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[GMR-PERFORMANCE]

This bike came to us after a dealer had installed a 259E cam V&H power dual head pipe and Rinehart mufflers. Customer was not thrilled about lack of low end, at some point the dealer install larger injectors and 10.5 piston kit with .050 head gasket. I never took the top end apart and have no idea what was really done. I did do a CCP test with 259 cam and our 577 cam. With 259 it was 200 and with our cam 209 comp test. More than I would like to see. However even in the super hot temps and a hefty amount of compression the engine was very easy and tame to tune. Taking much more timing than I would have thought. After completing tune, I took it for a nice hot ride in stop and go traffic with out any Ing ping. I tried to induce it with 6th gear lugging at low Rpm.

Graph is showing what it came in tuned as , even with re tuning the graph was rough and did not improve much at all.  Again this is just one of those bikes that was not making the HP that I have seen. A larger T/b in my opinion would have been a better choice but that was not up to me. We swapped cams retuned and made the low end power the customer was looking to start with. Overall not impressed with the HP however the TQ is very stout. Seat of the pants feel is outstanding and the bike pulls extremely with just a flick of the throttle.

Having a printer issue in dyno room so this is one screen pic I took SAE power was 109 hp and 125 tq.  Huge change from what he started with.

[lilcoot]

That's a pretty shocking difference. 

So was the bulk of the improvement from the cam or the quality of your tune?

[GMR-PERFORMANCE]

As I said I did clean the tune up and it did not show enough improvement to really even bother. The graph would not smooth out like the other cam did, I checked cam timing worked back and forth with timing .. This may be a issue with the heads being a poor set, you will see where there is a large amount of core shift or casting flash in the port. Hard to say as I never took the heads off.  The t/b is another issue as a larger unit would have been better. As to the why the 259 cam did not work I will never know I have tuned other 259's and they seemed to be better than this be a rather large margin. I performed Negative hp test on engine and then just drive line all in what I see from other bikes.  A engine is made up of parts and when one does not work well with the others the end result is less than positive.  Our cam made a huge change in the tq curve down low and over all customer is happy and that is what counts.

He may bring it back for head work and the larger t/b as he has seen what the cam can do with ported heads and t/b He really wanted hp in the 120+

[hrdtail78]

Over 110tq from 2600 to 5300, and 120 from 2800 to 4800.  Great bolt in cam.  Nice job Steve.