I am building a new motor. It's a new Sportsman block from GM with splayed four bolt mains. The problem I am running into is that I've tried three different oil pans and none of them clear the main caps. The main cap ends are straight up from the inside the of the machined surface for the oil pan and that's where the pans hit. If you look at pretty much any oil pan, the surface where it meets the block down to the bottom of the pan isn't a true 90 degree, as it curves a little thereby making the width a slight bit narrower than the the opening/mounting surface on the block. Is this a common problem with Sportsman block and four bolt mains? r
I'm probably gonna get "pounded" for this, but back in the day there was a similar problem when we put a Ford "B" motor in an "A" body : The "A" pan was too narrow to clear the "B" rod caps, so our answer was to "massage" the "A" pan with a 'Ball-peen' hammer in 4 places on each side for the required clearance. It shouldn't take much similar "Massaging" on the modern pan(you could also use a little heat to make it easier to 'move') to get the necessary clearance. Unless you're building a 'show' motor, it shouldn't be especially noticeable, & if you are building a 'show' motor, it probably would be a good idea step-up & buy the proper factory pan.
As others have said. Order a GM pan that is made for that engine. You would think they would make a pan for the engine they build. Order the gasket as well. That might be part of the answer.
I've tried two stock pans and one new aftermarket pan. They all hit the mains. I didn't want to 'reshape' the pan if I didn't have to, but that might be the easiest way... r
May not be the cheapest option but the easiest way is to write the check and wait for the big brown truck to show up.
I understand, but going that way was always against my better judgement. Besides, I've never had alot of capitol wo work with and just made due with what I had available to me. r
Is this a one-piece rear main seal block, or a two-piece one? Blocks with 1-piece rear main seal use the Gen VI-style 6-bolt front cover (#809-10230954) and Gen VI-style oil pan. Blocks with 2-piece rear main seal use the Mark IV-style 10-bolt front cover and Mark IV-style oil pan. There deciding factor on exactly which pan will do the trick from the Gen VI parts bins is the stroke of the crank that you are running. $260 will put you in a pan that can handle a 4.625" stroke. Now, if you are running a stroke of just 4.00, you are looking at $170. Less than than, $90.
If you try to put the pan on, how far is the lip from the block when the main caps stop it from going on any farther?
Circa 2001, BBC pan rails changed, with what was then known as the Gen V block (EFI only, no fuel pump boss). These are known as the Vortec 8100. These were made until 2007/2009 (depending on model), until GM sold the engine line to the Workhorse division of Navistar. Mark IV parts to not readily interchange with Gen V/VI engines. Gen V/VI engines have metric fasteners. Heads don't interchange, etc. The GM Sportsman blocks are Gen VI (fuel pump boss reappeared on the Sportsman ones), different timing cover, added features for cooler lines, pressurized oil feed, one casting that supports either one-piece or two piece main seals, extra webbing, more core plugs, etc. I believe that you will need a 2001-later oil pan, known as a Gen V or Gen VI oil pan. If you are running a non-stock stroke, you will for-sure need an aftermarket pan, or will have to do some surgery.
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