Collector thoughts?

[Jon]

I have been using my old 1,5" (39mm) header on my engine up to this point, the engine is supposed to have a 1 3/4" i bought from CB. I wanted to build my own header and bought it with the intention to cut it up and shorten it. However the primaries are pretty short at 840 mm so I could in fact use it as is, But the collector seems to be to small to me. The opening is just 45 mm (small flange) and the taper is around 140 mm long. I would like to shorten the taper in to about 100mm and use the bigger flange on it.

Any thoughts of this?

The engine is a 2176 with 48x40 CNC CE heads. With JPM seats, Fk 89 advanced 2 deg. Scat Pro 1.4 rockers (actually 1.51) Lifts 16 mm.

[BeetleBug]

Do whatever your computer tells you 

[Jon]

There are little sence in using Engine Analyzer to this, as it clearly states that the results gained from a complex collector design will be TO optimistic... compared to real life.
So its time for some "monkey see - monkey do" 

[BeetleBug]

Well - I do prefer doers instead of thinkers any day 

[Jon]

I like both... think first... cut after.... a good description of what I did in the garage tonight to.
After some good advise on the phone I have cut and welded the CB system into a one of... Its amazing what you can get a monkey to do if you have enough peanuts.

[John Rayburn]

It's going to change your tune to a higher rpm range. It will come on later and rev higher.

[Roman]

A 2" collector opening would do magic for your engine.