A friend came round today for me to fit a new Rocker Gasket popped the rocker off and look what's missing 4 cam caps different to the early 8V
Early 8V DX Engine 5 cam caps if that's right with the later 8valvers that's new to me. found manual for late 2.0L AGG 8V and yes it only has 4 cam caps. but the photo of the one in the first post is a 1990 Cabrio 8V has it had a different head fitted or did the late Cabrio's have the later Head.
intersting , i've been into 16v's for years so didn't realise the 8v's only had 4 caps having not worked on one for 14 years.
It`s a good way to differentiate if a head uses hydraulic or solid lifters. Hydraulic = 4 caps, solid = 5 caps. As Chris says, seems odd, and I`ve never found out a reason why...
The first of hydraulic tappet type heads drop the cam bearing between cyl 3 & 4. It does make it easy to identify the difference between them and the earlier mechanical tappet type. The followers make it easy too as the hydraulic type are completely flat at the top where as the mechanical type have the shim on top located by a small shoulder around the perimeter of the shim. The base circles of the cams are different also so not interchangeable without extensive work. Interestingly, some of the new hydraulic head types have gone back to using the missing cam bearing. AGG and AKL for example. The above is based on original specs and can change on modified engine that run under bucket shims and non standard base circle cams.
Same thing i was thinking too, when you have the opposing forces of the Tappets on No3 Cylinder and No4. mind you they don't rev as high as a 16v so maybe not an issue when they won't be revved over 6500k potential cams snappage on a high lift race cam ?
interesting what are the 8V crossflow 5 caps any pix, the 8V crossflow engines really interest me, and the potential you could get from one.
Yes the crossflow heads all seem to go back to the 5 caps. I too have an interest in the crossflow head as I reckon there is real potential with them. Std they have 7mm stems valves (lighter), smaller base circle cam (lighter), bigger exhaust ports than std dx or pb style heads and cooler inlet side. I have got a couple of crossflow inlet manifolds for webers and been fitting a 304deg cam. Just sorting the tappet shimming and its a go.
That photo of that 8v Crossflow on TB's always gets me excited p.s. Cork Gasket ! that's what he bought for me to fit, the old one i took off was the same.
pre-67: if its a mk1 gl its not got hydro tappets, they didn't come in till 87. Plus 1.5 engines didn't exist on mk1 cabs, roccos or mk2s when hydro tappets came in, since they stopped putting 1.5 blocks in euro models in 84 as above, 4 caps = hydro tappets, and there is an oil squirter where the missing cam cap is. My guess is to prevent over-pressurisation of the hydro tappets, acts as a primitive relief valve?
