View single post by gmgiltd
 Posted: 07-28-2015 04:44 pm
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gmgiltd

 

Joined: 07-10-2012
Location: Whitehills , United Kingdom
Posts: 142
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Hi Nigel,
I was not aware that there are more than one version of the Jensen dellorto air box, live and learn.
One thing I didn't mention is that the head and intake manifold were ported to Sunbeam rally spec.(remember them). When Mike Taylor reconditioned the head and put in his even bigger sport 300 valves he commented that it was a good hand porting job. Side by side with his latest £1200+vat CNC ported head the ports look small but he is getting around 300hp on his 2.5litre rally cross engine at 8k+ rpm - way too radical for me.
Usually with air boxes bigger is better as the airflow is more even to the carbs/injectors- there's a lot more turbulence around pancake filters-that's the theory anyway and if you look at the induction system on any modern bike engine it seems to be correct.
Has your head been ported and what cams are in it?
Gordon