Holt 75 from Italy

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gbritnell

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One thing you might consider while you're at this stage of the build is to see if you can adapt some type of seal (0-ring) into the front and rear main bearings. Even though my engine has very small clearances once it gets warm it does leak oil past the bearing. Another leak area which I don't think can be fixed without considerable modifications to the original drawings is the lifter guides. Here again even with a close fit the pumping action of the liter in the guide tends to draw oil up around the lifter and it seeps down the block. It's not bad but annoying. My engine is mounted to a set of skids made from wood and I have created 2 drip pans from brass sheet which straddle the skid. This help to keep the engine much neater when running.
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Foketry

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One thing you might consider while you're at this stage of the build is to see if you can adapt some type of seal (0-ring) into the front and rear main bearings. Even though my engine has very small clearances once it gets warm it does leak oil past the bearing. Another leak area which I don't think can be fixed without considerable modifications to the original drawings is the lifter guides. Here again even with a close fit the pumping action of the liter in the guide tends to draw oil up around the lifter and it seeps down the block. It's not bad but annoying. My engine is mounted to a set of skids made from wood and I have created 2 drip pans from brass sheet which straddle the skid. This help to keep the engine much neater when running.
gbritnell
Thanks for suggestion, i keep it in mind
My crankshaft is round, maybe it will lift less oil qty than a flat crankshaft, i hope....:( , i'm going to put some Oring
 
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necchiom

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Wow: Awesome project and realization! Bravissimo.
 

rodue

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One problem with the one I built and one my friend built is with out a oil ring it throw a lot of oil. That may be brought on by the crankshaft Your construction of the crank may illuminate that problem. I built this deflector to help keep the engine clean
 
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Foketry

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When I first built my engine I machined the heads from the drawings. Like you I thought there would be an issue with the depth of the spark plug hole and initially made my own plugs with a much longer reach. When it was time to replace the plugs I tried a set of Rimfire plugs, the longest version and the engine runs just fine with those so I wouldn't work about trying to make a counterbore for the spark plugs. If you make it like you show on the model it would probably help.
gbritnell
Thanks for the suggestion, i ave already ordered the spark plugs long reach in USA (S/S Machine OH)

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The partially worked heads

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partially worked heads
 

rodue

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great work its nice to have that equipment to mill I am doing the old way and too late to make changes.
 

Foketry

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great work its nice to have that equipment to mill I am doing the old way and too late to make changes.
I had a manual milling machine and a manual lathe.
I bought Chinese drives, italian ball screws and i did the wiring .
I converted them into CNC machines with great satisfaction
But i think if i have been able to transform the machines, anyone is able to do this.

A question, why did you put the bent copper tube in the exhaust manifold ?
 
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