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-   -   Ported polished head (http://www.chinariders.net/showthread.php?t=24084)

G2ic22 07-06-2019 10:58 PM

Ported polished head
 
3 Attachment(s)
Bike is running good if anyone wants to know the head from powersportsmax.com was right one had decent casting and is running strong and made world difference

Cravin01 07-06-2019 11:08 PM

Looks great , cant wait to hear what the gains equate too as far as top speed. I've been tempted to break out the dremel JerryHawk250 talked me into buying.

G2ic22 07-06-2019 11:17 PM

Great gains all the way through the powerband. I thought lose a little low end because I ported exhaust side as big as I could go matching the crush gasket pre crushed and it has more torque way noticable from bottom all the way to redline.

Megadan 07-06-2019 11:35 PM

Quote:

Originally Posted by G2ic22 (Post 313687)
Bike is running good if anyone wants to know the head from powersportsmax.com was right one had decent casting and is running strong and made world difference

Welcome to the ported head club! Nice work on that exhaust port. Very similar to what mine ended up looking like. Also, thank you for confirming that head works, it gives a good affordable option for those that don't want to dig into the stock head or drop $90+ for the CSC head.

Did you leave the compression alone and just go for the port work?

Quote:

Originally Posted by Cravin01 (Post 313688)
Looks great , cant wait to hear what the gains equate too as far as top speed. I've been tempted to break out the dremel JerryHawk250 talked me into buying.

The top speed will still be greatly determined by your sprocket combo. The port work just helps you get the most out of the stock cam profile, but the power curve will still fall off by about 8000rpm. That said, it does help to stretch out the top end just a little bit more past 7500. My top speed only improved by maybe 5mph average with the same gearing combo over an unported Hawk. The difference is in how quickly the bike goes through those gears. The engine still pulls its best around 6000-7000rpm, so matching your gearing to reach your desired fastest speed within that range is what you want to aim for. Since I mainly want to be able to reach and hold 60mph under any conditions I have achieved exactly that, with my engine sitting right at about 7000rpm at 60mph, and a good amount of throttle left if needed.

The real gain is in the lower to upper mid range power, and then a little bit up top. Combined with a 30mm smooth bore carb and it REALLY wakes things up.

G2ic22 07-06-2019 11:54 PM

I did deck the head 1mm like you and Jerry Hawk. I'm currently running the mikuni vm26 until the adapter comes in from taobao. I'm going to switch the rear sprocket to a 50 I do off road riding and hills rocky terrain and dont like the transition from 1st to second lose power and need to utalize second more efficiently. Love the torque gain with the ported head did wonders. I was riding at over 10000 feet above sea level and it ran fine just minor adjustments on trail no jet changes. Cant wait to get the nibbi on and dial that in. I met some ktm yanaha and honda guys up there who were extremely impressed when I said it was 1400 bucks and I have like another 500 in mods. I can say this is the best money spent for what the results are you csnt beat the hawk took the rocky terrain and hills no problem besides trying go to second gear while climbing but I bet the bigger rear sprocket will fix that.

Megadan 07-07-2019 12:07 AM

Just wait until you get that smooth bore carb on there. I was impressed with the ported head and a PZ30, but blown away by the difference with the PE30 carb on the ported head.

G2ic22 07-07-2019 12:10 AM

Yeah the intake adapter is at the San Francisco USPS so hopefully I'll have the nibbi on by this weekend. I bought the pilot and main jet kits for it to so I'm ready!!!

Cravin01 07-07-2019 01:49 AM

Well I can fly to about 56 to 59 and then it's a slow climb to 64 and that about it unless there is a downgrade so 5mph gain is welcome.

G2ic22 I will probably just port my stock head, Do you think if you could do it again you would go that route or is there a big benefit to the new head? I'm just crazy enough to destroy my stock head with little care as long as there is a replacement available.

Megadan 07-07-2019 02:05 AM

Quote:

Originally Posted by Cravin01 (Post 313704)
Well I can fly to about 56 to 59 and then it's a slow climb to 64 and that about it unless there is a downgrade so 5mph gain is welcome.

G2ic22 I will probably just port my stock head, Do you think if you could do it again you would go that route or is there a big benefit to the new head? I'm just crazy enough to destroy my stock head with little care as long as there is a replacement available.

If you ported the head, adjusted your jetting, then that slow climb to 64 will be a little bit quicker, likely topping you out around 65-ish, maybe a little more depending on other factors. The motor will still be very RPM/Gear dependent thanks to the cam profile. What may change is the ability to go with taller gearing without losing much in the way of acceleration. My bike pulls like it has a 17/50 tooth sprocket combination when it is geared like a 17/45.

If the budget is tight then just port the stock head. It has to come off either way lol. Since you already have the Wen rotary tool, you should just need a new gasket set, possibly a rotary burr set if you don't have one, and the time to do it, so maybe a $20 investment. If you do mess up bad enough then a new head would be about $50 if you buy the head he has Link: https://www.motopartsmax.com/index.p...ducts_id/11145

I opted to buy a different head just so I didn't have any down time. That said, if you commit to doing the work the bike would only be down a couple of days at most. I went slow and kept going back to touch up my work so it took me about 8 to 10 hours to get the results I was after. That includes all of the time I spent on the cumbustion chamber with smoothing it out and polish work. If you are after just cleaning up the ports, then it could be done in maybe 4-6 hours taking your time.

If you want to "port match" the ports at all, then a new exhaust gasket is a great way to do this. I put one in and worked to the edges, leaving just a little bit of a ridge on the inside for potential crush space/expansion. On the intake side you can bolt up the intake to the head and use a small sharpie to try and mark the areas that hang into the intake path for a reference point, and then go by feel after that.

Pulling the head only takes about 20-30 minutes (double that if adult refreshments are included lol), which is one big advantage of the OHV engines. No timing chain, cam, etc. to worry about. Get the plastics and tank out of the way, remove the spark plug, unbolt header and intake, set motor to TDC, remove the valve cover, remove the 3 bolts for the rocker assembly, remove the push rods, remove the 5 head nuts/bolts, remove head.

Cravin01 07-07-2019 02:22 AM

Sounds like a a good time for a rotary tool and adult refreshments at you house Dan, That way I get it done right the first time!

I really enjoy tearing into this bike but it would be nice to have Dan the China bike Professor on hand and maybe ARH, JerryHawk and Weldangrind as a think tank for a few adds to the bike.

Megadan 07-07-2019 03:46 AM

Quote:

Originally Posted by Cravin01 (Post 313708)
Sounds like a a good time for a rotary tool and adult refreshments at you house Dan, That way I get it done right the first time!

I really enjoy tearing into this bike but it would be nice to have Dan the China bike Professor on hand and maybe ARH, JerryHawk and Weldangrind as a think tank for a few adds to the bike.

Heck, it's only about a 680 mile drive/ride. On one of these bikes, that would probably take about 14-16 hours lol. Honestly, if I had the time off to spare I am crazy enough to make that ride on my Hawk, although to be honest I would rather use my VFR for a myriad of reasons, including the fact that I could cut that time down to probably 9 hours.

I think you have the ability to do this job right the first time. Just take your time, do small amounts of work at a time and double check it as you go.

JerryHawk250 07-07-2019 07:48 AM

Welcome to da club. Nice work. :tup: Has to be one of the best mods you can do. The 30mm smooth bore carb is the icing on the cake.

JerryHawk250 07-07-2019 07:51 AM

Quote:

Originally Posted by Cravin01 (Post 313704)
Well I can fly to about 56 to 59 and then it's a slow climb to 64 and that about it unless there is a downgrade so 5mph gain is welcome.

G2ic22 I will probably just port my stock head, Do you think if you could do it again you would go that route or is there a big benefit to the new head? I'm just crazy enough to destroy my stock head with little care as long as there is a replacement available.

Go for it Paul. Doing the stock head will only make you be more careful not to screw it up. Lol I did mine in the winter time when I knew I wouldn't be riding much anyway.

herbie 07-07-2019 11:04 AM

Man you guys are killing me! When does the farkling and mods ever end! Wait a minute that was the wife coming through!! :lmao:

G2ic22 07-07-2019 09:38 PM

Quote:

Originally Posted by Cravin01 (Post 313704)
Well I can fly to about 56 to 59 and then it's a slow climb to 64 and that about it unless there is a downgrade so 5mph gain is welcome.

G2ic22 I will probably just port my stock head, Do you think if you could do it again you would go that route or is there a big benefit to the new head? I'm just crazy enough to destroy my stock head with little care as long as there is a replacement available.

fj

The head was almost identical in every way to the original hawk. I would say worth buying it casting was decent. I would say nothing better than the stock hawk head. Probably use stock hawk head but I got one in case had issues I could just put the old one back. But starting with a fresh head was n ihhce dont half to clean it up and all that. I think doing a good lapping of the valves helped along with decking the head. Seems like it's got more seal and harder to crank now and takes a minute to warm up before you can ride but might be lean on pilot jet but since I have the nibbi not going to mess with the vm26 anymore. Took it on 100 mile trip since installing head and seems to run better the more I ride it. For 64 bucks shipped with head gasket it's great price. The brand is XPro and has good reviews on products from them.


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