I have heard alot of comments about the M5 3,8 L engine that it have some weaknesses. What weaknesses are there and is it true? What makes the M5 3,6 L engine better, if you compare the two engines? I am very interested in buying a M5 3,8 L and that´s why I ask the question?
Nope other way round my friend. The 3.8 is the better block owing to the power output, the stronger double wound chain and stronger 6spd gearbox from late 93.
The main weakness is rough running at low revs (as highly tuned cars do) and the fact the power delivery all happens after 4K revs. Think of a turbo.
The sound on both the 3.6 and 3.8 block under acceleration is God singing.
Apart from the odd oil leak now and then, they are quite reliable for such a highly tuned block with most on the board now well over 100K and going strong.
Remember 345bhp out of a 6 cylinder is still impressive by todays standards!
regards
M5 Powered
__________________
1995 M5 Limited Edition (02/50)Rosso Red
Pilot Sport 2 Rubber
Valentine One With Conceal
Twin Head LRC100 IR Jammer System
Origin Blue B2 GPS
Both 3.6 and 3.8 have the Duplex timing chain. The 3.8 block is not physically or mechanically (only slightly here) stronger than the 3.6, it just makes more power.
Both are strong engines. The difference lies mostly in the bigger bore and longer stroke (96.4mm x 90mm) of the 3.8. The 3.8 also features different intake and exhaust valve sizes. Weakness lies in that the 6 cylinder crankshaft is very long and at high rpms has a tendency to bend.
Might as well get a 3.8L over a 3.6L. Both have the same basic weaknesses, and the hp/L ratio is higher on the 3.8.
I never knew that, my local stealership told me the 3.6 wasn't a duplex chain when I first started getting advice on M5's. Was it a duplex on the original late 70's racing engine its derived from?
Never heard of the crank bending, although its understandable with such high revs possible and if you've had the rev limiter increased from stock.
That's the great thing about these cars...you never stop learning about them!!
__________________
1995 M5 Limited Edition (02/50)Rosso Red
Pilot Sport 2 Rubber
Valentine One With Conceal
Twin Head LRC100 IR Jammer System
Origin Blue B2 GPS
Regarding reliabiliy issues on E34 m5 engines both versons are very strong, they just have different weakneses. and some common ones. but considering the power outputs very few indeed.
Both 3.6 and 3.8 are prone to oil leaks from the front timing cover gaskets and sump gusket.
The main difference is that the 3.8 was further developed to improve its power delivery, the 3.8 engine is more torquey and has a more linear power delivery, it also develops more power thanks to larger valves , different cams and cam timing, and larger throttle valves and more modern ECU system. For further information read both the technical files for the 3.6 and 3.8 engines.
For either model you should expect to cover more than 200,000 kms before needing any major surgery, providing its well maintained and not abused.
The later models have the benefit of the further develpment made by BMW and in some aspects are more complex, like EDC suspension, etc, but can prove more expensive to maintain when repairs are needed.
I never knew that, my local stealership told me the 3.6 wasn't a duplex chain when I first started getting advice on M5's. Was it a duplex on the original late 70's racing engine its derived from?
The S38B35, the engine that was put in the US-Spec E28 M5 had a duplex timing chain, the first-example of duplex chains in the S38 lineage. The M88/3, the engine put in the Euro/ZA Spec E28 M5 had a single timing chain.
Joe,
On the oil pan gasket, can you just remove the oil pan and replace it? I need to replace mine.
Let’s not forget that 3.6 litre engine block is made out of iron and as such is much stronger than 3.8 litre engine that is made out of aluminium. I also believe that the 5-speed gearbox is equal in strength to the 6-speed one except 5-speed is not as heavy.
The 3.8l engine definately has a cast iron block. It's quite an heavy engine. It also has some improvements in design to allow for better cooling, but the distance between bores is not long.
Both are strong engines. The difference lies mostly in the bigger bore and longer stroke (96.4mm x 90mm) of the 3.8. The 3.8 also features different intake and exhaust valve sizes. Weakness lies in that the 6 cylinder crankshaft is very long and at high rpms has a tendency to bend.
Found the bore to be the same as when i was sent the wrong block on my rebuild the pistons were exactly the same with the same rings as well,the stroke however was longer on the 3,8L
Amazing what you learn by other peoples mistakes
__________________
Steve Mac
_________________
If knowledge is power,,,how brainy are my Baby`s
2001 Le Mans beast ///M5
1995 Fjord grey M5 she's a lady
2002 Black Beauty 320i Sport!!
decisions decisions
Originally posted by Marek ...the 5-speed gearbox is equal in strength to the 6-speed one...
Gearwise, yes.
But, the synchos meshes are not a strong, nor as long lived. The 5 speed box will go "loose" and become quite noisy at big miles, whereas the 6 speed would still be relatively quiet.
There was a thread giving details some time ago, I`ll see if I can find it later.
Ivan.
__________________
"Never enter Karussell when on the brakes! I have gone round there on the roof, I know what I'm talking about." ~ Sabine Schmitz
Linear Mode
