First post, sorry if this subject has been discussed hundreds of times. I need an oil recommendation for a break in of sorts. The situation is this. Ford 5.4 modular motor, boosted (S/C). Fairly fresh rebuild, bored .030" over. Builder filled with 15w40 semi-syn when he finished the build. Told me to drive it home, approximately 25 miles, then change the oil to 5w20 of any brand I liked. I filled with Motorcraft 5w30 semi-syn and the truck leaked from the rear main, the oil cooler housing and the passenger side head oil gallery plug. Called the builder, he towed back to his shop, replaced the rear main, cooler gasket and sealed the gallery plug. Told me to keep using the same oil, no problem.
I was having consumption issues, so went to 5w30, which the builder said was fine. The motor has approximately 400-500 miles on it now and is using oil like crazy. Like 1 qt every 120 miles or so. There are no visible leaks anywhere. I went to M1 5w30 and it got worse. I called the builder back, he said the rings apparently had not seat yet and could take several thousand miles for that to take place. He said to switch to a conventional oil until it stops consuming oil and the rings seat fully. He said by using a synthetic, or even semi synthetic, the rings won't set.
I know the logical question will be about the PCV valve. There is none. It is vented to a filtered catch can off each valve cover. That is, each cover has it's own can. These setups have a tendency to draw oil into the intake through the PCV system. Builder suggested the breathers until it was all broken in.
So essentially, my question is this. In order to get these rings seated, which oil would be recommend and what weight? He suggested staying at 5w20-5w30 but said could go to 15w40. I'm not so sure of that, as I had understood the Ford mod motors needed a bit lighter weight oil for the timing chain setup. I was thinking just plain Pennzoil 5w30, or Castrol GTX. Havoline isn't available in my area and from reading this site, those seem to be the main 3 looked upon as good oil. 30wt break in oil is a no go. Any help and guidance appreciated.
I was having consumption issues, so went to 5w30, which the builder said was fine. The motor has approximately 400-500 miles on it now and is using oil like crazy. Like 1 qt every 120 miles or so. There are no visible leaks anywhere. I went to M1 5w30 and it got worse. I called the builder back, he said the rings apparently had not seat yet and could take several thousand miles for that to take place. He said to switch to a conventional oil until it stops consuming oil and the rings seat fully. He said by using a synthetic, or even semi synthetic, the rings won't set.
I know the logical question will be about the PCV valve. There is none. It is vented to a filtered catch can off each valve cover. That is, each cover has it's own can. These setups have a tendency to draw oil into the intake through the PCV system. Builder suggested the breathers until it was all broken in.
So essentially, my question is this. In order to get these rings seated, which oil would be recommend and what weight? He suggested staying at 5w20-5w30 but said could go to 15w40. I'm not so sure of that, as I had understood the Ford mod motors needed a bit lighter weight oil for the timing chain setup. I was thinking just plain Pennzoil 5w30, or Castrol GTX. Havoline isn't available in my area and from reading this site, those seem to be the main 3 looked upon as good oil. 30wt break in oil is a no go. Any help and guidance appreciated.