Hey Guys,

Been playing with my mini a bit recently as my Dad just came back from the UK with a set of Mini Sport 1.5 roller tip rockers. What a pleasant surprise Anyway, I've been thinking about fitting them but I'm worried that they may kiss the pistons because of the setup I run. Basically this is the cam I'm running http://www.pipercams.co.uk/pipercams/ww ... d=MINBP300 Now my motor is essentially a 110S block 100 thou oversize with flat top mazda pistons on a small journal crank, and I'm pretty sure small journal rods as well, but I can't remember. I remember my mechanic talking about using large journal rods to stroke it but it was years ago and I can't remember what we decided. Or it could have been the other way round, too many moons and cans have passed since then, but I know it's a small journal crank for sure.

What is the easiest/best method to check if these will give too much lift and bang the pistons? Should I just put them on and turn it over by hand to see if clears or is there a safer way? The engine is currently in the car for a change so I would like to do it all in situ.

Cheers,
Keels.

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-Wasabi
1972 Clubman - Daily Driver
1962 850 - EW1 Powered

they'll never bang the pistons - not possible - valves aren't open when the pistons are at the top of the bore (or open a teeny tiny bit)

What you might find though is that they'll fully compress the valve springs which will break things. This is dependant on the cam you're using, but is a wise investment anyway: http://www.minis.com.au/minis/catalog/i ... Path=21_44

Yep, been there, done that.

Good thread here including discussion on retainer types:
http://www.ausmini.com/forums/viewtopic.php?t=42723

By the way, I have a set of the C-AEA526 springs still in the packet if you're after them. Bought for the original head, but I've gone for the 7 port head instead.

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Too many cars, and too little time.

that's what I'm using

Thanks guys. I have a set of double valve springs in there as well, but unsure of what brand/model/specs etc. So you want to avoid pushing the valve all the way down? Looks like I misunderstood what others were telling me. I'm guessing this is because once the spring gets to full compression you just smash lifters/cam/push rods/valve tops etc etc??

I think I might just throw them on and turn it over by hand and see if it gets close to full compression. If it looks like it's not going to work than look at different springs or just put them back on the shelf for the next build?

Cheers,
Keels.

_________________
-Wasabi
1972 Clubman - Daily Driver
1962 850 - EW1 Powered

As Simon said, the valves can travel down as far as you like (lift) without hitting anything. The trouble is that springs designed for less lift cannot physically compress that far without the coils of the spring bottoming out (coil bind).

You can try turning it over by hand carefully, but standard Cooper S spec double valve springs will not be suitable.

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Too many cars, and too little time.

Lockie91 found out the hard way that 1.5 rockers and stock valve springs don't play well together. But the bloke who built the motor (in UK) obviously didn't know or care.
C-AEA526 springs work well with 1.5s, I use them in both my 1360 and the wife's 1412.

Don't forget to add .003" to the valve clearance when using 1.5 rockers.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Okie Dokie...

So I went digging through some crap in my shed cos I was sure there was another set of valve springs new in a bag hanging around somewhere. Well I found them. Right under the box the rockers were in, and also the last spot in the shed I hadn't already looked. So I found the receipt to find out what model they were to see if they would work. What I came back with are these http://www.minisport.com/mini-spare-par ... -LIFT.html Will these work or are they total overkill?

I popped the rocker cover to have a looksee and these are the springs that are in it at the moment

Now I'm guessing that there is no way to tell what these are without pulling them out and testing them somehow. While looking in the rocker box I did discover this little piece of paper...

Is this an appropriate way to test if the springs are good? I've read else where that the only true way to test is to pull them out, put them in a vice, clamp them shut, measure, and check against the installed height.

So my next question is, is it worth changing the valve springs before chucking on the rockers and if so what is the best way to do it?

Once again, thanks for all the help guys.

Cheers,
Keels

_________________
-Wasabi
1972 Clubman - Daily Driver
1962 850 - EW1 Powered

Those Minisport springs are overkill for road use, 180lb C-AEA526 springs are more than enough.
You can get these from various Mini places here in Oz, or bring in from Minispares UK. The springs you show in your pic look suspiciously like these, so I would bolt the 1.5 rockers on, adjust them then measure the gap between the coils at full lift. You want 1mm or more gap here.

[edit] Whilst you are at it, measure the valve lift...

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Chers Doc, you're a champion. I'll give it a shot on Friday, have the day off so it's time to play Minis while the Mrs is at work.

Just out of curiosity, if I was to put in such a hard spring (240lb), what effects would it have on the motor compared to the 180lb ones? Would it make much difference in the general running of the motor?

Also, the big girl is in need of a tune anyway, how different if at all is the tune of a car with standard rockers compared to 1.5s? Is it more mixture or different needles altogether?

Cheers,
Keels.

_________________
-Wasabi
1972 Clubman - Daily Driver
1962 850 - EW1 Powered

Can't help you with the mixtures, but I can show you what a high lift cam looks like once you've worn through the outer hardened surface. It's not pretty.

Unless you're really going to rev the guts out of it, prematurely wearing the cam and a slight reduction in power is all you will achieve with excessively hard spring rates.

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Too many cars, and too little time.

Too easy. Well I'll try bolt them on tomorrow and check the gap in the coils, if it's not right, I'll get the recommended springs. Once it's all together I'll send it off to my Mini mechanic to tune and he can take care of the tuning side of things.

Thanks again guys, Ausmini has proved once again an invaluable resource for me

Cheers,
Keels.

_________________
-Wasabi
1972 Clubman - Daily Driver
1962 850 - EW1 Powered

"if I was to put in such a hard spring (240lb), what effects would it have on the motor compared to the 180lb ones?"
The harder springs will sap more power out of your engine when compared to the 180s

on a slightly different note, check your rocker cover clears the rockers.. my new alloy one from minisport sa didnt, nor did my mg metro steel rocker cover (standard style) the only one that did was my old ribbed one which is a bit taller, they sounded overly rattly when i first started it with mine on, looked at the rocker cover to find two dents either side where they were hitting it

The common recent shiny Chinese alloy ones (with ribs on top only) don't even clear Corolla rockers...
If the roller ones are only hitting at the back you can slot the 2 holes in the cover forward 1mm or so, then push the cover back.
Otherwise as said, find one of the earlier sand cast ribbed Oz made covers, they have heaps of room.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.