Older A series cams
Turbo Mini Forums

Hi,
Not being an A series expert I have an older A series engine (1275 GT I believe from around 1970) which I have turbocharged.

I will be rebuilding it shortly and changing the camshaft and oil pump.
My question is will a newer A+ cam fit in my older engine with a Metro turbo oil pump?

Are the bearing sizes the same? Any issues?

Thanks

I'm 99% certain the bearing sizes are the same, so any (1275) cam fits any block, but pump drive connections are different on the earlier engines, a star and spline arrangement rather than peg/slot.

But if you're going to be using the later camshaft, no problem - the metro turbo pump has the peg/slot drive.

It's actually a case of you MUST use the newer cam if you want to use the high capacity oil pump.

Schrödinger's cat - so which one am I ???

Thanks,
That's what I thought.
Is there anything I should be aware of?
Are the lobes the same width, pump bolting pattern? etc etc

I've never seen it myself but, according to Vizard, some early cams had narrower lobes but as long as you use new followers with your new cam it shouldn't be an issue. There is nothing in Vizard to suggest the recesses around the followers were machined any differently if it was using a narrow lobe cam but, like I say, I've never seen a narrow lobe one anyway. A trial fit would soon confirm.

Pump bolting is a bit strange, the early blocks used 4 bolts in a square pattern and although the later blocks still have four threaded holes, the high capacity pump only uses two bolts

http://www.minispares.com/Product.aspx?ty=...0TYPE%20POWER...

It's not a mismatch, they just have two holes instead of four !!!

(small bore blocks were always different with three bolts in a triangle)

EDIT - just checked in Vizard (instead of relying on my memory) and it looks like the narrow lobe cams were in the small bore blocks only....

Edited by Rod S on 1st Nov, 2008.

Schrödinger's cat - so which one am I ???

Wow thanks for that info.
Sorry for asking but my Vizard book is packed away and I can't get hold of it.

what Rod said :)