ok just wanted give you a heads up before you pulled the trigger, didn't know they were interchangeable. glad you cleared that up.

Yea, $500 for a crank is just crazy! You could probably find a wrecked truck or one with a blown head gasket for not much more than that.

Abran had a crank and rods a few weeks ago, but don't know if he still has it or what he wanted for it.

You may have to call some of the parts reapers on here. drillbit, paul grant,will tillery or one of them. I know those things are heavy so shipping may be too much.

 

Thanks! I'll talk to them! I am close to paying a few hundred for one. This helps talk me down. I can use my company shipping account to make it cheaper.

I also checked into whether a balance issue would exist using a different flex plate. I've been reading up on the Buick 215 and Rover variation on it. Turns out our 4.0 and 4.6 engines are internally balanced and all of the components used with them are also individually balanced. Nice surprise to find!

 

Thanks, that is very good to know. Somewhere I read that the crank, flywheel and balancer were balanced together. I didn't figure that was correct, since if you had to change one part out it wouldn't be matched to the crank. I do see that the balancers have different gram weights so i guess that is just what it took to balance that particular part and has nothing to do with anything else.

also, if you find out any definite answers on whether the Buick 215 or 300 cam bearings will work in our engines, pass that info along as genuine and even aftermarket land rover cam bearings are outrageously over priced. I guess they price those according to whatever the market will bear.

You seem to be good with your research, much better than me and getting around in the rave manual is an experience in itself. When I was doing the head gaskets, oil pump and timing set on my 03, I spent more time trying to navigate the rave than I did actually doing the work. old age I guess? that and being way behind the curve with computer skills. and it doesn't help that they call parts by different names than the other engines I'm used to tinkering with.

also another thing... I see connecting rods on fleabay that are advertised as fitting both bosch 4.0 and 4.6. It is my understanding that they are not the same, maybe in length? So either the seller doesn't know that they are not the same or whoever told me that they are not the same is wrong. You may want to look into that since if they are the same it would save you from having to buy connecting rods. Probably just the ebay seller is wrong in his/her listing?

I'm not sure if you had a chance to read in my 4.0 thread where I replied your questions earlier but, I was saying if you need a copy of the pdf I have for pinning sleeves and parts list with part #'s, I can email that to you but you'll have to PM me an email address. I can't attach it to a PM. May be something you would like to save even if you are not doing it now. You may already have the pdf?

Thanks for all of the research and info. It is very helpful.

 

this is a great thread man. just sayin' good job.

 

rotating assembles are balanced ie. flywheel. crank, rods, pistons and harmonic balancers are all part of that assembly.

 

bummer drow,

So if a person needed a new flywheel due to a bad ring gear or something would he have to have the whole rotating assembly rebalanced?

I totally trust everything you say, you've been working on these forever, so I'm not doubting, just asking. I'm still learning and so much conflicting info floating around.

 

I'd like some definitive answers, too. Here's the link to the site I read about our components not needing to be balanced because they were individually balanced.

Affordable Aluminum Buick / Rover Stroker Motor, by Kurt Schley

BEWARE! While reading it, you will be strongly tempted to rebuild your engine as a stroker! My wife won't let me, so it's off the table...for now.

Oh, and on the cam bearings, my machinist, who has worked on these engines for a long time says he has no issue using 215 or 300 bearings on the rover engine! Hooray for cheap bearings! Unfortunately, I already paid $70 for mine... but they're being installed now, and I am taking the block to be pressure tested on Monday.

 

thanks for the info on buick bearings. good to hear it coming from a machinist that has been working on these for a long time.

oh well $70 wasn't that bad. I guess those are unfinished and your machinist will finish them. I see some for almost $200.

Good to hear on your block pressure test, let us know how that comes out and how much it cost.

 

"So if a person needed a new flywheel due to a bad ring gear or something would he have to have the whole rotating assembly rebalanced?"

NO, but you do have make sure it came off of the the same type of assembly, as you have found out there are differences between the 4.0 and the 4.6 that people over look.

Yes the parts will fit and they can be bolted together but will they WORK TOGETHER is a different story. Is the motor going to shake itself apart at 4k rpms? will you only get 10k out of the bearing because the lower end is so far out of balance.

Balancing is the single most expensive part of rebuilding a engine, which is why you can save so much buy using a complete assembly that has already been matched.

Weight balance is a big one that people skip over; with out going threw a bunch of part number I'll guess that there are at least 4 or 5 different flywheel and harmonic balancers combination because they are weighted differently.

JMO

 

Thanks for this. The need for some definite and test input would be helpful here. I would like to see something definite from someone who has built a few of these 4.0's into 4.6's.

The Stroker write up says he uses all of the different parts interchangeably and has done so on dozens of engines because the land rover 4.0 and 4.6 assemblies were independently balanced. Is that true? No clue. I hope so, but is there anything official from Land Rover about their rotating assemblies?

The write up mentions other variations on the Buick 215 require balancing, but not the rover 4.0 or 4.6. I would really like to know his source for that info.

Has anyone put a 4.6 crank and rods into a 4.0 and had any issues?

I think I'm going to do some research on our engine and contact the land rover engineers who designed our 4.0 and 4.6 engines. I'm still in college and my budget won't allow for rebuilding the engine for my stupid mistakes the first time. I want to do a few cheap easy upgrades while I have it apart, but only if I can know it's not going to hurt in the end.