Diamond Cut fins....cooling effect? BS or hype? What about Fitch ?

[RKC03]

Gotta say it really enhances the engines looks, but the makers claim a cooling effect also  , was trying to find one of my mags to recall the price, seems like 4 bills  , anybody "invest" in having it done....can you say their claim is legit? Seems like they couldn't advertise that if it weren't true  , and another is it true is the "Fitch" fuel catalyst, claim it does this and that...is it no one has challenged these people or what?  Watta Ya think?       
                                                                                                                                         RKC03   

[Sonny S.]

Personally I'm not in to the looks of the " bling " Diamond cut cyl/head. I've worked on 2 bikes that had them and I will tell you that they are hard on the knuckles  .

As for the cooling properties I could see how it " could possibly " increase cooling. However, keep in mind that if it increases it 1 tenth of 1 percent, they can claim it increases cooling. If you are going to do it because of the bling factor then go ahead. If you are going to lay down that kinda cash because of the cooling benefits.... well, prolly not a good return on your money.

Have no experience with Fitch.

[jsachs1]

The basis for their patent is "the cuts aid in cooling".I know others that do fin cutting,and may or may not be involved in litigation  Guess we'll have to see how it plays out.
John

[calgary56]

Yes, it has a proven cooling effect.

From the Patent Website: ....

1st test showed the increased surface area created by the diamond cutting produced no significant cooling effect for stationary cylinders (no air flow).

However: .....

In a second test, the same two cylinder and cylinder head arrangements were again heated to a temperature of 200 degrees Celsius. Thereafter, the two arrangements were placed in the air flow path of a cooling fan. The velocity of the air flow was measured as 2.27 meters per second or 9.8 Kilometers per hour (8.96 feet per second or 6.1 miles per hour). Readings were then taken from the various thermocouples at intervals of four seconds. The results of this second test are shown in the graphs of FIGS. 22. and 23. FIG. 22 illustrates the results of the conventional control ("smooth") arrangement while FIG. 23 illustrates the results of the inventive ("knurl") arrangement. As may be noted from a comparison of the two graphs, the heat transfer rate of the front fins was significantly higher for the fins of the inventive arrangement in comparison to the heat transfer of the control front fins. According to the information provided in FIGS. 22 and 23, the 13th layer front fin of the conventional control arrangement required 600 seconds to cool from 200 degrees Celsius to 60 degrees Celsius. In contrast, the 13th layer front fin of the inventive arrangement required only 220 seconds to cool to the same temperature. It follows that the inventive arrangement achieved a temperature of 60 degrees Celsius in approximately one third of the time required by the conventional control arrangement. Furthermore, the inventive fin configuration obtained an average rate of temperature decrease of 1.16 degrees (F.) per second over the first 100 seconds of operation as compared to 0.58 degrees (F.) per second for the control fin. The inventive fin therefore had a rate of temperature decrease which was twice that of the control fin for the first 100 seconds of operation.

Turning to the test results for the 16th layer front fin, the control arrangement achieved a reading of 60 degrees C. after 860 seconds, while the 16th layer front fin of the inventive arrangement obtained this temperature after only 590 seconds. It follows that the inventive 16th layer front fin obtained the same temperature reading of the control fin in approximately two thirds of the time required by the control arrangement. The fins as numbered in the test were numbered from top to bottom. Thus layer I is the uppermost fin of the cylinder head of the tested cylinder head/cylinder assemblies and layer 16 is the bottommost fin of the underlying cylinder of the tested cylinder head/cylinder assemblies. A comparison of the temperature readings of the 16th layer control fin and the corresponding 16th layer inventive fin are shown more clearly in FIG. 24.

Recognizing that the rate of heat transfer is directly dependent on temperature one can verify that the inventive arrangement achieves a significantly higher heat transfer rate than the conventional fin construction known in the art.

[hoghead90]

Calgary56, did you sleep at a Holiday Inn Express? 

[Guitarplayer]

Hoghead....lol    I'd love to have a set of these on my bike, but think it would be too difficult for me to do.  I imagine it would cost another $400 or more to have it done for me.  I see twincam heads for sale on e'bay all the time... thought about buying a set and sending them out.  Is that what everyone else does?  or do you tear your existing ones off and wait?

[Bakon]

I have had it done to two bikes. Loved it. I sent mine in once and had it done locally once. Dont know who did it locally, dealer had them done while apart. Cooling, I dont know but it makes sense.
UPSed them to Vegas the first time, marked the heads and jugs to check and see if I got the right ones back. No problem and easy to deal with.

[someday69]

while I had my heads off,I found out it too expensive to net them powder coated,,then I was think'in of drill'in very small holes into the heads,and use those fake diamonds....but man Im glad I did'nt...then again,,,if you could get industrial diamonds..and glue'em on it might shine like hell....still glad I did'nt try it..

[hoghead90]

Hoghead....lol    I'd love to have a set of these on my bike, but think it would be too difficult for me to do.  I imagine it would cost another $400 or more to have it done for me.  I see twincam heads for sale on eBay all the time... thought about buying a set and sending them out.  Is that what everyone else does?  or do you tear your existing ones off and wait?

I would say if you're in the north country, like myself, it would be a good project to have done. If you were going to have some motor work done anyway. If ya can afford an extra set, buying them off eBay would be an option. Then if you don't like them, sell'em.

[HIPPO]

I wouldn't count on the diamond cut to save a engine from overheating. Figures it would gain some heat transfer from surface and lose some from being shiny. Maybe there is a gain if one splits hairs.
I guess 99.99999999999999999999999% that do it is because they like bling.

I had that Fitch thing in my tank almost since the bike was new, but it was given to me for "testing".
At the time we had a long discussion with Todd. Seems like maybe on bikes that require very high octane fuel to keep them from pinging it allows for the use of slightly lower octane. Hard to verify on a Delphi bike unless one wants to go through controlled runs recording ignition timing retard with and without.

Hasn't hurt anything and it was free.

[hotham]

Sure they look nice, but I can find something better to spend my $400 on.  That buys a lot of BEER !

[~JC~]

I hate these male enhancement commercials. ~JC~

[~JC~]

Oops!, forgot the 

BTW, if my engine starts running at 200deg C, I suspect I would need more than diamond cut fins. Probably need the Fitch too!  ~JC~

[RevJim708]

Fellow I worked with put two of them (Fitch) in his snowmobile. Swore up and down that it ran better.
Parts man at the local dealership used Fitch in an old Shovel. He too swore up and down that it made the bike run better. He told me the Navy had tested it and was using them. 
Me! I'm not going to spend the money on them to see if they work or not. If I got them for free I would try them...
Rev Jim...........

[Rags722]

I'm no expert, and I didn't stay in a Holiday Inn Express last night, but I spent a lifetime juggling data in presentations to prove a point that didn't exist.
Here is how I look at the cooling effect of diamond cut fins. People telling you how much they cool an engine are stressing by diamond cutting the edge of the fin, you have almost doubled your effective surface area, so it has to cool better.  I actually think this statement is factual, but they are neglecting to mention you really have not done squat to the TOTAL surface area of the fin. Count the entire top and bottom of the fin plus the edge, which makes up an insignificant percentage of the TOTAL surface area and I think you will agree diamond cutting for heat relief is like fighting for peace or screwing for virginity. It just isn't going to get the job done.
Then again, I never bought into the guy that runs a motor without oil to show how great his oil is.  Seems to me in the end, both motors wind up junk. One just got there a few seconds quicker.
Rags 

[calgary56]

rags - are you saying the patent testing is false?

[Bakon]

I had the diamond cut done for the looks mostly. Did like that it may help cool some. But I also have run oil coolers since day 1 on all my TC bikes. The Sporty doesn't have one but it rarely gets out anymore.

[V24me]

Rags,
Even if the total surface area is only slightly increased, you have to look at which part of the surface area does the most cooling.  The edge of the fin is probably responsible for the majority of the heat loss.  Heat is wicked down the fin to the edge where incidentally the most cool air can move past picking up the heat.  Think of your body getting cold in the winter when it's frigid outside.  Your fingers get colder, quicker than say the rest of your arms even though the surface area on your hands is far less than the surface area of the rest of your arms.  Put a pair of gloves on, even when only wearing a t-shirt and your whole body will stay alot warmer.

That being said, I do have the diamond cut jugs/heads, along with alot of other 'bling' and I have to say, it's the one thing that gets the most positive comments.  If I only had one visual mod to do, I would do it all over again.  As for the cooling, I never thought of it and have no idea how much it helps, but I also have never had any 'too hot' situations. 

Do it for looks and know it won't make your motor run any Hotter!

[Bakon]

Anybody remeber using an old toothbrush to clean the fins on their air cooled 2 stroke dirt bike? Before dirt bikes had radiators?

[randallwhitman]

Any good oil cooler will do a hell of a lot more than cutting the fins.

[Rags722]

rags - are you saying the patent testing is false?

No, I'm just saying that sometimes, people can make the same set of numbers mean different things... or the 100 other tests didn't show squat, or the testing process yielded the results they wanted but the same test with a smaller or larger fan would not show squat.

Rags,
Even if the total surface area is only slightly increased, you have to look at which part of the surface area does the most cooling.  The edge of the fin is probably responsible for the majority of the heat loss.  Heat is wicked down the fin to the edge where incidentally the most cool air can move past picking up the heat.   

Do it for looks and know it won't make your motor run any Hotter!

Well, I agree that it shouldn't make your motor run any hotter!  However, if the bulk of the cooling comes from the edge of the fin, why not just shave the fins down to half the current size to save material costs?  Or, why not drill holes in the fins from top to bottom to increase the "edge effect".  Then H-D wouldn't have all the high heat complaints and could sell back the material they made while drilling holes. ( actually, the more I think about it, I like the concept of drilling holes in fins).

Look, I'm no expert on cooling or the effect on diamond cutting.  I'm just saying I can't see where diamond cutting would produce any SIGNIFICANT results.