Topic: sad first start after rebuild...WHats this new leak?

[Elan]

750 k2 engine.

So i guess ill start this with when I was primimg the oil pump. I tried everyones tricks(air, filling that side galley, dump oil into the tappets, dropped the pump and primed) and still wasnt getting pressure. I finally decided to just start it and see if the pressure would build. 2 minutes and still no pressure. Then I see oil dripping steadily from the head. Its dripping from above the head gasket so im fairly certain thats not the problem. Its leaking from a fin between exhaust ports 3 and 4. THe part of the head you can see through right to the carbs.

Any ideas?

[Kevin D]

Slipped puck?

[Elan]

yeah I know I didnt coat the pucks with hondabond or the sort... seems like I should have...

[Kevin D]

I was advised to put just a bit of Hondabond around the edges of the puck. 

 The cam tower studs are another troublesome area. Mine are loctited in.

The leaking rebuilt motor happened to me one time.

I found your build thread and your gorgeous motor - thats a beauty Elan!

[Retro Rocket]

Why would you risk running a new engine with no oil pressure.?

[Elan]

Thanks kevin! Ill definately look at the  cam studs.

retro, I knew oil was getting to the top, and everything inside had assembly lube on it.  Ive hearda few people mention here about the oil light not actually coming off until up to 2 minutes after running.  I dont see a huge risk if everythings got some lube and your only idling for a short period if time...

[Kevin D]

cam tower studs

I have read several stories here at sohc4 about cam tower studs stripping out.

[Elan]

Ok so I pulled the engine, took off the cam and rockers, put time-serts at the 4 long cam holder bolts, put loctite on them, and put hondabond on the pucks.  Got a new oil presure sensor and had pressure immediately.  Sharted her up. LEAKING STILL !!

It is leaking from both sides, inbetween exaust 1+2 and 3+4. It appears to be bubbling upward from the stud I have pictured below... What exactly is that?  What do I need to do here?
p.s. the 836 sounded great, and idled nicely.

[Elan]

Also, it seems to leak more when revving.  It that stud pictured one that travels all the way to the crankcase?

[Elan]

Also, it seems to leak more when revving.  It that stud pictured one that travels all the way to the crankcase?

Anyone?

[gnarlycharlie4u]

did you install heavy duty cylinder studs?

[Ernest T]

Let me preface this by saying I've never disassembled a Honda SOHC motor, but I've rebuilt many others.  I've got a CB400F motor sitting on my benchg that needs a new cam adjuster so I won''t be a virgin long.  I looked at the cylinder fiche and there are two o-rings hanging out in space at the top of the picture, index number 12.  It looks like they probably go between the cylinder and head.  In my experience, the studs that carry oil are sealed with these o-rings and the engine will leak if they are not installed.

[Elan]

i Didnt install heavy duty studs, from what I understand, they are not really necessary unles upgrading the cam..

I know there are orings that I installed, but cant remember which studs they went on...

[gnarlycharlie4u]

i Didnt install heavy duty studs, from what I understand, they are not really necessary unles upgrading the cam..

I know there are orings that I installed, but cant remember which studs they went on...

the stock studs are just barely capable (actually they're not even that) with the stock setup, with an 836 they're almost certainly inadequate.

[bollingball]

Picture 26 of your build 

[MCRider]

cam tower studs

I have read several stories here at sohc4 about cam tower studs stripping out.

I had an acute case of this. If the oil is coming from the front, and between the head and cam cover gasket, in the fins in between, its the pucks or cam bearing hold down studs. Assume the pucks OK.

My studs were removed to port the head. Then smarty me i decided to use bolts. This stripped out the stud holes. One can run the studs in, with some thread sealer till they bottom and stop with little torque on them to distort the threads. The torque then comes from the nuts used to hold down the bearing and the load is on the threads of the stud, not the threads of the head.

Anyway, once those head threads are stripped out I say its a mortal wound.      Helicoils and Keen serts etc, will only open new pathways for the oil to wick out.  On mine I could look in between the fins with a flashlight and actually see the oil dripping from the bottom of those holes.

On my current project, i have a head that has only been disassembled once before in its life (instead of 10-20 times). I reinstalled the studs with thread sealer and didn't tighten them too tight.

I'm hoping for no leaks, but i feel for you, its my fear too.

[MCRider]

i Didnt install heavy duty studs, from what I understand, they are not really necessary unles upgrading the cam..

I know there are orings that I installed, but cant remember which studs they went on...

The HD studs being discussed here are for the headgasket leak itself, and yes they are not necessary but care should be given to reassembly. Your leak is above the head gasket and those HD studs would have no bearing.

Those two Orings go on the rear of the engine on the studs 1 to either side of the cam chain tunnel. Between the case and the cylinder and the cylinder and the head. Those passageways carry pressure and if they weren't there you'd know it.

Your leak is a wicki leak. The oil is seeping under the cam bearing and/or down thru hold down studs, and thru their respective holes and dripping out between the fins. No pressure.

[Elan]

i Didnt install heavy duty studs, from what I understand, they are not really necessary unles upgrading the cam..

I know there are orings that I installed, but cant remember which studs they went on...

the stock studs are just barely capable (actually they're not even that) with the stock setup, with an 836 they're almost certainly inadequate.

I dont know, i remember hondaman saying the stock studs should be fine if I'm just putting in bigger pistons. Im trying to find the thread...

[MCRider]

I just watched your video. Wow, your problem is worse than mine ever was. Still its from the front, above the head gasket and there is no pressure there. Pressurized oil enters the cam area from 2 places, the two rear studs, one on either side of the cam chain tunnel. It is directed into the cam bearing blocks and squirts out onto the cam lobes and rockers. From that point on it is gravity flow back to the bottom.

 I'm open for suggestions. I can't focus on which stud you were referring to. Is it front or rear?

[Elan]

i Didnt install heavy duty studs, from what I understand, they are not really necessary unles upgrading the cam..

I know there are orings that I installed, but cant remember which studs they went on...

The HD studs being discussed here are for the headgasket leak itself, and yes they are not necessary but care should be given to reassembly. Your leak is above the head gasket and those HD studs would have no bearing.

Those two Orings go on the rear of the engine on the studs 1 to either side of the cam chain tunnel. Between the case and the cylinder and the cylinder and the head. Those passageways carry pressure and if they weren't there you'd know it.

Your leak is a wicki leak. The oil is seeping under the cam bearing and/or down thru hold down studs, and thru their respective holes and dripping out between the fins. No pressure.

I think your right. But what I dont get: it seemed like the oil was bubbling upward.. is that possible? 

So I just need to take out the cam bearing studs and apply loctite?

[Elan]

i Didnt install heavy duty studs, from what I understand, they are not really necessary unles upgrading the cam..

I know there are orings that I installed, but cant remember which studs they went on...

The HD studs being discussed here are for the headgasket leak itself, and yes they are not necessary but care should be given to reassembly. Your leak is above the head gasket and those HD studs would have no bearing.

Those two Orings go on the rear of the engine on the studs 1 to either side of the cam chain tunnel. Between the case and the cylinder and the cylinder and the head. Those passageways carry pressure and if they weren't there you'd know it.

Your leak is a wicki leak. The oil is seeping under the cam bearing and/or down thru hold down studs, and thru their respective holes and dripping out between the fins. No pressure.

I think your right. But what I dont get: it seemed like the oil was bubbling upward.. is that possible? 

So I just need to take out the cam bearing studs and apply loctite?

I just watched your video. Wow, your problem is worse than mine ever was. Still its from the front, above the head gasket and there is no pressure there. Pressurized oil enters the cam area from 2 places, the two rear studs, one on either side of the cam chain tunnel. It is directed into the cam bearing blocks and squirts out onto the cam lobes and rockers. From that point on it is gravity flow back to the bottom.

 I'm open for suggestions. I can't focus on which stud you were referring to. Is it front or rear?

Its between the exhaust ports. it looked like the oil was bubbling upward from this stud, but I could be mistaken I suppose...

[MCRider]

i Didnt install heavy duty studs, from what I understand, they are not really necessary unles upgrading the cam..

I know there are orings that I installed, but cant remember which studs they went on...

The HD studs being discussed here are for the headgasket leak itself, and yes they are not necessary but care should be given to reassembly. Your leak is above the head gasket and those HD studs would have no bearing.

Those two Orings go on the rear of the engine on the studs 1 to either side of the cam chain tunnel. Between the case and the cylinder and the cylinder and the head. Those passageways carry pressure and if they weren't there you'd know it.

Your leak is a wicki leak. The oil is seeping under the cam bearing and/or down thru hold down studs, and thru their respective holes and dripping out between the fins. No pressure.

I think your right. But what I dont get: it seemed like the oil was bubbling upward.. is that possible? 

So I just need to take out the cam bearing studs and apply loctite?

Had your cam bearing hold down studs ever been removed? Are they the ones with the timeserts in them?

The four studs we are talking about go into holes that are thru the head and open to the atmosphere. The 4 in the rear have blind bottoms and are not an issue.

Can't see how it could go up. That stud top between 2-3 is nearly directly below the opening of the cam bearing hold down stud hole. If you follow that stud down thru the head you'll see the hole open up right above the sparkplug hole. The oil would drip right onto the head of that stud or near to it. It will be very hot and could appear to be boiling.

[MCRider]

I would use loctite Thread Sealer. The issue is sealing the threads, more than gluing the stud in place. The stud doesn't have to be real tight, a good uh with a 6inch wrench should do it. Then let the sealer set up before proceeding.  Clean befroe of course, get all old oil out with something, acetone on a Qtip or something.

If those holes are the ones with the timeserts in them, I don't have much hope. 

[Elan]

The four studs we are talking about go into holes that are thru the head and open to the atmosphere. The 4 in the rear have blind bottoms and are not an issue.

Can't see how it could go up. That stud top between 2-3 is nearly directly below the opening of the cam bearing hold down stud hole. If you follow that stud down thru the head you'll see the hole open up right above the sparkplug hole. The oil would drip right onto the head of that stud or near to it. It will be very hot and could appear to be boiling.
[/quote]

I never removed the studs.

So to confirm, the studs that can be seen between exhaust ports 1+2 and 3+4 are the cam bearing studs right?  Looking back at my pictures, I noticed that each cam bearing cover had a stud and a bolt, not 2 studs. is that right? see picture...

[Elan]

the timeserts were used for the 4 cam tower bolts...