found this video interesting.. 360 dyno testing.
- Thread starter abodyjoe
- Start date
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I heard him say something about that, never seen the video, aren't edelbocks on par with a decent ported 340/360 head ?
Yeah he mentioned that and I don't remember it from before. I thought that was surprising
It doesn't surprise me at all. If the engine is airflow & rpm limited by the cam, [ engine had a mild cam ] then installing heads that have bigger ports/higher airflow when the current heads already satisfy the airflow requirements of the engine, then the 'big' heads will add nothing...
Could actually hurt performance from big port volume reducing velocity.
Could actually hurt performance from big port volume reducing velocity.
Yeah I was thinking about that too. The cam was pretty small at that stage. But to gain nothing was surprising. Sure a set of ported J heads can be effective, but man that short side on the exhaust port is just awful. The Eddie's in stock form are definitely better there.
I definitely wouldn't expect it to gain 50 hp or anything like that but for it to basically be a draw was surprising to me.
If you look at Earlie A's flow chart 360 vs ed vs sm and look at stock X head 1 column below .350 and under there fairly similar to the eddies, and really not too behind above that, and it ported 360 don't seem to take much catching up on low lifts.
My guess at the lifts were dealing with the difference wasn't that huge and at the higher .400-.500 where there would be decent gain maybe velocity did play a roll.
https://www.motortrend.com/how-to/mopp-0001-360-engine-head-porting/
My guess at the lifts were dealing with the difference wasn't that huge and at the higher .400-.500 where there would be decent gain maybe velocity did play a roll.
Table 1: Intake Port Modification Sequence | ||||||||||
| Col. 1* | Col. 2* | Col. 3 | Col. 4 | Col. 5 | Col. 6 | Col. 7 | Col. 8 | Col. 9 | Col. 10* | |
| 360 Head: | 360 Head: | 360 Head: | 360 Head: | 360 Head: | 360 Head: | 360 Head: | 360 Head: | |||
| Stock | Stock | 30- | Throat/ | Blend | Guide | Radius | Gasket | Short side | Fully | |
| Lift | 340 "X" | 360 | degree | Bowl | Guide | Boss Roof | Intake | Port | radius | Ported/ |
| (in. ) | Head | Head | seats | Blend | Boss Web | Blend | Valve | Match | blend | Polished |
| 0.000 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| 0.025 | 15.0 | 12.9 | 20.1 | 19.4 | 19.6 | 18.5 | 18.2 | 19.0 | 21.0 | 20.6 |
| 0.050 | 31.5 | 29.8 | 38.1 | 37.9 | 37.5 | 37.4 | 38.4 | 38.0 | 39.3 | 39.8 |
| 0. 100 | 58.3 | 50.2 | 75.8 | 74.2 | 73.4 | 70.7 | 72.6 | 73.2 | 74.4 | 77.1 |
| 0.150 | 91.6 | 79.5 | 112.3 | 106.8 | 107.9 | 105.0 | 108.0 | 108.0 | 109.4 | 111.8 |
| 0. 200 | 124.7 | 112.6 | 140.0 | 132.6 | 134.3 | 133.5 | 134.7 | 137.8 | 136.7 | 137.3 |
| 0.250 | 152.5 | 142.2 | 162.0 | 157.0 | 158.7 | 158.4 | 159.6 | 164.5 | 161.7 | 162.6 |
| 0. 300 | 172.0 | 164.8 | 179.8 | 177.4 | 180.1 | 179.2 | 180.1 | 185.3 | 184.2 | 185.5 |
| 0.350 | 193.6 | 183.5 | 193.2 | 197.8 | 200.0 | 200.1 | 201.3 | 209.5 | 207.0 | 206.6 |
| 0.400 | 208.3 | 188.2 | 194.4 | 208.7 | 215.1 | 217.6 | 216.4 | 227.6 | 225.0 | 224.8 |
| 0.450 | 215.4 | 193.8 | 190.0 | 197.9 | 210.7 | 222.8 | 214.3 | 225.2 | 236.5 | 236.4 |
| 0.500 | 221.0 | 192.6 | 190.9 | 197.0 | 205.4 | 211.0 | 208.4 | 218.9 | 227.8 | 228.0 |
| 0.550 | 220.7 | 190.3 | 191.4 | 197.0 | 204.9 | 209.0 | 209.3 | 215.9 | 224.0 | 224.0 |
| 0. 600 | 210.0 | 189.1 | 187.5 | 196.6 | 205.6 | 209.0 | 209.0 | 216.3 | 224.7 | 224.3 |
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