Quote:
Originally Posted by Panoz Paul
For Kel ; I thought I would provide some specs of the engine ... Ford Racing Crate / 340 hp ( M-6007-XEFMS ) Alum. heads W/ 1.94 in ; 1.54 ex ... Cam : M-6250-E303 W/ .498 lift ; .050 dur @ 220 w/ 1.6 ratio lifters that were changed to 1.7's ... Engine is all forged ... Is the Demon 650 the carb to go with & what / who's manifold ???
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Paul, your set up is not so far off what I ran initially with the 5.0 that made 340hp at the wheels and 335 tq.
Regards manifold, I think the best manifold for your current combo Paul is the Edelbrock RPM Air Gap. This will make great torque from down low and good hp up to 5500 - 6000rpm. This manifold would best suit the rest of your combination (heads and cam) which is targetted more at a power range of 2500 - 5500rpm.
If you think that you may push the engine rpm harder at some stage (as your forged engine is capable of running to 7000rpm+ should you choose) you could consider the Edelbrock Victor Junior manifold (builds more hp from 5500/6000 up) but you will lose some low end power and torque on the 5.0 and the car would most likely be slightly slower with this manifold at this stage. However should you upgrade in future (bigger heads/cam/compression for higher rpm) this manifold would give you some room to grow into power wise without spending more $$.
Carb wise Paul, I have used 650cfm Mighty Demons for some time and like them (great features for the price, many of which previously were only available with custom carbs). There is not much of a difference between a Mighty Demon and a Holley HP series carb. Either is a good choice. I purchased my current 650cfm Mighty Demon via E Bay for around USD$230 or 240. The person I purchased it off bought it new but couldnt get it to run properly on thier engine. Bolted straight on, changed the air bleeds/jets that they had screwed up and it has run great ever since.
Regards baseline jetting for a 650cfm carb for your combo at the track, I would start off with around 71's in the primaries and 84's in the secondaries. This is based off what we ended up running in my 5.0 (73's & 86's) but backed off a little as my engine had a bit more cam and bigger heads (185cc runners and 2.02 inlet valves). You need to do some plug chops to ensure you tailor the jetting to your setup.
If you havent tuned a carb in race conditions before Paul, I strongly recommend that you take the car and have it dynoed to get initial set up correct. This way you can bolt a detonation set to the engine and get timing and jetting optimised for the fuel you run on and ensure you have a safe tune for the engine. I
always do this as I beleive it is the best way to get the job done. You can waste more time and money trying to get this right at the track and end up damaging your engine.
There after, I do change jets (but only a size or so) at the track to allow for changed altitude or atmospheric conditions.
Hope this helps, Kel.