Topic: Oil flow

[Joao_f3rr3ira]

Hello everyone! I'm rebuilding a 750 F2 SS from 78. Since I'm cleaning the oil lines due to the sandblast I was wondering how can I maximize the oil flow on my engine. Are there any locations in the cases, cylinder and head where I can drill or bore some holes to improve the oil flow?
I already drilled 8 holes on each tower of the head as well as I bored 4 holes that I think are collecting holes for the oil to fall from the head as seen in this photo. Can someone give me an opinion and send me some photos?

Thanks,

[flybox1]

Yes, Good.
Make sure the oiling holes in the rockers line up with the waists in the rocker shafts for best oiling.
As I said in your other (duplicate) thread, Hondamans book lists these hacks.
Only other I can think of is the clutch basket mod.

[70CB750]

You could also ditch those 8 bolts that hold rocker shafts from rotation.

As far as oil flow, get Mr.Elan's kit and rebuild your oil pump.

http://forums.sohc4.net/index.php/topic,145425.msg1685402.html#msg1685402

[Bodi]

Why do you believe the original oiling system is faulty?
The CB750 has high pressure and lower pressure oiling paths. To ensure good high pressure lubrication to the crankshaft plain bearings, confirm the bearing clearances are in spec and that your oil pump clearances are OK.
The lower pressure oil lubricates the valvegear and transmission. The valvegear gets oil through restrictive orifices from the high pressure gallery: sending more oil to the head means opening up those orifices which will reduce gallery pressure - not good. The transmission gets oil from the scavenge pump.
Why open up the return holes from the head, this is what you seem to be describing? (no picture) The oil gets back to the sump with what Honda designed.
What's the reason for drilling the cam towers?
The cam lubrication may look haphazard, but has proven reliable. The cam "bearing" loads are light, these and the followers aren't known to fail prematurely frompoor lubrication.
If there's something that can be done to improve lubrication and extend engine life, I'm interested.
Honda was not perfect, the CB450 and several other engines have poor top end lubrication and external feed line mods are helpful. The CB350 Four and CB400F could use an external feed to the valvegear as well but there's just no good way to do it.
The vital thing with any of these bikes is to do regular changes with appropriate oil and good quality filters.

[madmtnmotors]

I bored 4 holes that I think are collecting holes for the oil to fall from the head

Don't know what you are trying to describe here, but it does not sound good. I do not see these four holes in the photo. Where are these?

[evanphi]

Make sure the oiling holes in the rockers line up with the waists in the rocker shafts for best oiling.

This is an important one, especially if you're going to be removing those bolts to stop the shaft from spinning. I only had to widen one of mine, FWIW. A tedious check, but worth it.

[Joao_f3rr3ira]

Hi guys,

Sorry for not posting a photo showing those four holes. Here they are.
I'm not saying that the motor has a bad oil system, on the contrary. What I want is to facilitate further more the circulation of the oil. I will inspect the oil pump and check for oil clearances with plastigage on the crankshaft journals. I'm also planning on lighten and balance the crankshaft, is it worth removing the four balls on the crank and substitute for grub screws?

Make sure the oiling holes in the rockers line up with the waists in the rocker shafts for best oiling.

This is an important one, especially if you're going to be removing those bolts to stop the shaft from spinning. I only had to widen one of mine, FWIW. A tedious check, but worth it.

Evanphi can you send me some photos so I can have a reference?

Thanks,

[MRieck]

Chamfering those oil return holes doesn't hurt.

[754]

The oil holes by design also help trap debris from going down into lower end.
 So bigger may end up letting more debris get down the holes.
 In Sept i blew a cam bearing took 1/8 inch off cam journal and two cam lobes, plus wear on four rockers and a cam holder.. And most of the debris stayed up top ..in the pockets under the cam , off the end, and Beside the oil drain.... Very little got past the oil hole..
 Maybe something to think about...

[Joao_f3rr3ira]

Hello guys,

Thanks for the advice 754. I didn't open those holes too much.
One other thing, today I started removing the imperfections of the forging process on the inside of the cases using my rotary tool. Once I finish this I pretend to polish a bit some areas of the interior of the cases so the oil flows more easily. I do this in all of my 50cc engines, and its the first time that I do this in a big engine. I know that this is not a big deal but in my opinion I think that improves the oil circulation don't you think? 
I would like to get my hands on the hondaman manual, how can I order that manual?

Thanks,

[edwardmorris]

.....I would like to get my hands on the hondaman manual, how can I order that manual?

Thanks,

http://www.lulu.com/shop/mark-paris/my-cb750-book-hardcover-edition/hardcover/product-22322967.html

[70CB750]

Forging process?

[Joao_f3rr3ira]

The process of making the cases of the motor is to fill a mold with melted metal rigth? This process creates sharp edges and imperfections in the interior of the cases that may dificult the oil to slip.

[flybox1]

you can paint the inside of the cases with Glyptal

http://www.eastwood.com/glyptal-red-enamel-set.html

[70CB750]

That is correct, liquid aluminum is pushed into the mold.

The process of making the cases of the motor is to fill a mold with melted metal rigth? This process creates sharp edges and imperfections in the interior of the cases that may dificult the oil to slip.

[05c50]

The process of making the cases of the motor is to fill a mold with melted metal rigth? This process creates sharp edges and imperfections in the interior of the cases that may dificult the oil to slip.

"Forging is a manufacturing process involving the shaping of metal using localized compressive forces. The blows are delivered with a hammer (often a power hammer) or a die"

"Casting is a manufacturing process in which a liquid material is usually poured into a mold, which contains a hollow cavity of the desired shape, and then allowed to solidify."

Perhaps you meant casting instead of forging.

...........Paul

[Joao_f3rr3ira]

Yes you're right 

[HondaMan]

Hello everyone! I'm rebuilding a 750 F2 SS from 78. Since I'm cleaning the oil lines due to the sandblast I was wondering how can I maximize the oil flow on my engine. Are there any locations in the cases, cylinder and head where I can drill or bore some holes to improve the oil flow?

One thing that works: remove the silly "oil cooler" between the oil filter and the front engine case. You will need a shorter oil filter bolt afterward such as the type from the earlier 750 (i.e. the 1969-1975 "K" models). It only lowers oil temperatures a couple of degrees: you can do FAR better by using the proper 20w50 weight oils, which run much cooler than 10w40 oils in these engines. This increases oil flow as well, by increasing the oil pump efficiency with the more viscous oils.

[strynboen]

on cbx engines ve use rubber plade barikades to hold ekstra oil in the cam areias..both for better lube and less rattling.
..so  draning all oil fast aut of the head...you do the engine a bad job..


a better flow is done at the pressure side..not the drain side..get a pump WHO gives more ccm3 oil pr minut..that gives resultates..and bringes heat aut of the head..but it need to be taken aut of the oil Again,, by a termostat regulated radiator.
.done right it Works ..done wrong it just kills the engine
stock engines holds 40+ years..can you beat that..

[01Thomas]

Strynboen, do you have a picture/photo of these oil barricades on the CBX motor? A friend of mine could be interested.

regards
Thomas

on cbx engines ve use rubber plade barikades to hold ekstra oil in the cam areias..both for better lube and less rattling.
..so  draning all oil fast aut of the head...you do the engine a bad job..


a better flow is done at the pressure side..not the drain side..get a pump WHO gives more ccm3 oil pr minut..that gives resultates..and bringes heat aut of the head..but it need to be taken aut of the oil Again,, by a termostat regulated radiator.
.done right it Works ..done wrong it just kills the engine
stock engines holds 40+ years..can you beat that..

[Joao_f3rr3ira]

Hello everyone,

Strynboen I know what you mean, my intention is not to dry some areas faster than the oil can replace.
Here are some photos of what I done so far in the cases. Keep in mind that its not finished yet, I still have to shave some areas a little more and polish.

Thanks,

[Joao_f3rr3ira]

More pics...

[strynboen]

its standart on the cbx engines.
...came from Honda as this.(.even this erly 78)..so not a later fix..
.it keep the cam floodet vith oil..so it not drain off to kvik..the cam is still pressure feed..so it are not a primitive sekundar oil dilever system..but more a.(.get it a littel better factory fix)
..mine vas cracked..so need a set new one..this Winter..they are hard to find as new..and used ones on e bay looks like crap...think cbx World is the place to find some

sorry for this off topic

[strynboen]

is it for no debries haning on the Sharp egdes..to get all dirt dovn to the filter??

a oil thange once a year vill klean it up better.

.Peugeot have serios problems ..ther oil sump drain..did not full emty the sump..and turbo vas suck up at the lo´vest point..and suck up all debries vho vas left dovn there.
..that vas a serios problem.

.but the sohc engines have no problems like that...crankshaft vask all stuff good araund..at 7000 rpm..so the filter gets most taken aut..
taken a engine apart i never seen builds up of dirt..only in the oil  pan buttom.
.im mostly Work on 550 engines..750 can be a different ..
sorry for my English....