X5 4.6is Engine Block from 4.4

[kclow]

My 4.6 block has developed 3 cracks behind one of the sleeve. I was advised by the machine shop that it will be risky to resleeve, and advised me to locate another block. However, finding a 4.6 block is tough. Has anyone managed to use a 4.4 block and rebored instead? Will it work? Thanks!

[diyanich]

Hi there,

I read a thread about the 4.6 block and 4.4 heads on an e39.
As far as I understand it reboring a 4.4 would remove a sleeve coating.

Originally Posted by kclow

My 4.6 block has developed 3 cracks behind one of the sleeve. I was advised by the machine shop that it will be risky to resleeve, and advised me to locate another block. However, finding a 4.6 block is tough. Has anyone managed to use a 4.4 block and rebored instead? Will it work? Thanks!

[kclow]

Originally Posted by diyanich

Hi there,

I read a thread about the 4.6 block and 4.4 heads on an e39.
As far as I understand it reboring a 4.4 would remove a sleeve coating.

Yes, I will need to resleeve after boring. However I read that the 4.6 has a larger bore plus also longer stroke, thus not sure it it will work. Also, the 4.4 block I have currently located is not from an X5 but from a 540, thus some mounting points seems different. Maybe I need to find a 4.4 from an X4 for comparison?

[diyanich]

have a look here

BMW X5 M62 | Engine Swap | Questions?

Originally Posted by kclow

Yes, I will need to resleeve after boring. However I read that the 4.6 has a larger bore plus also longer stroke, thus not sure it it will work. Also, the 4.4 block I have currently located is not from an X5 but from a 540, thus some mounting points seems different. Maybe I need to find a 4.4 from an X4 for comparison?

[Nick P]

There's no such a thing as a "sleeve" in M62 block - these are made of alusil which is a material and not a coating like nikasil - you can rebore the 4.4 block just by 1 mm to get the 93 mm 4.6 bore. The only thing being neccessary is a lapping of cylinder walls with special "brush" to disclose the Si-crystals in the Al-matrix, which are holding the oil particles for better lubrication.

Actually the only difference between Alpina 4.6 block and BMWs 4.6 block is that the Alpina used the 4.4 blocks and BMW used different casting form for 93 mm bore of 4.6 l block.

The block height of 3.0 L M60, 3.5 M62, 4.0 M60, 4.4 L M62, 4.6 M60 and M62, 4.8 M62 and 4.9 S62 are the same!

So - just go on!

[Qsilver7]

I'm not sure how to work around this issue...but there is a slight difference between the M62TU used in the e38/e39 sedans versus the M62TU used in the e53 X5 (the e53 engine has a different BMW part nbr versus the e38/e39 sedans which use the same engine part nbr). The front drive shafts run thru the oil pan (on the e53) which was done to help create a lower center of gravity,, maintain the 50/50 weight balance, and to fit the front AWD stuff.

Just thought Id mention this little kink (in case you didn't know) before you buy an M62TU from an e38/e39 and get a big surprise...see the text highlighted in yellow below:

[Nick P]

Originally Posted by Qsilver7

I'm not sure how to work around this issue...but there is a slight difference between the M62TU used in the e38/e39 sedans versus the M62TU used in the e53 X5 (the e53 engine has a different BMW part nbr versus the e38/e39 sedans which use the same engine part nbr). The front drive shafts run thru the oil pan (on the e53) which was done to help create a lower center of gravity,, maintain the 50/50 weight balance, and to fit the front AWD stuff.

Just thought Id mention this little kink (in case you didn't know) before you buy an M62TU from an e38/e39 and get a big surprise...see the text highlighted in yellow below:

What does it have to do with the block? The front diff is flanged on the oil pan, the block is the same. The other thing, which is different on X5 is the alternator holder and oil pan ventillation tubing - regarding the block itself, theres no differences between the M62TU blocks, only the very first M62s had a nikasil coating like the predecessor M60.

So every M62TU can be used in X5 - even the 3.5l version - saw a couple of these engines in X5, due the rather unpolular 3.5l engines are much cheaper, at least here in Europe - you can get a complete engine for less than 400$

[BRABUSBENZ21]

Originally Posted by kclow

My 4.6 block has developed 3 cracks behind one of the sleeve. I was advised by the machine shop that it will be risky to resleeve, and advised me to locate another block. However, finding a 4.6 block is tough. Has anyone managed to use a 4.4 block and rebored instead? Will it work? Thanks!

I just sleeved my 4.6is block with darton cast iron sleeves. I also had the sleeves diamond honed, and plated with a special chemical that makes the cylinder extra hard. So yes it is possible to resleeve your block. I also had the cylinders fitted with custom JE Forged Pistons. According to the guy at the Machine shop it is suppose be more reliable and have a higher compression vs factory. I should have my block back this week

[Nick P]

Originally Posted by BRABUSBENZ21

I just sleeved my 4.6is block with darton cast iron sleeves. I also had the sleeves diamond honed, and plated with a special chemical that makes the cylinder extra hard. So yes it is possible to resleeve your block. I also had the cylinders fitted with custom JE Forged Pistons. According to the guy at the Machine shop it is suppose be more reliable and have a higher compression vs factory. I should have my block back this week

JE pistons are made for iron sleeves you can't use them in alusil block (or you have to coat the stock pistons with ferrostane or similar material), but there's no need to sleeve the block - you can just bore it out from 92 to 93 mm and re-use the old pistins with new piston rings - it's much much cheaper, than putting the sleeves and new pistons.

1 mm bigger bore costs here in Europe about 600-700 Euro for 8 cylinders, a used 4.4 block is about 200-300 Euro max. a set of new piston rings is something like 150 Euros. Thats it!

[BRABUSBENZ21]

Originally Posted by Nick P

JE pistons are made for iron sleeves you can't use them in alusil block (or you have to coat the stock pistons with ferrostane or similar material), but there's no need to sleeve the block - you can just bore it out from 92 to 93 mm and re-use the old pistins with new piston rings - it's much much cheaper, than putting the sleeves and new pistons.

1 mm bigger bore costs here in Europe about 600-700 Euro for 8 cylinders, a used 4.4 block is about 200-300 Euro max. a set of new piston rings is something like 150 Euros. Thats it!

If you bore the block out, you will need to get the bore re-alusil or nikasiled.