DriftMe said:
I think you got that wrong, 4-valves on any motor is better than two large valves. I won't get into the details, but I think I'll stick to the 5M-GE for my purposes. How many MPG should a fairly new 5M-GE get according to specs.
No I didn't, you are partially wrong and you misinterpreted what I said. When I said theres no advantage I was refereing to a 7m head on a 5m bottom. Its the same amount of work to get a 7m head working on a 5m block as it is to just swap in the whole 7mge, less actually. Then you get the dissplacement bump, the right pistons for the head and a newer bottom end. As for the 2 valve bit, your also wrong. 2 bigger, beefier valves are stronger and allow more flow then 4 little valves, not to mention it makes a cheaper and easier head rebuild. Now the benefits of a 4 valve head on an NA engine probably overweigh those strengths, but its a whole other matter on a heavily boosted engine. A 7mgte bottom with 5m or 6m head would be a wonderful combination.
As for the worse gas milage in the truck, its hard to say. Definatly worse wind resistence, but those old toy trucks aren't that heavy, and our cars aren't exactly paperweights. Keep in mind gas milage is directly proportionant to RPM and load. The more torque you have to play with, the lower final drive ratio you can run with a lower rpm at the same speed. Bigger tires will travel a longer distance at the same rpm. 5mge swaps are pretty common on old toyota pickups, and when the 4bangers are swapped out for them they usually get better gas milage as the motor doesn't have to work so hard to move the truck. A gutless 4 cylinder will be working under max load to keep a vehicle like that going, while a torquey 6 cylinder will be just cruising at low rpm.
Supra motors are pretty common swaps in toyota pickups, check around for some forums on those trucks and there should be plenty of info out there on this. The diff I'm putting in my supra came off a supra that was having its 5m swapped to a pickup.
