Newman cam profiles

[Charles P]

A new Newman 70-30 cam you have to fit the centre bearing as an assembly as the cam peaks will not go through the cam ring when it is fitted to the crankcase.  Terry.

Terry

Is that a cam with a 318 lift, as per the original post , or does the 70-30 cam that you mention have a higher lift?
I know that a 375 lift Nippy won't fit but I have a seen a 330 inlet lift cam fit.

Thanks

Charles

[Terrytuned]

Charles it has a 318thou lift a reground original cam with a 312 lift will clear but not a new one as the base his a bigger profile. Terry.

[Charles P]

Charles it has a 318thou lift a reground original cam with a 312 lift will clear but not a new one as the base his a bigger profile.   Terry.

Ah yes. The impact of base circles. 
That will also affect the con rod clearance mentioned by Alan. 

Thanks 

Charles

[Zetomagneto]

Charles, its clearance for the Conrods needed between the lobes, not in line with the lobes surely?

[Dirk73]

Many thanks for the replies, i am completely amazed at the amount of knowledge here. I've rebuilt quite a few classic motors but this is my first serious A7 engine rebuild.

Thanks Paul, i use a similar method for finding TDC with the DTI, just marking when the piston goes past 0.2mm on the DTI in either direction and then halving it for TDC (this may not be as dead accurate as your bolt method), i understand what you are conveying about setting the timing from peak inlet lift in relation to TDC.

Bob, yes it's a new cam not a regrind. Alan & Zeto, it's a 1&5/16" pheonix crank so clears ok.

Terry, yes i did have to push the centre bearing race in at the same time as the cam as the lobes are too big and this was the only way to fit it. Your tool as illustrated would have indeed made the task easier.

I haven't got it timed right at the moment as max inlet opening is around 120 degrees.
But if set back to 110 then the cam would show timing of 30 BTDC, 70 ABDC, and is definately 318 lift.

Terry & Charles P, guessing that you have experience using this cam (or others that run one), is it what most would call a full race cam? i.e. the engine will be somewhat fickle below 4500rpm and won't wake up and pull hard until 5000-7500?

I'm in two minds whether to use it, as it's going in a roadgoing ulster rep. If not it will find it's way back to that well known auction site!
Thanks again, Dirk

[Terrytuned]

Dirk have not used cam with std profile followers, the useful power with reprofiled followers is 4000 to 7000rpm if you drop off the power band it just takes longer to accelerate. From a racing point of view follower profile makes quite a difference it may be more docile with std followers and have more torque. Terry.