Hi all – I’m in the process of re-building my 2.25L - 3 main petrol engine and wanting to improve performance. Now don’t get me wrong – I’m not wanting a 120kW stage 3 super modified fire breathing axle snapping Nos injected Landy !!
Most forums and website claim best power increase via a 2.5 Cam, increased compression Ratio 9:1 and better carburetion

~ That’s all fine and well but can anyone please supply the 2.5 cam specification in terms of valve timing, lift, LCA etc ….

~ What camshaft was used on the 3main bearing motor with the 8:1 CR?

The way I understand the history was that the original 2.25L engine with a 7:1CR made 70bhp@4250rpm; 124lbft@2500rpm and that the subsequent 2.25L engine with the 8:1CR made 70bhp@4000rpm; 120lbft@1500rpm. Peak torque moved from 2500rpm to 1500rpm cause of the revised cam timing - is this correct?

Valve timing 2.25L (7:1CR)
Inlet opens = 6 BTDC
Inlet Closes = 52 ABDC
Inlet Peak = 113 ATDC
Exhaust opens = 34 BBDC
Exhaust closes = 24 ATDC
Exhaust peak = 95 BTDC

Valve timing 2.25L (8:1CR)
Inlet opens = 16 BTDC
Inlet Closes = 42 ABDC
Inlet Peak = 103 ATDC
Exhaust opens = 51 BBDC
Exhaust closes = 13 ATDC
Exhaust peak = 109 BTDC

My understanfing is that the 7:1 and 8:1 were made at the same time and the 8:1 version was for export.
If you get a copy of the big white book (Green in later edditions) it details all sorts of stuff about the cam etc...
The method i would take to get more Ommph out of a 3 bering 2.25 would be a rebore + new rings + pistons + twin su or large web + K&N air filter + tiptop ignition.
Start with the cheep bits first.
There is a company that does performance cams and gasflowed pipes etc...
it was in a LRM artical about 3 months ago.

Hey Clivees,
I've got both the original manuals and this is were I found some of the cam specs listed above. I'm looking for the 2.5L cam specs...
The ignition was changed from points to Petronix, SU's was bought secondhand from 2.6 Rover(HIF 44's) and new original pistons to be installed. I had a look at the Automotive Component Remanufacturing site (company based in Flintshire) but the pricing of the performance Cam is very high and the import duties will kill me.....btw, the word is that the 2.5 cam performs as well as the ACR cam!!?

I'd be inclined to find an adaptor plate for a V8 3.5 and an engine to go in front of it... ...

Why bother to change the cam when you can upgrade it by moving the camshaft timing? Works for me!