Vintage79
Vintage79 New Reader
8/16/14 2:03 p.m.

See my post and replies from last winter re "1988 Ford 460 EFI build" for previous messages. Finally got heads back in May. Compliments to the integrity and customer service of Scotty AKA The Mad Porter in Tacoma WA: I received the heads and shortly after his phone call. Another customer had an exhaust valve seize in the guide during cam break-in, and Scott learned that his machine shop supplier had changed the seat grind resulting in .044 in rather than .050 in width to valve seating surface; less cooling resulted. He had me return the heads at his expense to have seats reground to expected specs. My cam breakin was a happily uneventful 20 minutes as a result! Block was very clean and seemed happy, so other than changing cam to the mild RV grind he sent with lifters and new moly pushrods to match spring pressures and cam profile demands, block was left alone. Heads were in remarkably good shape for 135,000 miles---one exhaust valve was moderately recessed into the head, so that cylinder would have been weak on contributing to torque for sure. Three race weekends later can report the change in fuel economy (er---consumption). I'm towing C6 trans, 4.10 rear gears, with gross combined weight for truck, pickup camper and race trailer at about 19,000 lb. Torque in the desired 3000 rpm range is noticeably better; "walks" up grades with 3-4 in. vacuum that were full throttle before with same gearing. Even lowered trans temp at crest of one long grade from 230 to 210 degrees, because able to climb at 3000 rpm rather than ~2500, so less torque converter slip and heat. Fuel consumption is now at about 6.0 mpg. Last summer pre-head and cam work, towing my Subaru for GCW only about 14,500 lb. we got less than 5 mpg, around 4.5 more like. Though I'd hoped for more, I doubt this should surprise me. Work included adding adjustable fuel pressure regulator to the EFI system, at 45-46 lb with vacuum disconnected (Scott's recommendation). FYI this is the same regulator as used on a 5 liter Mustang GT, a BBK 1706 as I recall. Not all good news though. Added mechanical oil pressure gauge, seemed good but idle pressure steadily declined over these few trips to 15 lb or less at 700 rpm in Drive. On the way home last weekend, after engine braking downgrade at ~4000 rpm, up next grade horrible loud bottom end noises began and she stopped. Something was more tired than we realized...... Now we're tearing her out again to do the block and see what happened to those lovely heads (hopefully only a couple of bent valves) and new cam and lifters. No oil on ground and no parts sticking out of block. More to follow.

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