Excessive Smoke - Help

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Mej999@icloud.com
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Excessive Smoke - Help

Post by Mej999@icloud.com » Wed Dec 04, 2019 9:21 am

Hi,


I bought a V8 engine that was smoking excessively when revved up, no problem ticking over.

In order to rule out over fuelling, fitted a manifold with SU carbs on, no different.

Stripped down and found that the 4.6 had 3.9 heads fitted. Engine was extremely clean inside.

I found 5 of the rubber washer type valve stem seals had split/come off and thought that that was the problem.

Pulled all pistons out and no broken rings, bores all looked ok. Fitted new Big End bearings while I was in there.

Rebuilt, new head gaskets, valve stem seals (Cup type) etc and no difference, still smoking badly. Tried to upload video, but can not seem to manage. Smoke is very smelly.

Look forward to hearing from you.

Michael



unstable load
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Re: Excessive Smoke - Help

Post by unstable load » Wed Dec 04, 2019 1:25 pm

What colour is the smoke?
As a general rule of thumb, blue smoke is oil, black is fuel and white can be steam or brake fluid from the booster.
Cheers,
John

Mej999@icloud.com
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Re: Excessive Smoke - Help

Post by Mej999@icloud.com » Wed Dec 04, 2019 3:25 pm

Difficult to distinguish. Blue black, probably more blue. Certainly not white

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ChrisJC
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Re: Excessive Smoke - Help

Post by ChrisJC » Wed Dec 04, 2019 9:26 pm

Can you run a compression test and a leakdown test? Sounds like it could be rings not bedded in.

Chris.
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DaveEFI
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Re: Excessive Smoke - Help

Post by DaveEFI » Thu Dec 05, 2019 10:02 am

Yup - if the pistons were out, did you fit new rings and de-glazed the bores? But if it was doing it before, maybe not the answer. Have you checked all the the crankcase breather system is clear?
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Mej999@icloud.com
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Re: Excessive Smoke - Help

Post by Mej999@icloud.com » Thu Dec 05, 2019 8:20 pm

Hi,

I have ran it for a while this afternoon and things are better, rings may be bedding in as suggested.

I have also tested the Maf and voltages are higher than stipulated, so I think it is poss a conbination of oil getting past the rings and over fuelling.

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