Any idea what would cause the Valley Plate to have a bu

Posted By: Bratt Racing

Any idea what would cause the Valley Plate to have a bu - 07/15/14 04:01 PM

Does anyone have any idea what would cause the Valley Plate to have a bubble or hump in it? I noticed it after we ran last round at Night Under Fire at Trails. The car runs fine. Last evening I went through the test of checking the compression, presser in the radiator, if any water spit out of the plug holes and if the damper may have been plugged up. At first I thought I might have blown a head gasket but everything checked out ok. Tonight I am going to pull the manifold off. Looking for ideas I am a little baffled now.

Posted By: MR_P_BODY

Re: Any idea what would cause the Valley Plate to have a bu - 07/15/14 04:24 PM

Quote:

Does anyone have any idea what would cause the Valley Plate to have a bubble or hump in it? I noticed it after we ran last round at Night Under Fire at Trails. The car runs fine. Last evening I went through the test of checking the compression, presser in the radiator, if any water spit out of the plug holes and if the damper may have been plugged up. At first I thought I might have blown a head gasket but everything checked out ok. Tonight I am going to pull the manifold off. Looking for ideas I am a little baffled now.

How thick is this "plate" but it sounds like it isnt
breathing enough and is building back pressure in
the crank case... what kind of breathers are you running
and are you running evacs with a exhaust system

Posted By: Al_Alguire

Re: Any idea what would cause the Valley Plate to have a bu - 07/15/14 04:59 PM

To much pressure in the crankcase.

Posted By: Sport440

Re: Any idea what would cause the Valley Plate to have a bu - 07/15/14 05:06 PM

Yes, to much pressure in the crankcase. Hopefully your breather is clogged. If not suspect a cracked piston or broken rings.

I wouldnt race it again, without checking the above.

Posted By: CompWedgeEngines

Re: Any idea what would cause the Valley Plate to have a bu - 07/15/14 05:27 PM

Quote:

To much pressure in the crankcase.

As noted by everyone, certainly crankcase pressure. Hopefully a breather issue, but if you are running pan evac system, check the " check valves". they are only supposed to breathe one way. Very common for them to go bad.

On a side note, I have seen many many cars pop the intake valley pan into a bubble, and keep running. It isnt always internal, so dont go tearing to much down yet. Sounds like someone was on the right track checking for head gasket and compression, which all sounds stable.

Just to be sure, you havent had any backfires while starting the car or otherwise have you?

Has anyone checked the rocker arms/valve adjusment/pushrods?

Keep looking at the breathing of the engine side of things. Breathers, check valves, header collectors ( cracked etc), baffles ( or not) in the valve covers, sucked in valve cover grommets, or no clearance between valve cover baffles and breathers themselves and so forth. If that all checks out, then I'd say go deeper with testing, leakdown etc, but dont rip it all apart until you know for sure the engine is able to breathe correctly.

Posted By: Sport440

Re: Any idea what would cause the Valley Plate to have a bu - 07/15/14 06:26 PM

Quote:

Quote:

To much pressure in the crankcase.

On a side note, I have seen many many cars pop the intake valley pan into a bubble, and keep running.

I wasnt so lucky. At the end of the season I was making some test and tune runs playing with the timing. The 3rd run seemed fine but the pan bubbled up witch it had never done. I figured something was wrong but figured another pass couldnt hurt it. Last one of the season It wasnt making any sounds or anything. Run it one more time and check it out later

Well I lost number 3 piston and then finally the block because stupid me didnt shut the engine down fast enough. I kind of just listend to it rattle abit tryiny to figure the sounds out and then boom, dead stop.

Now Im not saying you cant run with a bubbled intake pan, but you better know what the problem was that caused it first. I didnt and ran it "one" more time.

Posted By: CompWedgeEngines

Re: Any idea what would cause the Valley Plate to have a bu - 07/15/14 07:00 PM

Quote:

Quote:

Quote:

To much pressure in the crankcase.

On a side note, I have seen many many cars pop the intake valley pan into a bubble, and keep running.

I wasnt so lucky. At the end of the season I was making some test and tune runs playing with the timing. The 3rd run seemed fine but the pan bubbled up witch it had never done. I figured something was wrong but figured another pass couldnt hurt it. Last one of the season It wasnt making any sounds or anything. Run it one more time and check it out later

Well I lost number 3 piston and then finally the block because stupid me didnt shut the engine down fast enough. I kind of just listend to it rattle abit tryiny to figure the sounds out and then boom, dead stop.

Now Im not saying you cant run with a bubbled intake pan, but you better know what the problem was that caused it first. I didnt and ran it "one" more time.

I hear ya...better safe than sorry.

I had a customer who did his own hardblocking, and had another shop do the block work. He fired it up, and about pass # 3, the intake valley pan looked like a wart! Seems they failed to properly finish the cylinders after the hardblocking and/or bolting on a torque plate. Needless to say, I got the engine job, and found cylinders almost .003-.004 out of round, taper and etc...rings never had a chance to seal. Hard to say if they even broke it in right regardless....but lots of good ways to ruin crankcase seal....

Posted By: Bratt Racing

Re: Any idea what would cause the Valley Plate to have a bu - 07/16/14 01:57 AM

Quote:

Quote:

Does anyone have any idea what would cause the Valley Plate to have a bubble or hump in it? I noticed it after we ran last round at Night Under Fire at Trails. The car runs fine. Last evening I went through the test of checking the compression, presser in the radiator, if any water spit out of the plug holes and if the damper may have been plugged up. At first I thought I might have blown a head gasket but everything checked out ok. Tonight I am going to pull the manifold off. Looking for ideas I am a little baffled now.

How thick is this "plate" but it sounds like it isnt
breathing enough and is building back pressure in
the crank case... what kind of breathers are you running
and are you running evacs with a exhaust system

Stock valley plate tin. MR Gasket breathers evacs. I have used them in the past never no issues.

Posted By: Bratt Racing

Re: Any idea what would cause the Valley Plate to have a bu - 07/16/14 01:59 AM

Quote:

Quote:

To much pressure in the crankcase.

As noted by everyone, certainly crankcase pressure. Hopefully a breather issue, but if you are running pan evac system, check the " check valves". they are only supposed to breathe one way. Very common for them to go bad.

On a side note, I have seen many many cars pop the intake valley pan into a bubble, and keep running. It isnt always internal, so dont go tearing to much down yet. Sounds like someone was on the right track checking for head gasket and compression, which all sounds stable.

Just to be sure, you havent had any backfires while starting the car or otherwise have you?

Has anyone checked the rocker arms/valve adjusment/pushrods?

Keep looking at the breathing of the engine side of things. Breathers, check valves, header collectors ( cracked etc), baffles ( or not) in the valve covers, sucked in valve cover grommets, or no clearance between valve cover baffles and breathers themselves and so forth. If that all checks out, then I'd say go deeper with testing, leakdown etc, but dont rip it all apart until you know for sure the engine is able to breathe correctly.

I am in the process of checking what you recommended. Could a leaky header gasket cause this?

Posted By: Sport440

Re: Any idea what would cause the Valley Plate to have a bu - 07/16/14 02:16 AM

Absolutely not.

Causes.
Plugged breather valve
Excessive ring blowby.
Blown head gasket passing gasses into crankcase.
Cracked piston.

Only X amount of ways to pressurize the crankcase.

Posted By: Bratt Racing

Re: Any idea what would cause the Valley Plate to have a bu - 07/16/14 02:22 AM

Thanks guys for your help. Think we might have just found it. the check value for the evac to the exhaust looks like it is bad. I am going to purchase a new kit tonight and the header gaskets.
My grandson has been helping me and learning at the same time. This is a new motor with only about 20 pass on it.

Posted By: a493demon

Re: Any idea what would cause the Valley Plate to have a bu - 07/16/14 02:37 AM

i would go though about 2 or 3 check valve's a year.
just start it and see if it's blowing up the hose into the valve cover .

Posted By: MR_P_BODY

Re: Any idea what would cause the Valley Plate to have a bu - 07/16/14 02:58 AM

Quote:

i would go though about 2 or 3 check valve's a year.
just start it and see if it's blowing up the hose into the valve cover .

I know most guys screw then on the nipple thats coming
out of the collector BUT you can put a 45 street elbow
on it and a 4" or so nipple then screw on the valve
IF you have the room... I move mine about 8" from
the point where it goes into the collector to reduce
the heat

Posted By: RapidusMaximus

Re: Any idea what would cause the Valley Plate to have a bu - 07/16/14 03:41 AM

When I switched to Flying Toilet alky fuel injection I had to put a vacuum pump on to cure that issue, pan evac that I had used for years was no longer effective. I was bulging a tin valley pan every weekend.

Posted By: Sport440

Re: Any idea what would cause the Valley Plate to have a bu - 07/16/14 03:57 AM

Quote:

When I switched to Flying Toilet alky fuel injection I had to put a vacuum pump on to cure that issue, pan evac that I had used for years was no longer effective. I was bulging a tin valley pan every weekend.

Why was that?? Do you know?

Posted By: RapidusMaximus

Re: Any idea what would cause the Valley Plate to have a bu - 07/16/14 10:50 AM

Quote:

Quote:

When I switched to Flying Toilet alky fuel injection I had to put a vacuum pump on to cure that issue, pan evac that I had used for years was no longer effective. I was bulging a tin valley pan every weekend.

Why was that?? Do you know?

Never figured it out...didn't do it on alky carbs, started after I switched to injection. Freshened the engine at the end of the season and couldn't find the cause, never removed the vacuum pump so I never knew if I cured the problem with the freshen up. It never bulged another valley pan.

Posted By: Dduster

Re: Any idea what would cause the Valley Plate to have a bu - 07/16/14 10:03 PM

Quote:

Absolutely not.

Causes.
Plugged breather valve
Excessive ring blowby.
Blown head gasket passing gasses into crankcase.
Cracked piston.

Only X amount of ways to pressurize the crankcase.

What do you think would be the leakdown values for a cylinder with excessive blow-by to create crankcase pressure? 100% perfect, what is the leakdown magnitude (%) for 'not good'? I've gotten different answers for this question before so i'm just trying to see where the average 'no good' value falls?

Posted By: Sport440

Re: Any idea what would cause the Valley Plate to have a bu - 07/16/14 10:59 PM

Quote:

Quote:

Absolutely not.

Causes.
Plugged breather valve
Excessive ring blowby.
Blown head gasket passing gasses into crankcase.
Cracked piston.

Only X amount of ways to pressurize the crankcase.

What do you think would be the leakdown values for a cylinder with excessive blow-by to create crankcase pressure? 100% perfect, what is the leakdown magnitude (%) for 'not good'? I've gotten different answers for this question before so i'm just trying to see where the average 'no good' value falls?

Any engine will create positive crankcase pressure. Unless its got a vac system.

But if your looking for leak down No good value numbers, your right that can vary.

For a race engine over 10% no good, some will say over 5% no good. "No good meaning, your not getting the Most from your Motor"

Anything over 20% can indicate more then Just rings. As in burnt valves ,head gasket, piston issues etc. 30% 50% no question. "No good meaning, something may be broke Alice"

Posted By: sr4440

Re: Any idea what would cause the Valley Plate to have a bu - 07/17/14 01:13 AM

Quote:

Quote:

Quote:

When I switched to Flying Toilet alky fuel injection I had to put a vacuum pump on to cure that issue, pan evac that I had used for years was no longer effective. I was bulging a tin valley pan every weekend.

Why was that?? Do you know?

Never figured it out...didn't do it on alky carbs, started after I switched to injection. Freshened the engine at the end of the season and couldn't find the cause, never removed the vacuum pump so I never knew if I cured the problem with the freshen up. It never bulged another valley pan.

I have found on the dyno that Alky injection has more blow by then a carb. Also one thing no one has mention is ring flutter, wouldn't show up on a leak down but when rings go into flutter, blowby goes way up.

Joe

Posted By: sr4440

Re: Any idea what would cause the Valley Plate to have a bu - 07/17/14 01:30 AM

Quote:

Absolutely not.

Causes.
Plugged breather valve
Excessive ring blowby.
Blown head gasket passing gasses into crankcase.
Cracked piston.

Only X amount of ways to pressurize the crankcase.

I had to laugh, as a drag racer I can always find a new way to do something and this was no exception. About 15 years ago, I had a valley plate bulge due to an oil leak. Let me explain, aluminum oil pan had a pin hole leak around drain plug. So I drain the oil and get out the welder to fix it. This is when I found out that I should have hooked up a vacuum to engine and let it run 10 mins or so. I started to weld on the pan and after a few seconds the leftover methanol fumes ignited.

This is why a oil leak caused the valley pan to bulge, it also caused the aluminum oil pan to bulge, both valve covers to split into 2 and my ears to ring for a � hour.

Joe

Posted By: 69dart

Re: Any idea what would cause the Valley Plate to have a bu - 07/17/14 02:04 AM

The only time I had a valley pan do that was when I tried some collector insert mufflers and it made a ton of exhaust back pressure.