Can we swap cross bolted mains onto TDC?

[sd_iconoclast]

It is my understanding that the 3x00 engines have cross bolted mains and cast aluminum oil pans, Is there any reason we cannot swap these onto a TDC? Is a timing cover change required also?

[SappySE107]

RE: Can we swap cross bolted mains onto TDC?

Its not a direct swap, something has to be modified. Hopefully next week my shop partner will have the trucks out of the shop so I can get to the 3100 block he has. I have a DOHC block that I want to test fit the mains/pan with cause I am interested in knowing what it takes to swap this as well.

[sd_iconoclast]

Do you know if the timing covers or oil pans will at least bolt up?

[SappySE107]

oil pan will not bolt up as the bolt pattern is different to the block. I have no idea on the timing cover yet.

[Fierobsessed]

Timing covers are not swappable. The TDC uses a HUGE timing cover that serves as the belt housing and holds the Idlers and tensioners for the timing belt as well. The pushrod one covers the chain and not much more... Ironically though, they can still actually be swapped. But there is no good reason in the world that would require you to do that. The mains swap directly to the block, You only need the first 3 mains since the rear main is identicle. After a mains swap, you MUST align bore the mains and block since they were not machined togather origionally. Where the oil pan meets the timing cover has not changed in design since 87, so that is a non issue. The block needs to be drilled and tapped all along the base of the block to accept the 3100-3400 oilpan, also the unused holes must be sealed or else they will leak. So far no one has attemped this swap, but it looks at the very least...feasable. Roughly 1/3rd of the bolt holes line up. Most on one side and none on the other.

[farmerz24]

i think it is fesiable and will work. fierobsessed: you talk about align boring the mains and block.. is this the same process or 2 different ones? i thought only the crank mains had to be lined bored. also, how does the bearing still fit in there perfectly if they are actually removing material?

[Fierobsessed]

I meant just the crank mains. And actually, I don't know the answer to the second question. It's not something I have ever had done to my engines. If I had to guess, I would say they remove so little material that it doesn't even register on the plastigage. But again, I really don't know.

[sd_iconoclast]

i think it is fesiable and will work. fierobsessed: you talk about align boring the mains and block.. is this the same process or 2 different ones? i thought only the crank mains had to be lined bored. also, how does the bearing still fit in there perfectly if they are actually removing material?

Align boring the mains or block is only one process. A few thousandths are shaved off the mating surfaces of the bearing caps, making the hole for the bearings very slightly football shaped. They are then align bored.

[butchville]

also you can get bearings with diff thick thrust widths to set end clearances. if you didn't know