Hawk is here, yay!

[Weldangrind]

That's a very low price, considering the milling and polishing. It would be tough for you to perform the valve grind on the head to the same level.

[Megadan]

It's mildly discounted, but not by much. Since it is a 1 cylinder, a lot of his services are broken down into a "per" basis. I think even at full price it would be around $180-190 for everything.

[JerryHawk250]

Dan, If I'm calculating this right, decking .5mm should put you at 9.5:1. That should be a safe start.

[Megadan]

Originally Posted by JerryHawk250

Dan, If I'm calculating this right, decking .5mm should put you at 9.5:1. That should be a safe start.

That is pretty close to what I calculated. I ended up around 9.6:1. As long as I stay below 10:1 I will be comfortable with it.

[Weldangrind]

IIRC, smaller displacement can tolerate higher compression, but you run the risk of breaking a kicker or kicker shaft if you go nuts. I'd stick right around 9.6:1.

[JerryHawk250]

I agree. My Honda 200x stock was 9.6:1 and was kick start only. When I bumped it up to 10:1 it was a lot harder to kick start and not to mention if you hit it just right you will damn near break the kickers leg. but man she run like a bat out of hell. Back then we use a high tech 6" wide HF bench mount belt sander to shave it down. lol

[Megadan]

There is also the strain on the electric start to consider, the heat management of the engine, and a few other factors as well - one being longevity. I have seen examples of people taking off up to 1mm and achieving the 10:1 territory, but with no known long term examples to go off of I would rather take a small step and see how it goes.

A mild bump in compression shouldn't do any harm, and should give a little extra oomph to the motor.

[JerryHawk250]

You should add an oil cooler too to help keep the temps down. 10:1 on the 200x held up, but I think they use far more superior metals too. When I cleaned out the centrifuge filter over the weekend I was surprised how much the hawk and 200x were alike except for the OHV on the 200x.

[Megadan]

Originally Posted by JerryHawk250

You should add an oil cooler too to help keep the temps down. 10:1 on the 200x held up, but I think they use far more superior metals too. When I cleaned out the centrifuge filter over the weekend I was surprised how much the hawk and 200x were alike except for the OHV on the 200x.

The oil cooler is already part of the plan as I mentioned before. I just had to use that money for the front wheel. I still plan on the twin cooler idea. The reason I was considering the valve cover cooler was to get cooled oil directly to the head, but i still may just do a series twin setup. I will probably just order both kits and have all the hardware on hand to pick either option.

[Megadan]

Updates....

Still waiting on my front wheel. I have a feeling I may be waiting quite a while before it arrives. Heard/read couple of people waited as long as 2 months for theirs. Oh well, at least it is the end of riding here for a while.

Looking into using a CRF230F intake manifold/ Carb insulator for running socket style carbs on our engines. I ordered a gasket so I can compare the pattern to the CG250, but as far as I can tell the patterns look very similar. If they will bolt up, much like the exhausts, there may need to be a small bit of modification to actually make it work. The advantage is, it'places the carb in the right place and angle to work with the Hawks. So, here is hoping it works. Picture - http://www.off-road.com/aimages/arti.../380749/04.jpg

In other news, I placed my order for my oil cooler setup. I probably went a little overboard, but I couldn't find a non valve cover cooler with the stacked plate style coolers on it, so I ordered the same one as JerryHawk250, and then separately ordered two coolers similar to the style that is used in the kits Matt sells. I also placed an order for a different style oil filter, just to give it a try. (will link below).

So, Jerry, if you want to still try a dual cooler setup, the one that is coming in my kit isn't going to be used....wink wink.

Oil cooler kit, the "export style". http://www.engtaobao.com/item/25407512835.html

Oil coolers (in silver): http://www.engtaobao.com/item/42906213894.html

Filter: http://www.engtaobao.com/item/25408944660.html

As far as the filter, since the cooler kit comes with the screen and spring style one already, I ordered the Large stainless steel filter element. It's cleanable, but it can also be replaced with a paper filter for a Suzuki 125. This is just a curiosity thing, but it's a definite option for those that want to replace the screen. The catch is that it requires the oil cooler setup.

Two coolers is probably overkill, and I am entertaining using a thermostatic bypass in the system as well, but that can also be added later if I decide that it needs it. I could also simply make some plastic/cardboard screen inserts to block the coolers on colder days. Running two coolers does have a couple of advantages though.

1. I plan to run them in a series, so in one cooler, crossover to the second, and then out of the second. If I put the crossover on the bottom of the two coolers this will make the in and out on the top of each end, just like running a bigger single cooler horizontally.

2. Tucking each one up under the tank "fins" will give it some symmetry (that matters to me lol) and obviously put it all in a great airflow path.

My mounting plans are to build a central bracket that bolts to the frame and have each cooler mount to those. The trick will be getting the right side cooler high enough to clear the header pipe. There should be plenty of room, but it may require a little more creative work.

I am considering mounting a little fan to one of the coolers with a toggle switch, so if I sit or do some slow crawling on hot days I can turn it on.

Total cost for all of the oil cooler and filter stuff I ordered was $109. This can obviously be done cheaper if you aren't as picky as I am. Order the kit, and the same seller also sells just the oil cooler that comes with the kit for another 20 bucks. Leave out the filter, and the total cost comes out to around $65ish. This price will probably go up a tiny bit as I will likely be using my own lines and fittings.



Anyway, that's my ramblings.

[pete]

Are going to have the pump suck oil though 2 coolers a filter & the lines ?..
Or am I reading your post wrong ?



..

[JerryHawk250]

Originally Posted by Megadan

Updates....

So, Jerry, if you want to still try a dual cooler setup, the one that is coming in my kit isn't going to be used....wink wink.

If that's a offer I'm all in. I know one makes a difference. Two has to be better, right?

[Megadan]

2 small coolers and maybe a stainless mesh filter element. The two coolers part will be no different than a larger single cooler which has been run on this same engine in other bikes.

I could also simply run a T fitting for feed and return and run them in parallel instead of in a series. It makes no difference to me how it is run. Just all Ideas at this point, since I likely have a 3 week long wait for any parts to arrive.

If your concern is strain on the system due to the filter. I chose the stainless mesh style filter specifically because they generally have an extremely low pressure drop across the medium - aka much lower resistance than a paper element. Combine that with a very large surface area, and larger capacity of it's "module" that it mounts in, I am not too worried about the filter causing any increased strain on the system.

The oil coolers, being a stacked plate design, are also known for their properties of very low flow resistance. The relative volume of the cooler to the inlet and outlet flow means that they usually don't suffer from pressure drop of any meaningful level.

Running them vertically (cooler inlets and outlets are on the sides top and bottom) in a series as I mentioned would simplify the plumbing and also gives the same advantage of running a single large cooler by having the feed and return on the top. The only possible disadvantage is an increase in resistance as the oil travels across one cooler, then another.

Running them parallel to one another would split the flow between the coolers, greatly reducing the flow resistance, but does slightly increase the complexity of the plumbing with the need for 2 Y or T fittings. It also means that the inlets and outlets are top and bottom, creating a potential issue for the coolers to drain back into the sump. Yes, a check valve can solve that issue if it arises, but that again increases the complexity of the system.

If you want to argue the necessity of two coolers, don't bother. It would be an argument of opinion with a man (me) that likes overkill. This is my compromise to running one very large oil cooler, which has other larger obstacles to overcome. Outside of relocating the horn, and removing its bracket from the frame, the 2 smaller coolers don't require changing anything about the bike, and utilize a part of it's existing design that is otherwise surperfluous - the plastic tank panels.

Plus, my primary concern is with pushing this bike hard at highway speeds on 90+ degree days. The cylinder temps may be fine and dandy, but the oil takes a ton of abuse. I can tell by the way my bike shifts and idles when the oil has lost its viscosity from heat absorbtion, which after a 10 minute run at 60mph is pretty common on those hot days. I would rather have cooling capacity I don't need, than cooling capacity I don't have.

[Megadan]

Originally Posted by JerryHawk250

If that's a offer I'm all in. I know one makes a difference. Two has to be better, right?

Think of it as gratuity for doing the leg work on the center stand and skid plate.

Plus, I have this keen interest to see what our individual approaches are to a dual cooler setup. I remember you mentioning wanting to do one originally, and since you have all of the other hardware, there wouldn't be a whole lot to change.

[JerryHawk250]

Thanks, I'll just have to figure out were to relocate the horn to. But right now the skid plate and center stand are priority.