2 bearing crank in 3 bearing case

[Ian Williams]

Besides possibly not aligning jets properly as I understood things form discussion's I had with the former owner of this engine the failure was as attributed to a mason bee building a nest in the oil line, Alistair failed to discover this blockage until after the problems had occurred. He may not have built the remote oil feed to the best design also restricting volume of flow to the big ends, I was too busy to rebuild the engine for him at the time he was asking so did not get the chance to examine it.

[Hedd_Jones]

A friend who has built a type 59 Bugatti motor virtually from scratch is advising laser welding for the crankshaft build-up. At the moment, this is the way I plan top go.

Do you know if the crank was nitrided?
The IKE site suggests they were EN40B, a nitriding steel, although the website may not be the most reliable source.
If it is nitrided then laser welding may not be advisable 

Charles

The crankshaft we had made was EN40B. Not nitrided. Gunmetal bearings.

[Humps]

No, but have yet to get the crank out of the case. Marcus did make one observation that the oil hole in the
 journal is blocked, and I always assumed this was white metal as a result of running the bearing, but a quick test with a Stanley knife proved that the blocking material is much harder than white metal?r

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Thanks Ian, that certainly answers one question.
Keith

[Hedd_Jones]

You will probably find that steel from the crank has also embedded into the fill material in the oil hole.

I see that quite a lot when a bronze bearing/steel shaft is run too hot. The bronze is wiped into the oil grooves, but particles and layers of steel do get embedded in it also. Also steel gets embedded in the bearing surface itself.

[Humps]

Once again, I really appreciate all the advice that has been posted and it forms a good basis for inspection and remedial work when I get the crankshaft out.
Unfortunately I got distracted when trying to separate the block from the crankcase.
I thought that they would simply separate, assuming a gasket had been used, but in fact a silicone sealant had been used and no gasket.
Once I had driven in a SS spatula and destroyed the oil-tightness I was committed to the separation which is still proving very stubborn. I am also aware of the fragility of the alloy crankcase.
I have discovered that mineral turps breaks down the sealant, but this does not necessarily penetrate between the two surfaces.
I'll win in the end, it's just a matter of patience and continuing to work at it.
Keith

[Ian Williams]

You have a lot to learn about the idiosyncrasies of successful A7 engine building Keith, not using gasket in joints like the Block Crankcase being just one. Forget the old paper gaskets they will leak, two schools of thought exist, 1; glue the block down with a reliable sealant, there are several people here people who have their favourites, personally I was a Loctite fan. 2; the next school of thought, one which I am now a convert is to use a gasket made from silicon baking sheet, the 7 Workshop and VAR club spares sell them ready cut. I have used them on a number of engines now with no issues thus far, there are a number of others who report to have had the same positive results.

[Greig Smith]

We've made & fitted the double oil jet conversion to both our single seaters. Out of curiosity I aligned the oil jets with wire before using the pumping paraffin trick. It was interesting to see the actual direction of the oil jet stream & all 4 oil jets required further tweaking for optimal oiling. As per Mike Forrest's advice bending them inwards changed the oil feed duration from around 30* to around 80* of crank rotation. 80x2 = 160* oil feed. Better then the original.

The Phoenix oil pockets were alarmingly small & I opened them up and radiused the holes. This was a picture part way through the process. This was the most difficult thing to do as the crank was hard.

1.32nd over bore on the oil pump, 1 gallon sump & notched the extension to ensure good flow. 

Aye
Greig

[Bob Culver]

It is questionable whehter oil drops arriving outside of the drilling are driven in by the impact or flung off by cenrtrifugal force. On my standard car I deepened troughs on the inner side

[Dave Wortley]

I have done 3 engines  with doubled up jets. It's a simple mod compared to all the complications of pressure feed and unless you are building  an out and out racer it seems worthwhile. Best to align jets with the Forrest "oil in boots" method.

[Humps]

I have now separated the block from the crankcase and this enables one to see the action of the jets.
Using a hypodermic syringe I can squirt fluid through the jets and see where it lands on the crankshaft.
It is immediately apparent that the jets do squirt onto the crankshaft, but in each case they miss the troughs. As suggested by one poster, it would appear wise to widen the troughs?
All other oil passages flow freely including those to the remote oil filter and from there back to the crankcase.
I did find evidence of a Mason Bee nest under one of the valves, so this does give credence to Ian's though about a Mason Bee somehow blocking an oil jet or crankshaft?
The Number 2 big end shows signs of just beginning to break down with the crankshaft lightly scored at one side.