Author Topic: 1978 cb750k engine oil pan swap onto K2  (Read 389 times)

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Offline willbird

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1978 cb750k engine oil pan swap onto K2
« on: May 28, 2024, 02:49:42 PM »
I ordered a 1978 CB750K oil pan from Ebay. They have more and larger cooling fins than the earlier ones.



Just want to make sure that they interchange with the K2 without any issues before I install it. Will have pan off to replace the oil drainback stopper and figured I might as well look for the oil pan that has more/larger cooling fins and put that one on it.

Offline HondaMan

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Re: 1978 cb750k engine oil pan swap onto K2
« Reply #1 on: May 28, 2024, 08:49:45 PM »
Honda was concerned about the higher operating temperatures of the F and K7/8 engines, so they added a 'cooling spacer plate' under the F2/3 oil filter housing and made the fins a little taller on the oil pans. This was due to the then-new side-effects of leaner-burning engines - they run hotter - to meet emissions standards.
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Offline willbird

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Re: 1978 cb750k engine oil pan swap onto K2
« Reply #2 on: May 29, 2024, 04:06:42 AM »
Honda was concerned about the higher operating temperatures of the F and K7/8 engines, so they added a 'cooling spacer plate' under the F2/3 oil filter housing and made the fins a little taller on the oil pans. This was due to the then-new side-effects of leaner-burning engines - they run hotter - to meet emissions standards.

This oil pan bolts right up to the older engines though ?

Offline willbird

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Re: 1978 cb750k engine oil pan swap onto K2
« Reply #3 on: May 30, 2024, 07:39:19 AM »
Part arrived USPS today. Seems like an exact interchange, bolts line up and a couple layers of foam weatherstrip laid on the oil pickup seem to show about the same sump depth. Checking on a K3 engine I have on an engine stand. Drain plug is in a slightly different location and the K8 may hold slightly more oil due to that difference, small difference.