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455 engine

 
Sam Yeager Sam Yeager
New User | Posts: 1 | Joined: 12/13
Posted: 12/21/13
10:27 AM

Recently have a 455 professionally built. Having problems with blow by when engine runs at high rpms.  ???  

Poncho462 Poncho462
User | Posts: 103 | Joined: 01/12
Posted: 12/21/13
11:19 AM

It would be helpful if we had more information...

Was there a particular break-in procedure followed?

What type and weight of break-in oil was used?  Regular?  Synthetic?

Do you know what type of rings were used?  Material?  conventional design?

Add anything else you think was pertinent or unusual....  
"Wherever you go, there you are."..Buckaroo Banzai, 1984

shyrgfuh70 shyrgfuh70
User | Posts: 93 | Joined: 12/13
Posted: 12/21/13
12:52 PM

+1 poncho


did you do a wet and dry compression test?

did you do a leak down test?

did you do an oil consumption test?  

Sam Yeager77 Sam Yeager77
New User | Posts: 12 | Joined: 12/13
Posted: 12/21/13
01:18 PM

Break-in 2000rpms 15 minutes. Used camp cam break in oil 10w30 regular.
All engine parts from Engine Parts Warehouse, can't find invoice right now.
Engine built by professional, built several other motors for me.  

Sam Yeager77 Sam Yeager77
New User | Posts: 12 | Joined: 12/13
Posted: 12/21/13
01:25 PM

Did dry compression test, all clys were 135 to 140
Never performed leak down or oil consumption test???  

shyrgfuh70 shyrgfuh70
User | Posts: 93 | Joined: 12/13
Posted: 12/21/13
06:25 PM

"Recently have a 455 professionally built. Having problems with blow by when engine runs at high rpms."  

Did dry compression test, all clys were 135 to 140

Never performed leak down or oil consumption test"



Why do you think you have a blow by prob?

what are the numbers on your cyl head?

exactly what cam are you using?  

Poncho462 Poncho462
User | Posts: 103 | Joined: 01/12
Posted: 12/22/13
03:16 PM

What is total mileage and/or running time on the engine?  I assumed a few hundred miles at least, but if less might be significant.

I second the question asked earlier by somebody smarter than me, "What makes you think you have blow-by?  Symptom(s), oil out the breather? Do breather(s) have some provision to  prevent direct throwing of oil through them? Smoke out the pipes?  High oil consumption?

To maybe get ahead of the curve, have you verified the correct installation and operation of PCV valve, if you have one?  
"Wherever you go, there you are."..Buckaroo Banzai, 1984

Sam Yeager77 Sam Yeager77
New User | Posts: 12 | Joined: 12/13
Posted: 12/22/13
03:18 PM

Blow out comes out the dip stick tube and rear & sides of oil pan.
Motor has 6X heads. Com Cam - 51-246-4......lift 525 / 525 - dur  248 / 248  

dond1965 dond1965
User | Posts: 116 | Joined: 12/13
Posted: 12/22/13
04:08 PM

maybe the oil is coming from the rear main seal, and is being blown around. hope the rear seal is'nt a rope type.  

shyrgfuh70 shyrgfuh70
User | Posts: 93 | Joined: 12/13
Posted: 12/22/13
04:26 PM

"maybe the oil is coming from the rear main seal, and is being blown around. hope the rear seal isn't a rope type."  



Do you have any type of synthetic oil in it now?

i think pontiacman8 is the only person in the world other than the factory that can install a rope seal and have it not leak. i HATE them.


XXXXX


"I second the question asked earlier by somebody smarter than me, "What makes you think you have blow-by?"



Thanks but if i'm so smart, why didn't I ask if it was SMOKING?

Hey, if it does not smoke it may not have much blow by.

Does it smoke?


xxxxx


"Motor has 6X heads."



Ok those heads come in 2 different cc’s, if your engine is bored .040” over you have one of the following:

101 cc = 8.79

94 cc = 9.26

If you milled the heads to 91 cc and 0 decked the block it would have 9.89 static compression.

Using the best case scenario of 9.89 static compression with that cam [ivc 73 abdc] your effective compression is the following:

Dynamic = 7.41  

Cylinder cranking compression = 143 psi.

Since you have 143 psi but likely have less than 9.89 static your cranking compression should be less than 243 psi so it is hard to believe you have blow by or at least very much but since it is hurling then there is obviously a problem.

Once your problem is fixed, if you still have 130 - 140 compression I would mill the heads .025" from stock to boost compression a bit. That cam wants a lot of it but too much and your iron heads will cause pinging.


xxxxx


Comp Cam - 51-246-4, lift 525/525, dur @ .050" 248/248, adv dur 294, lsa 110, ivc 73 abdc.  



Uh...wow...ok, I hope you ported the bejesus out of your heads.


xxxxx


INTAKE/CARB - Just curious what are you running?

Do you drag race this?


xxxxx


Do you have a pcv valve?

If not then install one with a foam cover like a moroso.

I would do a wet and leak down test.  

Poncho462 Poncho462
User | Posts: 103 | Joined: 01/12
Posted: 12/22/13
06:02 PM

Are you running a windage tray of any type?

Sounds like churning and whipping of oil in the sump by the crank, possibly due to over-fill.

If stock sump, should have about 4 quarts, with one in the filter if it is the larger size.  If aftermarket sump, find out for sure what it should have in it.

It sounds possible that you might have accidentally overfilled the sump with oil?

On a rebuild it is possible to end up with a new, wrong length dipstick, which if short could result in too much oil if you do not know and count how many quarts put in.  Or...did the engine come with oil in it?  
"Wherever you go, there you are."..Buckaroo Banzai, 1984

Poncho462 Poncho462
User | Posts: 103 | Joined: 01/12
Posted: 12/22/13
06:04 PM

Sorry...duplicate msg popped up  
"Wherever you go, there you are."..Buckaroo Banzai, 1984

shyrgfuh70 shyrgfuh70
User | Posts: 93 | Joined: 12/13
Posted: 12/22/13
06:09 PM

+1 poncho

That's out of the box thinking, i like that suggestion.  

Sam Yeager77 Sam Yeager77
New User | Posts: 12 | Joined: 12/13
Posted: 12/22/13
06:48 PM

Intake...65 Tri-power
Only race up and down the street!!
New PVC valve in valley pan. Friend suggested valley pan maybe stopped up!
Put another PVC in valve cover, have not run since. Also, running solid lifters, to check adjustment next.
Motor does not smoke...runs great...no blow by at low rpms...go out and kick in the other carbs two or three times...come back home, several oil puddles after a couple of hours, coming from rear & sides of oil pan, still pushing a little out the dip stick and leaks on headers for a little burn off.  

shyrgfuh70 shyrgfuh70
User | Posts: 93 | Joined: 12/13
Posted: 12/22/13
07:15 PM

is it synthetic oil?

as poncho asked, how many qts?

windage tray?

did you port the heads much?



you can put a plastic or rubber hose in the valley pan and blow in it to see if it is plugged.

stick a screw driver in the valley pan or valve cover to feel for baffle. if there is no baffle your pcv might suck up flying oil. the foam on the pcv prevents this.  

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