205 turbo crank pressure problems
Discussion
Hi i have a 205 turbo sprint car and im getting major problems with crankcase pressure , if i give the car full boost it blows the dipstick out and sprays engine with oil ,checked all breathers for blockages and all ok, plugs all ok no signs of oil, turbo seals seem ok no oil in pipes to intercooler or in air filter ,im aware that you can get pressure from worn rings but i have no loss of power at all , just wondering if a stuck wastegate could cause this problem ie excess boost pressure leaking past rings ? any advice gratefully received regards steve
ha ha hope you won on grand national ! to be honest i didnt build this engine it was built in holland, cars a griffe maxi turbo i know its got forged pistons its in a diesel block and its a t28 turbo heads nicely ported but apart from that not sure of spec i know its a stressed unit putting out 290 bhp so i guess somethings got to give at some point any suggestions on rebuild spec appreciated :-)
just to add a bit more input the engine was built with all new rods and pistons in 2009 i didnt build engine its a left hooker griffe from holland with my very untrained eye i cant see any other damage or signs of wear on the other pistons no signs of any pitting on piston tops, big end bearings look fine etc i have an article in a dutch magazine in which the car was featured i cant read dutch but i can make out a few things it mentions 7,2:1 i assume thats compression ratio which seems low to me even for a turbo car ? dont think 1.2bar is low boost to be honest , i drive car hard its a sprint car so it gets max attack although only for a short time
Pushing an already built modern engine to the limit to see what happens is totally different to having to re-build a very old one which was designed as N/A and has seen a lot of action.
Some engine makers are known for over specifying parts, many are not.
There is a lot more to engine (component) failure than bending a rod and det'. I've taken out failed pistons with no signs of det whatsoever and seen plenty of unexplained big end bearing failures.
Unexplainable by the customer that is, until a strip down revealed that the old rods had gone oval around the bearing journal due to the constant stress on a weaker grade of steel. Also old factory rods for lower power often have no positive location for the end cap and weak bolts, this leads to the cap walking around and bearing failure.
Do people blame the failure of a bearing on the rod? No.
Do people blame the bending of a rod on the actual rod? Yes.
Both can be incorrect assumptions, quite often you have to look further than the end of your nose.
The re-fitting of a 20yr old stressed component in a new build is laughable, not when decent rods can be had for not much more money than new OE ones in many cases.
There is a lot of enjoyment to be had from taking a properly built strong engine by the scruff of the neck and giving it hell, much more than pussy footing around wondering if something might break....
Evoluzione said:
stevieturbo said:
It's an engine running very low boost, so under very little pressure. Boost rarely ever kills rods, rpm does. And doubtful this engine is a screamer.
It's all very well saying yes...buy this, buy that, lets buy the best of everything...for an engine barely making 50% more power than it had anyway.
Why stop and rods and pistons...why not crank, why not a better block, why not...etc etc
A prime example is the current phase of people buying 4.8 and 5.3 LS based motors in the US. They're boosting them with standard crank, rods etc to 4-5x the original power output and they're surviving quite happily. The short motors arent anything fancy at all, but they are so cheap to replace, they just dont care. Except they are holding incredible amounts of power.
OEM Subarus....the turbo engines right use the exact same rods as the 1.6, 1.8 etc n/a engines right through from the late 80's until early 2000's
Just because a rod is in a n/a engine, doesnt mean it is weak or unsuitable for boost.
The engine is fitted to a competition car running 1.2 bar more than standard, it's going to get plenty of abuse right from the off.It's all very well saying yes...buy this, buy that, lets buy the best of everything...for an engine barely making 50% more power than it had anyway.
Why stop and rods and pistons...why not crank, why not a better block, why not...etc etc
A prime example is the current phase of people buying 4.8 and 5.3 LS based motors in the US. They're boosting them with standard crank, rods etc to 4-5x the original power output and they're surviving quite happily. The short motors arent anything fancy at all, but they are so cheap to replace, they just dont care. Except they are holding incredible amounts of power.
OEM Subarus....the turbo engines right use the exact same rods as the 1.6, 1.8 etc n/a engines right through from the late 80's until early 2000's
Just because a rod is in a n/a engine, doesnt mean it is weak or unsuitable for boost.
Pushing an already built modern engine to the limit to see what happens is totally different to having to re-build a very old one which was designed as N/A and has seen a lot of action.
Some engine makers are known for over specifying parts, many are not.
There is a lot more to engine (component) failure than bending a rod and det'. I've taken out failed pistons with no signs of det whatsoever and seen plenty of unexplained big end bearing failures.
Unexplainable by the customer that is, until a strip down revealed that the old rods had gone oval around the bearing journal due to the constant stress on a weaker grade of steel. Also old factory rods for lower power often have no positive location for the end cap and weak bolts, this leads to the cap walking around and bearing failure.
Do people blame the failure of a bearing on the rod? No.
Do people blame the bending of a rod on the actual rod? Yes.
Both can be incorrect assumptions, quite often you have to look further than the end of your nose.
The re-fitting of a 20yr old stressed component in a new build is laughable, not when decent rods can be had for not much more money than new OE ones in many cases.
There is a lot of enjoyment to be had from taking a properly built strong engine by the scruff of the neck and giving it hell, much more than pussy footing around wondering if something might break....
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