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Tuesday question: marine exhaust manifold.

Leadfoot21 said:
Craigslist or FBMP used BBF valve covers bet you can buy a set of tall ones for next to nothing !
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Been looking. So far just one guy trying to sell a pair of Trick Flow covers for $150 and a couple guys parting out stock stuff.


Lbhsbz said:
Just turn up a slug on the lathe with with one end that fits in that balancer and the other end that fits in a 3/4" collet (turn both diameters in one fixturing) ...throw the slug in the collet and move the table around till it fits, then lock 'er down.
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I don't trust my lathe that much. :laughing:

Since I know the bore is already finished and round I'll check my work with the "turn the spindle by hand as you dial up the boring bar and make sure it doesn't start touching in just one place" method since I know tool contact is good for sub-thou accuracy.

Probably won't get to it until next week. Thursday through the weekend are busy AF.
 
Got to boring it today. After a couple light passes it became clear the centering is questionable. I'm going to order a coax.
 
Holy fuck these things are magical.

Took me 5min to set up. Another minute to get it "close enough the probe is touching the whole way around" and then 30sec to dial it in.

 
That's on my short list:smokin: I still don't understand why you wouldn't indicate the ID, the part that's machined to fit over the other rotating part? It is ok to only rotate an indicator 98% of a full circle:flipoff2:
 
Aaaand I bored it a hair too loose (tight slip vs light press)

Dimple and loctite time.

Also, holy fuck does my mill have a lot of fuckery on the Z. I went to set up the the boring head in the part and it was way off so I had to re-center the part using just the quill travel and that managed to maintain center between the tool change from indicator to bar.

Firstram said:
That's on my short list:smokin: I still don't understand why you wouldn't indicate the ID, the part that's machined to fit over the other rotating part? It is ok to only rotate an indicator 98% of a full circle:flipoff2:
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The ID has a keyway and I don't want my expensive coaxial indicator catching it and fucking off.
 
arse_sidewards said:
Aaaand I bored it a hair too loose (tight slip vs light press)

Dimple and loctite time.

Also, holy fuck does my mill have a lot of fuckery on the Z. I went to set up the the boring head in the part and it was way off so I had to re-center the part using just the quill travel and that managed to maintain center between the tool change from indicator to bar.


The ID has a keyway and I don't want my expensive coaxial indicator catching it and fucking off.
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Make a un-boring bar with a knurling wheel and put in the lathe...
 
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So on to the oil pan...

First step was to cut a template.
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Fits great.
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Cut the center out.
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Good enough for government
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I know 1/4 was overkill but the construction site I stole this from didn't have any 3/16. :flipoff2::flipoff2::flipoff2::flipoff2:
 
Boat sumps have pretty mediocre oil pans when it comes to sump design. You either get flat sump with baffles or a rear sump. Pickup is always in the rear.

Here's the OE pan.

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Finally got back onto this stupid project. Everything but the one big plate and the lip with the bolts is from the scrap pile. :smokin:

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Once I have it done I'll post side by side pics but this gets the engine a couple inches lower and corrects a major deficiency in the stock pan while I'm at it.

Still unsure of how I'm gonna shape the sump.
 
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cj3a said:
No skid plate necessary at this point.
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More like if I'm gonna base my engine location off a custom pan I'm not gonna build a part that can realistically break.

Besides, 30lb down low. :laughing:

cj3a said:
I have some pipe you can use for next time.
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I actually measured for pipe because that's cheap and easy. The crank is offset to one side relative to the pan rails and the high point is the pickup tube, not the crank so a pipe that fits over that results in a way deeper pan overall than what I wound up with. This engine is stupid tall so I need it as low as it can get.
 
We're getting there. Still a few more seams to weld before switching to the inside. This Forney brand rod is absolute dog shit. The needle scaler is getting a real workout knocking the slag off. If I had picked up a box of electrodes at HF when I picked up cutting discs to start this project I'd be done by now.


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Here it is vs the stock pan. The bump around the oil pan extends much less far back and the sump is both deeper and slightly larger which should give me an honest 5qt capacity. Most importantly, I deleted the valley that lets all your oil run forward out of the sump on prolonged deceleration.


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