1996 F250 460 baseline dyno results and head porting info-RESULTS ARE IN!
#47
Results are in, finally some numbers worth talking about. It was really hot today at the dyno, truck was running pretty warm and power was dropping after a few pulls so we shut it down. The best run of the day was the first pull, and It still was a little lean on the top end but close enough to make some decent power. I'd really like to re-dyno on a cooler day (it was 93* today) and play with the adjustable regulator some more but for now these results will do.
Overall, we picked up a solid 15% power, and strong torque gains as well (+32rwhp and 25rwtq) . The power difference is all across the board, from idle to redline. I probably could have revved it out a few more hundred rpm and squeaked a few more hp out of it looking at the curve, but again the conditions were less than optimal and I was happy with the gains we got. The truck is a blast to drive, it drives like stock but more power everywhere which will work great with pulling the boat. I have a set of headers to install next and will re-dyno as well after the swap and share results. We are still out of fuel on the top end, but if we can get some more torque out of it with headers in the low and midrange (where these engines normally operate anyway) I'm not going to complain.
Oh and because of the dramatic difference in temperature between the two dyno pulls, the chart below is with SAE correction for both days to get a better, more accurate comparison. Thanks for following this thread.
Overall, we picked up a solid 15% power, and strong torque gains as well (+32rwhp and 25rwtq) . The power difference is all across the board, from idle to redline. I probably could have revved it out a few more hundred rpm and squeaked a few more hp out of it looking at the curve, but again the conditions were less than optimal and I was happy with the gains we got. The truck is a blast to drive, it drives like stock but more power everywhere which will work great with pulling the boat. I have a set of headers to install next and will re-dyno as well after the swap and share results. We are still out of fuel on the top end, but if we can get some more torque out of it with headers in the low and midrange (where these engines normally operate anyway) I'm not going to complain.
Oh and because of the dramatic difference in temperature between the two dyno pulls, the chart below is with SAE correction for both days to get a better, more accurate comparison. Thanks for following this thread.
#51
Bobort, what are the squiggles in the stock curves? Also, will you be doing any towing/mpg studies on these heads. OEM engineers have to balance these things out but with the passage of time aftermarket development generally exceeds stock in all measures. I'm currently building a 460 efi '88 f250 for heavy towing/landscaping business. I'm impressed with the flat torque curve you are getting and am interested in possibly doing trick heads, aftermarket exhaust but keeping the efi as stock as possible. Changing the computer is easy but I'd like to keep speed density as changing to MAF seems a hassle. Many of the tricks in the Four Wheeler magazine "Project MPG" work well, and at the same time are not too much of a hassle. After seeing your results I think there is much to be gained with semi stock setups. Thoughts?
#52
The squiggle at the beginning of the stock curve was the converter locking up, I started recording the run before the converter locked. I will be recording mpg next time I fill up. This tank currently left in the truck was from the dyno and some tuning up and down the street (lots of WOT). Now that the tune is decent and we have some numbers I will TRY and take it easy driving around for a tank worth and record mileage. Before the head swap I was averaging 10mpg, which was about 50% street miles and 50% highway. One thing I did notice that is nice is on a long winding highway here with a pretty decent grade (hwy 17), before there were at least a couple points in the grade where the truck had to downshift out of overdrive to make the climb. This last weekend when I made the trip over it pulled the whole thing in overdrive without skipping a beat. 1500rpm-2000rpm the whole way over. Definitely notice the new torque down low. My stock 7.3 powerstroke could barely do that.
Bo
Bo
#53
Amazing work ... good job. i am currently in toyota tech school atm. here in California , i am currently in eniges class rite now . and my FORD got accepted as the class project to rebuild. so that will be fun ... i am buying a master engine rebuild kit for it , and sending out the heads to be ported and new lifters as well..
as for the cam prolly a 540 . everything use stock with a chip upgrade , like i said all the work is free.... useing the schools equipment gotta love it ... its still costly thou. i am useing your ported specs on my heads , and i wanted to say thanks for your time and effort in this ,,,, you have helpd out many many ppl. good job.
jayson
as for the cam prolly a 540 . everything use stock with a chip upgrade , like i said all the work is free.... useing the schools equipment gotta love it ... its still costly thou. i am useing your ported specs on my heads , and i wanted to say thanks for your time and effort in this ,,,, you have helpd out many many ppl. good job.
jayson
#54
Just got off the dyno, and don't have time to post sheets (heading out of town early in the morning) but we found a little more power I installed a set of headman headers (I did some cleanup porting on these) and a 3.5" exhaust with flowmaster muffler dumped at the axle. For a pretty crappy set of headers I am impressed with the gains. Although I can't say this was a true back to back test because tonight was cooler and I actually got to do some tuning with the fuel pressure, needless to say we picked up a ton of power and torque.
Peak power of the night was 276whp and peak torque is now up to 389# I found about half of those gains just messing with the fuel pressure regulator and finding a happy spot with pressure. We are STILL lean on the top end (14.5:1 A/F) and I bet with some more fuel this pig would put down 300hp and 400#tq to the ground. Keep in mind folks, this is almost blower territory power and we are still on a stock speed density computer and 87 octane gas!
I will post a bunch of graphs when I am back in town, just thought I'd share some good news before I cut out.
Bo
Peak power of the night was 276whp and peak torque is now up to 389# I found about half of those gains just messing with the fuel pressure regulator and finding a happy spot with pressure. We are STILL lean on the top end (14.5:1 A/F) and I bet with some more fuel this pig would put down 300hp and 400#tq to the ground. Keep in mind folks, this is almost blower territory power and we are still on a stock speed density computer and 87 octane gas!
I will post a bunch of graphs when I am back in town, just thought I'd share some good news before I cut out.
Bo
#55
#56
Peak power of the night was 276whp and peak torque is now up to 389# I found about half of those gains just messing with the fuel pressure regulator and finding a happy spot with pressure. We are STILL lean on the top end (14.5:1 A/F) and I bet with some more fuel this pig would put down 300hp and 400#tq to the ground. Keep in mind folks, this is almost blower territory power and we are still on a stock speed density computer and 87 octane gas!
I will post a bunch of graphs when I am back in town, just thought I'd share some good news before I cut out.
Bo
I will post a bunch of graphs when I am back in town, just thought I'd share some good news before I cut out.
Bo
#58
I am wondering if you are installing new-hardened seats on the exhaust side. Ford only induction hardens the seats and it is really thin area that is hard. I was in the shop when they cut my heads for new hard seats and you could tell it only took a couple of revolutions to break through the hardened area. I think most any valve job would remove most if not all the hardened metal from the valve seat area.
Bill
Bill