ArdWrknTrk Posted July 14 Share Posted July 14 is there a thick film ignition module in the mix? It's DS-II Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted July 14 Share Posted July 14 Yeah how it sounds and acts sounds like when you hit a rev limiter, it starts popping and snorting although it will keep revving through it but not very well. I gave up on it for a bit, took a rest and got some food. I'll OHM the coil and pickup in a bit. The old engine WOT was around 12-12.5:1. I thought about possible valve float but the springs that came with those heads are a bit stiffer than what the cam calls for, so I highly doubt that's it. I did 1 full turn on the lifter preload and wasn't nowhere even near the max travel for the plungers in the lifters. Float doesn't act like ignition... popping and bucking. I sure know what spark scatter feels like, but I've had bad pickups before. 🙃 Link to comment Share on other sites More sharing options...
mat in tn Posted July 14 Share Posted July 14 It's DS-II and this dist was on a different engine and worked well? I'm thinking top bearing causing pickup interference. a difference in tolerances can make this show up. Link to comment Share on other sites More sharing options...
mat in tn Posted July 14 Share Posted July 14 and this dist was on a different engine and worked well? I'm thinking top bearing causing pickup interference. a difference in tolerances can make this show up. sorry I just read back through. is this a roller cam? adding preload is not only about rocker geometry. it is loading one spring against another which is hydraulicly supported. you may very well have too much preload if you have a good pump and new lifters. AND if it is not a roller cam then you may be eating your cam. back these off.. otherwise you may have lessened the seat pressure of the valves and possibly slightly open when at the rpm where lifters can no longer bleed off any pressure. Link to comment Share on other sites More sharing options...
FordFETruck Posted July 14 Share Posted July 14 sorry I just read back through. is this a roller cam? adding preload is not only about rocker geometry. it is loading one spring against another which is hydraulicly supported. you may very well have too much preload if you have a good pump and new lifters. AND if it is not a roller cam then you may be eating your cam. back these off.. otherwise you may have lessened the seat pressure of the valves and possibly slightly open when at the rpm where lifters can no longer bleed off any pressure. Alright I went out and did some tests. Ignition coil and pickup coil test fine, I tested fuel pressure and it was just under 4 PSI and dropped when I revved it, so I readjusted to 5.5 PSI and it no longer drops when I rev it. Checked float levels, they're fine so I went out and test drove it and the AFR's were going crazy lean when the secondaries opened up. I laid it to the floor and it was going 15:1 and leaner and started pinging then I let off. I think the secondary jetting just needs returned close to stock. It has 68 jets in the secondary and came with 73 stock. Although, raising the fuel pressure did help it out slightly. As for the cam it's a comp cams 255 DEH hyd flat tappet. Rocker arm geometry was good with 1 turn preload, I spent a bit of time checking this. I ran 1 turn preload on the old engine for years and everything looked great coming out. 1 turn winds up being about .050" preload on this setup. The instructions in with the cam recommended .020-.060". The lifters are OEM Ford F1DZ-6500-A and had a crapload more available travel than the comp cams lifters I had in the old engine. Link to comment Share on other sites More sharing options...
mat in tn Posted July 15 Share Posted July 15 Alright I went out and did some tests. Ignition coil and pickup coil test fine, I tested fuel pressure and it was just under 4 PSI and dropped when I revved it, so I readjusted to 5.5 PSI and it no longer drops when I rev it. Checked float levels, they're fine so I went out and test drove it and the AFR's were going crazy lean when the secondaries opened up. I laid it to the floor and it was going 15:1 and leaner and started pinging then I let off. I think the secondary jetting just needs returned close to stock. It has 68 jets in the secondary and came with 73 stock. Although, raising the fuel pressure did help it out slightly. As for the cam it's a comp cams 255 DEH hyd flat tappet. Rocker arm geometry was good with 1 turn preload, I spent a bit of time checking this. I ran 1 turn preload on the old engine for years and everything looked great coming out. 1 turn winds up being about .050" preload on this setup. The instructions in with the cam recommended .020-.060". The lifters are OEM Ford F1DZ-6500-A and had a crapload more available travel than the comp cams lifters I had in the old engine. I normally lean on the lesser side of preload. all preload lessens seat pressure. solid lift cams had an expected tolerance and if you did not hear them, they were often too tight. hydraulics are only a noise compensator and to reduce the need for adjustments. we give up a tad of lift and duration as a result, so the lift is compensated at grind. I just finished a 289 that did not like any preload at all with hydraulics. nearly zero is where it sits today. yesterday I shimmed a 5.0 valvetrain with fixed pedestal rockers and .015 shims I would have been near zero, so it has .010 and all were between 45 degree and 90 degrees rotation of preload. it's too easy to go back and add more if the valvetrain gets noisy. and with all the cam failures I keep hearing about, I would rather clearance a little more oiling anyway. Link to comment Share on other sites More sharing options...
FordFETruck Posted July 15 Share Posted July 15 I normally lean on the lesser side of preload. all preload lessens seat pressure. solid lift cams had an expected tolerance and if you did not hear them, they were often too tight. hydraulics are only a noise compensator and to reduce the need for adjustments. we give up a tad of lift and duration as a result, so the lift is compensated at grind. I just finished a 289 that did not like any preload at all with hydraulics. nearly zero is where it sits today. yesterday I shimmed a 5.0 valvetrain with fixed pedestal rockers and .015 shims I would have been near zero, so it has .010 and all were between 45 degree and 90 degrees rotation of preload. it's too easy to go back and add more if the valvetrain gets noisy. and with all the cam failures I keep hearing about, I would rather clearance a little more oiling anyway. I went out and put the stock secondary jets back in. Way too rich now, but still has the same problem although not as bad. Maybe I will re do the lifter preload at what, 1/2 turn? not sure how these OEM lifters react to preload like the aftermarket ones do. Link to comment Share on other sites More sharing options...
mat in tn Posted July 15 Share Posted July 15 I went out and put the stock secondary jets back in. Way too rich now, but still has the same problem although not as bad. Maybe I will re do the lifter preload at what, 1/2 turn? not sure how these OEM lifters react to preload like the aftermarket ones do. if using an adjustable setup. start with 90 degrees past contact. if using pedestal with shims find out which is too loose and go .010 though thinner. aside from zero preload, this should give full/near full travel and greatest seat pressure. without keeping lifter contact loaded 100% of the time. Link to comment Share on other sites More sharing options...
viven44 Posted July 15 Share Posted July 15 I went out and put the stock secondary jets back in. Way too rich now, but still has the same problem although not as bad. Maybe I will re do the lifter preload at what, 1/2 turn? not sure how these OEM lifters react to preload like the aftermarket ones do. Had no idea Ford was selling these lifters still. I assume these work on a 460 as well. - How well do the Ford lifters work vs aftermarket ones (comp cams, melling?).... - Any risk of Ford discontinuing these ? If so, I should stock up some. - Is there a Ford OEM Cam as well ?... stock grind is usually fine for my needs on the 460... Link to comment Share on other sites More sharing options...
Danny G Posted July 15 Share Posted July 15 Had no idea Ford was selling these lifters still. I assume these work on a 460 as well. - How well do the Ford lifters work vs aftermarket ones (comp cams, melling?).... - Any risk of Ford discontinuing these ? If so, I should stock up some. - Is there a Ford OEM Cam as well ?... stock grind is usually fine for my needs on the 460... At the junkyard this morning thought I got lucky would this air cleaner but it's rusted through doesn't appear to be the correct one anyway. You see anything I should be grabbing holler. I'm here for two more.hours. Link to comment Share on other sites More sharing options...
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