Topic: Going to do a port Job.

[MCRider]

Give Big Jay a shout if possible. Those valves look pretty bad, and the seats probably too. Nothing a pro grind job won't fix.

My guess is they leaked pretty bad and compression suffered. It was probably impossible to synch the carbs too. Rough idle, popping on decel, etc. Should run a lot better with the valves sorted out.

[Flying J]

My guess is they leaked pretty bad and compression suffered. It was probably impossible to synch the carbs too. Rough idle, popping on decel, etc. Should run a lot better with the valves sorted out.

Its a spare head from a fellow member so i dont know how it ran. But im trying to avoid all those problems for sure. Ill give JAY h\ a call.

[faux fiddy]

Tools for hard to reach-


Heat up small round or triangle files hot enough ( Just about red) and bend them into a nice curved 75- 90' ish shape.  They are easy to control , and can take off plenty, or smooth things out where no power tool has gone before. And be careful with taking too much off, make all the same and bla bla blah...

Surely you don't mind a little bit of hand work if you are already going to the trouble..

Also the angle grinder on a cable is a good one, but I will have to get a pic of it to post. Some things just can't be done the same way (easy) without it. 

Surely you don't mind a little bit of hand work if you are already going to the trouble..

[dave500]

hey if your not going to race it,,you can get away with murder on small engines!!just lap those valves ,,youve done a good clean up so far,the guides are crucial though,,yeah yeah ,,if you do the guides etc ,,this where plan A becomes plan B ,a bit of wear ,?,just lap those valves and put it back together,see whats its like,a good de-coke may be all you want to do!!youll be suprised!!,,if your keen to tinker and learn,,pulling the head again isnt a big deal,,ive removed and replaced the head on my 500 three times ,over 16000 klms,,using the same head gasket over and over,to machine the chamber volume to achive a desired compression ratio and balance,,ide never do that to a paying friend though,.ide make em buy two more gaskets and actually use them..

[Nikkisixx]

I've had this saved on my computer a while now:

http://www.motorcycleproject.com/motorcycle/text/cows-porting.html

long & short, until I have a flowbench in my house I'm not messing with it. It's one of the very, very few jobs I would outsource and let someone else do for me.

This article is dead on.  Read it, know it, love it.  Porting without flow testing is like peeing in the dark - you might hit it but probably not.  A good radiused competition valve job would do far more than hours of hogging material with a die grinder.  Time spent tuning the engine (carb sync and adjust, valve adjust, ignition dial in, etc.) is time better spent to unlock FREE horses.

Those rough spots that Honda left next to the valve guides look like they may lie in a high velocity/pressure area.  They are certainly not where you want air to go - they are right above the turn that leads to the valve seat.  Opening these rough spots up might create a low pressure area of swirl that could discourage the charge from flowing smoothly into the chamber.  Honda may have even left this area rough in the intake port to encourage atomization of the fuel/air charge.  I am just speculating since I don't have this head in front of me on a flow bench.   


OBLIGATORY EMOTICONS POSTED HERE:  IMHO

[MCRider]

My guess is they leaked pretty bad and compression suffered. It was probably impossible to synch the carbs too. Rough idle, popping on decel, etc. Should run a lot better with the valves sorted out.

Its a spare head from a fellow member so i dont know how it ran. But im trying to avoid all those problems for sure. Ill give JAY h\ a call.

I hope that you can, not the end of the world if you can't. Lapping them in, removing the black spots from the sealing "ring" area will give you improvement.

But a well done valve job includes a few things. The area of contact between the valve seat ring on the valve itself and the contact ring on the seat in the head, is moved further out on the edge of the valve. This effectively gives you a "bigger valve". The ring is made thinner as well, more acute. The seat in the head is flowed into itself by using 3 angles, sometimes 5 angles. The angle(s) approaching the seat are cut, the angle of the seat itself, and the angle(s) past the seat.

This cannot be accomplished by lapping. In a very tiny sense, lappping will spread the thickness of the seat, where thinning it is desired. And dull the approach and exit angles.  Lapping will make them seal once again. Back in the day, I lapped a lot of stockers.

Even on a stocker a 3/5 angle valve job will yield a crispness to the motor a stock motor won't have, an "edge" in performance.

[Flying J]

Thanks MCrider, that helps a lot. I called APE, i know they would do the best job but they are more $$$ and i would have to pay to ship. I found 1 local shop that would do valves and re surface for $170. I have a few more local shops to call but at that price to know that the valves are done right and the port job isn't all for not, is well worth it. I wont be able to do it just yet. I also have to check the valve guide wear.

[MCRider]

Thanks MCrider, that helps a lot. I called APE, i know they would do the best job but they are more $$$ and i would have to pay to ship. I found 1 local shop that would do valves and re surface for $170. I have a few more local shops to call but at that price to know that the valves are done right and the port job isn't all for not, is well worth it. I wont be able to do it just yet. I also have to check the valve guide wear.

APE is really good, and they are worth the money but they are a speed shop. 

But its not magic and a local shop that acts like they know what they are doing likely does know. Ask them what they do for the money like 3 angles, move the strip out on the valve face, narrow the strip (are you following this?) They may just be doing a quickie grind, but that may be all you care about.

If your guides are sloppy, a regular head shop can drive out the old guides, drive in new ones, then ream them to your valves. All standard stuff.  You supply the guides.

[Flying J]

All i asked was if it was a serdi valve job. Not that i know what that is but i was told it was the best.

[MCRider]

All i asked was if it was a serdi valve job. Not that i know what that is but i was told it was the best.

I think that's good enough.

[Flying J]

Almost a year later and i have the head ported and i just had the valves done. 3 angle cut was what i was told. cost me $125. They sand blasted my head. So now the head surface is not smooth.
 Do i have to have it resurfaced or is it fine?
They did the same to my cam journals. Is that bad? I assume that its ok because this is a fairly reputable machine shop but i figured i check with the pros.

[HondaMan]

Normally, they run the head through a parts washer, with strong detergents and solvents (like a big dishwasher).

They sandblasted the cam journals? 

If their surface is all roughed up, they also ruined the journals. I've not ever heard of someone doing that before. Those are bearings, they don't have inserts.

[crazypj]

Did you take any measurements or do any math to get port diameter close to valve head /throat size or just carve on things until they looked OK?

[Terry in Australia]

Can't open the pics (damn defence department computer!) so I'm just marking this spot until I get home.

[Flying J]

I didnt carve out anything really. I just smoothed out the casting marks and the transition to the guide. SO your saying the #$%*ed up my head. I didnt ask them to blast it. i said "I want a valve job". Are you sure it is messed up? Because im going to have to go back in there and get my money back + a new head.

[Terry in Australia]

I wouldn't throw that head away just yet mate, like HM, I wouldn't intentionally blast a bearing surface, but as long as your cam isn't rattling around the abraided surface might actually be good, as it'll hold some oil in there, I'd think? Cheers, Terry.

[Flying J]

Ok i can see that but the mating surface is blasted as well. I would assume it needs to be a machined flat surface. Did they need to sand blast it to do a valve job?

[Terry in Australia]

Once again, only my opinion mate, but I don't see a problem with blasting the gasket surface, as long as your head isn't warped, the gasket won't care. Cheers, Terry.

[Flying J]

close up.

[dave500]

i guess its a glass bead blast,make sure you blow the threads out good there might be a granule or two lurking,id have kept the blasting of the bearing and gasket areas though.itll be ok.

[Terry in Australia]

What Dave said +1 mate, if it's been blasted give it a thorough wash in warm soapy water, rinse, blow out all the threads and nooks and crannies with compressed air and give it a spray with WD 40 and it should be fine. Cheers, Terry.

[Retro Rocket]

What Dave said +1 mate, if it's been blasted give it a thorough wash in warm soapy water, rinse, blow out all the threads and nooks and crannies with compressed air and give it a spray with WD 40 and it should be fine. Cheers, Terry.

Terry, i would be very concerned with the cam bearing surface, as far as i know it shouldn't be blasted at all.?
Your thoughts.?

Mick

[Flying J]

I PMed MReich. Hopefully he will chime in and inform me.

[Terry in Australia]

What Dave said +1 mate, if it's been blasted give it a thorough wash in warm soapy water, rinse, blow out all the threads and nooks and crannies with compressed air and give it a spray with WD 40 and it should be fine. Cheers, Terry.

Terry, i would be very concerned with the cam bearing surface, as far as i know it shouldn't be blasted at all.?
Your thoughts.?

Mick

G'Day Mick, I had a Suzuki GS1000 head bead blasted and they forgot to mask off the cam bearing surfaces, (the Suzy heads don't have removeable cam towers like the superior CB750) so I cleaned it as described and reassembled the head on my bench and couldn't discern any "slop", so fitted it back on my bike (my GS1000S "Wes Cooley replica") and it's still going strong 10 years on, I've probably done 30,000 Kms since, so I'm pretty sure no damage was done. Cheers, Terry.

[Retro Rocket]

What Dave said +1 mate, if it's been blasted give it a thorough wash in warm soapy water, rinse, blow out all the threads and nooks and crannies with compressed air and give it a spray with WD 40 and it should be fine. Cheers, Terry.

Terry, i would be very concerned with the cam bearing surface, as far as i know it shouldn't be blasted at all.?
Your thoughts.?

Mick

G'Day Mick, I had a Suzuki GS1000 head bead blasted and they forgot to mask off the cam bearing surfaces, (the Suzy heads don't have removeable cam towers like the superior CB750) so I cleaned it as described and reassembled the head on my bench and couldn't discern any "slop", so fitted it back on my bike (my GS1000S "Wes Cooley replica") and it's still going strong 10 years on, I've probably done 30,000 Kms since, so I'm pretty sure no damage was done. Cheers, Terry.

I thought the smooth surface was there to promote "float" for the cam when oil was forced between it and the cam journal, i assumed that the rough surface would create turbulence and increase wear.....Interesting..

Mick