hi all just fitted a 2.1 zvh engine in to my s2 before i had a harvy gibbs built 1.6 cvh and i think that was much better! the zvh wont rev out as well, any one else had this problem? the zvh motor has just been set up on the rollers and made 240 bhp!

 

you cant beat harveys 1.6 cvh i went for a 2.1 before then i had a chat with harvey and he said he could buid me a 1.6 as quick and reliable . i wouldnt go back to a zvh now it seemed lazy compare 2 my new engine

 

i wish i had stuck with the 1.6 now!

 

That is a characteristic of the ZVH. It can be addressed with a different stroke crank and different length rods at a large expense.

The power restriction is the head, not the bottom end by the way. The only advantage is an increase in torque lower down which is a by product of having the longer stroke crank.

The CVH has a shorter stroke which will allow it to rev a lot more freely.

If you compare the power graphs of the 2 engines, you will find that the CVH produces peak power higher up than the ZVH if the spec of the 2 engines is pretty close.