Should this hole be blocked off?

[Jpich85]

I'm getting ready to rebuild the engine on my gsxr750 1985 and got the engine bits back from the cerakoters, 

After giving them a clean I noticed this hole near where the ignition pick is, which gets covered by the engine case.

I'm pretty sure this is usually blocked off by a brass bung like it is on the other side and like I think I can remember from previous engines I've had but there's no sign of anything ever being in there and I can't see how it just fell out. 

I've asked around and can't get a definite answer so thought I'd check with you guys. 

I'm not sure if something had fallen out and I need to make a new brass bung for or if it was like that from factory and just leave as is?

[Ted M]

Yes mate it should be blocked although I don’t know the material that the bung is made from. 

[fatblokeonbandit]

Yes

 

Ally plug by the look of it, ill have a better look later

 

[fatblokeonbandit]

better pic

 

[Jpich85]

1 hour ago, fatblokeonbandit said:

better pic

 

Thanks mate, 

I wouldn't of thought that would of fell out as it must be a tight fit in there. 

Would you make a bung up and fit it back in?

[fatblokeonbandit]

would be good to find out where its gone???? any pictures before it went away

[TonyGee]

ive seen a few crankcases on the bay and everyone has no blanking plug, if they are a tighish fit then they wouldn't normally fall out, but if they are loose then yeah they could just slide out, nothing in the parts diagram ???  did they maybe do away with them and rely on the cover to blank them off ? 

[fatblokeonbandit]

Ah, yours is. 750, mines 1100 didn’t realise.. 

I thought they were all the same, obviously not

[Jpich85]

6 hours ago, fatblokeonbandit said:

would be good to find out where its gone???? any pictures before it went away

 

5 hours ago, TonyGee said:

ive seen a few crankcases on the bay and everyone has no blanking plug, if they are a tighish fit then they wouldn't normally fall out, but if they are loose then yeah they could just slide out, nothing in the parts diagram ???  did they maybe do away with them and rely on the cover to blank them off ? 

So you guys think there should be a hole there? 

I found these on the bay and noticed some have the hole there too

[TonyGee]

I wouldn't like to say for definite if it should be plugged or not !!!  but when the cover is on it will act like a blanking plug.  

Edited May 7, 2023 by TonyGee

[fatblokeonbandit]

He’s right you know………

 

where does the hole go????

[Jpich85]

1 hour ago, TonyGee said:

I wouldn't like to say for definite if it should be plugged or not !!!  but when the cover is on it will act like a blanking plug.  

 

34 minutes ago, fatblokeonbandit said:

He’s right you know………

 

where does the hole go????

I have a feeling that it wasn't plugged as I can't see any signs of anything ever being pressed into that hole but just seems weird that it is left open. 

It feeds a long side the oil channel that the oil pressure switch screws into and feeds under the crank shells.

[george 1100]

The case cover blocks the hole

[Jpich85]

1 hour ago, george 1100 said:

The case cover blocks the hole

Thanks George, that's what mine is like, I'd just never seen it left open like that before or maybe I didn't notice it but it must be, 

Thanks everyone for confirming it and I'll continue building it back up once I get a few parts in. 

[Buzuki]

On 5/6/2023 at 11:26 PM, Jpich85 said:

I'm getting ready to rebuild the engine on my gsxr750 1985 and got the engine bits back from the cerakoters, 

After giving them a clean I noticed this hole near where the ignition pick is, which gets covered by the engine case.

I'm pretty sure this is usually blocked off by a brass bung like it is on the other side and like I think I can remember from previous engines I've had but there's no sign of anything ever being in there and I can't see how it just fell out. 

I've asked around and can't get a definite answer so thought I'd check with you guys. 

I'm not sure if something had fallen out and I need to make a new brass bung for or if it was like that from factory and just leave as is?

On the each side of the lower engine block half is one brass plug , they have to be there and have to seat very tight and secured with some kind of the liquid bond ,

that`s from the reason because one brass plug close the oil main gallery end , and second one close the oil sub gallery end , both of these oil galleries are under full oil pressure so no oil leak is allowed , 

btw, to perfectly clean lower crankcase block half ( main oil gallery & oil sub-gallery) those two brass plugs and two plugs with thread must be removed mandatory ! 

Edited May 8, 2023 by Buzuki

[clivegto]

All the ones I've seen are blocked. Have wondered about tapping into this for turbo oil feed or external cam oil feed.

[TiZiK]

8 minutes ago, clivegto said:

All the ones I've seen are blocked. Have wondered about tapping into this for turbo oil feed or external cam oil feed.

I contemplated this option as well.  The one on the left side would be ideal for turbo feed if pressure/flow is adequate and has no affect on main gallery pressure.

[clivegto]

1 hour ago, TiZiK said:

I contemplated this option as well.  The one on the left side would be ideal for turbo feed if pressure/flow is adequate and has no affect on main gallery pressure.

That's exactly what I was thinking as well 

Was just a little concerned about swarf when drilling it out.

Edited May 8, 2023 by clivegto

[Jpich85]

3 hours ago, Buzuki said:

On the each side of the lower engine block half is one brass plug , they have to be there and have to seat very tight and secured with some kind of the liquid bond ,

that`s from the reason because one brass plug close the oil main gallery end , and second one close the oil sub gallery end , both of these oil galleries are under full oil pressure so no oil leak is allowed , 

btw, to perfectly clean lower crankcase block half ( main oil gallery & oil sub-gallery) those two brass plugs and two plugs with thread must be removed mandatory ! 

Thanks for the help mate, I would expect each side to have a brass plug but from I've researched on the early 750 engines I don't think they put a brass plug in on the ignition pick up side, seems strange but I think the ignition engine cover just blocked it off.

[george 1100]

17 minutes ago, Jpich85 said:

Thanks for the help mate, I would expect each side to have a brass plug but from I've researched on the early 750 engines I don't think they put a brass plug in on the ignition pick up side, seems strange but I think the ignition engine cover just blocked it off.

Correct

[Upshotknothole]

Just out of curiosity I checked my later 749cc GSXR engine and that hole isn’t even there. My 1100s have it, but they must have removed it from the later 750 engines.

 

[Buzuki]

1 hour ago, Jpich85 said:

Thanks for the help mate, I would expect each side to have a brass plug but from I've researched on the early 750 engines I don't think they put a brass plug in on the ignition pick up side, seems strange but I think the ignition engine cover just blocked it off.

Without that small brass plug oil sub-gallery perfect oil sealing will be just impossible , ignition engine cover altogether with associated gasket have nothing in common with oil sealing role of the oil sub-gallery .

[george 1100]

5 hours ago, Upshotknothole said:

Just out of curiosity I checked my later 749cc GSXR engine and that hole isn’t even there. My 1100s have it, but they must have removed it from the later 750 engines.

 

Correct

[george 1100]

5 hours ago, Buzuki said:

Without that small brass plug oil sub-gallery perfect oil sealing will be just impossible , ignition engine cover altogether with associated gasket have nothing in common with oil sealing role of the oil sub-gallery .

Maybe it became an issue so on the later 750, they re-engineered it. Every photo I've seen of 85_86 cases has a hole 

Edited May 9, 2023 by george 1100

[Lachie04]

@Jpich85Where does it actually go doesn't seem to be on any engines post 88 
it's too high to be a full width oil gallery sure it's not just a blanked off casting
if it opens to the crankcase maybe part of a defunct oil return route and not pressurised like the gravity head oil return.

be interested to see where it goes 

 

88 750 case pic

 

 

 

Edited May 9, 2023 by Lachie04
added pic