Oil cooler valve cover (attempted install, some issues)

[TrustMeImAnEnginee]

If you have one of these oil cooler kits or are thinking of getting one, it might be good to read.

I bought an oil cooler kit from alibaba that replaces the valve cover with one ported for an oil cooler:

https://www.aliexpress.us/item/2251832467152642.html







And I was looking forward to it being all good right out of the box, but that's not how it was. I found a couple issues with it.

First and foremost, the gasket pattern does not match the stock valve cover. This was the deal breaker for me deciding not to install it, but if others are having a fine time with ones that are also like this I may reconsider.

I made a paper cutout tracing kinda closely the inner edge of the gasket on the oil cooler cover, see how it looks:


IMG20230121165125.jpg
IMG20230121165213.jpg


I also looked at the positioning of the hole where oil goes in related to the bolt holes, the hole and gasket are set inwards a little:

(images in second post)



Here it is fitted (loose):


IMG20230121172725_-_Copy.jpg
IMG20230121172709_-_Copy.jpg


Second issue, and this one can be resolved, is the oil jets and first passage going to the oil cooler inside the cover were smaller than the stock cover. I CAREFULLY used a 2mm drill bit to enlarge the oil jets and a long 5mm bit to enlarge the first passage. (I took the time to do this BEFORE test fitting the cover and calling off the install)



I figure even with the oil getting sprayed out of the jets after running through an oil cooler which will help cool the head, it would still be good to have the same amount as stock for lubrication and not less.

The stock angled oil passage from the round inlet was 5mm so I drilled the oil cooler cover up to that from about 4 or so on the first angled section. The second section leading out to the cooler wasn't as small but still a little less than 5mm so I hit it too. The passage leading to the jets seemed fine.



InkedIMG20230121163907.jpg



I also noticed the plug they put in where oil would flow through the original route leaked a little when blowing out shavings and just experimentally blocking the outlet to see if any holes I couldn't see had been opened.

Anyways, that's my experience with one of these valve cover oil cooler kits. if anyone is running one that fits like mine and isn't having issues or solved the fit problem somehow please post a reply.

Would also like to hear thoughts about drilling out the oil jets and the passages to match stock. If anyone knows why they were smaller to begin with (other than not getting drilled out at the factory) let me know.

If I just bought the wrong valve cover entirely, DEFINITELY let me know where I can get the right one.

[TrustMeImAnEnginee]

IMG20230121173018_-_Copy_3.jpg


IMG20230121173011_-_Copy_2.jpg


IMG20230121173110_-_Copy_2.jpg

images of the gasket position related to the holes

[XLsior]

the Cg125 rocker cover is a little smaller than a 250 head.

The oil cooler cover is clearly made for the smaller form factor...

the bolt pattern should be the same.

It shouldn't leak around the gasket as long as its flat.

Most people run with a lower screen plug adapter oil cooler.

[TrustMeImAnEnginee]

So this fit is normal for the oil cooler valve covers? I haven't seen a very clear view of the fit when others have installed them and I may have skimmed by a mention in text. If it's not an issue, cool. I just didn't like how it sat with the gasket close to the inner edge of the head and misaligned the round hole with the one on the head.

The oil passage and oil jets being smaller makes sense for a smaller engine too.

I have a screen plug oil cooler kit too, I wanted to try this one out since it should be less obstructive to the main oil pickup and leave the screen plug easily removable for oil changes. I have a temp sender in the bottom drain plug which might get damaged by pulling it every oil change.

[TrustMeImAnEnginee]

Should mention, the reason I started looking at oil coolers is I have my hawk geared 16f/40r (I'm small and light so it can handle that reasonably) and riding 60 mph I see the oil temp creep up as well as the head temp as long as I keep riding. Head temp has gotten up to around 360 and oil temp around 180 F, which rises when I come to a stop even with the engine cut off to around 200-210 F. Head temp measured with a TTO spark plug gauge and oil temp measured with a norxi. I'm planning for the hotter months where there may be issues with the oil temp, and got both options for a cooler to see how they work for myself.

[CheapThrills]

Curious, how are you monitoring oil/head temp?


Thx,

[TrustMeImAnEnginee]

Head temp gauge (self powered, requires notching the fin around the spark plug well):


https://www.amazon.com/gp/aw/d/B07D9TLBKY



Oil temp gauge (requires 12v, I soldered the wires to the turn signal harness plug pins w/switched power):


https://www.ebay.com/itm/18563024466...Bk9SR5CLvNfQYQ

[XLsior]

There should be a dedicated oil drain bolt on the case base. The screen cover just houses the mesh cone screen...which gets relocated to a separate housing inline with that type of oil cooler system.

never used a cover cooler setup so can't really make suggestions.

[Megadan]

Originally Posted by TrustMeImAnEnginee

Should mention, the reason I started looking at oil coolers is I have my hawk geared 16f/40r (I'm small and light so it can handle that reasonably) and riding 60 mph I see the oil temp creep up as well as the head temp as long as I keep riding. Head temp has gotten up to around 360 and oil temp around 180 F, which rises when I come to a stop even with the engine cut off to around 200-210 F. Head temp measured with a TTO spark plug gauge and oil temp measured with a norxi. I'm planning for the hotter months where there may be issues with the oil temp, and got both options for a cooler to see how they work for myself.

Oil temps below 200F are a good thing. Usually viscosity loss doesn't start happening to most oils until you reach over 210-220F.

360 for a head temp isn't that bad either. If the head starts going past 400 then you would start wanting to worry some.

I have never run the head style cooler, but there is a substantial volume of oil pumped up to the head, so it should be decently effective at keeping the oil temps under control and cooling the head down.

The screen port (I call them sump coolers) that XLsior is talking about is the style I run, and it is very effective. It draws the oil from the sump, pulls it through the cooler, and then into the oil pump to be pushed through the entire motor.