Talk Morgan Forums Morgan Sports Cars Morgan Photo Gallery Lightening Ford Crossflow Rockers

Once the rebuild of the 4/4 Series 2 gets underway, I intend replacing the 1200cc three main bearing pre-crossflow Ford Anglia engine with a tuned 1500cc five main bearing pre-crossflow. I haven't decided the specification but standard, even 1500 GT spec is not on my list.

As I'm a sad so-and-so, I bought a set of crossflow rockers from eBay in order to lighten them according to a spec that I have in my memory when I modified my 1972 4/4 way back in 1978.

In addition to lightening the rockers, I refaced the pads to remove any wear.

As standard the rockers are rather weighty and each weigh 64 grams; lightened they weigh 50 grams so a 20% improvement. The lightening will allow higher revs and put less strain on the valve train and camshaft. Well that's the idea anyway.
The next step is to buy a new steel rockershaft together with a set of steel rocker posts and steel rocker spacers to replace the weaker cast aluminium posts and spring spacers.

Fast road / racing spec?

Something along those lines Graham. At least fast road!

nice work

what's next ?

stefan

Looks good, I presume you'll be complimenting this with some port polishing and balancing the head cambers?

Nice work David

Lightening and polishing not only removes weight , but also the stress raisers in the castings are minimised.

It might be good to keep the pre-cross flow configuration so that the exhaust runs and other major items are kept close to the original layout.

I will keep the pre-crossflow configuration. The car is a late Series 2 so the body is the same as a Series 3, 4 and 5.

The other reason I want to keep the car in-period (except for the 100e sidevalve engine and three speed gearbox) is to have the car as a historic competition car.

You will probably know this Andy, Peter Morgan homologated the 4/4 in the 1960s with twin 40 DCOE carburettors and dry sump engine lubrication.

Ah yes - tweaking the old Ford engines.
I put a 1600 crossflow crank into a bored out 1500 block and achieved about 1750cc (with 125E conrods). The pistons came out of the top of the block so we machined them down all but a small section that went into the combustion chamber. The compression ratio was about 11.5:1 so would only run on 5 star. We added twin 45 DCOE carbs and a K3A Holbay cam. With a 4.44 diff we went quite well off the mark.

Although originally for motorcycles, Phil Irvings book 'Tuning for Speed' is an excellent and interesting read and covers work like port polishing and lightening components.

Some of the work was beautifully done and it's an art to get the balance just right between power and reliability.

John, your experience could be helpful. I'm not sure about going for an overbore but I suspect the block will take it as not only is the spare 1500 block an 'L' block, it is a rare '701M' one. I may well throw some questions in your direction but it'll probably be some time before I do.

Steve, yes Phil Irving's book has a lot to answer for as it got me into engine tuning; I owned a Vincent Comet at the time. The first set of rockers that I lightened and polished were on my BSA 650cc Super Rocket and I've been fettling ever since.