So, many people would call me retarded for this, but I'm going to be taking Industrial Welding Fundamentals I and Metalworking fundamentals I classes very soon. The fuel mileage in my engine has been going to shit for a long time now, and I'm pretty sure it's because of the fact I need to change my fluids and more importantly, last time I cleaned my throttle body, there was a good amount of thick sludge coming out. You guys might say "but hey that's kinda normal for a car with 212k miles" well, my throttle body is only 49mm, and you guys with the supercharged L67 get a 62mm thottle body. It would affect an L67 a lot less.
Anyway, I took out the supercharger from Parts Buick today, and the Lower intake manifold off the blown L36 in the shed. The LIM needs some SERIOUS cleaning and I'm gunna get a giant plastic tub and soak the LIM and supercharger parts in the tub with diesel in it. Diesel is one of the best solvents and that alone will be almost as good as hot tanking it if I leave it soaking for a few days. I'm also going to port and polish the LIM. New gasket set is available in stock nearby for like $40.
Here's the supercharger and the LIM next to each other. I already have a decently thought out plan but I don't know everything about how the supercharger works yet, and I'm no master tech either.
My plan so far? Wait until I learn how to weld pretty well in the next couple months. I'm going to take the LIM out of parts buick soon. I will take the parts buick LIM, and cut off the very top of it and fabricate myself a spacer and interface between the L36 LIM and the supercharger. I will need thick aluminum plates and I will trace the shape of my plenum and cut that out in aluminim and weld some thick aluminum sheet metal from the base of that to the plate I cut off the parts buick LIM top piece. This space/interconnect piece will do a few things. It will align the shorter M62 to my engine belts, It will serve as an interconnect and mounting system along with me trying to get the bracket tension thingy off parts buick if that fits, and also I plan on getting the heatercore out of parts buick and using that as a water- air intercooler. I have a decent amount of things I need to make this happen already, and just need some welding equipment, a new engine belt, the aluminum plates, and a new rotary tool because mine broke
Anyway, people have said it's a bad idea for this, that and ten other reasons, but having the M62 already saves me a lot of money. A 75mm throttle body is a huge upgrade for me, and even a good upgrade for you guys and that alone saves me like $500. Iv'e been thinking about my fuel mileage issue for a while, and I'm like maybe 17 mpg highway right now and even less in the city. It's getting pretty bad. I was about to take apart my entire manifold and throttle body today, but then I just looked at my manifold and realized how much I hate it and how much it sucks. Then I remembered something I came across a while ago online. A guy with a pontiac bonneville L36 put in the L67 throttle body, ported his LIM and exhaust manifold with no other mods other than an intake and he gained 10% volumetric efficiency. I'm thinking I'd be seeing slightly better with an even bigger 75mm throttle body. The reason this interests me is because the M62 spools way faster than an M90 which would get me peak torque faster. Not good for my transmission if I plan on adding huge power but I'm not. Anyway I should be seeing way better fuel economy because the M62 has less parasitic effect on the engine than an M90 as well. This just as much about fuel economy as making my car go fast.
It's not going to get done overnight so I have a lot of time to think about it, but I think it's totally doable if I get some help here and there like knowing exactly how the M62 works and what sensors Id need replaced and whatnot. The good thing is I can use the extra engine as a mock up and my daily driver isn't affected until the day I install.
One thing I noticed is that after physically holding the LIM, it seems incredibly simple to do a mild porting job. Also Iv'e worked with grinding and shaping metal here and there with random projects so it won't be too hard.
Edit:
I think I'd also weld an additional thick aluminum plate over my LIM to basically act as a permanent HV inset, make the two holes for the 10mm bolts and simply plug those holes with two small rubber corks afterwords. That should help the manifold flow a lot better too.