Upgrade on oil cooler??

[cbx1260cc]

I have a 1980 CBX as well as a 1983 1100F. The 1100F oil cooler looks to be a few rows bigger when compared to the CBX. As $$$'s are a bit short right now and I happen to have an extra 1100F cooler could I upgrade my CBX by using the 1100F cooler?.


Anyone done this?

Is it a bolt on option?


OR anyone have an aftermarket oil cooler they would consider selling at a reasonable price?


Thank you,
Ricardo

[EMS]

Ricardo: The 1100F cooler will work on a CBX, howver, it is not just a bolt on. The hose connections are in a different location and the mounting to the bike is different.

[cbx1260cc]

Mike,
THank you--not having bike in front of me I'd forgotten about connector location--top exit on one, bottom exit on the other.

Appreciate the courtesy of a reply.


Ricardo

[Douglas]

hey-Hey!!!,
The 1100F cooler will fit comfortably. Hose fittings are the same, and as noted the mounts are different. It is not so difficult to fabricate new ones with aluminium so that it looks pretty neat. I did this on my '82. Unfortunately, I can't give any quantitative results on how much cooler it ran. Still worth doing IMO.
cheers,
Douglas

[icouldabeenav8]

I just spotted this thread. You may benefit from my experiences. When I bought my CBX new, I was immediately bothered by the high operating temperature of the engine and consequently, the oil temperature. Because I wanted maximum engine longevity I set about investigating what I considered marginal operating conditions. I installed oil temp and pressure gauges (VDO, both electric) as well as a cylinder head temp gauge. My findings were:

1) In typical summer use in town, temperature crept up to 260/280F with rare excursions to the neighborhood of 300F.
2)Oil temperatures dropped about 10/15F on the open road.
3)Oil temps dropped 10/15F in the winter.
4)With the oil temp at 260/280F, the idle oil pressure was zero. Upon checking with VDO, they stated the sending unit would not send pressure information below approximately 3psi. So at an idle the oil pressure was probably around 3psi. Consulting with Honda in 1985/1986, I was told these factors were of no consequence and don't bother to try to solve a problem that Honda had determined was not a problem.
5)A mechanical oil pressure gauge was fitted and confirmed the results of the VDO gauge.
6)Cylinder head temperature was a stable 350F at the spark plug for #1 cylinder.
7)Oil temperature and pressure were measured at the oil galley behind the cylinder base.

These results caused me a lot of concern. I decided that I was going to exercise the nuclear option - no halfway measures. Oil at that temperature is universally thought to be dangerous to engine life. I wanted to bring the oil temps down to 180F, a safe temperature. Because the OEM and the CB1100F cooler was a joke (I had a CB1100F by that time), I bought a 13 row Earl's oil cooler ($85 back in the day) as well as a 180F oil thermostat in case it turned out that I was overcooling the oil. I decided to use some AN hardware and hoses I had laying around from other projects. It turned out to be remarkably easy to install the components. The CBX hose fittings were amputated from their respected hoses and welded to AN fittings. A new set of oil cooler brackets were mocked up in cardboard then cut and welded from pieces of aluminum. The thermostat fit under the fuel tank towards the rear like it was made to go there. The hose connections from the engine and from the cooler were made at the thermostat. No shakedown was required. For once one of my homebrew patchwork jobs operated flawlessly from the beginning. The new findings were:

1) Stable oil temperature of 180F with very slow dynamic changes from that temperature.
2)Quicker warmup to oil operating temperature.
3)Head temperatures around 15F cooler although over a long time it would creep to 350F but easily drop as road speed increased.
4)General perception of a much cooler running engine.

Here are some photos of the install taken in 2000.

[EMS]

Very nice! Great post. Thanks, icouldabeenav8!

[NobleHops]

Very nice! Great post. Thanks, icouldabeenav8!

Word - awesome info, thanks for taking the time to post that, great stuff. Oh and welcome to the site if I haven't said so already.

N.

[steve murdoch icoa #5322]

An excellent post with pics.
Now about the dust collecting on your bike...

[Don]

I'm also someone who thinks Honda's 'solution' was pretty inadequate . . . . even if you don't live and ride in a warm climate. I went with a 10 row Earl's cooler mounted using one of John Smarsh's kits - No thermostat. I also have an electric VDO oil temp gauge with the sender installed in one of the lower oil gallery caps

My results are not as stable as V-8's, but they are a great improvement over the stock arrangement . . . . I watched the temps pretty closely for about a year using the stock cooler before I installed the upgrade so I'm pretty well versed with the improvement the Earl's cooler made

My nominal oil temp now is 200 degrees, give or take a little depending on circumstances . . . . the oil will warm to about 200 no matter how cold the ambient temps or how I ride. 220 is pretty normal for steady 75 mph riding and it will get up to around 220/230 in stop and go town riding - I saw temps in the 275 range several times with the stock cooler. Once the oil gets really warm (either with stop and go riding or constant high speed riding) it takes quite a while riding a steady 45 or 50 to cool it back down even with the bigger cooler and that surprised me a bit - With the stock cooler about the only way to cool it back down was to park the bike for an hour or so. I was also really surprised to see how warm the oil gets with constant high speed riding, even using a cooler with more than twice the capacity of the stock '80 or later cooler

The 10 row is a pretty good compromise between the 'nuclear option' and the stock cooler - It fits the bike much better than the 13 row and when mounted properly, is almost indistinguishable from stock, yet it cools much better than the late model stock cooler

If I didn't have the larger oil cooler, I think I would consider synthetic oil a must . . . . but my X doesn't like synthetic

Don

[barryadam]

Don,

What mounting kits is that?
What is included with it?

Any links to it or pics?

Barry

[EMS]

Big oil coolers are nice and look "cool" (pun intended) but bear in mind that you want your oil to heat up above 212 in the sump on a pretty regular basis to make sure all the moisture evaporates out of it. Many bikes that are given an elaborate aftermarket oil cooler to show the rider's skills of "heating it up" will have their oil running too cold. I know it is more of an issue with bikes with an oil tank (dry sump) but it generally applies to all engines. Water turns to steam at 212F, and that's what you want. Lubrication oil has lousy lubrication capabilities in a motor below 140 - thus the need for a proper warm-up, but is generally good for high temps up to 250 with excursions to 275. High performance synthetic oils in race engines see peaks of 300 without causing problems.

[Rick Pope]

I've been toying with making a bracket to accomodate two stock coolers. Either stacked, or each mounted vertically. Of course the stock hoses won't work, but at 32 years old, they need to be tossed anyway. I've been hearing of line failures lately.

The lines themselves are standard size, just the fittings are special. You could go to any hose maker dealing in hot-rod stuff and get whatever you need made up. Adding a stock cooler to my existing one would be cheaper than buying something, and I'll need new hoses regardless of which route I take.

[Don]

Don,

What mounting kits is that?
What is included with it?

John Smarsh posts here occasionally - He's been making custom CBX stuff for ages. His 'kit' includes either a 10 or 13 row Earl's cooler, a pair of custom made AN adapters bent to a 135 degree angle which allows the oil lines to pass above the frame brace but under the tank and the other end of them can be ordered to fit either custom made braided stainless hoses, new fabric covered hoses (similar in looks to the stock ones) or a barbed fitting which will fit your factory hoses if you cut the ends off or a pair of custom made fittings which enable you to use the stock hoses intact. He also provides a custom made aluminum channel which fits the top of the cooler, plus a pair of modified rubber torsion mounts for the cooler which fit the stock oil cooler mounting 'ears'. It's a really nice kit and it's obvious that John has a lot of time and engineering in them

I don't have any pictures handy, but there are (or should be) many pictures of his various options in previous discussions of this subject here on the forum - Those discussions were what alerted me to getting with John to order the parts from him. I bought my Earl's cooler from Amazon for about $75 and everything else from John

The Earl's units are 2 inches thick, front to back so they will be a good deal more efficient than either an 1100F unit or a pair of stacked stock units. The 'footprint' of the 10 row isn't that much different from stock . . . . a little wider (but it still fits the stock mounts) and a little taller (the 13 row is quite a bit taller and comes close to interfereing with the tacho cable)

Anyway, with everything painted black, the 10 row installed on my bike is pretty invisible - Definitely not stock if you know what you're looking for, but not noticeable enough to catch your eye unless you're looking for it . . . . you don't really see it on my avatar photo, but it's there - You can see the custom 135 degree bends coming out on top of the cooler and going though the frame . . . . I haven't figured out a way to make them black without them getting chipped up in the installation process yet - They used to be available black anodized, but no longer. Maybe the next time I have the tank off I'll try painting them while they are installed so I won't have to put a wrench on them afterward



Good mod, worth the money and cools the oil much better than the stock unit . . . . but not so well that you have any worries about running too cold oil

Don

[barryadam]

Thanks Don.

Sorry, I only knew of him and his kits by his member name.

Barry

[icouldabeenav8]

Big oil coolers are nice and look "cool" (pun intended) but bear in mind that you want your oil to heat up above 212 in the sump on a pretty regular basis to make sure all the moisture evaporates out of it. Many bikes that are given an elaborate aftermarket oil cooler to show the rider's skills of "heating it up" will have their oil running too cold. I know it is more of an issue with bikes with an oil tank (dry sump) but it generally applies to all engines. Water turns to steam at 212F, and that's what you want. Lubrication oil has lousy lubrication capabilities in a motor below 140 - thus the need for a proper warm-up, but is generally good for high temps up to 250 with excursions to 275. High performance synthetic oils in race engines see peaks of 300 without causing problems.

Some additional observations.
1) Of course water doesn't boil until it reaches 212 degrees but with an oil temperature of say 180 degrees water still disappears from the oil for two reasons. First, the temperature of the engine parts (head, pistons, cylinder) the oil is circulating through can be 40 to 50 degrees higher than the oil or more, even higher in a turbo engine. In my case the external temperature of the cylinder head was always above 300 degrees within several minutes after starting which is 120 degrees above my oil temperature of 180 degrees. Second, at 180 degrees and with the agitation that a running engine entails, the water will likely dissipate for the same reason water evaporates from the environment without being boiled (If not agitated the water probably won't undergo this process). Granted these two processes take longer than boiling the water out of the oil but they are effective for the kind of driving I did with my CBX - no short trips but lengthy several hour runs whenever the bike was started.

In the past, I have placed oil temperature gauges in a number of automobiles I have owned. A large number of them seemed to hover at the magic spot of 180/190 degrees sump temperature in city/suburb driving going to 210 degrees if operated vigorously dropping back down to near 180 degrees when the thrashing ended. Enough of them had low sump temperatures for me to believe this is not a problem.

I once was involved in a situation where an auto engine's oil had been contaminated with a large amount of water from a cooling system flush. This problem on a sixties 283 Chevy was caused by the old setup of the thermostat housing and the close proximity of the oil filler tube. The cooling system flush was finished off by removing the thermostat housing and letting the water run out continuously while keeping the radiator topped up with a hose. Unfortunately as the water exited the thermostat housing, it swirled across the base of the oil filler tube which in that era Chevy was pressed into the intake manifold. Evidently the press fit did not mean the tube was sealed against the environment and a lot of water got into the engine sump.

After the engine was started and idled for a while we at some point discovered the water contamination. The oil was a milky white foamy emulsion indicating a large amount of water present. No one wanted to do a series of oil transfusions, so we hit upon our theory that the oil should evaporate if we let the engine idle long enough because of the heat of operation while still getting more than adequate lubrication because of the light load of idling. The car was idled for about an 11/2 hours without a thermostat (the engine oil probably didn't reach 160 degrees) and it worked! We decided not to change the oil because all traces of water had disappeared.

Having said all that about water in the oil, I am concerned about lubricity of the oil at 180 degrees compared to higher temps now that Chevrolet, for instance, says that oil temperature should be 240/250 degrees for best lubricity and least friction. For those reasons I am thinking about some way of blocking the cooler to modulate a higher temp or maybe utilizing a much higher temp thermostat. I'm just left with that little issue of nosediving oil pressure in the CBX as oil temp rises.