4.6 Replacing my 3.5

[John Hamilton]

Hey guys,
I just want to make sure I'm not missing anything important.  From reading here, I should be able to remove the SD1 timing cover, balancer and flywheel from my 3.5 and use them on my 4.6 engine, is that correct?  I want to replace the heavy steel flywheel with an aluminum unit while it's out, is there anything I need to do to use the new flywheel?  I understand I have to use an early camshaft and a spacer for the crankshaft, am I missing anything?  Does anyone have an aluminum flywheel or a racing cam for sale?

Thanks, John

[BlownMGB-V8]

Not sure about the camshaft and spacer John, but for a street engine I'd recommend about a 20lb flywheel rather than the aluminum one which will be around 10 or 11. It'll be more driver friendly. TA sells a billet steel one that is 26lbs. That one should work well with the larger displacement and can be further lightened to around 20 if you like. I've run a wide range of weights, and unless the car is being raced the aluminum is really a bit too light. Stock Buick flywheels tend to be around 30 lbs or more.

Jim

[John Hamilton]

I am racing this car, so I ordered an aluminum flywheel. I dropped all of my parts at the local machine shop today to get the block bored and the crank turned down to SBC rod journal size, but they said they couldn't narrow the Chevy rods for me. Any recommendations on a machine shop willing to perform this for me?

Thanks, John

[BlownMGB-V8]

First thing is to decide whether to cut one side or both, probably determined by how the insert seats and the big chamfer. To narrow the big end they can be turned, milled, or ground. I'd guess turning them might be the most satisfactory and any general machine shop with a decent sized engine lathe and a 2" expanding collet chuck can do that pretty quick and easy, especially if you bring them assembled and torqued, take them away the same and deburr them yourself. Or take them directly to the automotive shop for resizing. The main thing you want is for the two sides to be parallel and the small end shouldn't need to be cut.

Jim