Lo 65 - Coventry Climax V-8

Coventry Climax FWMV - 1.5 litre V-8 Engine
Mark	Year	Bore and Stroke	Valves per cylinder	Inlet valve dia	Exhaust pipe dia	Fuelling	Max bhp	rpm	Max torque lb/ft	rpm	Max rpm
I	1961-2	2.48"x2.36"	2	1.3"	1.25"	Weber carbs	181	8 500	118	7 500	9 000
II	1963	2.48"x2.36"	2	1.35"	1.25"	Weber carbs	186	8 500	119.3	7 500	9 000
III	1963	2.675"x2.03"	2	1.35"	1.25"	Lucas fuel inj	195	9 500	118	8 000	9 500
IV	1964	2.85"x1.79"	2	1.35"	1.375"	Lucas fuel inj	200	9 750	116.5	8 000	10 000
V	1964	2.85"x1.79"	2	1.4"	1.375"	Lucas fuel inj	203	9 750	115.2	8 000	10 000
VI	1965	2.85"x1.79"	4	1.04"	1.375"	Lucas fuel inj	212	10 300	119	8 000	11 000
VII	1965	2.85"x1.79"	4	1.107"	1.375"	Lucas fuel inj	213	10 500	115	9 000	11 000

Notes

Data source - primary data source is The Coventry Climax Racing Engine 1961-1965 - a paper produced by Coventry Climax for the Society of Automotive Engineers

Mk I - initial power output was 174 bhp, later increased to 181 bhp.
The weakness with using carburettors was over-richness accelerating out of corners on part throttle.
A number of maximum rpm figures are quoted. Power graphs end at 8 600 rpm, a figure mentioned by Tony Rudd as the allowed maximum. Other published graphs go to 9 000 rpm, and an article in Motor Racing states this was the limit before a problem with cracked con-rods arose. A temporary fix was made to the con-rods combined with a reduction in maximum revs to 8 500 rpm. New stronger con-rods were then introduced but the article is unclear as to whether the previous maximum was re-instated.
Dry weight with starter and dynamo - 270 lb

Mk II - a small number of engines were equipped with the larger inlet valve

Mk III - the majority of 1962 engines were rebuilt to this standard.
Changes included a shorter stroke, larger inlet valve (over the Mk1), and Lucas Fuel Injection.
The fuel injection gave clean acceleration out of a bend, but it took a while before the power output matched that of a carburettor.
This engine also had a flat crank. This had no effect on power but made exhaust installation easier.

Mk IV - used the even shorter stroke engine being developed for use with 4-valves per cylinder, with the 2-valve head.
A larger exhaust pipe diameter was also adopted.
Several engines were converted.

Mk V - one Mk IV was converted to a larger inlet valve for use by Jim Clark.

Mk VI - first 4 valve/cylinder version.
One manufactured for use by Lotus (Jim Clark).
A power output of 210 bhp is also quoted in the paper and other sources.
Dry weight with starter and alternator - 298 lb

Mk VII - second 4 valve/cylinder version.
One manufactured for use by the Brabham team