Camshaft timing out

Started by Hercplt, December 14, 2020, 02:15:40 PM

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MiniDave

#25
OK, semantics at play here......I never run them over 106 as it kills the bottom end and I like the torque, since I'm rarely running consistently about 5K.

Depends a lot on what you're after.......
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

Hercplt

Oh man... totally got myself confused... At 109 i'm still 3 degrees retarded... So i'll need to acquire a 6 degree offset key to get this down to 106.  Damn... cause that 3 degree key was expensive and 30 days from the UK!   50.gif
1980 Mini 1000 (Canadian Spec).
998cc +60.  12G295 Head (ported, skimmed etc), VP7 Cam, Twin HS2.... sweet sweet 7.5" Cooper brakes!

carockwell

If I remember right, a six degree key is kind of risky. It is so thin on the offset portion that it can, and does, break. Somebody correct me if I am wrong. If you need six degrees of offset you might have to buy a vernier sprocket. Ask some knowledgeable pros if they used a six degree offset key successfully or if they recommend going to a vernier adjustment system. Alternatively, you can use a 3 degree key and just accept being 3 degrees off.

Hercplt

Having looked at the 3 degree key... being a very slight off set... I can't imagine that the offset for a further 3 would be that big.  Given the width of the key I suspect it should work.   That being said, I've never used one.  A 9 degree key would be something else...

Great thought though...
1980 Mini 1000 (Canadian Spec).
998cc +60.  12G295 Head (ported, skimmed etc), VP7 Cam, Twin HS2.... sweet sweet 7.5" Cooper brakes!

MiniDave

#29
I don't think it's heavily stressed at the key anyway, while the key locates the cam it's the nut that's torqued on the front of the gear that holds it in place.

I believe MiniSpares has up to 10* offset keys.

Did you turn the key around and retest?

Offset keys are available from Mania or 7 Ent......I think in their demo video they use a 5* offset to get theirs into time, I would not hesitate to use a 6, just torque the nut down correctly when you're done and tap over the lock tab. If you don't want to cross the border because of cost, Steveston in BC might have them
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

Hercplt

Yup... tried the other way... went to 112.  Like Magic!

Ordered one from Hunter Classic Sports Cars in Victoria BC... Cheapest within Canada...

I'll let you all know how it goes!
1980 Mini 1000 (Canadian Spec).
998cc +60.  12G295 Head (ported, skimmed etc), VP7 Cam, Twin HS2.... sweet sweet 7.5" Cooper brakes!

MiniDave

Good, I'm glad it gave the right result, more experience is always valuable.

You'll get it sorted, I'm sure.  77.gif
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

Hercplt

Maybe I'm over thinking this... or inducing some sort of error.

I started fresh, used a 0deg key and timed it at 112.  I am looking for 106.

Now, I use a 6 degree key to advance the timing and now I am at 108.  Now I may just be a pilot, but I do know that 112-6=106... 8.gif

I may be inducing some measuring error, but I don't think so... as I am doing things the same each time.

If it is an error, perhaps I'm closer to 106 than I think.  Either way, I'm thinking of leaving it as is and see how it runs once back together.  AFAIK the engine always had a 0 deg key, so any closer to the ideal should have the car running better anyway whether advanced or retarded by about 2deg.

Thoughts?
1980 Mini 1000 (Canadian Spec).
998cc +60.  12G295 Head (ported, skimmed etc), VP7 Cam, Twin HS2.... sweet sweet 7.5" Cooper brakes!

jeff10049

Chain stretch/wear retards the timing, I would want to start slightly advanced.
I've had the same issue with keys sometimes you have to get a different key than you think to get the result you want. I know 6 degrees should be 6 but sometimes they don't work out that way manufacturing tolerance of the keys I guess?

MiniDave

#34
I agree with Jeff, and I would go ahead and put it in also.

One other thing you might try is to put it back a tooth on the chain then use your offset key to advance it back and see where you land.

It can be a frustrating process......
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

Hercplt

If I advanced it by a tooth... then retarded it back, about how many degrees would that tooth distance be?
1980 Mini 1000 (Canadian Spec).
998cc +60.  12G295 Head (ported, skimmed etc), VP7 Cam, Twin HS2.... sweet sweet 7.5" Cooper brakes!

MiniDave

No idea, that's why I suggested trying it - might work, might not.

I guess you could count the number of teeth on the gear, that should tell you how many degrees each is.
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

Hercplt

According to google its 13degrees.  So if going advanced to 99 then retarding by 6 should get me to 105... maybe 104 depending on if the key is off a bit...   Gonna try it... have nothing to lose!!

Cheers.
1980 Mini 1000 (Canadian Spec).
998cc +60.  12G295 Head (ported, skimmed etc), VP7 Cam, Twin HS2.... sweet sweet 7.5" Cooper brakes!

MiniDave

There you go!

Let us know what happens......  77.gif
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

Hercplt

Well... I advanced by a tooth... and retarded it by a 6 degree key... now I get about 101 in the end...

5 degrees advanced seems too much to me...

Thoughts?
1980 Mini 1000 (Canadian Spec).
998cc +60.  12G295 Head (ported, skimmed etc), VP7 Cam, Twin HS2.... sweet sweet 7.5" Cooper brakes!

MiniDave

#40
You have me very confused - if you're at 101 you're retarded, not advanced.

When you had it at 108 you were advanced, and both Jeff and I thought that after wearing in a bit you'd probably be right where you want to be. Or get one more offset key 2* more than you have and get it to 106.

Remember, as you face the water pump end of the engine, the crank rotates clockwise.
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

94touring

I'd have stayed at 108 and been 2 degrees advanced, anticipated chain stretch, and set my all in timing at 30 degrees and called it a day.

Hercplt

Ok... now I'm super confused.  Everywhere else I read they are saying that a number larger than your target is retarded from the ideal, and a number less is advanced of the target.  So advanced would mean that the valve opening is happening earlier (in advance) of the ideal.  Looking at the UK Mini forums they are all setting something like 104 when they are targeting 106.

The following quote is from Calvers website where he talks about timing...

"ADVANCED cam timing means that the valve events are occurring BEFORE the recommended point. Your measurement will therefore compute a reading LESS than 106. Generally this increases bottom and mid range outputs, but losses a little peak output. To correct this the cam will need turning counter-clockwise (anti-clockwise).

RETARDED cam timing means valve events are occurring AFTER the recommended point. Hence measurements and computations will give a value MORE than 106. Generally this increases peak outputs, but will lose bottom and some mid range output. To correct this the cam will need turning clockwise."


https://www.calverst.com/technical-info/cam-timing-introduction/

I'm still learning all this, so would love to continue hearing your thoughts... 

Lol, I have all winter!!  77.gif
1980 Mini 1000 (Canadian Spec).
998cc +60.  12G295 Head (ported, skimmed etc), VP7 Cam, Twin HS2.... sweet sweet 7.5" Cooper brakes!

94touring

Good thing I don't build engines cause I assumed 108 was 2 degrees advanced.

MiniDave

#44
I see his point, like I said before it's all semantics....set it at 108 with what you have or get another offset key and get it to 106.

My point of view is that the 106* is how many degrees past TDC the valve is fully opened - so I want it fully open by 106*, call it what you want!   ;D

You are opening it later and holding it open later in the cycle - so I do see your point.

I think pretty much all the engine builders agree that 104-106 is the sweet spot for a street motor.
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

Hercplt

Thanks MiniDave... appreciate it... I'm back on the same page.

However I just saw on theminiforum in the UK that the cam sprocket is 18 degrees per tooth (makes sense).  112-18=94+6=100 (which is exactly where I am... damn).

Anyone know where I can get one of those crank sprockets with the 2 degree increments?  and not be part of a whole set?

Gonna start over from scratch... again... but we'll get there.... I might just accept the 108 and see how it drives in the spring if it comes to that...

Thanks all!
1980 Mini 1000 (Canadian Spec).
998cc +60.  12G295 Head (ported, skimmed etc), VP7 Cam, Twin HS2.... sweet sweet 7.5" Cooper brakes!

MiniDave

#46
crank sprockets with 2* increments? did you mean a 2* crank key?

since you bought a 6* offset key  and it didn't get you where you wanted to be, I don't know whether it's better to buy another 6 or get an 8* and chance winding up at 104? If it were me, I would buy a 6,7 and 8 - that way I'm bound to get there!
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

Hercplt

Update.

I used the original timing chain this time (only about 3 years use), still in nice shape... Anyway...

0 degree key got 112... 6 degree advance key... bang on 106. 17.gif

Presumably this is due the chain having been already stretched a bit with use as expected?
1980 Mini 1000 (Canadian Spec).
998cc +60.  12G295 Head (ported, skimmed etc), VP7 Cam, Twin HS2.... sweet sweet 7.5" Cooper brakes!

94touring


MiniDave

Yeppers!

Button it up, run compression again and I'll bet things are where they should be. So, go take it for a drive!
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad