Does anyone know the bearing clearance for rods and mains in a 4.6?
I cannot find it in the Rave manual.
I want to plasti-gage the bearings before I reassemble this engine, to make sure none of them are tight.
Thanks

 

Check pg. 04-5 of the RAVE. For the "main bearing" is says 0.015-0.016 mm or 0.00059-0.00063 in.


It also states the "Big-End" bearings with the same clearance. I am assuming that "big end" is the big end of the rod?

Seems weird that the rod bearing and the crank bearing would have the same clearance. Perhaps someone else can further clarify.

 

Thanks
I saw that, but that makes no sense to me.
I'm not beliving this pos engine's tolerances are 4-5 decimal places, especially since it's revving out around 4k rpm.
Piston clearance is the same...nonsense.
I have the larger B pistons, which measure to the smaller A piston specs. Which tells me they are worn out.
Yet, the pistons are supposed to be .001-.002" smaller than the bore...which they are. Which means they are in spec, and contradicts the whole A-B size difference.
Pistons measure 3.699, and bores measure 3.700, with a couple bores being 3.703. And 3.7019 is supposed to be the limit. That aside, the others are good, and that's the bore, not the piston.
The Rave also says not to hone the cylinders, which I had done away.
I like How Land Rovers drive, handle, look, etc, but it never seases to amaze me what a fantastic piece of sh*t they are.
I will be fixing everything correctly on my 04, then it's going up for sale, or trade for a good truck.
I can't deal with this junk any longer.
Sounds like not only did LR use poor quality everything, but they really don't know what's going on either.

 

Does anyone else have any insight on this?
Anyone rebuilt a 4.6 and plasti-gaged or bore gage measured these clearances?
I do not belive the aftermarket bearings could even hold a 4-5 decimal place tolerance.
I don't want to just throw this thing together, have a tight bearing, and ruin all this time and money.
Then again, with such a small tolerance, if the crank turns and doesn't have any noticeable play, it should be ok.
The crank was polished, and bearings are standard size.
Thanks for any help, I'm really back to hating anything and everything Land Rover.

 

Not so odd to have the same/similar clearances since the diameters are relatively close to each other.

You may want to do some reading about diametrical clearance. LR does has had a tendency to use some oddball terms.

Your LR bearing clearances should be basically the same as other similar engines and not set in stone.
......

 

About 0.0005" Sixpack, you certainly don't want much more as it'll rattle. IMHO it's too little to Plastigauge successfully. Use specific assembly lube before assembling permanently.

Check out the max/min clearances in RAVE.

 

You're right, too small to plasti-gage.
Yes, I have assembly lube too.
Thanks

 

Thanks, but I was reffering to such a small bearing clearance.

And, the clearances will have to be checked with a bore gage.'

 

Exactly. I installed the cam bearings+cam, then the main bearings and main bearing caps. Then I attempted to rock the crank forward/backward. I pressed down on the front end of the crank. Then I pressed down on the rear end of the crank.

No rock equals good. What's the term that LR uses here, checking for "end float" that way? Heck, I think that I may have also checked for rocking prior to installing the main bearing caps, as well. Memory's foggy.


Then I turned the crank and got medium resistance. That's good. What you don't want is a seized crank (too much resistance equals too tight bearing clearance/tolerance).

You also don't want a crank that just spins freely, as that would suggest tolerances that are far too high equals gap too wide so you wouldn't get oil pressure.


If there was no crank grinding and you are using standard bearing size, how could there be too much or too little bearing clearance?

Using same crank as before with same bearing size as before in same block as before should equal pretty darn near the same tolerances generally, right??

 

Same block, same crank...but new All Makes bearings.
The bearings are the kicker.
Are they too tight?? Can their cheap production hold 4-5 decimal places??
That's my concern.