Topic: How's my porting job (750)?

[Garage_guy_chris]

I have a fairly nice head that was all rebuilt with stainless manley valves and mystery performance springs and retainers. Additionally Im planning on running a Kenny Harmon D grind on a Ebay Cruzin image 836cc. Problem was the ports were untouched and stock from the factory. I wanted to let Mike do his porting magic but i just cant swing the $$$ right now plus I have always wanted to try doing it myself. anyways i took my time and time it took (about 15 hours total) but here's what was done and some photos,

Basically done as per hondaman's book i wasnt looking to make any drastic changes just clean things up and make it like the best 69 head that came out of the factory.
-removed casting marks and mismatching between molding inserts,
-blended the spigots to the ports
-rounded out the bowls
-blended the ports to the valve seats (virtually no mat'l removed from seats)
-did a little work with burr's, then 80grit cartridge rolls then 120 grit cartridge rolls

this is what i ended up with, I would love to hear any input on it as its my first porting work.

Intake




Exhaust

[PeWe]

My CB750 K6 head has much more mtrl removed from the roof. It was ported 1983-84 so the port job today is probably a little bit different. Maybe not biggest hole. (I guess that the floor should not be as much carved today. D-shaped ports, D resting on its back, flat floor)
See photo below
Search on Internet about pocket porting. The area close to the seat as most important. There are also plenty of photos in these forums where people show their ported heads.

EDIT: Check this ongoing thread http://forums.sohc4.net/index.php/topic,132814.0.html

[calj737]

Looks well done, especially for a first time! Did you happen to try to match in the carb manifolds to the intake ports? Might be a little more benefit left in that-

[Garage_guy_chris]

Pewe - Thats a nice looking head .... I saw that thread in the high performance section,  i would love to go further and reshape the guide boss and taper the valve guides but i have 2 problems

1. I dont have a flow bench and don't want to imbalance the ports due to to many changes
2. guides are perfect and valves are freshly machined in, so removing the guides is out of the question on this one as i dont want to redo the valve job.

calj737- good point i will take a look at them in the next few days, i bought the cruzin-image (ebay) ones so be interesting to see how they are...

I have been looking at building a simple nanometer based flowbench but money is short at the moment and i would really like to be riding the bike rather than working on it endlessly.. Ive got some other engines and heads and i may start a 900-950cc build in a year or so when i get bored and want something to mess with.

[SOHC4 Cafe Racer Fan]

Looks like a good port job -- especially for a first timer!  Smoothing out the ports should aid flow and make that 836 kit and cam create some power gains.

[PeWe]

I saw a head that was ported just a little. A bike junk yard had got boxes full of parts from a CB750 guy that had passed away after decades with CB750.
The port job was mostly close to the seat with a carved pocket between valve guide and seat. The ports were otherwise opened just a little. I should have bought that head together with the other stuff I bought.