Author Topic: 1972 cb750 oil tank  (Read 342 times)

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Offline Terry.carter

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1972 cb750 oil tank
« on: May 01, 2024, 01:58:51 PM »
Hello I have a 72 Cb 750 with a custom oil tank that sits inside the frame. The hoses were disconnected when I got it. The tank has 3 stubbed out pipes on it where the hoses will connect. 2 half inch ones and a tiny one. My question is which hose goes where .?

Offline beemerbum

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Re: 1972 cb750 oil tank
« Reply #1 on: May 01, 2024, 04:26:08 PM »
A photo would be a big help in answering your question

Offline BenelliSEI

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Re: 1972 cb750 oil tank
« Reply #2 on: May 01, 2024, 05:19:53 PM »
The one that flows oil from the bottom of the tank will be the feed to the oil pressure pump in the engine. The one that throws oil back into the top of the tank will most likely be the return line, from the scavenge pump in the engine. The small one is probably a vent hose.

Offline Tracksnblades1

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Re: 1972 cb750 oil tank
« Reply #3 on: May 01, 2024, 06:40:03 PM »
The one that flows oil from the bottom of the tank will be the feed to the oil pressure pump in the engine. The one that throws oil back into the top of the tank will most likely be the return line, from the scavenge pump in the engine. The small one is probably a vent hose.

+1…if your tank doesn’t have a dedicated drain plug I would weld one in now..taking a hose off to change oil S*cks..

I’ve also seen and built (heliarced) custom aluminum tanks for our local chopper builder guy a long time ago..
His design kept the hoses side by side similar to Honda’s for aesthetics and ease of plumbing the hoses.

The supply aluminum nipple heliarced inside and out And as close to the bottom as the internal weld bead would allow. The scavenge aluminum nipple was actually more like a heavy wall pipe. Taller and bent to aim hot return higher up and away from the supply inlet.. his rationale was the hot return oil will follow the natural convection law and rise to the top. In addition as well, the specific gravity of the aerated scavenged oil will readily go to the top because of the air entrained within it.. Both less than desirable conditions having more time to cool and de-aerate vs being instantly sucked right back in the supply line and short cycled over and over…

I wonder now,40 years later, @ 10,000 rpms just how much of this can actually take place.. His tank designs did hold an extra quart though…
« Last Edit: May 01, 2024, 06:46:25 PM by Tracksnblades1 »
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Offline madmtnmotors

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Re: 1972 cb750 oil tank
« Reply #4 on: May 02, 2024, 04:07:20 AM »
A photo would be a big help in answering your question

I think you need at least 5 posts before you can add pictures.
TAMTF...


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