View single post by Judson Manning
 Posted: 04-27-2006 12:01 am
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Judson Manning



Joined: 03-14-2005
Location: Atlanta, Georgia USA
Posts: 406
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No problem Dan....we're all here to help each other from wasting any more money than necessary.  Now ship your engine to ATL so I can build a monster for you!  lol

Now back to the Tim/Judson/Greg 104/107 debate and what I mean by 'hot ticket':

Tim, we really need to get your three engines on the dyno.  Perhaps then we'll figure out why you have great luck with the Spec9 Dellortos and my engines prefer Spec10?

The data I've collected suggests there is little benefit to a 104/104 combo when compared to the 104/107 combo. 

Garry Kemp’s Creation (Erik Harkes Engine)

Cams:  268^ .425” lift Intake (modified 104)

            252^ .378” lift Exhaust (stock 107)

                                    210hp@6250rpm

                                    175ft.lbs@5000rpm

 

 

LotusBits.com Creation

Head ported from stock 126cfm to 170cfm

Cams:  272^ .410” lift Intake (stock 104)

            272^ .410” lift Exhaust (stock 104)

                                    218hp@7246rpm

                                    171ft.lbs@6232rpm

 

 

“Yellow Dog”

Richard Reyman’s 2.2Litre creation

Custom Cams

240hp@7000rpm

185ft.lbs@5500rpm


(If someone could post "Yellow Dog's" cam stats, or any other dyno results, that would be a huge help to us all).

We can be sure there are SIGNIFICANT differences between the 3 different dynos that tested these engines.  I'll assume they are all good to within ~5%.  If so, they all produce about the same amount of power, only at different rev points.

What I see is pretty simple:  Replacing a 107 Ex cam with a 104 cam only shifts Torque and HP up the rev range by ~1000rpm.  There are no appreciable gains.

While data doesn't lie, we really don't have enough of it to make a definitive conclusion.  One of these days we're going to do a 'dyno-days' so we can document all of these combinations instead of arguing about it....

 



Last edited on 04-27-2006 12:10 am by Judson Manning