slipper pad to be screwed into? So I can fit the plate, but nothing obvious to hold the slipper pad in place to me?

 

Cheers

Like I said you need the A+ front plate.

[Earwax]

Part number 12G2626  at minispares

[Spider]

I routinely fit them.

There's 2 holes (from memory) you need to drill in the A type Engine plate, one of which I countersink from the engine side and fit a 5/16" countersunk screw in to, then use an Late Timing Chain Cover.

Note that these late covers are not A+, they were started fitting from 1976, long before they started work on the A+.

[coopertaz]

fit the later, tensioner style, engine plate aswell as front cover

[fokko]

Regarding the tensioner: if you run a duplex chain (which you do) the tensioner will most probably suffer early breakage. Minispares also mention in their description of the timing chain tensioner pad that it is made for a simplex chain; https://minispares.c...ng/12G2621.aspx.

 

Plastic tensioner pad to take up the slack in single row timing chains on A plus engines that wears and should be replaced nearly every time you have the timing cover off.

[Spider]

 

Regarding the tensioner: if you run a duplex chain (which you do) the tensioner will most probably suffer early breakage. Minispares also mention in their description of the timing chain tensioner pad that it is made for a simplex chain; https://minispares.c...ng/12G2621.aspx.

 

Plastic tensioner pad to take up the slack in single row timing chains on A plus engines that wears and should be replaced nearly every time you have the timing cover off.

 

 

I wonder if the replacement tensioners are not as good as the factory items ? Just about every set I've done has been to a duplex, however I've not replaced a tensioner, just re-fitted the one that was in there. I've set them all to the tightest setting too. Been doing these going back to the late 70's and I haven't broken a tensioner - yet.

[fokko]

 

 

I wonder if the replacement tensioners are not as good as the factory items ? Just about every set I've done has been to a duplex, however I've not replaced a tensioner, just re-fitted the one that was in there. I've set them all to the tightest setting too. Been doing these going back to the late 70's and I haven't broken a tensioner - yet.

 

 

You are a lucky man or I am an unlucky man!    I have broken several and I now chose to go for a simplex setup (which should be more than up to the job). I just ordered some NOS simplex timing gears from Ebay .

[Spider]

 

 

 

I wonder if the replacement tensioners are not as good as the factory items ? Just about every set I've done has been to a duplex, however I've not replaced a tensioner, just re-fitted the one that was in there. I've set them all to the tightest setting too. Been doing these going back to the late 70's and I haven't broken a tensioner - yet.

 

 

You are a lucky man or I am an unlucky man!    I have broken several and I now chose to go for a simplex setup (which should be more than up to the job). I just ordered some NOS simplex timing gears from Ebay .

 

 

I wonder too if the 'stuff' they put (or don't put) in the Oil plays a part in the Tensioner's snapping ?

[fokko]

 

I wonder too if the 'stuff' they put (or don't put) in the Oil plays a part in the Tensioner's snapping ?

 

 

That could be, or the new tensioner pads are of inferior quality...

[gaspen]

Old topic, new question 

 

I am building a 850 engine, I will install a chain tensioner. I have two ideas for that extra hole :

 

1) Cut an 1/4" UNF thread into the plate and fit a short screw there. It is the same as on the upper quarter of the timing cover/plate.

 

2) Drill a 5/16" (8 mm) hole for a nut-and-bolt fixing. In this case I have to grind some material from the block. I also have a 998cc Mini, where someone made this in the past.

 

 20241110_153550.jpg   32.54K   1 downloads

 

 

[Spider]

Old topic, new question 

 

I am building a 850 engine, I will install a chain tensioner. I have two ideas for that extra hole :

 

1) Cut an 1/4" UNF thread into the plate and fit a short screw there. It is the same as on the upper quarter of the timing cover/plate.

 

2) Drill a 5/16" (8 mm) hole for a nut-and-bolt fixing. In this case I have to grind some material from the block. I also have a 998cc Mini, where someone made this in the past.

 

When I do the conversion on older engines, I drill them through at 8 mm, then countersink the hole from the back side and fit a countersunk screw in from the back. Works well and I find with countersunk screws, they will self lock, so you don't need to get in there with a tool, only a socket from the front on the nut.

 

If you do go this way and use a UNF bolt, just be aware, the countersink angle on most of these is 80^0, not the more common 90.

[gaspen]

 

Old topic, new question 

 

I am building a 850 engine, I will install a chain tensioner. I have two ideas for that extra hole :

 

1) Cut an 1/4" UNF thread into the plate and fit a short screw there. It is the same as on the upper quarter of the timing cover/plate.

 

2) Drill a 5/16" (8 mm) hole for a nut-and-bolt fixing. In this case I have to grind some material from the block. I also have a 998cc Mini, where someone made this in the past.

 

When I do the conversion on older engines, I drill them through at 8 mm, then countersink the hole from the back side and fit a countersunk screw in from the back. Works well and I find with countersunk screws, they will self lock, so you don't need to get in there with a tool, only a socket from the front on the nut.

 

If you do go this way and use a UNF bolt, just be aware, the countersink angle on most of these is 80^0, not the more common 90.

 

 

That's make more sense 

 

I did not know about 80 degrees. Actually it seems 82 with +/- 2 degrees tolerance 

 

Thank you !

Edited by gaspen, 10 November 2024 - 06:18 PM.