Hello Everyone,

Excellent site here and a wealth of useful information! I'm currently undertaking a Crossflow to an 1800 Zetec conversion, and I was looking at using the Crossflow carbs (2 x 40DCOE)

However whenever I see Zetec manifolds, they all appear to be for the silver top, the black top port shape is oval with a little cutout at the top where the injector would fire in its original installation. Blacktops are completely oval.

Is there any issue with using the silver top manifolds? I assume it will mean there is a little pocket of space where the manifold meets the head?

Does this have any adverse effects at all? Reduced power etc?

Thanks all in advance

Ben

I don't know the answer to your question, but if you look on the website of companies like Dunnell Engines or Borton Power you will be able to see if they list different inlet manifolds for the silver and blacktop versions.

Are you sure? My 2003 blacktop has the injector cut outs the same as the 1.8 silvertop I had in before hand.

As^^ your man says ive never seen a black top or a silver top engine with oval inlet ports without the injector cut out.

I think you mean the manifold only has an oval port and no ingector cut out ?

Thats how they all are, weber to jenvey, silver and black top all the manifolds are just oval.

As to if it reduces power, must do but as a ported 2.0 with cams will do 220bhp + no ones seems to bother.

On the other hand you will have issues with the progression drillings running the 40's on a 16v engine

Thanks gents, for some unknown reason I had it in my head that blacktops only had oval ports with no injector cutout!

Thanks again

Ben

My blacktop has had a standard silvertop manifold fitted for nearly 6 years now without issue...

I took my home made manifold and bike carbs straight off my silvertop and bolted them to my blacktop. no issues at all. Straight swap.

Cheers Gents,

Do you have any recommendations for a Twin 40 DCOE manifold? I've seen some on eBay for £80 which seemed incredibly cheap!

Thanks

Ben