Excessive carbon on B Heads
#1
Excessive carbon on B Heads
I just bought a 97 MK VIII engine at a very low price. I will be retrofitting it into my 98 GT.
The catches:
1) I do not know if it runs
2) Had to drive for three hours each way to get to the engine
3) The engine had the valve covers removed, as well as the upper intake, so bolts were missing and water got inside
4) Had to remove it from the totaled car which was parked on soggy dirt with a hoist from the seller, with little tools (I had a neurological flatulence and forgot my tools at home)
Needless to say it was an ordeal, and at the end of a five-hour struggle with the help from the seller I was finally able to load it on my truck.
It came with all the accessories, connections, intake tube, filter housing with MAF, and the throttle body and cruise control cables, wiring (will dump)and vacuum lines (will reuse).
The previous owner took out the valve covers and the upper intake. With the intense rainy season the engine got flooded, with about 3 gal of water on the pan, and about 1/2 gal in the intake.
I took it apart and cleaned it up. Amazingly enough the engine seem to still be in good shape, and after a good clean it spins freely.
I found a considerable amount of carbon deposits in the intake, mostly I the non-injected ports, and a couple of square ports with deposits as well.
The engine has about 150K miles of unknown use and care. I am in a tight budget and am trying to avoid taking the heads off, but want to make things the right way.
Is the amount of carbon normal for the age and use?
How concern should I be in regards to the state of the engine?
The catches:
1) I do not know if it runs
2) Had to drive for three hours each way to get to the engine
3) The engine had the valve covers removed, as well as the upper intake, so bolts were missing and water got inside
4) Had to remove it from the totaled car which was parked on soggy dirt with a hoist from the seller, with little tools (I had a neurological flatulence and forgot my tools at home)
Needless to say it was an ordeal, and at the end of a five-hour struggle with the help from the seller I was finally able to load it on my truck.
It came with all the accessories, connections, intake tube, filter housing with MAF, and the throttle body and cruise control cables, wiring (will dump)and vacuum lines (will reuse).
The previous owner took out the valve covers and the upper intake. With the intense rainy season the engine got flooded, with about 3 gal of water on the pan, and about 1/2 gal in the intake.
I took it apart and cleaned it up. Amazingly enough the engine seem to still be in good shape, and after a good clean it spins freely.
I found a considerable amount of carbon deposits in the intake, mostly I the non-injected ports, and a couple of square ports with deposits as well.
The engine has about 150K miles of unknown use and care. I am in a tight budget and am trying to avoid taking the heads off, but want to make things the right way.
Is the amount of carbon normal for the age and use?
How concern should I be in regards to the state of the engine?
#2
An update on the engine:
I cleaned the cam and rollers and looked at them closely and they seem to be working fine with good lifting action.
The timing chains have very little stretching and the tensioners are about 1/4 out of the way.
I removed and re-lubricated each one of the rod bearings and they look flawless, as well as the crank journals.
In general the engine looks extremely good in spite of the water.
I guess I got lucky this time (thus far).
I cleaned the cam and rollers and looked at them closely and they seem to be working fine with good lifting action.
The timing chains have very little stretching and the tensioners are about 1/4 out of the way.
I removed and re-lubricated each one of the rod bearings and they look flawless, as well as the crank journals.
In general the engine looks extremely good in spite of the water.
I guess I got lucky this time (thus far).
#3
If it were me, and I had an engine that had water in it, and the engine was already out of the vehicle (and the intake already off to boot), I would want to pull the heads and check the valves, and use some new head gaskets. Also, since you're talking about carbon build up, if the combustion chamber has lots of carbon in it, that can raise your compression ratio, and hot spots from even a little carbon can cause detonation.
#4
Good point.
I had not considered this. Given the fact that the compression ratio in these engines is 9.9:1 , any reduction in the volume, and especially an irregular shaped one, could produce detonations.
Hyper-eutectic pistons are known for their total lack of tolerance to detonations, and any, during even brief periods of time (the ones you hear and the ones you don't) will destroy the rings seats quickly. There will be no evident loss of power or performance, but an increased oil consumption. It already happened to me when I retrofitted PI heads and had the brilliant idea of getting a tune with the SCT, instead of taking the car to a tuner.
I had not considered this. Given the fact that the compression ratio in these engines is 9.9:1 , any reduction in the volume, and especially an irregular shaped one, could produce detonations.
Hyper-eutectic pistons are known for their total lack of tolerance to detonations, and any, during even brief periods of time (the ones you hear and the ones you don't) will destroy the rings seats quickly. There will be no evident loss of power or performance, but an increased oil consumption. It already happened to me when I retrofitted PI heads and had the brilliant idea of getting a tune with the SCT, instead of taking the car to a tuner.
#6
I am planning on installing an oil/particle separator in the vacuum line, between the intake and the PVC valve.
Looking at the prices for such simple devices I am leaning toward an inline oil and water separator used in compressed air, which I can get from Harbor Freight for 1/6 of the price.
Any CONS in using this other than the aesthetics piece?
Looking at the prices for such simple devices I am leaning toward an inline oil and water separator used in compressed air, which I can get from Harbor Freight for 1/6 of the price.
Any CONS in using this other than the aesthetics piece?
Thread
Thread Starter
Forum
Replies
Last Post