No one would or should say they don't run ( at all ). So I guess its all what the individual likes and what the particular motor build will support, some like a choppy idle and some don't - I like what gives the best all around performance. A customer has a 302 and a 390 with the Thumper Cams and he loves them. I also have a 390 with a cam with 214 int/ 224 exh duration and it exhibits the same attributes. It has 15 inches of vacumm at idle, tons of low end torque - good top end, great drivability, good fuel economy, and best of all great exhaust sound. I have had several different cams in this engine but so far this one is my favorite. Motor has marine cam straight up ,Īluminum heads 2.02 int / 1.6 exh / 1.7 roller rockers, Weiand hi rise with 600cfm Slayer carb, recurved Ford electronic dist, long tube equal length 1 5/8th headers / auto in a 78 Fairmont with 2 1/2 in exhaust. Always good to have data like that to pull from, and would be beneficial in cases like this. 050" (112 LSA/109 ICL) Xtreme Energy solid roller lobe'd cam, with no other changes. 050" (112 LSA/108 ICL) Xtreme Energy hydraulic roller lobe'd cam to a 236/236. I recently got to try a hydraulic roller against a solid roller in a little 331 SBF.
Thumpr cam 350 on dyno full#
It would be interesting to try a hand full of cams in the same engine though.
Thumpr cam 350 on dyno plus#
My gut tells me that the exact same cam with the same LSA and ICL, but with a 4-6 degree split would have done the same thing, which goes more in line with my thoughts of inefficiency, plus the "poser" status. I think my previous comments about the Thumpr cams were that they were "all show, no go", but that would be comparatively speaking of course.even a 350 hp engine would make a 2400 lb car boogie. I would be curious to see which engine had the better flowing heads. I suppose this wasn't really an apple to apple comparison, which does muddy the waters quite a bit. Then throw one of the "typical" hydraulic rollers in there as well for a comparison. Now I need to build a dual Dominator 482 with CNC ported heads and a Thumpr to further muddy the waters Probably shows that the heads are the pivot, rather than the cam, and that they are good for the roughly 600 HP level on a 482 as prepped.Īnd no - I sure would not do this on a Galaxie with power brakes - but it ought to flat out rock in the Cobra its destined for. On different days under different conditions the two engines were still within 10HP at peak. I really expected the hydraulic roller with these unusual specs to get it's azz handed to it by the solid - but that was obviously not the case here at all. Looking back at the old build I think I was mistaken on the solid roller specs being single pattern - it was more likely to be 248/252. The single four package has a solid roller that is intuitively a better choice. We are comparing a dual plane single four barrel intake with a QFT 4500 against a dual plane dual quad package with two 600 cfm vacuum secondary carbs. Neat experiment, and it's always good to see data, but this confirmed my suspicions, and I'm with Barry.I wouldn't voluntarily spec a cam with these kind of events.Īlthough similar enough for discussion, the engines are far enough apart to leave questions unanswered. You can make a 445 with a 270H pull to 5500-6000 with a good head, right Ross? What's band-aid'ing the cam is the head, and even though I understand it's not a full CNC port like the EMC head, it's still pushing more air than an Edelbrock. This is still not a "Thumpr" cam, and even at this point, it has lost horsepower and vacuum, not only to a single pattern cam, but I'm sure it would be even further behind on an appropriately chosen dual pattern. I have never seen the need to open the split up that much in an FE, even on a road race or drag race engine where the extra duration helps the engine hang on longer at the peak, or carry the peak.īarry's results supports my assumptions. However, they have a very wide LSA, along with EFI, etc. get 20-30 degrees split to band-aid a poor exhaust port.