4.6 rebuild questions

[chris1d2se7]

Hi everyone,
My 4.0 2001 d2 has a slipped liner?/ cracked block etc. I picked up a 2003 4.6 block with pistons and crank looking ok. The problem is the cam is in 3 pieces and the cam bearings are shot (see pics). My questions are can I or a machine shop install and stake new bearings with the crank still in? and are the blocks for the later model 4.6s better/ thicker walls than the 4.0s?
Yes I searched a lot and if I had more $$ I would remove the internals and test the block and get the cam bearings professionally installed. I don't want to throw a lot of money at this truck. I just want my son to drive it for his senior year of high school coming up.
Does anyone have experience staking cam bearing? Please share if you can. Thanks

 

[bendts]

Holy crap - I'd be worried about what jammed up so bad as to break the cam into 3 paper weights.

 

[Mike26]

The later model 4.6 blocks were the same as the earlier 4.0 blocks in thickness, and in most cases crappier

 

[chris1d2se7]

I have read that the 4.6s used red grade and sometimes yellow grade blocks due to core shift, while the 4.0s used blue grade and sometimes yellow grade blocks. This would mean that the chances are that the 4.6 blocks have thicker piston walls than the 4.0s. Make sense?

 

[ptschram]

There is no difference in the metallurgy or design.

Anyone who took an engine that suffered damage like that and did not tear it down before beginning work is folly at the least.

I guarandamntee you that there are little bits of metal throughout the engine. Not to mention the rod journals are almost certainly at least 0.015" undersize.

Not to mention the likely reason for the cam failing so dramatically is due to mis-aligned (or not through-drilled at all) cam oiling galleries. It is very rare for a camshaft to break in such a fashion without a connecting rod having been involved or major oiling system problems.

 

[FB111]

Penny wise and a pound foolish.

 

[discostew]

What did the rest of the valve train look like ? When the valve train comes apart I figure it was over rev for a cause of failure . But it probably has metal thru out at this point . With all that damage to the cam bearings the block has to be destroyed . The bearings could have been moving around and blocked off the oil feed like PT was talking about . I know a machinist who stakes them but you have to start with a good block I would think.

 

[chris1d2se7]

I knew I could count on dweb to give me the straight truth.
I have never tore down a bottom end. So should I bother to tear the block down if it has metal throughout it? Do you think it is just junk? Here are some more pics. I don't know what happened to the valve train.

 

[KyleT]

Yes junk.

 

[ptschram]

I'm not gonna be so quick as to condemn it immediately before tear-down and inspection.

As you're less experienced, it will be a good exercise for you to disassemble the block. Be aware that the main caps are in very tightly and will need some persuasion to come out, do not use a tool that will scar the mating surfaces to pry the main caps out.

When removing connecting rods, be careful to not scar the crankshaft journals as that just causes more problems and expense down the road. I bought some sort of poly plumbing pipe to fit over the studs on the older blocks. For the DIS engines. use of two pieces of dowel rod stuffed in the bolt holes might be of help to guide the rods out-although as I think about it, as they use bolts and not studs/nnuts, you don't have the studs to worry about scraping along the crankshaft.

When you get it torn down, drag it to your local machine shop (pick the best one you can find-while there is no black magic to these engines, some machine shops are simply better than others). Have the machine shop guys remove the cam bearings (ain't no way I'd ever use cam bearings that were in use when a catastrophic failure like that occurred). and inspect to ensure that there are cam oiling holes in the block. There was a batch of blocks in late 2003 to early 2004 that had some problems with either the holes not being drilled, not being drilled in the right place, or not being the right size. When they inspect the crankshaft, tell them to expect 0.015" of wear on the connecting rod journals and less wear, but some on the main journals. The heads should be straightforward for any machine shop working on current engines.

When it comes time for parts, contact me as I can get the (for some) seemingly unobtainium undersize bearings, the correct (or exotic if you want to go that route) piston rings, the dowty washers for the cross-bolts. If you want to get really crazy, send me your block and I'll send it back with a displacement of 4.947 litres. Yes, I have just publicly disclosed the engine I'm building and I'm confident enough in this displacement to begin offering them to the public. No, you can't have the BIG bore engines...

If you want one of my engines, get your wallet out, they ain't gonna be cheap, but you'll have the only one around. Double the price for super-charged.

 

[robertf]

What brand piston ring do you carry?

 

[mbrummal]

snip..

If you want one of my engines, get your wallet out, they ain't gonna be cheap, but you'll have the only one around. Double the price for super-charged.

What's the price for the N/A motor?

 

[FB111]

From first post:
Yes I searched a lot and if I had more $$ I would remove the internals and test the block and get the cam bearings professionally installed. I don't want to throw a lot of money at this truck. I just want my son to drive it for his senior year of high school coming up.
Does anyone have experience staking cam bearing? Please share if you can. Thanks

Don't think he will be springing for the 4.9 liter

 

[chris1d2se7]

You never know if someone has money or just doesn't want to throw it anyway on a crap motor. A well built 4.9 might be an option if I decide to keep and invest in the truck. It has some frame rust so I don't know, but these things can be fixed... It might be cool to have the only 4.9 engine around.