???Blown Head Gasket???

[Thevmaxrider]

While you have it out it is the perfect time to do both heads. No sense in fixing one head gasket and not the other. Also a good time to change out the cam tensioners if needed and to do all those neat little inspections of internals. My thoughts are do it once and once only.

 

[RagingMain]

While you have it out it is the perfect time to do both heads. No sense in fixing one head gasket and not the other. Also a good time to change out the cam tensioners if needed and to do all those neat little inspections of internals. My thoughts are do it once and once only.

motor only has 15,000 miles from a rebuild from Sean
I do plan on going through and replacing all gaskets and I have had a small oil leak that has been giving me a headache so I will go after that

 

[spursmech]

RagingMain is

Hypocrite, Lunatic

Join Date: Jul 2007
Location: San Pedro Ca
Posts: 1,402
My VMax: 1986 1300 Conversion

Awards Showcase
Total Awards: 3

Re: ???Blown Head Gasket???
Now how do I go about finding what cylinder??? :confused2::confused2:

If I can I will do what we talked about earlier

One thing I was thinking was running the bike and pull the COPs one at a time. Without any compression it might not leak through.


:confused2: Hey, pulling the COP's off will not relieve the pressure in the cylinders. Just pull th motor and start the rebuild. Keep us posted, Spurs

 

[Rand-5107]

I didn't realize you had 15,000 mi. on this motor. It seemed like yesterday you were getting it from Sean and into your bike. This is the 1300 Venture conversion? Maybe when Sean gets back he'll have some ideas.

 

[RagingMain]

I didn't realize you had 15,000 mi. on this motor. It seemed like yesterday you were getting it from Sean and into your bike. This is the 1300 Venture conversion? Maybe when Sean gets back he'll have some ideas.

That was 2 years ago. 6/20/08 to be exact. I remember it was a birthday present to myself :eusa_dance:

Yes it is the 1300 conversion

 

[RagingMain]

If the cap is lifting before the design temp then obviously pressure is entering the coolant system from somewhere.

The fact that coolant flows into the overflow tank continuously while running and faster when you rev the motor seems like a cylinder to water jacket leak of some sort (head gasket, cracked head, or cracked cylinder). Does the flow into the overflow react nearly immediately with the increase in revs?

While the compression of the engine does not change when the engine is revved, the motor is essentially a positive displacement pump. The faster it revs, the more air it moves and thus pushes exhaust gas into the coolant at a faster rate.

It sounds like you have some motor work in your future :-(

I am not so sure I agree with this.
When an engine is just idling the butterfly is essentially closed so the engine is not getting much air.
As you rev up an engine more air enters the combustion chamber and since the cylinder is a fixed volume the more air that enters means that when the intake and exhaust valves are closed and the piston is traveling up it is going to make more pressure inside. This is of course before the spark.
Look at it this way as well. When you do a compression check you are supposed to ensure the carbs are wide open. If they are not you will not achieve an accurate test. The cylinder wasnt allowed as much air due to the restriction of the throttle plate as it could have if it was wide open.
Also with the spark, the more A/F mix going into the cylinder will give it more energy when the spark sparks, so more fuel means bigger explosion, which means more pressure inside a fixed volume.
Yes I know cam timing/overlap has a role to play and of course the speed at which the piston is traveling yet the fundamentals remain the same.

More fuel = more pressure when ignited.

Now I am not disagreeing I have some motor work ahead of me at all. :bang head:
That is scheduled for the next couple of days.

 

[one2dmax]

The compression doesn't change but the amount of pressure contained in the combustion chamber goes up in relation to the amount of fuel and air being combusted! The spark actually occurs before the piston is at top dead center so pressure increases more while the engine is running then it will while being rotated over for a compression test.

Sean

 

[RagingMain]

Ok got the rear head off today and took some pics of the pistons and valves.
Not sure if this is normal, 15000 miles.
Carbon build up is pretty easy to scrape off even with a finger nail.

 

[naughtyG]

This does look like a helluva load of buildup for 15k to me.. What fuel were you using?

 

[98Redlne]

Any evidence of the leaking gasket?

 

[98Redlne]

Any evidence of the leaking gasket?

And you all are correct about the compression.....I don't know what I was thinking :bang head:

 

[RagingMain]

I just got the first head off yesterday. Didnt see anything on the rear.
Taking the front off today.
Going to take my time and probably get some dye penetrant from work and rub down the jackets to look for any cracks just to make sure

 

[satariel666]

This does look like a helluva load of buildup for 15k to me.. What fuel were you using?

Yep, most defo way to much carbon for 15k.

Maybe some oil burning? :confused2:

 

[RagingMain]

Using Shell, Mobil, Chevron for 99% of the time
87 Octane
I do have a cooler plug due to the high compression pistons
will go back to the normal temp range.
try to dial in the low and midrange better once it is back together and run more sea foam/cleaner much more often

 

[wlodek1980]

have exactly the same problem, but in my transit van, diesel... coolant is black, with oily residue on top, and some pressure comes out from the crankcase (dipstick)
defo a blown headgasket or a warped head for me.

mind you, coolant hoses are not oil resistant, they soften and burst.

 

[RagingMain]

Got the front head off today
Found a small hole in the head gasket, only showed up when I was shining a light through from the other side.
Just waiting on parts to get her all back together.

 

[vmaximum]

damn Fargo, this is the 1st ive seen this post. what a drag. sounds like it is going somewhat smooth? good luck. i'd offer help but i dont know that much about the engine, i dont have that many tools and i dont think my extremely good looks would help out much.

 

[maleko89]

Fargo, glad you found something. When are you going to show me how to tear apart an engine?

 

[RagingMain]

Fargo, glad you found something. When are you going to show me how to tear apart an engine?

As soon as I learn how :biglaugh:

Found some pitting on one of the heads. Pretty close to the seating surface for the head gasket. Gonna blend the pits in with the rest of the head. Especially the ones furthest out.

 

[one2dmax]

Looks like something made it into the combustion chamber. Check the top of the pistons.
Sean